From 95f0e3a209b0045a56a06987d85981280f523270 Mon Sep 17 00:00:00 2001 From: Jiapeng Chong Date: Thu, 30 Mar 2023 10:00:14 +0800 Subject: x86/unwind/orc: Use swap() instead of open coding it Swap is a function interface that provides exchange function. To avoid code duplication, we can use swap function. ./arch/x86/kernel/unwind_orc.c:235:16-17: WARNING opportunity for swap(). Reported-by: Abaci Robot Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=4641 Signed-off-by: Jiapeng Chong Link: https://lore.kernel.org/r/20230330020014.40489-1-jiapeng.chong@linux.alibaba.com Signed-off-by: Josh Poimboeuf --- arch/x86/kernel/unwind_orc.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index 3ac50b7298d1..5fbcb229f707 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -219,7 +219,6 @@ static struct orc_entry *cur_orc_table = __start_orc_unwind; static void orc_sort_swap(void *_a, void *_b, int size) { struct orc_entry *orc_a, *orc_b; - struct orc_entry orc_tmp; int *a = _a, *b = _b, tmp; int delta = _b - _a; @@ -231,9 +230,7 @@ static void orc_sort_swap(void *_a, void *_b, int size) /* Swap the corresponding .orc_unwind entries: */ orc_a = cur_orc_table + (a - cur_orc_ip_table); orc_b = cur_orc_table + (b - cur_orc_ip_table); - orc_tmp = *orc_a; - *orc_a = *orc_b; - *orc_b = orc_tmp; + swap(*orc_a, *orc_b); } static int orc_sort_cmp(const void *_a, const void *_b) -- cgit v1.2.3 From 514ca14ed5444b911de59ed3381dfd195d99fe4b Mon Sep 17 00:00:00 2001 From: "ndesaulniers@google.com" Date: Mon, 17 Apr 2023 15:00:05 -0700 Subject: start_kernel: Add __no_stack_protector function attribute Back during the discussion of commit a9a3ed1eff36 ("x86: Fix early boot crash on gcc-10, third try") we discussed the need for a function attribute to control the omission of stack protectors on a per-function basis; at the time Clang had support for no_stack_protector but GCC did not. This was fixed in gcc-11. Now that the function attribute is available, let's start using it. Callers of boot_init_stack_canary need to use this function attribute unless they're compiled with -fno-stack-protector, otherwise the canary stored in the stack slot of the caller will differ upon the call to boot_init_stack_canary. This will lead to a call to __stack_chk_fail() then panic. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94722 Link: https://lore.kernel.org/all/20200316130414.GC12561@hirez.programming.kicks-ass.net/ Tested-by: Nathan Chancellor Acked-by: Michael Ellerman (powerpc) Acked-by: Miguel Ojeda Acked-by: Peter Zijlstra (Intel) Signed-off-by: Nick Desaulniers Link: https://lore.kernel.org/r/20230412-no_stackp-v2-1-116f9fe4bbe7@google.com Signed-off-by: Josh Poimboeuf Signed-off-by: ndesaulniers@google.com --- arch/powerpc/kernel/smp.c | 1 + include/linux/compiler_attributes.h | 12 ++++++++++++ init/main.c | 3 ++- 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 265801a3e94c..6903a7222273 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -1605,6 +1605,7 @@ static void add_cpu_to_masks(int cpu) } /* Activate a secondary processor. */ +__no_stack_protector void start_secondary(void *unused) { unsigned int cpu = raw_smp_processor_id(); diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index e659cb6fded3..84864767a56a 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -255,6 +255,18 @@ */ #define __noreturn __attribute__((__noreturn__)) +/* + * Optional: only supported since GCC >= 11.1, clang >= 7.0. + * + * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-no_005fstack_005fprotector-function-attribute + * clang: https://clang.llvm.org/docs/AttributeReference.html#no-stack-protector-safebuffers + */ +#if __has_attribute(__no_stack_protector__) +# define __no_stack_protector __attribute__((__no_stack_protector__)) +#else +# define __no_stack_protector +#endif + /* * Optional: not supported by gcc. * diff --git a/init/main.c b/init/main.c index af50044deed5..c445c1fb19b9 100644 --- a/init/main.c +++ b/init/main.c @@ -877,7 +877,8 @@ static void __init print_unknown_bootoptions(void) memblock_free(unknown_options, len); } -asmlinkage __visible void __init __no_sanitize_address __noreturn start_kernel(void) +asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector +void start_kernel(void) { char *command_line; char *after_dashes; -- cgit v1.2.3 From dc1d05536f44cee16e46e86316e6718b2c0d8872 Mon Sep 17 00:00:00 2001 From: "ndesaulniers@google.com" Date: Mon, 17 Apr 2023 15:00:06 -0700 Subject: start_kernel: Omit prevent_tail_call_optimization() for newer toolchains prevent_tail_call_optimization() was added in commit a9a3ed1eff36 ("x86: Fix early boot crash on gcc-10, third try") to work around stack canaries getting inserted into functions that would initialize the stack canary in the first place. Now that we have no_stack_protector function attribute (gcc-11+, clang-7+) and use it on start_kernel(), remove the call to prevent_tail_call_optimization() such that we may one day remove it outright. Reviewed-by: Nathan Chancellor Acked-by: Peter Zijlstra (Intel) Signed-off-by: Nick Desaulniers Link: https://lore.kernel.org/r/20230412-no_stackp-v2-2-116f9fe4bbe7@google.com Signed-off-by: Josh Poimboeuf --- init/main.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/init/main.c b/init/main.c index c445c1fb19b9..c0b6499c31db 100644 --- a/init/main.c +++ b/init/main.c @@ -1088,7 +1088,13 @@ void start_kernel(void) /* Do the rest non-__init'ed, we're now alive */ arch_call_rest_init(); + /* + * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10 + * and older. + */ +#if !__has_attribute(__no_stack_protector__) prevent_tail_call_optimization(); +#endif } /* Call all constructor functions linked into the kernel. */ -- cgit v1.2.3 From 89da5a69a831f20df6463fd524e1578e12a8f46f Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 12 Apr 2023 13:31:05 -0700 Subject: x86/unwind/orc: Add 'unwind_debug' cmdline option Sometimes the one-line ORC unwinder warnings aren't very helpful. Add a new 'unwind_debug' cmdline option which will dump the full stack contents of the current task when an error condition is encountered. Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/6afb9e48a05fd2046bfad47e69b061b43dfd0e0e.1681331449.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- Documentation/admin-guide/kernel-parameters.txt | 6 +++ arch/x86/kernel/unwind_orc.c | 49 ++++++++++++++++++++++++- 2 files changed, 54 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9e5bab29685f..f922eea6425e 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6563,6 +6563,12 @@ unknown_nmi_panic [X86] Cause panic on unknown NMI. + unwind_debug [X86-64] + Enable unwinder debug output. This can be + useful for debugging certain unwinder error + conditions, including corrupt stacks and + bad/missing unwinder metadata. + usbcore.authorized_default= [USB] Default USB device authorization: (default -1 = authorized except for wireless USB, diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index 5fbcb229f707..7891727f534e 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -13,8 +13,14 @@ #define orc_warn_current(args...) \ ({ \ - if (state->task == current && !state->error) \ + static bool dumped_before; \ + if (state->task == current && !state->error) { \ orc_warn(args); \ + if (unwind_debug && !dumped_before) { \ + dumped_before = true; \ + unwind_dump(state); \ + } \ + } \ }) extern int __start_orc_unwind_ip[]; @@ -23,8 +29,49 @@ extern struct orc_entry __start_orc_unwind[]; extern struct orc_entry __stop_orc_unwind[]; static bool orc_init __ro_after_init; +static bool unwind_debug __ro_after_init; static unsigned int lookup_num_blocks __ro_after_init; +static int __init unwind_debug_cmdline(char *str) +{ + unwind_debug = true; + + return 0; +} +early_param("unwind_debug", unwind_debug_cmdline); + +static void unwind_dump(struct unwind_state *state) +{ + static bool dumped_before; + unsigned long word, *sp; + struct stack_info stack_info = {0}; + unsigned long visit_mask = 0; + + if (dumped_before) + return; + + dumped_before = true; + + printk_deferred("unwind stack type:%d next_sp:%p mask:0x%lx graph_idx:%d\n", + state->stack_info.type, state->stack_info.next_sp, + state->stack_mask, state->graph_idx); + + for (sp = __builtin_frame_address(0); sp; + sp = PTR_ALIGN(stack_info.next_sp, sizeof(long))) { + if (get_stack_info(sp, state->task, &stack_info, &visit_mask)) + break; + + for (; sp < stack_info.end; sp++) { + + word = READ_ONCE_NOCHECK(*sp); + + printk_deferred("%0*lx: %0*lx (%pB)\n", BITS_PER_LONG/4, + (unsigned long)sp, BITS_PER_LONG/4, + word, (void *)word); + } + } +} + static inline unsigned long orc_ip(const int *ip) { return (unsigned long)ip + *ip; -- cgit v1.2.3 From 5e3992fe72748ed3892be876f09d4d990548b7af Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 18 Apr 2023 14:27:47 -0700 Subject: objtool: Limit unreachable warnings to once per function Unreachable instruction warnings are limited to once per object file. That no longer makes sense for vmlinux validation, which might have more unreachable instructions lurking in other places. Change it to once per function. Note this affects some other (much rarer) non-fatal warnings as well. In general I think one-warning-per-function makes sense, as related warnings can accumulate quickly and we want to eventually get back to failing the build with -Werror anyway. Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/9d38f881bfc34e031c74e4e90064ccb3e49f599a.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 5 +++-- tools/objtool/include/objtool/elf.h | 1 + tools/objtool/include/objtool/warn.h | 7 ++++++- 3 files changed, 10 insertions(+), 3 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 0fcf99c91400..98e6c3b5fefc 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -4514,6 +4514,7 @@ static int validate_sls(struct objtool_file *file) static int validate_reachable_instructions(struct objtool_file *file) { struct instruction *insn; + int warnings = 0; if (file->ignore_unreachables) return 0; @@ -4523,10 +4524,10 @@ static int validate_reachable_instructions(struct objtool_file *file) continue; WARN_INSN(insn, "unreachable instruction"); - return 1; + warnings++; } - return 0; + return warnings; } int check(struct objtool_file *file) diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index e1ca588eb69d..78e2d0fc21ca 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -61,6 +61,7 @@ struct symbol { u8 return_thunk : 1; u8 fentry : 1; u8 profiling_func : 1; + u8 warned : 1; struct list_head pv_target; struct list_head reloc_list; }; diff --git a/tools/objtool/include/objtool/warn.h b/tools/objtool/include/objtool/warn.h index b1c920dc9516..f195deab456e 100644 --- a/tools/objtool/include/objtool/warn.h +++ b/tools/objtool/include/objtool/warn.h @@ -55,7 +55,12 @@ static inline char *offstr(struct section *sec, unsigned long offset) #define WARN_INSN(insn, format, ...) \ ({ \ - WARN_FUNC(format, insn->sec, insn->offset, ##__VA_ARGS__); \ + struct instruction *_insn = (insn); \ + if (!_insn->sym || !_insn->sym->warned) \ + WARN_FUNC(format, _insn->sec, _insn->offset, \ + ##__VA_ARGS__); \ + if (_insn->sym) \ + _insn->sym->warned = 1; \ }) #define BT_FUNC(format, insn, ...) \ -- cgit v1.2.3 From ca653464dd097fe64e69f1735e9f348b2a0f8037 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 18 Apr 2023 14:27:48 -0700 Subject: objtool: Add verbose option for disassembling affected functions When a warning is associated with a function, add an option to disassemble that function. This makes it easier for reporters to submit the information needed to diagnose objtool warnings. Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/dd0fe13428ede186f09c74059a8001f4adcea5fc.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/Documentation/objtool.txt | 5 +++ tools/objtool/builtin-check.c | 5 +++ tools/objtool/check.c | 77 +++++++++++++++++++++++++++++++++ tools/objtool/include/objtool/builtin.h | 1 + 4 files changed, 88 insertions(+) diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Documentation/objtool.txt index 744db4218e7a..8db1f29bf432 100644 --- a/tools/objtool/Documentation/objtool.txt +++ b/tools/objtool/Documentation/objtool.txt @@ -244,6 +244,11 @@ To achieve the validation, objtool enforces the following rules: Objtool warnings ---------------- +NOTE: When requesting help with an objtool warning, please recreate with +OBJTOOL_VERBOSE=1 (e.g., "make OBJTOOL_VERBOSE=1") and send the full +output, including any disassembly below the warning, to the objtool +maintainers. + For asm files, if you're getting an error which doesn't make sense, first make sure that the affected code follows the above rules. diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 7c175198d09f..5e21cfb7661d 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -93,6 +93,7 @@ static const struct option check_options[] = { OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"), OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"), OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"), + OPT_BOOLEAN('v', "verbose", &opts.verbose, "verbose warnings"), OPT_END(), }; @@ -118,6 +119,10 @@ int cmd_parse_options(int argc, const char **argv, const char * const usage[]) parse_options(envc, envv, check_options, env_usage, 0); } + env = getenv("OBJTOOL_VERBOSE"); + if (env && !strcmp(env, "1")) + opts.verbose = true; + argc = parse_options(argc, argv, check_options, usage, 0); if (argc != 1) usage_with_options(usage, check_options); diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 98e6c3b5fefc..0bd0ca4c767c 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -4530,6 +4530,81 @@ static int validate_reachable_instructions(struct objtool_file *file) return warnings; } +/* 'funcs' is a space-separated list of function names */ +static int disas_funcs(const char *funcs) +{ + const char *objdump_str, *cross_compile; + int size, ret; + char *cmd; + + cross_compile = getenv("CROSS_COMPILE"); + + objdump_str = "%sobjdump -wdr %s | gawk -M -v _funcs='%s' '" + "BEGIN { split(_funcs, funcs); }" + "/^$/ { func_match = 0; }" + "/<.*>:/ { " + "f = gensub(/.*<(.*)>:/, \"\\\\1\", 1);" + "for (i in funcs) {" + "if (funcs[i] == f) {" + "func_match = 1;" + "base = strtonum(\"0x\" $1);" + "break;" + "}" + "}" + "}" + "{" + "if (func_match) {" + "addr = strtonum(\"0x\" $1);" + "printf(\"%%04x \", addr - base);" + "print;" + "}" + "}' 1>&2"; + + /* fake snprintf() to calculate the size */ + size = snprintf(NULL, 0, objdump_str, cross_compile, objname, funcs) + 1; + if (size <= 0) { + WARN("objdump string size calculation failed"); + return -1; + } + + cmd = malloc(size); + + /* real snprintf() */ + snprintf(cmd, size, objdump_str, cross_compile, objname, funcs); + ret = system(cmd); + if (ret) { + WARN("disassembly failed: %d", ret); + return -1; + } + + return 0; +} + +static int disas_warned_funcs(struct objtool_file *file) +{ + struct symbol *sym; + char *funcs = NULL, *tmp; + + for_each_sym(file, sym) { + if (sym->warned) { + if (!funcs) { + funcs = malloc(strlen(sym->name) + 1); + strcpy(funcs, sym->name); + } else { + tmp = malloc(strlen(funcs) + strlen(sym->name) + 2); + sprintf(tmp, "%s %s", funcs, sym->name); + free(funcs); + funcs = tmp; + } + } + } + + if (funcs) + disas_funcs(funcs); + + return 0; +} + int check(struct objtool_file *file) { int ret, warnings = 0; @@ -4674,6 +4749,8 @@ int check(struct objtool_file *file) warnings += ret; } + if (opts.verbose) + disas_warned_funcs(file); if (opts.stats) { printf("nr_insns_visited: %ld\n", nr_insns_visited); diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h index 2a108e648b7a..fcca6662c8b4 100644 --- a/tools/objtool/include/objtool/builtin.h +++ b/tools/objtool/include/objtool/builtin.h @@ -37,6 +37,7 @@ struct opts { bool no_unreachable; bool sec_address; bool stats; + bool verbose; }; extern struct opts opts; -- cgit v1.2.3 From ced23d2e3762ecfb859ae65d3a351218edff7205 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 18 Apr 2023 14:27:49 -0700 Subject: objtool: Include backtrace in verbose mode Include backtrace in verbose mode. This makes it easy to gather all the information needed for diagnosing objtool warnings. Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/c255224fabcf7e64bac232fec1c77c9fc2d7d7ab.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/Documentation/objtool.txt | 4 ++-- tools/objtool/check.c | 26 ++++++++++---------------- tools/objtool/include/objtool/warn.h | 14 ++++++++------ 3 files changed, 20 insertions(+), 24 deletions(-) diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Documentation/objtool.txt index 8db1f29bf432..9ec8cbf20668 100644 --- a/tools/objtool/Documentation/objtool.txt +++ b/tools/objtool/Documentation/objtool.txt @@ -246,8 +246,8 @@ Objtool warnings NOTE: When requesting help with an objtool warning, please recreate with OBJTOOL_VERBOSE=1 (e.g., "make OBJTOOL_VERBOSE=1") and send the full -output, including any disassembly below the warning, to the objtool -maintainers. +output, including any disassembly or backtrace below the warning, to the +objtool maintainers. For asm files, if you're getting an error which doesn't make sense, first make sure that the affected code follows the above rules. diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 0bd0ca4c767c..71985f3a6fa6 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3657,8 +3657,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, ret = validate_branch(file, func, alt->insn, state); if (ret) { - if (opts.backtrace) - BT_FUNC("(alt)", insn); + BT_INSN(insn, "(alt)"); return ret; } } @@ -3703,8 +3702,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, ret = validate_branch(file, func, insn->jump_dest, state); if (ret) { - if (opts.backtrace) - BT_FUNC("(branch)", insn); + BT_INSN(insn, "(branch)"); return ret; } } @@ -3802,8 +3800,8 @@ static int validate_unwind_hint(struct objtool_file *file, { if (insn->hint && !insn->visited && !insn->ignore) { int ret = validate_branch(file, insn_func(insn), insn, *state); - if (ret && opts.backtrace) - BT_FUNC("<=== (hint)", insn); + if (ret) + BT_INSN(insn, "<=== (hint)"); return ret; } @@ -3861,8 +3859,7 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn) ret = validate_unret(file, alt->insn); if (ret) { - if (opts.backtrace) - BT_FUNC("(alt)", insn); + BT_INSN(insn, "(alt)"); return ret; } } @@ -3888,10 +3885,8 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn) } ret = validate_unret(file, insn->jump_dest); if (ret) { - if (opts.backtrace) { - BT_FUNC("(branch%s)", insn, - insn->type == INSN_JUMP_CONDITIONAL ? "-cond" : ""); - } + BT_INSN(insn, "(branch%s)", + insn->type == INSN_JUMP_CONDITIONAL ? "-cond" : ""); return ret; } @@ -3913,8 +3908,7 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn) ret = validate_unret(file, dest); if (ret) { - if (opts.backtrace) - BT_FUNC("(call)", insn); + BT_INSN(insn, "(call)"); return ret; } /* @@ -4216,8 +4210,8 @@ static int validate_symbol(struct objtool_file *file, struct section *sec, state->uaccess = sym->uaccess_safe; ret = validate_branch(file, insn_func(insn), insn, *state); - if (ret && opts.backtrace) - BT_FUNC("<=== (sym)", insn); + if (ret) + BT_INSN(insn, "<=== (sym)"); return ret; } diff --git a/tools/objtool/include/objtool/warn.h b/tools/objtool/include/objtool/warn.h index f195deab456e..ac04d3fe4dd9 100644 --- a/tools/objtool/include/objtool/warn.h +++ b/tools/objtool/include/objtool/warn.h @@ -63,12 +63,14 @@ static inline char *offstr(struct section *sec, unsigned long offset) _insn->sym->warned = 1; \ }) -#define BT_FUNC(format, insn, ...) \ -({ \ - struct instruction *_insn = (insn); \ - char *_str = offstr(_insn->sec, _insn->offset); \ - WARN(" %s: " format, _str, ##__VA_ARGS__); \ - free(_str); \ +#define BT_INSN(insn, format, ...) \ +({ \ + if (opts.verbose || opts.backtrace) { \ + struct instruction *_insn = (insn); \ + char *_str = offstr(_insn->sec, _insn->offset); \ + WARN(" %s: " format, _str, ##__VA_ARGS__); \ + free(_str); \ + } \ }) #define WARN_ELF(format, ...) \ -- cgit v1.2.3 From fedb724c3db5490234ddde0103811c28c2fedae0 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 18 Apr 2023 14:27:50 -0700 Subject: objtool: Detect missing __noreturn annotations Most "unreachable instruction" warnings these days seem to actually be the result of a missing __noreturn annotation. Add an explicit check for that. Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/6e2b93d8c65eaed6c4166a358269dc0ef01f890c.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/Documentation/objtool.txt | 6 ++++++ tools/objtool/check.c | 14 +++++++++++++- 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Documentation/objtool.txt index 9ec8cbf20668..f9345e0ce740 100644 --- a/tools/objtool/Documentation/objtool.txt +++ b/tools/objtool/Documentation/objtool.txt @@ -303,6 +303,12 @@ the objtool maintainers. If it's not actually in a callable function (e.g. kernel entry code), change ENDPROC to END. +3. file.o: warning: objtool: foo+0x48c: bar() is missing a __noreturn annotation + + The call from foo() to bar() doesn't return, but bar() is missing the + __noreturn annotation. NOTE: In addition to adding the __noreturn + annotation, the function name also needs to be added to + 'global_noreturns' in tools/objtool/check.c. 4. file.o: warning: objtool: func(): can't find starting instruction or diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 71985f3a6fa6..8d1b4226608c 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -4507,7 +4507,8 @@ static int validate_sls(struct objtool_file *file) static int validate_reachable_instructions(struct objtool_file *file) { - struct instruction *insn; + struct instruction *insn, *prev_insn; + struct symbol *call_dest; int warnings = 0; if (file->ignore_unreachables) @@ -4517,6 +4518,17 @@ static int validate_reachable_instructions(struct objtool_file *file) if (insn->visited || ignore_unreachable_insn(file, insn)) continue; + prev_insn = prev_insn_same_sec(file, insn); + if (prev_insn && prev_insn->dead_end) { + call_dest = insn_call_dest(prev_insn); + if (call_dest) { + WARN_INSN(insn, "%s() is missing a __noreturn annotation", + call_dest->name); + warnings++; + continue; + } + } + WARN_INSN(insn, "unreachable instruction"); warnings++; } -- cgit v1.2.3 From 55eeab2a8a11b71586ef0ad3adf532ca5f97d4be Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 18 Apr 2023 14:27:51 -0700 Subject: objtool: Ignore exc_double_fault() __noreturn warnings This is a hack, but it works for now. Problem is, exc_double_fault() may or may not return, depending on whether CONFIG_X86_ESPFIX64 is set. But objtool has no visibility to the kernel config. "Fix" it by silencing the exc_double_fault() __noreturn warning. This removes the following warning: vmlinux.o: warning: objtool: xenpv_exc_double_fault+0xd: exc_double_fault() is missing a __noreturn annotation Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/a45b085071d3a7d049a20f9e78754452336ecbe8.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 8d1b4226608c..8dac1e35264e 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -4505,6 +4505,35 @@ static int validate_sls(struct objtool_file *file) return warnings; } +static bool ignore_noreturn_call(struct instruction *insn) +{ + struct symbol *call_dest = insn_call_dest(insn); + + /* + * FIXME: hack, we need a real noreturn solution + * + * Problem is, exc_double_fault() may or may not return, depending on + * whether CONFIG_X86_ESPFIX64 is set. But objtool has no visibility + * to the kernel config. + * + * Other potential ways to fix it: + * + * - have compiler communicate __noreturn functions somehow + * - remove CONFIG_X86_ESPFIX64 + * - read the .config file + * - add a cmdline option + * - create a generic objtool annotation format (vs a bunch of custom + * formats) and annotate it + */ + if (!strcmp(call_dest->name, "exc_double_fault")) { + /* prevent further unreachable warnings for the caller */ + insn->sym->warned = 1; + return true; + } + + return false; +} + static int validate_reachable_instructions(struct objtool_file *file) { struct instruction *insn, *prev_insn; @@ -4521,7 +4550,7 @@ static int validate_reachable_instructions(struct objtool_file *file) prev_insn = prev_insn_same_sec(file, insn); if (prev_insn && prev_insn->dead_end) { call_dest = insn_call_dest(prev_insn); - if (call_dest) { + if (call_dest && !ignore_noreturn_call(prev_insn)) { WARN_INSN(insn, "%s() is missing a __noreturn annotation", call_dest->name); warnings++; -- cgit v1.2.3 From 34245659debd194cbd4148d2ee5176306bdf8899 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 18 Apr 2023 14:27:52 -0700 Subject: objtool: Remove superfluous global_noreturns entries lbug_with_loc() no longer exists, and resume_play_dead() is static (objtool only checks globals and weaks). Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/2725d7f2ccc2361c6903de9ebaa2b5bb304f7ac2.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 8dac1e35264e..8c2762de7ae3 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -217,7 +217,6 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, "kthread_complete_and_exit", "kthread_exit", "kunit_try_catch_throw", - "lbug_with_loc", "machine_real_restart", "make_task_dead", "mpt_halt_firmware", @@ -225,7 +224,6 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, "panic", "panic_smp_self_stop", "rest_init", - "resume_play_dead", "rewind_stack_and_make_dead", "sev_es_terminate", "snp_abort", -- cgit v1.2.3 From d59fec29b131f30b27343d54bdf1071ee98eda8e Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 18 Apr 2023 14:27:53 -0700 Subject: tools/lib/subcmd: Replace NORETURN usage with __noreturn NORETURN is redundant with __noreturn, just use the latter. Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/c7c83d1e6b3d2b0c3e65dd3790c22c772d3b2527.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/lib/subcmd/parse-options.h | 8 ++------ tools/lib/subcmd/subcmd-util.h | 5 ++--- 2 files changed, 4 insertions(+), 9 deletions(-) diff --git a/tools/lib/subcmd/parse-options.h b/tools/lib/subcmd/parse-options.h index 41b9b942504d..8e9147358a28 100644 --- a/tools/lib/subcmd/parse-options.h +++ b/tools/lib/subcmd/parse-options.h @@ -6,10 +6,6 @@ #include #include -#ifndef NORETURN -#define NORETURN __attribute__((__noreturn__)) -#endif - enum parse_opt_type { /* special types */ OPTION_END, @@ -183,9 +179,9 @@ extern int parse_options_subcommand(int argc, const char **argv, const char *const subcommands[], const char *usagestr[], int flags); -extern NORETURN void usage_with_options(const char * const *usagestr, +extern __noreturn void usage_with_options(const char * const *usagestr, const struct option *options); -extern NORETURN __attribute__((format(printf,3,4))) +extern __noreturn __attribute__((format(printf,3,4))) void usage_with_options_msg(const char * const *usagestr, const struct option *options, const char *fmt, ...); diff --git a/tools/lib/subcmd/subcmd-util.h b/tools/lib/subcmd/subcmd-util.h index b2aec04fce8f..dfac76e35ac7 100644 --- a/tools/lib/subcmd/subcmd-util.h +++ b/tools/lib/subcmd/subcmd-util.h @@ -5,8 +5,7 @@ #include #include #include - -#define NORETURN __attribute__((__noreturn__)) +#include static inline void report(const char *prefix, const char *err, va_list params) { @@ -15,7 +14,7 @@ static inline void report(const char *prefix, const char *err, va_list params) fprintf(stderr, " %s%s\n", prefix, msg); } -static NORETURN inline void die(const char *err, ...) +static __noreturn inline void die(const char *err, ...) { va_list params; -- cgit v1.2.3 From 6245ce4ab670166efcdae843c35c14e4c0811aa3 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 18 Apr 2023 14:27:54 -0700 Subject: objtool: Move noreturn function list to separate file This makes it a little cleaner and easier to maintain. Suggested-by: Peter Zijlstra Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/cecacf07a69a244c74474c18b7652627de67a528.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/Documentation/objtool.txt | 5 ++-- tools/objtool/check.c | 44 +++----------------------------- tools/objtool/noreturns.h | 45 +++++++++++++++++++++++++++++++++ 3 files changed, 50 insertions(+), 44 deletions(-) create mode 100644 tools/objtool/noreturns.h diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Documentation/objtool.txt index f9345e0ce740..fe39c2a8ef0d 100644 --- a/tools/objtool/Documentation/objtool.txt +++ b/tools/objtool/Documentation/objtool.txt @@ -306,9 +306,8 @@ the objtool maintainers. 3. file.o: warning: objtool: foo+0x48c: bar() is missing a __noreturn annotation The call from foo() to bar() doesn't return, but bar() is missing the - __noreturn annotation. NOTE: In addition to adding the __noreturn - annotation, the function name also needs to be added to - 'global_noreturns' in tools/objtool/check.c. + __noreturn annotation. NOTE: In addition to annotating the function + with __noreturn, please also add it to tools/objtool/noreturns.h. 4. file.o: warning: objtool: func(): can't find starting instruction or diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 8c2762de7ae3..a13c257f80dd 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -192,49 +192,11 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, struct instruction *insn; bool empty = true; - /* - * Unfortunately these have to be hard coded because the noreturn - * attribute isn't provided in ELF data. Keep 'em sorted. - */ +#define NORETURN(func) __stringify(func), static const char * const global_noreturns[] = { - "__invalid_creds", - "__module_put_and_kthread_exit", - "__reiserfs_panic", - "__stack_chk_fail", - "__ubsan_handle_builtin_unreachable", - "arch_call_rest_init", - "arch_cpu_idle_dead", - "btrfs_assertfail", - "cpu_bringup_and_idle", - "cpu_startup_entry", - "do_exit", - "do_group_exit", - "do_task_dead", - "ex_handler_msr_mce", - "fortify_panic", - "hlt_play_dead", - "hv_ghcb_terminate", - "kthread_complete_and_exit", - "kthread_exit", - "kunit_try_catch_throw", - "machine_real_restart", - "make_task_dead", - "mpt_halt_firmware", - "nmi_panic_self_stop", - "panic", - "panic_smp_self_stop", - "rest_init", - "rewind_stack_and_make_dead", - "sev_es_terminate", - "snp_abort", - "start_kernel", - "stop_this_cpu", - "usercopy_abort", - "x86_64_start_kernel", - "x86_64_start_reservations", - "xen_cpu_bringup_again", - "xen_start_kernel", +#include "noreturns.h" }; +#undef NORETURN if (!func) return false; diff --git a/tools/objtool/noreturns.h b/tools/objtool/noreturns.h new file mode 100644 index 000000000000..cede6068ddf6 --- /dev/null +++ b/tools/objtool/noreturns.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * This is a (sorted!) list of all known __noreturn functions in the kernel. + * It's needed for objtool to properly reverse-engineer the control flow graph. + * + * Yes, this is unfortunate. A better solution is in the works. + */ +NORETURN(__invalid_creds) +NORETURN(__module_put_and_kthread_exit) +NORETURN(__reiserfs_panic) +NORETURN(__stack_chk_fail) +NORETURN(__ubsan_handle_builtin_unreachable) +NORETURN(arch_call_rest_init) +NORETURN(arch_cpu_idle_dead) +NORETURN(btrfs_assertfail) +NORETURN(cpu_bringup_and_idle) +NORETURN(cpu_startup_entry) +NORETURN(do_exit) +NORETURN(do_group_exit) +NORETURN(do_task_dead) +NORETURN(ex_handler_msr_mce) +NORETURN(fortify_panic) +NORETURN(hlt_play_dead) +NORETURN(hv_ghcb_terminate) +NORETURN(kthread_complete_and_exit) +NORETURN(kthread_exit) +NORETURN(kunit_try_catch_throw) +NORETURN(machine_real_restart) +NORETURN(make_task_dead) +NORETURN(mpt_halt_firmware) +NORETURN(nmi_panic_self_stop) +NORETURN(panic) +NORETURN(panic_smp_self_stop) +NORETURN(rest_init) +NORETURN(rewind_stack_and_make_dead) +NORETURN(sev_es_terminate) +NORETURN(snp_abort) +NORETURN(start_kernel) +NORETURN(stop_this_cpu) +NORETURN(usercopy_abort) +NORETURN(x86_64_start_kernel) +NORETURN(x86_64_start_reservations) +NORETURN(xen_cpu_bringup_again) +NORETURN(xen_start_kernel) -- cgit v1.2.3 From ff9a6459bbec06df7da2545020d7383aba13b3fb Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Fri, 2 Jun 2023 10:54:53 -0700 Subject: objtool: Add __kunit_abort() to noreturns Fixes a bunch of warnings like: drivers/input/tests/input_test.o: warning: objtool: input_test_init+0x1cb: stack state mismatch: cfa1=4+64 cfa2=4+56 lib/kunit/kunit-test.o: warning: objtool: kunit_log_newline_test+0xfb: return with modified stack frame ... Fixes: 260755184cbd ("kunit: Move kunit_abort() call out of kunit_do_failed_assertion()") Reported-by: Stephen Rothwell Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20230602175453.swsn3ehyochtwkhy@treble --- tools/objtool/noreturns.h | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/objtool/noreturns.h b/tools/objtool/noreturns.h index cede6068ddf6..1514e84d5cc4 100644 --- a/tools/objtool/noreturns.h +++ b/tools/objtool/noreturns.h @@ -7,6 +7,7 @@ * Yes, this is unfortunate. A better solution is in the works. */ NORETURN(__invalid_creds) +NORETURN(__kunit_abort) NORETURN(__module_put_and_kthread_exit) NORETURN(__reiserfs_panic) NORETURN(__stack_chk_fail) -- cgit v1.2.3 From d49d1666aab51ad3caf79f414aff6b641837a6ea Mon Sep 17 00:00:00 2001 From: Lu Hongfei Date: Tue, 30 May 2023 15:56:49 +0800 Subject: tools: Remove unnecessary variables There are several places where warnings variables are not needed, remove them and directly return 0. Signed-off-by: Lu Hongfei Link: https://lore.kernel.org/r/20230530075649.21661-1-luhongfei@vivo.com Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index a13c257f80dd..4b869de7e827 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3799,7 +3799,7 @@ static int validate_unwind_hints(struct objtool_file *file, struct section *sec) static int validate_unret(struct objtool_file *file, struct instruction *insn) { struct instruction *next, *dest; - int ret, warnings = 0; + int ret; for (;;) { next = next_insn_to_validate(file, insn); @@ -3897,7 +3897,7 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn) insn = next; } - return warnings; + return 0; } /* @@ -4132,7 +4132,6 @@ static int add_prefix_symbols(struct objtool_file *file) { struct section *sec; struct symbol *func; - int warnings = 0; for_each_sec(file, sec) { if (!(sec->sh.sh_flags & SHF_EXECINSTR)) @@ -4146,7 +4145,7 @@ static int add_prefix_symbols(struct objtool_file *file) } } - return warnings; + return 0; } static int validate_symbol(struct objtool_file *file, struct section *sec, -- cgit v1.2.3 From 4a03aa34432abe0703abf232f31fc5e2ed8256f6 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 14 Nov 2022 16:23:45 +0100 Subject: lkdtm: Avoid objtool/ibt warning For certain configs objtool will complain like: vmlinux.o: warning: objtool: lkdtm_UNSET_SMEP+0x1c3: relocation to !ENDBR: native_write_cr4+0x41 What happens is that GCC optimizes the loop: insn = (unsigned char *)native_write_cr4; for (i = 0; i < MOV_CR4_DEPTH; i++) to read something like: for (insn = (unsigned char *)native_write_cr4; insn < (unsigned char *)native_write_cr4 + MOV_CR4_DEPTH; insn++) Which then obviously generates the text reference native_write_cr4+041. Since none of this is a fast path, simply confuse GCC enough to inhibit this optimization. Reported-by: kernel test robot Signed-off-by: Peter Zijlstra (Intel) Acked-by: Kees Cook Link: https://lore.kernel.org/r/Y3JdgbXRV0MNZ+9h@hirez.programming.kicks-ass.net Signed-off-by: Josh Poimboeuf --- drivers/misc/lkdtm/bugs.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index 48821f4c2b21..92110cb6a0eb 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -487,6 +487,7 @@ static void lkdtm_UNSET_SMEP(void) * the cr4 writing instruction. */ insn = (unsigned char *)native_write_cr4; + OPTIMIZER_HIDE_VAR(insn); for (i = 0; i < MOV_CR4_DEPTH; i++) { /* mov %rdi, %cr4 */ if (insn[i] == 0x0f && insn[i+1] == 0x22 && insn[i+2] == 0xe7) -- cgit v1.2.3 From 020126239b8f376ed2f0bef9dc07d0b280a0b7f5 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 16 May 2023 06:56:46 -0700 Subject: Revert "x86/orc: Make it callthunk aware" Commit 396e0b8e09e8 ("x86/orc: Make it callthunk aware") attempted to deal with the fact that function prefix code didn't have ORC coverage. However, it didn't work as advertised. Use of the "null" ORC entry just caused affected unwinds to end early. The root cause has now been fixed with commit 5743654f5e2e ("objtool: Generate ORC data for __pfx code"). Revert most of commit 396e0b8e09e8 ("x86/orc: Make it callthunk aware"). The is_callthunk() function remains as it's now used by other code. Link: https://lore.kernel.org/r/a05b916ef941da872cbece1ab3593eceabd05a79.1684245404.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- arch/x86/include/asm/alternative.h | 5 ----- arch/x86/kernel/callthunks.c | 2 +- arch/x86/kernel/unwind_orc.c | 21 +-------------------- 3 files changed, 2 insertions(+), 26 deletions(-) diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index d7da28fada87..6c15a622ad60 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -113,7 +113,6 @@ extern void callthunks_patch_builtin_calls(void); extern void callthunks_patch_module_calls(struct callthunk_sites *sites, struct module *mod); extern void *callthunks_translate_call_dest(void *dest); -extern bool is_callthunk(void *addr); extern int x86_call_depth_emit_accounting(u8 **pprog, void *func); #else static __always_inline void callthunks_patch_builtin_calls(void) {} @@ -124,10 +123,6 @@ static __always_inline void *callthunks_translate_call_dest(void *dest) { return dest; } -static __always_inline bool is_callthunk(void *addr) -{ - return false; -} static __always_inline int x86_call_depth_emit_accounting(u8 **pprog, void *func) { diff --git a/arch/x86/kernel/callthunks.c b/arch/x86/kernel/callthunks.c index 22ab13966427..8e0a9b637e23 100644 --- a/arch/x86/kernel/callthunks.c +++ b/arch/x86/kernel/callthunks.c @@ -293,7 +293,7 @@ void *callthunks_translate_call_dest(void *dest) return target ? : dest; } -bool is_callthunk(void *addr) +static bool is_callthunk(void *addr) { unsigned int tmpl_size = SKL_TMPL_SIZE; void *tmpl = skl_call_thunk_template; diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index 7891727f534e..4ee16b02628a 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -183,21 +183,6 @@ static struct orc_entry null_orc_entry = { .type = ORC_TYPE_CALL }; -#ifdef CONFIG_CALL_THUNKS -static struct orc_entry *orc_callthunk_find(unsigned long ip) -{ - if (!is_callthunk((void *)ip)) - return NULL; - - return &null_orc_entry; -} -#else -static struct orc_entry *orc_callthunk_find(unsigned long ip) -{ - return NULL; -} -#endif - /* Fake frame pointer entry -- used as a fallback for generated code */ static struct orc_entry orc_fp_entry = { .type = ORC_TYPE_CALL, @@ -250,11 +235,7 @@ static struct orc_entry *orc_find(unsigned long ip) if (orc) return orc; - orc = orc_ftrace_find(ip); - if (orc) - return orc; - - return orc_callthunk_find(ip); + return orc_ftrace_find(ip); } #ifdef CONFIG_MODULES -- cgit v1.2.3 From ac27ecf68a1ada240bb71531dc2d30cde04ad70a Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 16:07:41 -0700 Subject: x86/entry: Move thunk restore code into thunk functions There's no need for both thunk functions to jump to the same shared thunk restore code which lives outside the thunk function boundaries. It disrupts i-cache locality and confuses objtool. Keep it simple by keeping each thunk's restore code self-contained within the function. Fixes a bunch of false positive "missing __noreturn" warnings like: vmlinux.o: warning: objtool: do_arch_prctl_common+0xf4: preempt_schedule_thunk() is missing a __noreturn annotation Fixes: fedb724c3db5 ("objtool: Detect missing __noreturn annotations") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202305281037.3PaI3tW4-lkp@intel.com/ Link: https://lore.kernel.org/r/46aa8aeb716f302e22e1673ae15ee6fe050b41f4.1685488050.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- arch/x86/entry/thunk_64.S | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk_64.S index 5e37f41e5f14..27b5da2111ac 100644 --- a/arch/x86/entry/thunk_64.S +++ b/arch/x86/entry/thunk_64.S @@ -26,17 +26,7 @@ SYM_FUNC_START(\name) pushq %r11 call \func - jmp __thunk_restore -SYM_FUNC_END(\name) - _ASM_NOKPROBE(\name) - .endm - - THUNK preempt_schedule_thunk, preempt_schedule - THUNK preempt_schedule_notrace_thunk, preempt_schedule_notrace - EXPORT_SYMBOL(preempt_schedule_thunk) - EXPORT_SYMBOL(preempt_schedule_notrace_thunk) -SYM_CODE_START_LOCAL(__thunk_restore) popq %r11 popq %r10 popq %r9 @@ -48,5 +38,11 @@ SYM_CODE_START_LOCAL(__thunk_restore) popq %rdi popq %rbp RET - _ASM_NOKPROBE(__thunk_restore) -SYM_CODE_END(__thunk_restore) +SYM_FUNC_END(\name) + _ASM_NOKPROBE(\name) + .endm + +THUNK preempt_schedule_thunk, preempt_schedule +THUNK preempt_schedule_notrace_thunk, preempt_schedule_notrace +EXPORT_SYMBOL(preempt_schedule_thunk) +EXPORT_SYMBOL(preempt_schedule_notrace_thunk) -- cgit v1.2.3 From 1e4b619185e83e54aca617cf5070c64a88fe936b Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Mon, 5 Jun 2023 09:12:21 -0700 Subject: objtool: Allow stack operations in UNWIND_HINT_UNDEFINED regions If the code specified UNWIND_HINT_UNDEFINED, skip the "undefined stack state" warning due to a stack operation. Just ignore the stack op and continue to propagate the undefined state. Link: https://lore.kernel.org/r/820c5b433f17c84e8761fb7465a8d319d706b1cf.1685981486.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 12 ++++++++++++ tools/objtool/include/objtool/cfi.h | 1 + 2 files changed, 13 insertions(+) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 4b869de7e827..b11c25a715ac 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -33,6 +33,7 @@ static unsigned long nr_cfi, nr_cfi_reused, nr_cfi_cache; static struct cfi_init_state initial_func_cfi; static struct cfi_state init_cfi; static struct cfi_state func_cfi; +static struct cfi_state force_undefined_cfi; struct instruction *find_insn(struct objtool_file *file, struct section *sec, unsigned long offset) @@ -2240,6 +2241,11 @@ static int read_unwind_hints(struct objtool_file *file) insn->hint = true; + if (hint->type == UNWIND_HINT_TYPE_UNDEFINED) { + insn->cfi = &force_undefined_cfi; + continue; + } + if (hint->type == UNWIND_HINT_TYPE_SAVE) { insn->hint = false; insn->save = true; @@ -2793,6 +2799,10 @@ static int update_cfi_state(struct instruction *insn, struct cfi_reg *cfa = &cfi->cfa; struct cfi_reg *regs = cfi->regs; + /* ignore UNWIND_HINT_UNDEFINED regions */ + if (cfi->force_undefined) + return 0; + /* stack operations don't make sense with an undefined CFA */ if (cfa->base == CFI_UNDEFINED) { if (insn_func(insn)) { @@ -4607,6 +4617,8 @@ int check(struct objtool_file *file) init_cfi_state(&init_cfi); init_cfi_state(&func_cfi); set_func_state(&func_cfi); + init_cfi_state(&force_undefined_cfi); + force_undefined_cfi.force_undefined = true; if (!cfi_hash_alloc(1UL << (file->elf->symbol_bits - 3))) goto out; diff --git a/tools/objtool/include/objtool/cfi.h b/tools/objtool/include/objtool/cfi.h index b1258e79a1b7..c8a6bec4f6b9 100644 --- a/tools/objtool/include/objtool/cfi.h +++ b/tools/objtool/include/objtool/cfi.h @@ -36,6 +36,7 @@ struct cfi_state { bool drap; bool signal; bool end; + bool force_undefined; }; #endif /* _OBJTOOL_CFI_H */ -- cgit v1.2.3 From a9da8247627eefc73f909bf945031a5431a53993 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Mon, 5 Jun 2023 09:12:22 -0700 Subject: drm/vmwgfx: Add unwind hints around RBP clobber VMware high-bandwidth hypercalls take the RBP register as input. This breaks basic frame pointer convention, as RBP should never be clobbered. So frame pointer unwinding is broken for the instructions surrounding the hypercalls. Fortunately this doesn't break live patching with CONFIG_FRAME_POINTER, as it only unwinds from blocking tasks, and stack traces from preempted tasks are already marked unreliable anyway. However, for live patching with ORC, this could actually be a theoretical problem if vmw_port_hb_{in,out}() were still compiled with a frame pointer due to having an aligned stack. In practice that hasn't seemed to be an issue since the objtool warnings have only been seen with CONFIG_FRAME_POINTER. Add unwind hint annotations to tell the ORC unwinder to mark stack traces as unreliable. Fixes the following warnings: vmlinux.o: warning: objtool: vmw_port_hb_in+0x1df: return with modified stack frame vmlinux.o: warning: objtool: vmw_port_hb_out+0x1dd: return with modified stack frame Fixes: 89da76fde68d ("drm/vmwgfx: Add VMWare host messaging capability") Reported-by: kernel test robot Link: https://lore.kernel.org/oe-kbuild-all/202305160135.97q0Elax-lkp@intel.com/ Link: https://lore.kernel.org/r/4c795f2d87bc0391cf6543bcb224fa540b55ce4b.1685981486.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- arch/x86/include/asm/unwind_hints.h | 9 +++++++++ drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h | 16 ++++++++++++---- 2 files changed, 21 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/unwind_hints.h b/arch/x86/include/asm/unwind_hints.h index 01cb9692b160..85cc57cb6539 100644 --- a/arch/x86/include/asm/unwind_hints.h +++ b/arch/x86/include/asm/unwind_hints.h @@ -76,9 +76,18 @@ #else +#define UNWIND_HINT_UNDEFINED \ + UNWIND_HINT(UNWIND_HINT_TYPE_UNDEFINED, 0, 0, 0) + #define UNWIND_HINT_FUNC \ UNWIND_HINT(UNWIND_HINT_TYPE_FUNC, ORC_REG_SP, 8, 0) +#define UNWIND_HINT_SAVE \ + UNWIND_HINT(UNWIND_HINT_TYPE_SAVE, 0, 0, 0) + +#define UNWIND_HINT_RESTORE \ + UNWIND_HINT(UNWIND_HINT_TYPE_RESTORE, 0, 0, 0) + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_UNWIND_HINTS_H */ diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h b/drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h index 0b74ca2dfb7b..23899d743a90 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h @@ -105,10 +105,14 @@ flags, magic, bp, \ eax, ebx, ecx, edx, si, di) \ ({ \ - asm volatile ("push %%rbp;" \ + asm volatile ( \ + UNWIND_HINT_SAVE \ + "push %%rbp;" \ + UNWIND_HINT_UNDEFINED \ "mov %12, %%rbp;" \ VMWARE_HYPERCALL_HB_OUT \ - "pop %%rbp;" : \ + "pop %%rbp;" \ + UNWIND_HINT_RESTORE : \ "=a"(eax), \ "=b"(ebx), \ "=c"(ecx), \ @@ -130,10 +134,14 @@ flags, magic, bp, \ eax, ebx, ecx, edx, si, di) \ ({ \ - asm volatile ("push %%rbp;" \ + asm volatile ( \ + UNWIND_HINT_SAVE \ + "push %%rbp;" \ + UNWIND_HINT_UNDEFINED \ "mov %12, %%rbp;" \ VMWARE_HYPERCALL_HB_IN \ - "pop %%rbp" : \ + "pop %%rbp;" \ + UNWIND_HINT_RESTORE : \ "=a"(eax), \ "=b"(ebx), \ "=c"(ecx), \ -- cgit v1.2.3 From 809373e17b2649948cc681dd1962b2736b22c7a6 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:20:53 -0700 Subject: objtool: Tidy elf.h Reorganize elf.h a bit: - Move the prototypes higher up so they can be used by the inline functions. - Move hash-related code to the bottom. - Remove the unused ELF_HASH_BITS macro. No functional changes. Link: https://lore.kernel.org/r/b1490ed85951868219a6ece177a7cd30a6454d66.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/include/objtool/elf.h | 96 ++++++++++++++++++------------------- 1 file changed, 47 insertions(+), 49 deletions(-) diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 78e2d0fc21ca..b24f83e7ca34 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -83,8 +83,6 @@ struct reloc { bool jump_table_start; }; -#define ELF_HASH_BITS 20 - struct elf { Elf *elf; GElf_Ehdr ehdr; @@ -110,53 +108,6 @@ struct elf { struct symbol *symbol_data; }; -#define OFFSET_STRIDE_BITS 4 -#define OFFSET_STRIDE (1UL << OFFSET_STRIDE_BITS) -#define OFFSET_STRIDE_MASK (~(OFFSET_STRIDE - 1)) - -#define for_offset_range(_offset, _start, _end) \ - for (_offset = ((_start) & OFFSET_STRIDE_MASK); \ - _offset >= ((_start) & OFFSET_STRIDE_MASK) && \ - _offset <= ((_end) & OFFSET_STRIDE_MASK); \ - _offset += OFFSET_STRIDE) - -static inline u32 sec_offset_hash(struct section *sec, unsigned long offset) -{ - u32 ol, oh, idx = sec->idx; - - offset &= OFFSET_STRIDE_MASK; - - ol = offset; - oh = (offset >> 16) >> 16; - - __jhash_mix(ol, oh, idx); - - return ol; -} - -static inline u32 reloc_hash(struct reloc *reloc) -{ - return sec_offset_hash(reloc->sec, reloc->offset); -} - -/* - * Try to see if it's a whole archive (vmlinux.o or module). - * - * Note this will miss the case where a module only has one source file. - */ -static inline bool has_multiple_files(struct elf *elf) -{ - return elf->num_files > 1; -} - -static inline int elf_class_addrsize(struct elf *elf) -{ - if (elf->ehdr.e_ident[EI_CLASS] == ELFCLASS32) - return sizeof(u32); - else - return sizeof(u64); -} - struct elf *elf_open_read(const char *name, int flags); struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr); @@ -186,6 +137,24 @@ struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *se unsigned long offset, unsigned int len); struct symbol *find_func_containing(struct section *sec, unsigned long offset); +/* + * Try to see if it's a whole archive (vmlinux.o or module). + * + * Note this will miss the case where a module only has one source file. + */ +static inline bool has_multiple_files(struct elf *elf) +{ + return elf->num_files > 1; +} + +static inline int elf_class_addrsize(struct elf *elf) +{ + if (elf->ehdr.e_ident[EI_CLASS] == ELFCLASS32) + return sizeof(u32); + else + return sizeof(u64); +} + #define for_each_sec(file, sec) \ list_for_each_entry(sec, &file->elf->sections, list) @@ -198,4 +167,33 @@ struct symbol *find_func_containing(struct section *sec, unsigned long offset); for_each_sec(file, __sec) \ sec_for_each_sym(__sec, sym) +#define OFFSET_STRIDE_BITS 4 +#define OFFSET_STRIDE (1UL << OFFSET_STRIDE_BITS) +#define OFFSET_STRIDE_MASK (~(OFFSET_STRIDE - 1)) + +#define for_offset_range(_offset, _start, _end) \ + for (_offset = ((_start) & OFFSET_STRIDE_MASK); \ + _offset >= ((_start) & OFFSET_STRIDE_MASK) && \ + _offset <= ((_end) & OFFSET_STRIDE_MASK); \ + _offset += OFFSET_STRIDE) + +static inline u32 sec_offset_hash(struct section *sec, unsigned long offset) +{ + u32 ol, oh, idx = sec->idx; + + offset &= OFFSET_STRIDE_MASK; + + ol = offset; + oh = (offset >> 16) >> 16; + + __jhash_mix(ol, oh, idx); + + return ol; +} + +static inline u32 reloc_hash(struct reloc *reloc) +{ + return sec_offset_hash(reloc->sec, reloc->offset); +} + #endif /* _OBJTOOL_ELF_H */ -- cgit v1.2.3 From 2707579dfa615a5dda4aabb92e433f03a87b5ec5 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:20:54 -0700 Subject: objtool: Remove flags argument from elf_create_section() Simplify the elf_create_section() interface a bit by removing the flags argument. Most callers don't care about changing the section header flags. If needed, they can be modified afterwards, just like any other section header field. Link: https://lore.kernel.org/r/515235d9cf62637a14bee37bfa9169ef20065471.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 17 ++++++++++------- tools/objtool/elf.c | 10 +++++----- tools/objtool/include/objtool/elf.h | 2 +- tools/objtool/orc_gen.c | 4 ++-- 4 files changed, 18 insertions(+), 15 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index b11c25a715ac..eaf681557096 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -677,11 +677,14 @@ static int create_static_call_sections(struct objtool_file *file) list_for_each_entry(insn, &file->static_call_list, call_node) idx++; - sec = elf_create_section(file->elf, ".static_call_sites", SHF_WRITE, + sec = elf_create_section(file->elf, ".static_call_sites", sizeof(struct static_call_site), idx); if (!sec) return -1; + /* Allow modules to set the low bits of static_call_site::key */ + sec->sh.sh_flags |= SHF_WRITE; + idx = 0; list_for_each_entry(insn, &file->static_call_list, call_node) { @@ -763,7 +766,7 @@ static int create_retpoline_sites_sections(struct objtool_file *file) if (!idx) return 0; - sec = elf_create_section(file->elf, ".retpoline_sites", 0, + sec = elf_create_section(file->elf, ".retpoline_sites", sizeof(int), idx); if (!sec) { WARN("elf_create_section: .retpoline_sites"); @@ -809,7 +812,7 @@ static int create_return_sites_sections(struct objtool_file *file) if (!idx) return 0; - sec = elf_create_section(file->elf, ".return_sites", 0, + sec = elf_create_section(file->elf, ".return_sites", sizeof(int), idx); if (!sec) { WARN("elf_create_section: .return_sites"); @@ -861,7 +864,7 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file) if (!idx) return 0; - sec = elf_create_section(file->elf, ".ibt_endbr_seal", 0, + sec = elf_create_section(file->elf, ".ibt_endbr_seal", sizeof(int), idx); if (!sec) { WARN("elf_create_section: .ibt_endbr_seal"); @@ -920,7 +923,7 @@ static int create_cfi_sections(struct objtool_file *file) idx++; } - sec = elf_create_section(file->elf, ".cfi_sites", 0, sizeof(unsigned int), idx); + sec = elf_create_section(file->elf, ".cfi_sites", sizeof(unsigned int), idx); if (!sec) return -1; @@ -968,7 +971,7 @@ static int create_mcount_loc_sections(struct objtool_file *file) list_for_each_entry(insn, &file->mcount_loc_list, call_node) idx++; - sec = elf_create_section(file->elf, "__mcount_loc", 0, addrsize, idx); + sec = elf_create_section(file->elf, "__mcount_loc", addrsize, idx); if (!sec) return -1; @@ -1013,7 +1016,7 @@ static int create_direct_call_sections(struct objtool_file *file) list_for_each_entry(insn, &file->call_list, call_node) idx++; - sec = elf_create_section(file->elf, ".call_sites", 0, sizeof(unsigned int), idx); + sec = elf_create_section(file->elf, ".call_sites", sizeof(unsigned int), idx); if (!sec) return -1; diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 500e92979a31..7598c0a2633d 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -1059,7 +1059,7 @@ static int elf_add_string(struct elf *elf, struct section *strtab, char *str) } struct section *elf_create_section(struct elf *elf, const char *name, - unsigned int sh_flags, size_t entsize, int nr) + size_t entsize, int nr) { struct section *sec, *shstrtab; size_t size = entsize * nr; @@ -1117,7 +1117,7 @@ struct section *elf_create_section(struct elf *elf, const char *name, sec->sh.sh_entsize = entsize; sec->sh.sh_type = SHT_PROGBITS; sec->sh.sh_addralign = 1; - sec->sh.sh_flags = SHF_ALLOC | sh_flags; + sec->sh.sh_flags = SHF_ALLOC; /* Add section name to .shstrtab (or .strtab for Clang) */ shstrtab = find_section_by_name(elf, ".shstrtab"); @@ -1153,7 +1153,7 @@ static struct section *elf_create_rel_reloc_section(struct elf *elf, struct sect strcpy(relocname, ".rel"); strcat(relocname, base->name); - sec = elf_create_section(elf, relocname, 0, sizeof(GElf_Rel), 0); + sec = elf_create_section(elf, relocname, sizeof(GElf_Rel), 0); free(relocname); if (!sec) return NULL; @@ -1185,9 +1185,9 @@ static struct section *elf_create_rela_reloc_section(struct elf *elf, struct sec strcat(relocname, base->name); if (addrsize == sizeof(u32)) - sec = elf_create_section(elf, relocname, 0, sizeof(Elf32_Rela), 0); + sec = elf_create_section(elf, relocname, sizeof(Elf32_Rela), 0); else - sec = elf_create_section(elf, relocname, 0, sizeof(GElf_Rela), 0); + sec = elf_create_section(elf, relocname, sizeof(GElf_Rela), 0); free(relocname); if (!sec) return NULL; diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index b24f83e7ca34..2c28aeeb3cb2 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -109,7 +109,7 @@ struct elf { }; struct elf *elf_open_read(const char *name, int flags); -struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr); +struct section *elf_create_section(struct elf *elf, const char *name, size_t entsize, int nr); struct symbol *elf_create_prefix_symbol(struct elf *elf, struct symbol *orig, long size); diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c index 48efd1e2f00d..d5f750be7d7d 100644 --- a/tools/objtool/orc_gen.c +++ b/tools/objtool/orc_gen.c @@ -237,12 +237,12 @@ int orc_create(struct objtool_file *file) WARN("file already has .orc_unwind section, skipping"); return -1; } - orc_sec = elf_create_section(file->elf, ".orc_unwind", 0, + orc_sec = elf_create_section(file->elf, ".orc_unwind", sizeof(struct orc_entry), nr); if (!orc_sec) return -1; - sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), nr); + sec = elf_create_section(file->elf, ".orc_unwind_ip", sizeof(int), nr); if (!sec) return -1; -- cgit v1.2.3 From a5bd623653231bce8657978e9d2c2ebfaf19e297 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:20:55 -0700 Subject: objtool: Improve reloc naming - The term "reloc" is overloaded to mean both "an instance of struct reloc" and "a reloc section". Change the latter to "rsec". - For variable names, use "sec" for regular sections and "rsec" for rela sections to prevent them getting mixed up. - For struct reloc variables, use "reloc" instead of "rel" everywhere for consistency. Link: https://lore.kernel.org/r/8b790e403df46f445c21003e7893b8f53b99a6f3.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 134 ++++++++++++++--------------- tools/objtool/elf.c | 164 ++++++++++++++++++------------------ tools/objtool/include/objtool/elf.h | 2 +- 3 files changed, 151 insertions(+), 149 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index eaf681557096..f4c52a2c8d5b 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -494,7 +494,7 @@ static int add_pv_ops(struct objtool_file *file, const char *symname) { struct symbol *sym, *func; unsigned long off, end; - struct reloc *rel; + struct reloc *reloc; int idx; sym = find_symbol_by_name(file->elf, symname); @@ -504,19 +504,19 @@ static int add_pv_ops(struct objtool_file *file, const char *symname) off = sym->offset; end = off + sym->len; for (;;) { - rel = find_reloc_by_dest_range(file->elf, sym->sec, off, end - off); - if (!rel) + reloc = find_reloc_by_dest_range(file->elf, sym->sec, off, end - off); + if (!reloc) break; - func = rel->sym; + func = reloc->sym; if (func->type == STT_SECTION) - func = find_symbol_by_offset(rel->sym->sec, rel->addend); + func = find_symbol_by_offset(reloc->sym->sec, reloc->addend); - idx = (rel->offset - sym->offset) / sizeof(unsigned long); + idx = (reloc->offset - sym->offset) / sizeof(unsigned long); objtool_pv_add(file, idx, func); - off = rel->offset + 1; + off = reloc->offset + 1; if (off > end) break; } @@ -581,20 +581,20 @@ static struct instruction *find_last_insn(struct objtool_file *file, */ static int add_dead_ends(struct objtool_file *file) { - struct section *sec; + struct section *rsec; struct reloc *reloc; struct instruction *insn; /* * Check for manually annotated dead ends. */ - sec = find_section_by_name(file->elf, ".rela.discard.unreachable"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.unreachable"); + if (!rsec) goto reachable; - list_for_each_entry(reloc, &sec->reloc_list, list) { + list_for_each_entry(reloc, &rsec->reloc_list, list) { if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } insn = find_insn(file, reloc->sym->sec, reloc->addend); @@ -623,13 +623,13 @@ reachable: * GCC doesn't know the "ud2" is fatal, so it generates code as if it's * not a dead end. */ - sec = find_section_by_name(file->elf, ".rela.discard.reachable"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.reachable"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + list_for_each_entry(reloc, &rsec->reloc_list, list) { if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } insn = find_insn(file, reloc->sym->sec, reloc->addend); @@ -1044,15 +1044,15 @@ static int create_direct_call_sections(struct objtool_file *file) static void add_ignores(struct objtool_file *file) { struct instruction *insn; - struct section *sec; + struct section *rsec; struct symbol *func; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.func_stack_frame_non_standard"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.func_stack_frame_non_standard"); + if (!rsec) return; - list_for_each_entry(reloc, &sec->reloc_list, list) { + list_for_each_entry(reloc, &rsec->reloc_list, list) { switch (reloc->sym->type) { case STT_FUNC: func = reloc->sym; @@ -1065,7 +1065,8 @@ static void add_ignores(struct objtool_file *file) break; default: - WARN("unexpected relocation symbol type in %s: %d", sec->name, reloc->sym->type); + WARN("unexpected relocation symbol type in %s: %d", + rsec->name, reloc->sym->type); continue; } @@ -1284,17 +1285,17 @@ static void add_uaccess_safe(struct objtool_file *file) */ static int add_ignore_alternatives(struct objtool_file *file) { - struct section *sec; + struct section *rsec; struct reloc *reloc; struct instruction *insn; - sec = find_section_by_name(file->elf, ".rela.discard.ignore_alts"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.ignore_alts"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + list_for_each_entry(reloc, &rsec->reloc_list, list) { if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } @@ -2204,7 +2205,7 @@ static void set_func_state(struct cfi_state *state) static int read_unwind_hints(struct objtool_file *file) { struct cfi_state cfi = init_cfi; - struct section *sec, *relocsec; + struct section *sec; struct unwind_hint *hint; struct instruction *insn; struct reloc *reloc; @@ -2214,8 +2215,7 @@ static int read_unwind_hints(struct objtool_file *file) if (!sec) return 0; - relocsec = sec->reloc; - if (!relocsec) { + if (!sec->rsec) { WARN("missing .rela.discard.unwind_hints section"); return -1; } @@ -2295,15 +2295,15 @@ static int read_unwind_hints(struct objtool_file *file) static int read_noendbr_hints(struct objtool_file *file) { - struct section *sec; struct instruction *insn; + struct section *rsec; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.noendbr"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.noendbr"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + list_for_each_entry(reloc, &rsec->reloc_list, list) { insn = find_insn(file, reloc->sym->sec, reloc->sym->offset + reloc->addend); if (!insn) { WARN("bad .discard.noendbr entry"); @@ -2318,17 +2318,17 @@ static int read_noendbr_hints(struct objtool_file *file) static int read_retpoline_hints(struct objtool_file *file) { - struct section *sec; + struct section *rsec; struct instruction *insn; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + list_for_each_entry(reloc, &rsec->reloc_list, list) { if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } @@ -2354,17 +2354,17 @@ static int read_retpoline_hints(struct objtool_file *file) static int read_instr_hints(struct objtool_file *file) { - struct section *sec; + struct section *rsec; struct instruction *insn; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.instr_end"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.instr_end"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + list_for_each_entry(reloc, &rsec->reloc_list, list) { if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } @@ -2377,13 +2377,13 @@ static int read_instr_hints(struct objtool_file *file) insn->instr--; } - sec = find_section_by_name(file->elf, ".rela.discard.instr_begin"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.instr_begin"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + list_for_each_entry(reloc, &rsec->reloc_list, list) { if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } @@ -2401,17 +2401,17 @@ static int read_instr_hints(struct objtool_file *file) static int read_validate_unret_hints(struct objtool_file *file) { - struct section *sec; + struct section *rsec; struct instruction *insn; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.validate_unret"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.validate_unret"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + list_for_each_entry(reloc, &rsec->reloc_list, list) { if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } @@ -2430,19 +2430,19 @@ static int read_validate_unret_hints(struct objtool_file *file) static int read_intra_function_calls(struct objtool_file *file) { struct instruction *insn; - struct section *sec; + struct section *rsec; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + list_for_each_entry(reloc, &rsec->reloc_list, list) { unsigned long dest_off; if (reloc->sym->type != STT_SECTION) { WARN("unexpected relocation symbol type in %s", - sec->name); + rsec->name); return -1; } @@ -3342,15 +3342,15 @@ static inline bool func_uaccess_safe(struct symbol *func) static inline const char *call_dest_name(struct instruction *insn) { static char pvname[19]; - struct reloc *rel; + struct reloc *reloc; int idx; if (insn_call_dest(insn)) return insn_call_dest(insn)->name; - rel = insn_reloc(NULL, insn); - if (rel && !strcmp(rel->sym->name, "pv_ops")) { - idx = (rel->addend / sizeof(void *)); + reloc = insn_reloc(NULL, insn); + if (reloc && !strcmp(reloc->sym->name, "pv_ops")) { + idx = (reloc->addend / sizeof(void *)); snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx); return pvname; } @@ -3361,14 +3361,14 @@ static inline const char *call_dest_name(struct instruction *insn) static bool pv_call_dest(struct objtool_file *file, struct instruction *insn) { struct symbol *target; - struct reloc *rel; + struct reloc *reloc; int idx; - rel = insn_reloc(file, insn); - if (!rel || strcmp(rel->sym->name, "pv_ops")) + reloc = insn_reloc(file, insn); + if (!reloc || strcmp(reloc->sym->name, "pv_ops")) return false; - idx = (arch_dest_reloc_offset(rel->addend) / sizeof(void *)); + idx = (arch_dest_reloc_offset(reloc->addend) / sizeof(void *)); if (file->pv_ops[idx].clean) return true; @@ -4410,7 +4410,7 @@ static int validate_ibt(struct objtool_file *file) if (sec->sh.sh_flags & SHF_EXECINSTR) continue; - if (!sec->reloc) + if (!sec->rsec) continue; /* @@ -4437,7 +4437,7 @@ static int validate_ibt(struct objtool_file *file) strstr(sec->name, "__patchable_function_entries")) continue; - list_for_each_entry(reloc, &sec->reloc->reloc_list, list) + list_for_each_entry(reloc, &sec->rsec->reloc_list, list) warnings += validate_ibt_data_reloc(file, reloc); } diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 7598c0a2633d..86ae62dfdba2 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -233,17 +233,17 @@ struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *se unsigned long offset, unsigned int len) { struct reloc *reloc, *r = NULL; + struct section *rsec; unsigned long o; - if (!sec->reloc) + rsec = sec->rsec; + if (!rsec) return NULL; - sec = sec->reloc; - for_offset_range(o, offset, offset + len) { elf_hash_for_each_possible(reloc, reloc, hash, - sec_offset_hash(sec, o)) { - if (reloc->sec != sec) + sec_offset_hash(rsec, o)) { + if (reloc->sec != rsec) continue; if (reloc->offset >= offset && reloc->offset < offset + len) { @@ -534,7 +534,7 @@ err: } static struct section *elf_create_reloc_section(struct elf *elf, - struct section *base, + struct section *sec, int reltype); int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, @@ -542,7 +542,7 @@ int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, { struct reloc *reloc; - if (!sec->reloc && !elf_create_reloc_section(elf, sec, SHT_RELA)) + if (!sec->rsec && !elf_create_reloc_section(elf, sec, SHT_RELA)) return -1; reloc = malloc(sizeof(*reloc)); @@ -552,18 +552,18 @@ int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, } memset(reloc, 0, sizeof(*reloc)); - reloc->sec = sec->reloc; + reloc->sec = sec->rsec; reloc->offset = offset; reloc->type = type; reloc->sym = sym; reloc->addend = addend; list_add_tail(&reloc->sym_reloc_entry, &sym->reloc_list); - list_add_tail(&reloc->list, &sec->reloc->reloc_list); + list_add_tail(&reloc->list, &sec->rsec->reloc_list); elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); - sec->reloc->sh.sh_size += sec->reloc->sh.sh_entsize; - sec->reloc->changed = true; + sec->rsec->sh.sh_size += sec->rsec->sh.sh_entsize; + sec->rsec->changed = true; return 0; } @@ -865,9 +865,9 @@ int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, return elf_add_reloc(elf, sec, offset, type, sym, addend); } -static int read_rel_reloc(struct section *sec, int i, struct reloc *reloc, unsigned int *symndx) +static int read_rel_reloc(struct section *rsec, int i, struct reloc *reloc, unsigned int *symndx) { - if (!gelf_getrel(sec->data, i, &reloc->rel)) { + if (!gelf_getrel(rsec->data, i, &reloc->rel)) { WARN_ELF("gelf_getrel"); return -1; } @@ -878,9 +878,9 @@ static int read_rel_reloc(struct section *sec, int i, struct reloc *reloc, unsig return 0; } -static int read_rela_reloc(struct section *sec, int i, struct reloc *reloc, unsigned int *symndx) +static int read_rela_reloc(struct section *rsec, int i, struct reloc *reloc, unsigned int *symndx) { - if (!gelf_getrela(sec->data, i, &reloc->rela)) { + if (!gelf_getrela(rsec->data, i, &reloc->rela)) { WARN_ELF("gelf_getrela"); return -1; } @@ -894,7 +894,7 @@ static int read_rela_reloc(struct section *sec, int i, struct reloc *reloc, unsi static int read_relocs(struct elf *elf) { unsigned long nr_reloc, max_reloc = 0, tot_reloc = 0; - struct section *sec; + struct section *rsec; struct reloc *reloc; unsigned int symndx; struct symbol *sym; @@ -903,51 +903,52 @@ static int read_relocs(struct elf *elf) if (!elf_alloc_hash(reloc, elf->text_size / 16)) return -1; - list_for_each_entry(sec, &elf->sections, list) { - if ((sec->sh.sh_type != SHT_RELA) && - (sec->sh.sh_type != SHT_REL)) + list_for_each_entry(rsec, &elf->sections, list) { + if ((rsec->sh.sh_type != SHT_RELA) && + (rsec->sh.sh_type != SHT_REL)) continue; - sec->base = find_section_by_index(elf, sec->sh.sh_info); - if (!sec->base) { + rsec->base = find_section_by_index(elf, rsec->sh.sh_info); + if (!rsec->base) { WARN("can't find base section for reloc section %s", - sec->name); + rsec->name); return -1; } - sec->base->reloc = sec; + rsec->base->rsec = rsec; nr_reloc = 0; - sec->reloc_data = calloc(sec->sh.sh_size / sec->sh.sh_entsize, sizeof(*reloc)); - if (!sec->reloc_data) { + rsec->reloc_data = calloc(rsec->sh.sh_size / rsec->sh.sh_entsize, + sizeof(*reloc)); + if (!rsec->reloc_data) { perror("calloc"); return -1; } - for (i = 0; i < sec->sh.sh_size / sec->sh.sh_entsize; i++) { - reloc = &sec->reloc_data[i]; - switch (sec->sh.sh_type) { + for (i = 0; i < rsec->sh.sh_size / rsec->sh.sh_entsize; i++) { + reloc = &rsec->reloc_data[i]; + switch (rsec->sh.sh_type) { case SHT_REL: - if (read_rel_reloc(sec, i, reloc, &symndx)) + if (read_rel_reloc(rsec, i, reloc, &symndx)) return -1; break; case SHT_RELA: - if (read_rela_reloc(sec, i, reloc, &symndx)) + if (read_rela_reloc(rsec, i, reloc, &symndx)) return -1; break; default: return -1; } - reloc->sec = sec; + reloc->sec = rsec; reloc->idx = i; reloc->sym = sym = find_symbol_by_index(elf, symndx); if (!reloc->sym) { WARN("can't find reloc entry symbol %d for %s", - symndx, sec->name); + symndx, rsec->name); return -1; } list_add_tail(&reloc->sym_reloc_entry, &sym->reloc_list); - list_add_tail(&reloc->list, &sec->reloc_list); + list_add_tail(&reloc->list, &rsec->reloc_list); elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); nr_reloc++; @@ -1140,40 +1141,41 @@ struct section *elf_create_section(struct elf *elf, const char *name, return sec; } -static struct section *elf_create_rel_reloc_section(struct elf *elf, struct section *base) +static struct section *elf_create_rel_reloc_section(struct elf *elf, + struct section *sec) { char *relocname; - struct section *sec; + struct section *rsec; - relocname = malloc(strlen(base->name) + strlen(".rel") + 1); + relocname = malloc(strlen(sec->name) + strlen(".rel") + 1); if (!relocname) { perror("malloc"); return NULL; } strcpy(relocname, ".rel"); - strcat(relocname, base->name); + strcat(relocname, sec->name); - sec = elf_create_section(elf, relocname, sizeof(GElf_Rel), 0); + rsec = elf_create_section(elf, relocname, sizeof(GElf_Rel), 0); free(relocname); - if (!sec) + if (!rsec) return NULL; - base->reloc = sec; - sec->base = base; + sec->rsec = rsec; + rsec->base = sec; - sec->sh.sh_type = SHT_REL; - sec->sh.sh_addralign = 8; - sec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx; - sec->sh.sh_info = base->idx; - sec->sh.sh_flags = SHF_INFO_LINK; + rsec->sh.sh_type = SHT_REL; + rsec->sh.sh_addralign = 8; + rsec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx; + rsec->sh.sh_info = sec->idx; + rsec->sh.sh_flags = SHF_INFO_LINK; - return sec; + return rsec; } static struct section *elf_create_rela_reloc_section(struct elf *elf, struct section *base) { char *relocname; - struct section *sec; + struct section *rsec; int addrsize = elf_class_addrsize(elf); relocname = malloc(strlen(base->name) + strlen(".rela") + 1); @@ -1185,23 +1187,23 @@ static struct section *elf_create_rela_reloc_section(struct elf *elf, struct sec strcat(relocname, base->name); if (addrsize == sizeof(u32)) - sec = elf_create_section(elf, relocname, sizeof(Elf32_Rela), 0); + rsec = elf_create_section(elf, relocname, sizeof(Elf32_Rela), 0); else - sec = elf_create_section(elf, relocname, sizeof(GElf_Rela), 0); + rsec = elf_create_section(elf, relocname, sizeof(GElf_Rela), 0); free(relocname); - if (!sec) + if (!rsec) return NULL; - base->reloc = sec; - sec->base = base; + base->rsec = rsec; + rsec->base = base; - sec->sh.sh_type = SHT_RELA; - sec->sh.sh_addralign = addrsize; - sec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx; - sec->sh.sh_info = base->idx; - sec->sh.sh_flags = SHF_INFO_LINK; + rsec->sh.sh_type = SHT_RELA; + rsec->sh.sh_addralign = addrsize; + rsec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx; + rsec->sh.sh_info = base->idx; + rsec->sh.sh_flags = SHF_INFO_LINK; - return sec; + return rsec; } static struct section *elf_create_reloc_section(struct elf *elf, @@ -1215,28 +1217,28 @@ static struct section *elf_create_reloc_section(struct elf *elf, } } -static int elf_rebuild_rel_reloc_section(struct section *sec) +static int elf_rebuild_rel_reloc_section(struct section *rsec) { struct reloc *reloc; int idx = 0; void *buf; /* Allocate a buffer for relocations */ - buf = malloc(sec->sh.sh_size); + buf = malloc(rsec->sh.sh_size); if (!buf) { perror("malloc"); return -1; } - sec->data->d_buf = buf; - sec->data->d_size = sec->sh.sh_size; - sec->data->d_type = ELF_T_REL; + rsec->data->d_buf = buf; + rsec->data->d_size = rsec->sh.sh_size; + rsec->data->d_type = ELF_T_REL; idx = 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + list_for_each_entry(reloc, &rsec->reloc_list, list) { reloc->rel.r_offset = reloc->offset; reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - if (!gelf_update_rel(sec->data, idx, &reloc->rel)) { + if (!gelf_update_rel(rsec->data, idx, &reloc->rel)) { WARN_ELF("gelf_update_rel"); return -1; } @@ -1246,29 +1248,29 @@ static int elf_rebuild_rel_reloc_section(struct section *sec) return 0; } -static int elf_rebuild_rela_reloc_section(struct section *sec) +static int elf_rebuild_rela_reloc_section(struct section *rsec) { struct reloc *reloc; int idx = 0; void *buf; /* Allocate a buffer for relocations with addends */ - buf = malloc(sec->sh.sh_size); + buf = malloc(rsec->sh.sh_size); if (!buf) { perror("malloc"); return -1; } - sec->data->d_buf = buf; - sec->data->d_size = sec->sh.sh_size; - sec->data->d_type = ELF_T_RELA; + rsec->data->d_buf = buf; + rsec->data->d_size = rsec->sh.sh_size; + rsec->data->d_type = ELF_T_RELA; idx = 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + list_for_each_entry(reloc, &rsec->reloc_list, list) { reloc->rela.r_offset = reloc->offset; reloc->rela.r_addend = reloc->addend; reloc->rela.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - if (!gelf_update_rela(sec->data, idx, &reloc->rela)) { + if (!gelf_update_rela(rsec->data, idx, &reloc->rela)) { WARN_ELF("gelf_update_rela"); return -1; } @@ -1278,11 +1280,11 @@ static int elf_rebuild_rela_reloc_section(struct section *sec) return 0; } -static int elf_rebuild_reloc_section(struct elf *elf, struct section *sec) +static int elf_rebuild_reloc_section(struct elf *elf, struct section *rsec) { - switch (sec->sh.sh_type) { - case SHT_REL: return elf_rebuild_rel_reloc_section(sec); - case SHT_RELA: return elf_rebuild_rela_reloc_section(sec); + switch (rsec->sh.sh_type) { + case SHT_REL: return elf_rebuild_rel_reloc_section(rsec); + case SHT_RELA: return elf_rebuild_rela_reloc_section(rsec); default: return -1; } } @@ -1308,13 +1310,13 @@ int elf_write_insn(struct elf *elf, struct section *sec, int elf_write_reloc(struct elf *elf, struct reloc *reloc) { - struct section *sec = reloc->sec; + struct section *rsec = reloc->sec; - if (sec->sh.sh_type == SHT_REL) { + if (rsec->sh.sh_type == SHT_REL) { reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); reloc->rel.r_offset = reloc->offset; - if (!gelf_update_rel(sec->data, reloc->idx, &reloc->rel)) { + if (!gelf_update_rel(rsec->data, reloc->idx, &reloc->rel)) { WARN_ELF("gelf_update_rel"); return -1; } @@ -1323,7 +1325,7 @@ int elf_write_reloc(struct elf *elf, struct reloc *reloc) reloc->rela.r_addend = reloc->addend; reloc->rela.r_offset = reloc->offset; - if (!gelf_update_rela(sec->data, reloc->idx, &reloc->rela)) { + if (!gelf_update_rela(rsec->data, reloc->idx, &reloc->rela)) { WARN_ELF("gelf_update_rela"); return -1; } diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 2c28aeeb3cb2..a4e43a69f922 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -33,7 +33,7 @@ struct section { struct rb_root_cached symbol_tree; struct list_head symbol_list; struct list_head reloc_list; - struct section *base, *reloc; + struct section *base, *rsec; struct symbol *sym; Elf_Data *data; char *name; -- cgit v1.2.3 From 53257a977a69b5eabbaafb64dcd767d2a4fef2b3 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:20:56 -0700 Subject: objtool: Consolidate rel/rela handling The GElf_Rel[a] structs have more similarities than differences. It's safe to hard-code the assumptions about their shared fields as they will never change. Consolidate their handling where possible, getting rid of duplicated code. Also, at least for now we only ever create rela sections, so simplify the relocation creation code to be rela-only. Link: https://lore.kernel.org/r/dcabf6df400ca500ea929f1e4284f5e5ec0b27c8.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 12 +-- tools/objtool/elf.c | 202 ++++++++++-------------------------- tools/objtool/include/objtool/elf.h | 13 ++- 3 files changed, 68 insertions(+), 159 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index f4c52a2c8d5b..2ab8699bbd76 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -952,7 +952,7 @@ static int create_cfi_sections(struct objtool_file *file) static int create_mcount_loc_sections(struct objtool_file *file) { - int addrsize = elf_class_addrsize(file->elf); + size_t addr_size = elf_addr_size(file->elf); struct instruction *insn; struct section *sec; int idx; @@ -971,25 +971,25 @@ static int create_mcount_loc_sections(struct objtool_file *file) list_for_each_entry(insn, &file->mcount_loc_list, call_node) idx++; - sec = elf_create_section(file->elf, "__mcount_loc", addrsize, idx); + sec = elf_create_section(file->elf, "__mcount_loc", addr_size, idx); if (!sec) return -1; - sec->sh.sh_addralign = addrsize; + sec->sh.sh_addralign = addr_size; idx = 0; list_for_each_entry(insn, &file->mcount_loc_list, call_node) { void *loc; loc = sec->data->d_buf + idx; - memset(loc, 0, addrsize); + memset(loc, 0, addr_size); if (elf_add_reloc_to_insn(file->elf, sec, idx, - addrsize == sizeof(u64) ? R_ABS64 : R_ABS32, + addr_size == sizeof(u64) ? R_ABS64 : R_ABS32, insn->sec, insn->offset)) return -1; - idx += addrsize; + idx += addr_size; } return 0; diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 86ae62dfdba2..4bbdd8e6df2c 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -533,16 +533,15 @@ err: return -1; } -static struct section *elf_create_reloc_section(struct elf *elf, - struct section *sec, - int reltype); +static struct section *elf_create_rela_section(struct elf *elf, + struct section *sec); int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, unsigned int type, struct symbol *sym, s64 addend) { struct reloc *reloc; - if (!sec->rsec && !elf_create_reloc_section(elf, sec, SHT_RELA)) + if (!sec->rsec && !elf_create_rela_section(elf, sec)) return -1; reloc = malloc(sizeof(*reloc)); @@ -865,29 +864,25 @@ int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, return elf_add_reloc(elf, sec, offset, type, sym, addend); } -static int read_rel_reloc(struct section *rsec, int i, struct reloc *reloc, unsigned int *symndx) +static int read_reloc(struct section *rsec, int i, struct reloc *reloc) { - if (!gelf_getrel(rsec->data, i, &reloc->rel)) { - WARN_ELF("gelf_getrel"); - return -1; - } - reloc->type = GELF_R_TYPE(reloc->rel.r_info); - reloc->addend = 0; - reloc->offset = reloc->rel.r_offset; - *symndx = GELF_R_SYM(reloc->rel.r_info); - return 0; -} + bool rela = rsec->sh.sh_type == SHT_RELA; + void *retp; -static int read_rela_reloc(struct section *rsec, int i, struct reloc *reloc, unsigned int *symndx) -{ - if (!gelf_getrela(rsec->data, i, &reloc->rela)) { + if (rela) + retp = gelf_getrela(rsec->data, i, &reloc->rela); + else + retp = gelf_getrel(rsec->data, i, &reloc->rel); + + if (!retp) { WARN_ELF("gelf_getrela"); return -1; } - reloc->type = GELF_R_TYPE(reloc->rela.r_info); - reloc->addend = reloc->rela.r_addend; - reloc->offset = reloc->rela.r_offset; - *symndx = GELF_R_SYM(reloc->rela.r_info); + + reloc->offset = reloc->rel.r_offset; + reloc->type = GELF_R_TYPE(reloc->rel.r_info); + reloc->addend = rela ? reloc->rela.r_addend : 0; + return 0; } @@ -926,20 +921,13 @@ static int read_relocs(struct elf *elf) } for (i = 0; i < rsec->sh.sh_size / rsec->sh.sh_entsize; i++) { reloc = &rsec->reloc_data[i]; - switch (rsec->sh.sh_type) { - case SHT_REL: - if (read_rel_reloc(rsec, i, reloc, &symndx)) - return -1; - break; - case SHT_RELA: - if (read_rela_reloc(rsec, i, reloc, &symndx)) - return -1; - break; - default: return -1; - } + + if (read_reloc(rsec, i, reloc)) + return -1; reloc->sec = rsec; reloc->idx = i; + symndx = GELF_R_SYM(reloc->rel.r_info); reloc->sym = sym = find_symbol_by_index(elf, symndx); if (!reloc->sym) { WARN("can't find reloc entry symbol %d for %s", @@ -1141,86 +1129,42 @@ struct section *elf_create_section(struct elf *elf, const char *name, return sec; } -static struct section *elf_create_rel_reloc_section(struct elf *elf, - struct section *sec) +static struct section *elf_create_rela_section(struct elf *elf, + struct section *sec) { - char *relocname; struct section *rsec; + char *rsec_name; - relocname = malloc(strlen(sec->name) + strlen(".rel") + 1); - if (!relocname) { + rsec_name = malloc(strlen(sec->name) + strlen(".rela") + 1); + if (!rsec_name) { perror("malloc"); return NULL; } - strcpy(relocname, ".rel"); - strcat(relocname, sec->name); + strcpy(rsec_name, ".rela"); + strcat(rsec_name, sec->name); - rsec = elf_create_section(elf, relocname, sizeof(GElf_Rel), 0); - free(relocname); + rsec = elf_create_section(elf, rsec_name, elf_rela_size(elf), 0); + free(rsec_name); if (!rsec) return NULL; sec->rsec = rsec; rsec->base = sec; - rsec->sh.sh_type = SHT_REL; - rsec->sh.sh_addralign = 8; - rsec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx; - rsec->sh.sh_info = sec->idx; - rsec->sh.sh_flags = SHF_INFO_LINK; - - return rsec; -} - -static struct section *elf_create_rela_reloc_section(struct elf *elf, struct section *base) -{ - char *relocname; - struct section *rsec; - int addrsize = elf_class_addrsize(elf); - - relocname = malloc(strlen(base->name) + strlen(".rela") + 1); - if (!relocname) { - perror("malloc"); - return NULL; - } - strcpy(relocname, ".rela"); - strcat(relocname, base->name); - - if (addrsize == sizeof(u32)) - rsec = elf_create_section(elf, relocname, sizeof(Elf32_Rela), 0); - else - rsec = elf_create_section(elf, relocname, sizeof(GElf_Rela), 0); - free(relocname); - if (!rsec) - return NULL; - - base->rsec = rsec; - rsec->base = base; - rsec->sh.sh_type = SHT_RELA; - rsec->sh.sh_addralign = addrsize; + rsec->sh.sh_addralign = elf_addr_size(elf); rsec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx; - rsec->sh.sh_info = base->idx; + rsec->sh.sh_info = sec->idx; rsec->sh.sh_flags = SHF_INFO_LINK; return rsec; } -static struct section *elf_create_reloc_section(struct elf *elf, - struct section *base, - int reltype) -{ - switch (reltype) { - case SHT_REL: return elf_create_rel_reloc_section(elf, base); - case SHT_RELA: return elf_create_rela_reloc_section(elf, base); - default: return NULL; - } -} - -static int elf_rebuild_rel_reloc_section(struct section *rsec) +static int elf_rebuild_reloc_section(struct elf *elf, struct section *rsec) { + bool rela = rsec->sh.sh_type == SHT_RELA; struct reloc *reloc; - int idx = 0; + int idx = 0, ret; void *buf; /* Allocate a buffer for relocations */ @@ -1232,46 +1176,20 @@ static int elf_rebuild_rel_reloc_section(struct section *rsec) rsec->data->d_buf = buf; rsec->data->d_size = rsec->sh.sh_size; - rsec->data->d_type = ELF_T_REL; + rsec->data->d_type = rela ? ELF_T_RELA : ELF_T_REL; idx = 0; list_for_each_entry(reloc, &rsec->reloc_list, list) { reloc->rel.r_offset = reloc->offset; reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - if (!gelf_update_rel(rsec->data, idx, &reloc->rel)) { - WARN_ELF("gelf_update_rel"); - return -1; + if (rela) { + reloc->rela.r_addend = reloc->addend; + ret = gelf_update_rela(rsec->data, idx, &reloc->rela); + } else { + ret = gelf_update_rel(rsec->data, idx, &reloc->rel); } - idx++; - } - - return 0; -} - -static int elf_rebuild_rela_reloc_section(struct section *rsec) -{ - struct reloc *reloc; - int idx = 0; - void *buf; - - /* Allocate a buffer for relocations with addends */ - buf = malloc(rsec->sh.sh_size); - if (!buf) { - perror("malloc"); - return -1; - } - - rsec->data->d_buf = buf; - rsec->data->d_size = rsec->sh.sh_size; - rsec->data->d_type = ELF_T_RELA; - - idx = 0; - list_for_each_entry(reloc, &rsec->reloc_list, list) { - reloc->rela.r_offset = reloc->offset; - reloc->rela.r_addend = reloc->addend; - reloc->rela.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - if (!gelf_update_rela(rsec->data, idx, &reloc->rela)) { - WARN_ELF("gelf_update_rela"); + if (!ret) { + WARN_ELF("gelf_update_rel"); return -1; } idx++; @@ -1280,15 +1198,6 @@ static int elf_rebuild_rela_reloc_section(struct section *rsec) return 0; } -static int elf_rebuild_reloc_section(struct elf *elf, struct section *rsec) -{ - switch (rsec->sh.sh_type) { - case SHT_REL: return elf_rebuild_rel_reloc_section(rsec); - case SHT_RELA: return elf_rebuild_rela_reloc_section(rsec); - default: return -1; - } -} - int elf_write_insn(struct elf *elf, struct section *sec, unsigned long offset, unsigned int len, const char *insn) @@ -1311,24 +1220,21 @@ int elf_write_insn(struct elf *elf, struct section *sec, int elf_write_reloc(struct elf *elf, struct reloc *reloc) { struct section *rsec = reloc->sec; + int ret; - if (rsec->sh.sh_type == SHT_REL) { - reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - reloc->rel.r_offset = reloc->offset; + reloc->rel.r_offset = reloc->offset; + reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - if (!gelf_update_rel(rsec->data, reloc->idx, &reloc->rel)) { - WARN_ELF("gelf_update_rel"); - return -1; - } - } else { - reloc->rela.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); + if (rsec->sh.sh_type == SHT_RELA) { reloc->rela.r_addend = reloc->addend; - reloc->rela.r_offset = reloc->offset; + ret = gelf_update_rela(rsec->data, reloc->idx, &reloc->rela); + } else { + ret = gelf_update_rel(rsec->data, reloc->idx, &reloc->rel); + } - if (!gelf_update_rela(rsec->data, reloc->idx, &reloc->rela)) { - WARN_ELF("gelf_update_rela"); - return -1; - } + if (!ret) { + WARN_ELF("gelf_update_rela"); + return -1; } elf->changed = true; diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index a4e43a69f922..6f82f2515d6b 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -12,6 +12,7 @@ #include #include #include +#include #ifdef LIBELF_USE_DEPRECATED # define elf_getshdrnum elf_getshnum @@ -147,12 +148,14 @@ static inline bool has_multiple_files(struct elf *elf) return elf->num_files > 1; } -static inline int elf_class_addrsize(struct elf *elf) +static inline size_t elf_addr_size(struct elf *elf) { - if (elf->ehdr.e_ident[EI_CLASS] == ELFCLASS32) - return sizeof(u32); - else - return sizeof(u64); + return elf->ehdr.e_ident[EI_CLASS] == ELFCLASS32 ? 4 : 8; +} + +static inline size_t elf_rela_size(struct elf *elf) +{ + return elf_addr_size(elf) == 4 ? sizeof(Elf32_Rela) : sizeof(Elf64_Rela); } #define for_each_sec(file, sec) \ -- cgit v1.2.3 From eb0481bbc4ce386e73e28ad8590b4f12c8aded56 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:20:57 -0700 Subject: objtool: Fix reloc_hash size With CONFIG_DEBUG_INFO, DWARF creates a lot of relocations and reloc_hash is woefully undersized, which can affect performance significantly. Fix that. Link: https://lore.kernel.org/r/38ef60dc8043270bf3b9dfd139ae2a30ca3f75cc.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/elf.c | 16 +++++++--------- tools/objtool/include/objtool/elf.h | 8 +++++++- 2 files changed, 14 insertions(+), 10 deletions(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 4bbdd8e6df2c..f72ec6d8fb14 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -328,12 +328,12 @@ static int read_sections(struct elf *elf) } } - if (sec->sh.sh_flags & SHF_EXECINSTR) - elf->text_size += sec->sh.sh_size; - list_add_tail(&sec->list, &elf->sections); elf_hash_add(section, &sec->hash, sec->idx); elf_hash_add(section_name, &sec->name_hash, str_hash(sec->name)); + + if (is_reloc_sec(sec)) + elf->num_relocs += sec->sh.sh_size / sec->sh.sh_entsize; } if (opts.stats) { @@ -888,19 +888,18 @@ static int read_reloc(struct section *rsec, int i, struct reloc *reloc) static int read_relocs(struct elf *elf) { - unsigned long nr_reloc, max_reloc = 0, tot_reloc = 0; + unsigned long nr_reloc, max_reloc = 0; struct section *rsec; struct reloc *reloc; unsigned int symndx; struct symbol *sym; int i; - if (!elf_alloc_hash(reloc, elf->text_size / 16)) + if (!elf_alloc_hash(reloc, elf->num_relocs)) return -1; list_for_each_entry(rsec, &elf->sections, list) { - if ((rsec->sh.sh_type != SHT_RELA) && - (rsec->sh.sh_type != SHT_REL)) + if (!is_reloc_sec(rsec)) continue; rsec->base = find_section_by_index(elf, rsec->sh.sh_info); @@ -942,12 +941,11 @@ static int read_relocs(struct elf *elf) nr_reloc++; } max_reloc = max(max_reloc, nr_reloc); - tot_reloc += nr_reloc; } if (opts.stats) { printf("max_reloc: %lu\n", max_reloc); - printf("tot_reloc: %lu\n", tot_reloc); + printf("num_relocs: %lu\n", elf->num_relocs); printf("reloc_bits: %d\n", elf->reloc_bits); } diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 6f82f2515d6b..b81d78b35126 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -90,8 +90,9 @@ struct elf { int fd; bool changed; char *name; - unsigned int text_size, num_files; + unsigned int num_files; struct list_head sections; + unsigned long num_relocs; int symbol_bits; int symbol_name_bits; @@ -158,6 +159,11 @@ static inline size_t elf_rela_size(struct elf *elf) return elf_addr_size(elf) == 4 ? sizeof(Elf32_Rela) : sizeof(Elf64_Rela); } +static inline bool is_reloc_sec(struct section *sec) +{ + return sec->sh.sh_type == SHT_RELA || sec->sh.sh_type == SHT_REL; +} + #define for_each_sec(file, sec) \ list_for_each_entry(sec, &file->elf->sections, list) -- cgit v1.2.3 From ff4082730c2aaff3706232266e09d1ae4b350521 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:20:58 -0700 Subject: objtool: Add mark_sec_changed() Ensure elf->changed always gets set when sec->changed gets set. Link: https://lore.kernel.org/r/9a810a8d2e28af6ba07325362d0eb4703bb09d3a.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/elf.c | 31 ++++++++++++++++--------------- tools/objtool/include/objtool/elf.h | 14 +++++++++++++- 2 files changed, 29 insertions(+), 16 deletions(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index f72ec6d8fb14..67967c231972 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -562,7 +562,8 @@ int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); sec->rsec->sh.sh_size += sec->rsec->sh.sh_entsize; - sec->rsec->changed = true; + + mark_sec_changed(elf, sec->rsec, true); return 0; } @@ -577,7 +578,7 @@ static void elf_dirty_reloc_sym(struct elf *elf, struct symbol *sym) struct reloc *reloc; list_for_each_entry(reloc, &sym->reloc_list, sym_reloc_entry) - reloc->sec->changed = true; + mark_sec_changed(elf, reloc->sec, true); } /* @@ -654,7 +655,7 @@ static int elf_update_symbol(struct elf *elf, struct section *symtab, symtab_data->d_align = 1; symtab_data->d_type = ELF_T_SYM; - symtab->changed = true; + mark_sec_changed(elf, symtab, true); symtab->truncate = true; if (t) { @@ -669,7 +670,7 @@ static int elf_update_symbol(struct elf *elf, struct section *symtab, shndx_data->d_align = sizeof(Elf32_Word); shndx_data->d_type = ELF_T_WORD; - symtab_shndx->changed = true; + mark_sec_changed(elf, symtab_shndx, true); symtab_shndx->truncate = true; } @@ -773,11 +774,11 @@ non_local: } symtab->sh.sh_size += symtab->sh.sh_entsize; - symtab->changed = true; + mark_sec_changed(elf, symtab, true); if (symtab_shndx) { symtab_shndx->sh.sh_size += sizeof(Elf32_Word); - symtab_shndx->changed = true; + mark_sec_changed(elf, symtab_shndx, true); } return sym; @@ -1040,7 +1041,8 @@ static int elf_add_string(struct elf *elf, struct section *strtab, char *str) len = strtab->sh.sh_size; strtab->sh.sh_size += data->d_size; - strtab->changed = true; + + mark_sec_changed(elf, strtab, true); return len; } @@ -1075,7 +1077,6 @@ struct section *elf_create_section(struct elf *elf, const char *name, } sec->idx = elf_ndxscn(s); - sec->changed = true; sec->data = elf_newdata(s); if (!sec->data) { @@ -1122,7 +1123,7 @@ struct section *elf_create_section(struct elf *elf, const char *name, elf_hash_add(section, &sec->hash, sec->idx); elf_hash_add(section_name, &sec->name_hash, str_hash(sec->name)); - elf->changed = true; + mark_sec_changed(elf, sec, true); return sec; } @@ -1208,9 +1209,8 @@ int elf_write_insn(struct elf *elf, struct section *sec, } memcpy(data->d_buf + offset, insn, len); - elf_flagdata(data, ELF_C_SET, ELF_F_DIRTY); - elf->changed = true; + mark_sec_changed(elf, sec, true); return 0; } @@ -1235,7 +1235,7 @@ int elf_write_reloc(struct elf *elf, struct reloc *reloc) return -1; } - elf->changed = true; + mark_sec_changed(elf, rsec, true); return 0; } @@ -1307,12 +1307,14 @@ int elf_write(struct elf *elf) if (sec->truncate) elf_truncate_section(elf, sec); - if (sec->changed) { + if (sec_changed(sec)) { s = elf_getscn(elf->elf, sec->idx); if (!s) { WARN_ELF("elf_getscn"); return -1; } + + /* Note this also flags the section dirty */ if (!gelf_update_shdr(s, &sec->sh)) { WARN_ELF("gelf_update_shdr"); return -1; @@ -1324,8 +1326,7 @@ int elf_write(struct elf *elf) return -1; } - sec->changed = false; - elf->changed = true; + mark_sec_changed(elf, sec, false); } } diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index b81d78b35126..56b66ff91943 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -39,7 +39,7 @@ struct section { Elf_Data *data; char *name; int idx; - bool changed, text, rodata, noinstr, init, truncate; + bool _changed, text, rodata, noinstr, init, truncate; struct reloc *reloc_data; }; @@ -164,6 +164,18 @@ static inline bool is_reloc_sec(struct section *sec) return sec->sh.sh_type == SHT_RELA || sec->sh.sh_type == SHT_REL; } +static inline bool sec_changed(struct section *sec) +{ + return sec->_changed; +} + +static inline void mark_sec_changed(struct elf *elf, struct section *sec, + bool changed) +{ + sec->_changed = changed; + elf->changed |= changed; +} + #define for_each_sec(file, sec) \ list_for_each_entry(sec, &file->elf->sections, list) -- cgit v1.2.3 From 6342a20efbd8b70d169c325b2c27a8a8f96388d5 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:20:59 -0700 Subject: objtool: Add elf_create_section_pair() When creating an annotation section, allocate the reloc section data at the beginning. This simplifies the data model a bit and also saves memory due to the removal of malloc() in elf_rebuild_reloc_section(). With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 53.49G - After: peak heap memory consumption: 49.02G Link: https://lore.kernel.org/r/048e908f3ede9b66c15e44672b6dda992b1dae3e.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/arch/powerpc/include/arch/elf.h | 11 +- tools/objtool/arch/x86/include/arch/elf.h | 11 +- tools/objtool/check.c | 129 ++++++++-------------- tools/objtool/elf.c | 151 ++++++++++++++++---------- tools/objtool/include/objtool/elf.h | 33 +++++- tools/objtool/orc_gen.c | 6 +- 6 files changed, 184 insertions(+), 157 deletions(-) diff --git a/tools/objtool/arch/powerpc/include/arch/elf.h b/tools/objtool/arch/powerpc/include/arch/elf.h index 73f9ae172fe5..66814fa28024 100644 --- a/tools/objtool/arch/powerpc/include/arch/elf.h +++ b/tools/objtool/arch/powerpc/include/arch/elf.h @@ -1,10 +1,13 @@ /* SPDX-License-Identifier: GPL-2.0-or-later */ - #ifndef _OBJTOOL_ARCH_ELF #define _OBJTOOL_ARCH_ELF -#define R_NONE R_PPC_NONE -#define R_ABS64 R_PPC64_ADDR64 -#define R_ABS32 R_PPC_ADDR32 +#define R_NONE R_PPC_NONE +#define R_ABS64 R_PPC64_ADDR64 +#define R_ABS32 R_PPC_ADDR32 +#define R_DATA32 R_PPC_REL32 +#define R_DATA64 R_PPC64_REL64 +#define R_TEXT32 R_PPC_REL32 +#define R_TEXT64 R_PPC64_REL32 #endif /* _OBJTOOL_ARCH_ELF */ diff --git a/tools/objtool/arch/x86/include/arch/elf.h b/tools/objtool/arch/x86/include/arch/elf.h index ac14987cf687..7131f7f51a4e 100644 --- a/tools/objtool/arch/x86/include/arch/elf.h +++ b/tools/objtool/arch/x86/include/arch/elf.h @@ -1,8 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ #ifndef _OBJTOOL_ARCH_ELF #define _OBJTOOL_ARCH_ELF -#define R_NONE R_X86_64_NONE -#define R_ABS64 R_X86_64_64 -#define R_ABS32 R_X86_64_32 +#define R_NONE R_X86_64_NONE +#define R_ABS32 R_X86_64_32 +#define R_ABS64 R_X86_64_64 +#define R_DATA32 R_X86_64_PC32 +#define R_DATA64 R_X86_64_PC32 +#define R_TEXT32 R_X86_64_PC32 +#define R_TEXT64 R_X86_64_PC32 #endif /* _OBJTOOL_ARCH_ELF */ diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 2ab8699bbd76..3bc97c2b4f01 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -8,7 +8,6 @@ #include #include -#include #include #include #include @@ -656,8 +655,8 @@ reachable: static int create_static_call_sections(struct objtool_file *file) { - struct section *sec; struct static_call_site *site; + struct section *sec; struct instruction *insn; struct symbol *key_sym; char *key_name, *tmp; @@ -677,25 +676,21 @@ static int create_static_call_sections(struct objtool_file *file) list_for_each_entry(insn, &file->static_call_list, call_node) idx++; - sec = elf_create_section(file->elf, ".static_call_sites", - sizeof(struct static_call_site), idx); + sec = elf_create_section_pair(file->elf, ".static_call_sites", + sizeof(*site), idx, idx * 2); if (!sec) return -1; - /* Allow modules to set the low bits of static_call_site::key */ + /* Allow modules to modify the low bits of static_call_site::key */ sec->sh.sh_flags |= SHF_WRITE; idx = 0; list_for_each_entry(insn, &file->static_call_list, call_node) { - site = (struct static_call_site *)sec->data->d_buf + idx; - memset(site, 0, sizeof(struct static_call_site)); - /* populate reloc for 'addr' */ - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(struct static_call_site), - R_X86_64_PC32, - insn->sec, insn->offset)) + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(*site), idx * 2, + insn->sec, insn->offset)) return -1; /* find key symbol */ @@ -735,10 +730,10 @@ static int create_static_call_sections(struct objtool_file *file) free(key_name); /* populate reloc for 'key' */ - if (elf_add_reloc(file->elf, sec, - idx * sizeof(struct static_call_site) + 4, - R_X86_64_PC32, key_sym, - is_sibling_call(insn) * STATIC_CALL_SITE_TAIL)) + if (!elf_init_reloc_data_sym(file->elf, sec, + idx * sizeof(*site) + 4, + (idx * 2) + 1, key_sym, + is_sibling_call(insn) * STATIC_CALL_SITE_TAIL)) return -1; idx++; @@ -766,26 +761,18 @@ static int create_retpoline_sites_sections(struct objtool_file *file) if (!idx) return 0; - sec = elf_create_section(file->elf, ".retpoline_sites", - sizeof(int), idx); - if (!sec) { - WARN("elf_create_section: .retpoline_sites"); + sec = elf_create_section_pair(file->elf, ".retpoline_sites", + sizeof(int), idx, idx); + if (!sec) return -1; - } idx = 0; list_for_each_entry(insn, &file->retpoline_call_list, call_node) { - int *site = (int *)sec->data->d_buf + idx; - *site = 0; - - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(int), - R_X86_64_PC32, - insn->sec, insn->offset)) { - WARN("elf_add_reloc_to_insn: .retpoline_sites"); + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(int), idx, + insn->sec, insn->offset)) return -1; - } idx++; } @@ -812,26 +799,18 @@ static int create_return_sites_sections(struct objtool_file *file) if (!idx) return 0; - sec = elf_create_section(file->elf, ".return_sites", - sizeof(int), idx); - if (!sec) { - WARN("elf_create_section: .return_sites"); + sec = elf_create_section_pair(file->elf, ".return_sites", + sizeof(int), idx, idx); + if (!sec) return -1; - } idx = 0; list_for_each_entry(insn, &file->return_thunk_list, call_node) { - int *site = (int *)sec->data->d_buf + idx; - *site = 0; - - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(int), - R_X86_64_PC32, - insn->sec, insn->offset)) { - WARN("elf_add_reloc_to_insn: .return_sites"); + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(int), idx, + insn->sec, insn->offset)) return -1; - } idx++; } @@ -864,12 +843,10 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file) if (!idx) return 0; - sec = elf_create_section(file->elf, ".ibt_endbr_seal", - sizeof(int), idx); - if (!sec) { - WARN("elf_create_section: .ibt_endbr_seal"); + sec = elf_create_section_pair(file->elf, ".ibt_endbr_seal", + sizeof(int), idx, idx); + if (!sec) return -1; - } idx = 0; list_for_each_entry(insn, &file->endbr_list, call_node) { @@ -884,13 +861,10 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file) !strcmp(sym->name, "cleanup_module"))) WARN("%s(): not an indirect call target", sym->name); - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(int), - R_X86_64_PC32, - insn->sec, insn->offset)) { - WARN("elf_add_reloc_to_insn: .ibt_endbr_seal"); + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(int), idx, + insn->sec, insn->offset)) return -1; - } idx++; } @@ -902,7 +876,6 @@ static int create_cfi_sections(struct objtool_file *file) { struct section *sec; struct symbol *sym; - unsigned int *loc; int idx; sec = find_section_by_name(file->elf, ".cfi_sites"); @@ -923,7 +896,8 @@ static int create_cfi_sections(struct objtool_file *file) idx++; } - sec = elf_create_section(file->elf, ".cfi_sites", sizeof(unsigned int), idx); + sec = elf_create_section_pair(file->elf, ".cfi_sites", + sizeof(unsigned int), idx, idx); if (!sec) return -1; @@ -935,13 +909,9 @@ static int create_cfi_sections(struct objtool_file *file) if (strncmp(sym->name, "__cfi_", 6)) continue; - loc = (unsigned int *)sec->data->d_buf + idx; - memset(loc, 0, sizeof(unsigned int)); - - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(unsigned int), - R_X86_64_PC32, - sym->sec, sym->offset)) + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(unsigned int), idx, + sym->sec, sym->offset)) return -1; idx++; @@ -971,7 +941,8 @@ static int create_mcount_loc_sections(struct objtool_file *file) list_for_each_entry(insn, &file->mcount_loc_list, call_node) idx++; - sec = elf_create_section(file->elf, "__mcount_loc", addr_size, idx); + sec = elf_create_section_pair(file->elf, "__mcount_loc", addr_size, + idx, idx); if (!sec) return -1; @@ -979,17 +950,17 @@ static int create_mcount_loc_sections(struct objtool_file *file) idx = 0; list_for_each_entry(insn, &file->mcount_loc_list, call_node) { - void *loc; - loc = sec->data->d_buf + idx; - memset(loc, 0, addr_size); + struct reloc *reloc; - if (elf_add_reloc_to_insn(file->elf, sec, idx, - addr_size == sizeof(u64) ? R_ABS64 : R_ABS32, - insn->sec, insn->offset)) + reloc = elf_init_reloc_text_sym(file->elf, sec, idx * addr_size, idx, + insn->sec, insn->offset); + if (!reloc) return -1; - idx += addr_size; + reloc->type = addr_size == 8 ? R_ABS64 : R_ABS32; + + idx++; } return 0; @@ -999,7 +970,6 @@ static int create_direct_call_sections(struct objtool_file *file) { struct instruction *insn; struct section *sec; - unsigned int *loc; int idx; sec = find_section_by_name(file->elf, ".call_sites"); @@ -1016,20 +986,17 @@ static int create_direct_call_sections(struct objtool_file *file) list_for_each_entry(insn, &file->call_list, call_node) idx++; - sec = elf_create_section(file->elf, ".call_sites", sizeof(unsigned int), idx); + sec = elf_create_section_pair(file->elf, ".call_sites", + sizeof(unsigned int), idx, idx); if (!sec) return -1; idx = 0; list_for_each_entry(insn, &file->call_list, call_node) { - loc = (unsigned int *)sec->data->d_buf + idx; - memset(loc, 0, sizeof(unsigned int)); - - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(unsigned int), - R_X86_64_PC32, - insn->sec, insn->offset)) + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(unsigned int), idx, + insn->sec, insn->offset)) return -1; idx++; diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 67967c231972..5cbc9d578a45 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -533,41 +533,6 @@ err: return -1; } -static struct section *elf_create_rela_section(struct elf *elf, - struct section *sec); - -int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, - unsigned int type, struct symbol *sym, s64 addend) -{ - struct reloc *reloc; - - if (!sec->rsec && !elf_create_rela_section(elf, sec)) - return -1; - - reloc = malloc(sizeof(*reloc)); - if (!reloc) { - perror("malloc"); - return -1; - } - memset(reloc, 0, sizeof(*reloc)); - - reloc->sec = sec->rsec; - reloc->offset = offset; - reloc->type = type; - reloc->sym = sym; - reloc->addend = addend; - - list_add_tail(&reloc->sym_reloc_entry, &sym->reloc_list); - list_add_tail(&reloc->list, &sec->rsec->reloc_list); - elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); - - sec->rsec->sh.sh_size += sec->rsec->sh.sh_entsize; - - mark_sec_changed(elf, sec->rsec, true); - - return 0; -} - /* * Ensure that any reloc section containing references to @sym is marked * changed such that it will get re-generated in elf_rebuild_reloc_sections() @@ -841,13 +806,57 @@ elf_create_prefix_symbol(struct elf *elf, struct symbol *orig, long size) return sym; } -int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, - unsigned long offset, unsigned int type, - struct section *insn_sec, unsigned long insn_off) +static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, + unsigned int reloc_idx, + unsigned long offset, struct symbol *sym, + s64 addend, unsigned int type) +{ + struct reloc *reloc; + + if (reloc_idx >= rsec->sh.sh_size / elf_rela_size(elf)) { + WARN("%s: bad reloc_idx %u for %s with size 0x%lx", + __func__, reloc_idx, rsec->name, rsec->sh.sh_size); + return NULL; + } + + reloc = malloc(sizeof(*reloc)); + if (!reloc) { + perror("malloc"); + return NULL; + } + memset(reloc, 0, sizeof(*reloc)); + + reloc->idx = reloc_idx; + reloc->sec = rsec; + reloc->offset = offset; + reloc->type = type; + reloc->sym = sym; + reloc->addend = addend; + + list_add_tail(&reloc->sym_reloc_entry, &sym->reloc_list); + list_add_tail(&reloc->list, &rsec->reloc_list); + elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); + + mark_sec_changed(elf, rsec, true); + + return reloc; +} + +struct reloc *elf_init_reloc_text_sym(struct elf *elf, struct section *sec, + unsigned long offset, + unsigned int reloc_idx, + struct section *insn_sec, + unsigned long insn_off) { struct symbol *sym = insn_sec->sym; int addend = insn_off; + if (!(insn_sec->sh.sh_flags & SHF_EXECINSTR)) { + WARN("bad call to %s() for data symbol %s", + __func__, sym->name); + return NULL; + } + if (!sym) { /* * Due to how weak functions work, we must use section based @@ -857,12 +866,29 @@ int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, */ sym = elf_create_section_symbol(elf, insn_sec); if (!sym) - return -1; + return NULL; insn_sec->sym = sym; } - return elf_add_reloc(elf, sec, offset, type, sym, addend); + return elf_init_reloc(elf, sec->rsec, reloc_idx, offset, sym, addend, + elf_text_rela_type(elf)); +} + +struct reloc *elf_init_reloc_data_sym(struct elf *elf, struct section *sec, + unsigned long offset, + unsigned int reloc_idx, + struct symbol *sym, + s64 addend) +{ + if (sym->sec && (sec->sh.sh_flags & SHF_EXECINSTR)) { + WARN("bad call to %s() for text symbol %s", + __func__, sym->name); + return NULL; + } + + return elf_init_reloc(elf, sec->rsec, reloc_idx, offset, sym, addend, + elf_data_rela_type(elf)); } static int read_reloc(struct section *rsec, int i, struct reloc *reloc) @@ -1048,7 +1074,7 @@ static int elf_add_string(struct elf *elf, struct section *strtab, char *str) } struct section *elf_create_section(struct elf *elf, const char *name, - size_t entsize, int nr) + size_t entsize, unsigned int nr) { struct section *sec, *shstrtab; size_t size = entsize * nr; @@ -1129,7 +1155,8 @@ struct section *elf_create_section(struct elf *elf, const char *name, } static struct section *elf_create_rela_section(struct elf *elf, - struct section *sec) + struct section *sec, + unsigned int reloc_nr) { struct section *rsec; char *rsec_name; @@ -1142,46 +1169,50 @@ static struct section *elf_create_rela_section(struct elf *elf, strcpy(rsec_name, ".rela"); strcat(rsec_name, sec->name); - rsec = elf_create_section(elf, rsec_name, elf_rela_size(elf), 0); + rsec = elf_create_section(elf, rsec_name, elf_rela_size(elf), reloc_nr); free(rsec_name); if (!rsec) return NULL; - sec->rsec = rsec; - rsec->base = sec; - + rsec->data->d_type = ELF_T_RELA; rsec->sh.sh_type = SHT_RELA; rsec->sh.sh_addralign = elf_addr_size(elf); rsec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx; rsec->sh.sh_info = sec->idx; rsec->sh.sh_flags = SHF_INFO_LINK; + sec->rsec = rsec; + rsec->base = sec; + return rsec; } +struct section *elf_create_section_pair(struct elf *elf, const char *name, + size_t entsize, unsigned int nr, + unsigned int reloc_nr) +{ + struct section *sec; + + sec = elf_create_section(elf, name, entsize, nr); + if (!sec) + return NULL; + + if (!elf_create_rela_section(elf, sec, reloc_nr)) + return NULL; + + return sec; +} + static int elf_rebuild_reloc_section(struct elf *elf, struct section *rsec) { - bool rela = rsec->sh.sh_type == SHT_RELA; struct reloc *reloc; int idx = 0, ret; - void *buf; - - /* Allocate a buffer for relocations */ - buf = malloc(rsec->sh.sh_size); - if (!buf) { - perror("malloc"); - return -1; - } - - rsec->data->d_buf = buf; - rsec->data->d_size = rsec->sh.sh_size; - rsec->data->d_type = rela ? ELF_T_RELA : ELF_T_REL; idx = 0; list_for_each_entry(reloc, &rsec->reloc_list, list) { reloc->rel.r_offset = reloc->offset; reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - if (rela) { + if (rsec->sh.sh_type == SHT_RELA) { reloc->rela.r_addend = reloc->addend; ret = gelf_update_rela(rsec->data, idx, &reloc->rela); } else { diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 56b66ff91943..74f63934afd3 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -111,15 +111,26 @@ struct elf { }; struct elf *elf_open_read(const char *name, int flags); -struct section *elf_create_section(struct elf *elf, const char *name, size_t entsize, int nr); + +struct section *elf_create_section(struct elf *elf, const char *name, + size_t entsize, unsigned int nr); +struct section *elf_create_section_pair(struct elf *elf, const char *name, + size_t entsize, unsigned int nr, + unsigned int reloc_nr); struct symbol *elf_create_prefix_symbol(struct elf *elf, struct symbol *orig, long size); -int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, - unsigned int type, struct symbol *sym, s64 addend); -int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, - unsigned long offset, unsigned int type, - struct section *insn_sec, unsigned long insn_off); +struct reloc *elf_init_reloc_text_sym(struct elf *elf, struct section *sec, + unsigned long offset, + unsigned int reloc_idx, + struct section *insn_sec, + unsigned long insn_off); + +struct reloc *elf_init_reloc_data_sym(struct elf *elf, struct section *sec, + unsigned long offset, + unsigned int reloc_idx, + struct symbol *sym, + s64 addend); int elf_write_insn(struct elf *elf, struct section *sec, unsigned long offset, unsigned int len, @@ -159,6 +170,16 @@ static inline size_t elf_rela_size(struct elf *elf) return elf_addr_size(elf) == 4 ? sizeof(Elf32_Rela) : sizeof(Elf64_Rela); } +static inline unsigned int elf_data_rela_type(struct elf *elf) +{ + return elf_addr_size(elf) == 4 ? R_DATA32 : R_DATA64; +} + +static inline unsigned int elf_text_rela_type(struct elf *elf) +{ + return elf_addr_size(elf) == 4 ? R_TEXT32 : R_TEXT64; +} + static inline bool is_reloc_sec(struct section *sec) { return sec->sh.sh_type == SHT_RELA || sec->sh.sh_type == SHT_REL; diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c index d5f750be7d7d..bae343908867 100644 --- a/tools/objtool/orc_gen.c +++ b/tools/objtool/orc_gen.c @@ -118,8 +118,8 @@ static int write_orc_entry(struct elf *elf, struct section *orc_sec, orc->bp_offset = bswap_if_needed(elf, orc->bp_offset); /* populate reloc for ip */ - if (elf_add_reloc_to_insn(elf, ip_sec, idx * sizeof(int), R_X86_64_PC32, - insn_sec, insn_off)) + if (!elf_init_reloc_text_sym(elf, ip_sec, idx * sizeof(int), idx, + insn_sec, insn_off)) return -1; return 0; @@ -242,7 +242,7 @@ int orc_create(struct objtool_file *file) if (!orc_sec) return -1; - sec = elf_create_section(file->elf, ".orc_unwind_ip", sizeof(int), nr); + sec = elf_create_section_pair(file->elf, ".orc_unwind_ip", sizeof(int), nr, nr); if (!sec) return -1; -- cgit v1.2.3 From fcf933552bebdecd72b324738c6635f46b0df569 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:00 -0700 Subject: objtool: Keep GElf_Rel[a] structs synced Keep the GElf_Rela structs synced with their 'struct reloc' counterparts instead of having to go back and "rebuild" them later. Link: https://lore.kernel.org/r/156d8a3e528a11e5c8577cf552890ed1f2b9567b.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/elf.c | 55 ++++++++++++++--------------------------------------- 1 file changed, 14 insertions(+), 41 deletions(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 5cbc9d578a45..8d491b2d123e 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -534,16 +534,18 @@ err: } /* - * Ensure that any reloc section containing references to @sym is marked - * changed such that it will get re-generated in elf_rebuild_reloc_sections() - * with the new symbol index. + * @sym's idx has changed. Update the relocs which reference it. */ -static void elf_dirty_reloc_sym(struct elf *elf, struct symbol *sym) +static int elf_update_sym_relocs(struct elf *elf, struct symbol *sym) { struct reloc *reloc; - list_for_each_entry(reloc, &sym->reloc_list, sym_reloc_entry) - mark_sec_changed(elf, reloc->sec, true); + list_for_each_entry(reloc, &sym->reloc_list, sym_reloc_entry) { + if (elf_write_reloc(elf, reloc)) + return -1; + } + + return 0; } /* @@ -716,13 +718,14 @@ __elf_create_symbol(struct elf *elf, struct symbol *sym) hlist_del(&old->hash); elf_hash_add(symbol, &old->hash, old->idx); - elf_dirty_reloc_sym(elf, old); - if (elf_update_symbol(elf, symtab, symtab_shndx, old)) { WARN("elf_update_symbol move"); return NULL; } + if (elf_update_sym_relocs(elf, old)) + return NULL; + new_idx = first_non_local; } @@ -833,12 +836,13 @@ static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, reloc->sym = sym; reloc->addend = addend; + if (elf_write_reloc(elf, reloc)) + return NULL; + list_add_tail(&reloc->sym_reloc_entry, &sym->reloc_list); list_add_tail(&reloc->list, &rsec->reloc_list); elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); - mark_sec_changed(elf, rsec, true); - return reloc; } @@ -1203,31 +1207,6 @@ struct section *elf_create_section_pair(struct elf *elf, const char *name, return sec; } -static int elf_rebuild_reloc_section(struct elf *elf, struct section *rsec) -{ - struct reloc *reloc; - int idx = 0, ret; - - idx = 0; - list_for_each_entry(reloc, &rsec->reloc_list, list) { - reloc->rel.r_offset = reloc->offset; - reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - if (rsec->sh.sh_type == SHT_RELA) { - reloc->rela.r_addend = reloc->addend; - ret = gelf_update_rela(rsec->data, idx, &reloc->rela); - } else { - ret = gelf_update_rel(rsec->data, idx, &reloc->rel); - } - if (!ret) { - WARN_ELF("gelf_update_rel"); - return -1; - } - idx++; - } - - return 0; -} - int elf_write_insn(struct elf *elf, struct section *sec, unsigned long offset, unsigned int len, const char *insn) @@ -1351,12 +1330,6 @@ int elf_write(struct elf *elf) return -1; } - if (sec->base && - elf_rebuild_reloc_section(elf, sec)) { - WARN("elf_rebuild_reloc_section"); - return -1; - } - mark_sec_changed(elf, sec, false); } } -- cgit v1.2.3 From 5201a9bcb7d3f98ab99c17325b0aa925c2888ca3 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:01 -0700 Subject: objtool: Don't free memory in elf_close() It's not necessary, objtool's about to exit anyway. Link: https://lore.kernel.org/r/74bdb3058b8f029db8d5b3b5175f2a200804196d.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/elf.c | 24 ++++-------------------- 1 file changed, 4 insertions(+), 20 deletions(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 8d491b2d123e..8d53f18a9502 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -1350,30 +1350,14 @@ int elf_write(struct elf *elf) void elf_close(struct elf *elf) { - struct section *sec, *tmpsec; - struct symbol *sym, *tmpsym; - struct reloc *reloc, *tmpreloc; - if (elf->elf) elf_end(elf->elf); if (elf->fd > 0) close(elf->fd); - list_for_each_entry_safe(sec, tmpsec, &elf->sections, list) { - list_for_each_entry_safe(sym, tmpsym, &sec->symbol_list, list) { - list_del(&sym->list); - hash_del(&sym->hash); - } - list_for_each_entry_safe(reloc, tmpreloc, &sec->reloc_list, list) { - list_del(&reloc->list); - hash_del(&reloc->hash); - } - list_del(&sec->list); - free(sec->reloc_data); - } - - free(elf->symbol_data); - free(elf->section_data); - free(elf); + /* + * NOTE: All remaining allocations are leaked on purpose. Objtool is + * about to exit anyway. + */ } -- cgit v1.2.3 From caa4a6b74b405ddaea40e2946cc3983aac96451d Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:02 -0700 Subject: objtool: Add for_each_reloc() Link: https://lore.kernel.org/r/dbfcb1037d8b958e52d097b67829c4c6811c24bb.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 24 ++++++++++++------------ tools/objtool/include/objtool/elf.h | 6 ++++++ 2 files changed, 18 insertions(+), 12 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 3bc97c2b4f01..e21138d36e00 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -591,7 +591,7 @@ static int add_dead_ends(struct objtool_file *file) if (!rsec) goto reachable; - list_for_each_entry(reloc, &rsec->reloc_list, list) { + for_each_reloc(rsec, reloc) { if (reloc->sym->type != STT_SECTION) { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; @@ -626,7 +626,7 @@ reachable: if (!rsec) return 0; - list_for_each_entry(reloc, &rsec->reloc_list, list) { + for_each_reloc(rsec, reloc) { if (reloc->sym->type != STT_SECTION) { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; @@ -1019,7 +1019,7 @@ static void add_ignores(struct objtool_file *file) if (!rsec) return; - list_for_each_entry(reloc, &rsec->reloc_list, list) { + for_each_reloc(rsec, reloc) { switch (reloc->sym->type) { case STT_FUNC: func = reloc->sym; @@ -1260,7 +1260,7 @@ static int add_ignore_alternatives(struct objtool_file *file) if (!rsec) return 0; - list_for_each_entry(reloc, &rsec->reloc_list, list) { + for_each_reloc(rsec, reloc) { if (reloc->sym->type != STT_SECTION) { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; @@ -1991,7 +1991,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn, * Each @reloc is a switch table relocation which points to the target * instruction. */ - list_for_each_entry_from(reloc, &table->sec->reloc_list, list) { + for_each_reloc_from(table->sec, reloc) { /* Check for the end of the table: */ if (reloc != table && reloc->jump_table_start) @@ -2270,7 +2270,7 @@ static int read_noendbr_hints(struct objtool_file *file) if (!rsec) return 0; - list_for_each_entry(reloc, &rsec->reloc_list, list) { + for_each_reloc(rsec, reloc) { insn = find_insn(file, reloc->sym->sec, reloc->sym->offset + reloc->addend); if (!insn) { WARN("bad .discard.noendbr entry"); @@ -2293,7 +2293,7 @@ static int read_retpoline_hints(struct objtool_file *file) if (!rsec) return 0; - list_for_each_entry(reloc, &rsec->reloc_list, list) { + for_each_reloc(rsec, reloc) { if (reloc->sym->type != STT_SECTION) { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; @@ -2329,7 +2329,7 @@ static int read_instr_hints(struct objtool_file *file) if (!rsec) return 0; - list_for_each_entry(reloc, &rsec->reloc_list, list) { + for_each_reloc(rsec, reloc) { if (reloc->sym->type != STT_SECTION) { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; @@ -2348,7 +2348,7 @@ static int read_instr_hints(struct objtool_file *file) if (!rsec) return 0; - list_for_each_entry(reloc, &rsec->reloc_list, list) { + for_each_reloc(rsec, reloc) { if (reloc->sym->type != STT_SECTION) { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; @@ -2376,7 +2376,7 @@ static int read_validate_unret_hints(struct objtool_file *file) if (!rsec) return 0; - list_for_each_entry(reloc, &rsec->reloc_list, list) { + for_each_reloc(rsec, reloc) { if (reloc->sym->type != STT_SECTION) { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; @@ -2404,7 +2404,7 @@ static int read_intra_function_calls(struct objtool_file *file) if (!rsec) return 0; - list_for_each_entry(reloc, &rsec->reloc_list, list) { + for_each_reloc(rsec, reloc) { unsigned long dest_off; if (reloc->sym->type != STT_SECTION) { @@ -4404,7 +4404,7 @@ static int validate_ibt(struct objtool_file *file) strstr(sec->name, "__patchable_function_entries")) continue; - list_for_each_entry(reloc, &sec->rsec->reloc_list, list) + for_each_reloc(sec->rsec, reloc) warnings += validate_ibt_data_reloc(file, reloc); } diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 74f63934afd3..a938cb1d4172 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -209,6 +209,12 @@ static inline void mark_sec_changed(struct elf *elf, struct section *sec, for_each_sec(file, __sec) \ sec_for_each_sym(__sec, sym) +#define for_each_reloc(rsec, reloc) \ + list_for_each_entry(reloc, &rsec->reloc_list, list) + +#define for_each_reloc_from(rsec, reloc) \ + list_for_each_entry_from(reloc, &rsec->reloc_list, list) + #define OFFSET_STRIDE_BITS 4 #define OFFSET_STRIDE (1UL << OFFSET_STRIDE_BITS) #define OFFSET_STRIDE_MASK (~(OFFSET_STRIDE - 1)) -- cgit v1.2.3 From e0a9349b4c590145c6a83e6c9f7701cec42debbd Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:03 -0700 Subject: objtool: Allocate relocs in advance for new rela sections Similar to read_relocs(), allocate the reloc structs all together in an array rather than allocating them one at a time. Link: https://lore.kernel.org/r/5332d845c5a2d6c2d052075b381bfba8bcb67ed5.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/elf.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 8d53f18a9502..5f69d4590117 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -814,7 +814,7 @@ static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, unsigned long offset, struct symbol *sym, s64 addend, unsigned int type) { - struct reloc *reloc; + struct reloc *reloc, empty = { 0 }; if (reloc_idx >= rsec->sh.sh_size / elf_rela_size(elf)) { WARN("%s: bad reloc_idx %u for %s with size 0x%lx", @@ -822,12 +822,13 @@ static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, return NULL; } - reloc = malloc(sizeof(*reloc)); - if (!reloc) { - perror("malloc"); + reloc = &rsec->reloc_data[reloc_idx]; + + if (memcmp(reloc, &empty, sizeof(empty))) { + WARN("%s: %s: reloc %d already initialized!", + __func__, rsec->name, reloc_idx); return NULL; } - memset(reloc, 0, sizeof(*reloc)); reloc->idx = reloc_idx; reloc->sec = rsec; @@ -1185,6 +1186,13 @@ static struct section *elf_create_rela_section(struct elf *elf, rsec->sh.sh_info = sec->idx; rsec->sh.sh_flags = SHF_INFO_LINK; + rsec->reloc_data = calloc(rsec->sh.sh_size / rsec->sh.sh_entsize, + sizeof(struct reloc)); + if (!rsec->reloc_data) { + perror("calloc"); + return NULL; + } + sec->rsec = rsec; rsec->base = sec; -- cgit v1.2.3 From ebcef730a19ba7ca446169f391d2e51722d68043 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:04 -0700 Subject: objtool: Get rid of reloc->list Now that all relocs are allocated in an array, the linked list is no longer needed. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 49.02G - After: peak heap memory consumption: 45.56G Link: https://lore.kernel.org/r/71e7a2c017dbc46bb497857ec97d67214f832d10.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/elf.c | 32 +++++++++++++------------------- tools/objtool/include/objtool/elf.h | 18 +++++++++++++----- 2 files changed, 26 insertions(+), 24 deletions(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 5f69d4590117..19ac53ad76ee 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -293,7 +293,6 @@ static int read_sections(struct elf *elf) sec = &elf->section_data[i]; INIT_LIST_HEAD(&sec->symbol_list); - INIT_LIST_HEAD(&sec->reloc_list); s = elf_getscn(elf->elf, i); if (!s) { @@ -333,7 +332,7 @@ static int read_sections(struct elf *elf) elf_hash_add(section_name, &sec->name_hash, str_hash(sec->name)); if (is_reloc_sec(sec)) - elf->num_relocs += sec->sh.sh_size / sec->sh.sh_entsize; + elf->num_relocs += sec_num_entries(sec); } if (opts.stats) { @@ -407,7 +406,7 @@ static int read_symbols(struct elf *elf) if (symtab_shndx) shndx_data = symtab_shndx->data; - symbols_nr = symtab->sh.sh_size / symtab->sh.sh_entsize; + symbols_nr = sec_num_entries(symtab); } else { /* * A missing symbol table is actually possible if it's an empty @@ -701,7 +700,7 @@ __elf_create_symbol(struct elf *elf, struct symbol *sym) return NULL; } - new_idx = symtab->sh.sh_size / symtab->sh.sh_entsize; + new_idx = sec_num_entries(symtab); if (GELF_ST_BIND(sym->sym.st_info) != STB_LOCAL) goto non_local; @@ -816,13 +815,13 @@ static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, { struct reloc *reloc, empty = { 0 }; - if (reloc_idx >= rsec->sh.sh_size / elf_rela_size(elf)) { - WARN("%s: bad reloc_idx %u for %s with size 0x%lx", - __func__, reloc_idx, rsec->name, rsec->sh.sh_size); + if (reloc_idx >= sec_num_entries(rsec)) { + WARN("%s: bad reloc_idx %u for %s with %d relocs", + __func__, reloc_idx, rsec->name, sec_num_entries(rsec)); return NULL; } - reloc = &rsec->reloc_data[reloc_idx]; + reloc = &rsec->relocs[reloc_idx]; if (memcmp(reloc, &empty, sizeof(empty))) { WARN("%s: %s: reloc %d already initialized!", @@ -841,7 +840,6 @@ static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, return NULL; list_add_tail(&reloc->sym_reloc_entry, &sym->reloc_list); - list_add_tail(&reloc->list, &rsec->reloc_list); elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); return reloc; @@ -944,14 +942,13 @@ static int read_relocs(struct elf *elf) rsec->base->rsec = rsec; nr_reloc = 0; - rsec->reloc_data = calloc(rsec->sh.sh_size / rsec->sh.sh_entsize, - sizeof(*reloc)); - if (!rsec->reloc_data) { + rsec->relocs = calloc(sec_num_entries(rsec), sizeof(*reloc)); + if (!rsec->relocs) { perror("calloc"); return -1; } - for (i = 0; i < rsec->sh.sh_size / rsec->sh.sh_entsize; i++) { - reloc = &rsec->reloc_data[i]; + for (i = 0; i < sec_num_entries(rsec); i++) { + reloc = &rsec->relocs[i]; if (read_reloc(rsec, i, reloc)) return -1; @@ -967,7 +964,6 @@ static int read_relocs(struct elf *elf) } list_add_tail(&reloc->sym_reloc_entry, &sym->reloc_list); - list_add_tail(&reloc->list, &rsec->reloc_list); elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); nr_reloc++; @@ -1093,7 +1089,6 @@ struct section *elf_create_section(struct elf *elf, const char *name, memset(sec, 0, sizeof(*sec)); INIT_LIST_HEAD(&sec->symbol_list); - INIT_LIST_HEAD(&sec->reloc_list); s = elf_newscn(elf->elf); if (!s) { @@ -1186,9 +1181,8 @@ static struct section *elf_create_rela_section(struct elf *elf, rsec->sh.sh_info = sec->idx; rsec->sh.sh_flags = SHF_INFO_LINK; - rsec->reloc_data = calloc(rsec->sh.sh_size / rsec->sh.sh_entsize, - sizeof(struct reloc)); - if (!rsec->reloc_data) { + rsec->relocs = calloc(sec_num_entries(rsec), sizeof(struct reloc)); + if (!rsec->relocs) { perror("calloc"); return NULL; } diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index a938cb1d4172..a09da208ddb8 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -33,14 +33,13 @@ struct section { GElf_Shdr sh; struct rb_root_cached symbol_tree; struct list_head symbol_list; - struct list_head reloc_list; struct section *base, *rsec; struct symbol *sym; Elf_Data *data; char *name; int idx; bool _changed, text, rodata, noinstr, init, truncate; - struct reloc *reloc_data; + struct reloc *relocs; }; struct symbol { @@ -68,7 +67,6 @@ struct symbol { }; struct reloc { - struct list_head list; struct hlist_node hash; union { GElf_Rela rela; @@ -197,6 +195,11 @@ static inline void mark_sec_changed(struct elf *elf, struct section *sec, elf->changed |= changed; } +static inline unsigned int sec_num_entries(struct section *sec) +{ + return sec->sh.sh_size / sec->sh.sh_entsize; +} + #define for_each_sec(file, sec) \ list_for_each_entry(sec, &file->elf->sections, list) @@ -210,10 +213,15 @@ static inline void mark_sec_changed(struct elf *elf, struct section *sec, sec_for_each_sym(__sec, sym) #define for_each_reloc(rsec, reloc) \ - list_for_each_entry(reloc, &rsec->reloc_list, list) + for (int __i = 0, __fake = 1; __fake; __fake = 0) \ + for (reloc = rsec->relocs; \ + __i < sec_num_entries(rsec); \ + __i++, reloc++) #define for_each_reloc_from(rsec, reloc) \ - list_for_each_entry_from(reloc, &rsec->reloc_list, list) + for (int __i = reloc->idx; \ + __i < sec_num_entries(rsec); \ + __i++, reloc++) #define OFFSET_STRIDE_BITS 4 #define OFFSET_STRIDE (1UL << OFFSET_STRIDE_BITS) -- cgit v1.2.3 From be9a4c116824c39720001db5bc45fe7528b26cff Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:05 -0700 Subject: objtool: Get rid of reloc->idx Use the array offset to calculate the reloc index. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 45.56G - After: peak heap memory consumption: 43.83G Link: https://lore.kernel.org/r/7351d2ebad0519027db14a32f6204af84952574a.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/elf.c | 6 ++---- tools/objtool/include/objtool/elf.h | 10 +++++++--- 2 files changed, 9 insertions(+), 7 deletions(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 19ac53ad76ee..70c801254566 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -829,7 +829,6 @@ static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, return NULL; } - reloc->idx = reloc_idx; reloc->sec = rsec; reloc->offset = offset; reloc->type = type; @@ -954,7 +953,6 @@ static int read_relocs(struct elf *elf) return -1; reloc->sec = rsec; - reloc->idx = i; symndx = GELF_R_SYM(reloc->rel.r_info); reloc->sym = sym = find_symbol_by_index(elf, symndx); if (!reloc->sym) { @@ -1237,9 +1235,9 @@ int elf_write_reloc(struct elf *elf, struct reloc *reloc) if (rsec->sh.sh_type == SHT_RELA) { reloc->rela.r_addend = reloc->addend; - ret = gelf_update_rela(rsec->data, reloc->idx, &reloc->rela); + ret = gelf_update_rela(rsec->data, reloc_idx(reloc), &reloc->rela); } else { - ret = gelf_update_rel(rsec->data, reloc->idx, &reloc->rel); + ret = gelf_update_rel(rsec->data, reloc_idx(reloc), &reloc->rel); } if (!ret) { diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index a09da208ddb8..2a14da633d56 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -76,9 +76,8 @@ struct reloc { struct symbol *sym; struct list_head sym_reloc_entry; unsigned long offset; - unsigned int type; s64 addend; - int idx; + unsigned int type; bool jump_table_start; }; @@ -200,6 +199,11 @@ static inline unsigned int sec_num_entries(struct section *sec) return sec->sh.sh_size / sec->sh.sh_entsize; } +static inline unsigned int reloc_idx(struct reloc *reloc) +{ + return reloc - reloc->sec->relocs; +} + #define for_each_sec(file, sec) \ list_for_each_entry(sec, &file->elf->sections, list) @@ -219,7 +223,7 @@ static inline unsigned int sec_num_entries(struct section *sec) __i++, reloc++) #define for_each_reloc_from(rsec, reloc) \ - for (int __i = reloc->idx; \ + for (int __i = reloc_idx(reloc); \ __i < sec_num_entries(rsec); \ __i++, reloc++) -- cgit v1.2.3 From e4cbb9b81f1f7519c7ae3abda09cb15794022952 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:06 -0700 Subject: objtool: Get rid of reloc->offset Get the offset from the embedded GElf_Rel[a] struct. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 43.83G - After: peak heap memory consumption: 42.10G Link: https://lore.kernel.org/r/2b9ec01178baa346a99522710bf2e82159412e3a.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 14 +++++++------- tools/objtool/elf.c | 10 +++++----- tools/objtool/include/objtool/elf.h | 8 ++++++-- 3 files changed, 18 insertions(+), 14 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index e21138d36e00..e06ffad5a93c 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -511,11 +511,11 @@ static int add_pv_ops(struct objtool_file *file, const char *symname) if (func->type == STT_SECTION) func = find_symbol_by_offset(reloc->sym->sec, reloc->addend); - idx = (reloc->offset - sym->offset) / sizeof(unsigned long); + idx = (reloc_offset(reloc) - sym->offset) / sizeof(unsigned long); objtool_pv_add(file, idx, func); - off = reloc->offset + 1; + off = reloc_offset(reloc) + 1; if (off > end) break; } @@ -1998,7 +1998,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn, break; /* Make sure the table entries are consecutive: */ - if (prev_offset && reloc->offset != prev_offset + 8) + if (prev_offset && reloc_offset(reloc) != prev_offset + 8) break; /* Detect function pointers from contiguous objects: */ @@ -2023,7 +2023,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn, alt->insn = dest_insn; alt->next = insn->alts; insn->alts = alt; - prev_offset = reloc->offset; + prev_offset = reloc_offset(reloc); } if (!prev_offset) { @@ -4266,8 +4266,8 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn for (reloc = insn_reloc(file, insn); reloc; reloc = find_reloc_by_dest_range(file->elf, insn->sec, - reloc->offset + 1, - (insn->offset + insn->len) - (reloc->offset + 1))) { + reloc_offset(reloc) + 1, + (insn->offset + insn->len) - (reloc_offset(reloc) + 1))) { /* * static_call_update() references the trampoline, which @@ -4350,7 +4350,7 @@ static int validate_ibt_data_reloc(struct objtool_file *file, return 0; WARN_FUNC("data relocation to !ENDBR: %s", - reloc->sec->base, reloc->offset, + reloc->sec->base, reloc_offset(reloc), offstr(dest->sec, dest->offset)); return 1; diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 70c801254566..2b45460225d1 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -246,8 +246,9 @@ struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *se if (reloc->sec != rsec) continue; - if (reloc->offset >= offset && reloc->offset < offset + len) { - if (!r || reloc->offset < r->offset) + if (reloc_offset(reloc) >= offset && + reloc_offset(reloc) < offset + len) { + if (!r || reloc_offset(reloc) < reloc_offset(r)) r = reloc; } } @@ -830,11 +831,12 @@ static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, } reloc->sec = rsec; - reloc->offset = offset; reloc->type = type; reloc->sym = sym; reloc->addend = addend; + reloc->rel.r_offset = offset; + if (elf_write_reloc(elf, reloc)) return NULL; @@ -908,7 +910,6 @@ static int read_reloc(struct section *rsec, int i, struct reloc *reloc) return -1; } - reloc->offset = reloc->rel.r_offset; reloc->type = GELF_R_TYPE(reloc->rel.r_info); reloc->addend = rela ? reloc->rela.r_addend : 0; @@ -1230,7 +1231,6 @@ int elf_write_reloc(struct elf *elf, struct reloc *reloc) struct section *rsec = reloc->sec; int ret; - reloc->rel.r_offset = reloc->offset; reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); if (rsec->sh.sh_type == SHT_RELA) { diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 2a14da633d56..2070860a099e 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -75,7 +75,6 @@ struct reloc { struct section *sec; struct symbol *sym; struct list_head sym_reloc_entry; - unsigned long offset; s64 addend; unsigned int type; bool jump_table_start; @@ -204,6 +203,11 @@ static inline unsigned int reloc_idx(struct reloc *reloc) return reloc - reloc->sec->relocs; } +static inline unsigned long reloc_offset(struct reloc *reloc) +{ + return reloc->rel.r_offset; +} + #define for_each_sec(file, sec) \ list_for_each_entry(sec, &file->elf->sections, list) @@ -253,7 +257,7 @@ static inline u32 sec_offset_hash(struct section *sec, unsigned long offset) static inline u32 reloc_hash(struct reloc *reloc) { - return sec_offset_hash(reloc->sec, reloc->offset); + return sec_offset_hash(reloc->sec, reloc_offset(reloc)); } #endif /* _OBJTOOL_ELF_H */ -- cgit v1.2.3 From fcee899d2794319c9dbeb7b877b0c4ac92f5dd16 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:07 -0700 Subject: objtool: Get rid of reloc->type Get the type from the embedded GElf_Rel[a] struct. Link: https://lore.kernel.org/r/d1c1f8da31e4f052a2478aea585fcf355cacc53a.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/arch/x86/decode.c | 2 +- tools/objtool/arch/x86/special.c | 4 ++-- tools/objtool/check.c | 11 ++++++----- tools/objtool/elf.c | 6 ++---- tools/objtool/include/objtool/elf.h | 11 ++++++++++- 5 files changed, 21 insertions(+), 13 deletions(-) diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 9ef024fd648c..ffb12e83b238 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -84,7 +84,7 @@ bool arch_pc_relative_reloc(struct reloc *reloc) * All relocation types where P (the address of the target) * is included in the computation. */ - switch (reloc->type) { + switch (reloc_type(reloc)) { case R_X86_64_PC8: case R_X86_64_PC16: case R_X86_64_PC32: diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c index 7c97b7391279..1a54a249cb50 100644 --- a/tools/objtool/arch/x86/special.c +++ b/tools/objtool/arch/x86/special.c @@ -108,7 +108,7 @@ struct reloc *arch_find_switch_table(struct objtool_file *file, table_offset = text_reloc->addend; table_sec = text_reloc->sym->sec; - if (text_reloc->type == R_X86_64_PC32) + if (reloc_type(text_reloc) == R_X86_64_PC32) table_offset += 4; /* @@ -138,7 +138,7 @@ struct reloc *arch_find_switch_table(struct objtool_file *file, * indicates a rare GCC quirk/bug which can leave dead * code behind. */ - if (text_reloc->type == R_X86_64_PC32) + if (reloc_type(text_reloc) == R_X86_64_PC32) file->ignore_unreachables = true; return rodata_reloc; diff --git a/tools/objtool/check.c b/tools/objtool/check.c index e06ffad5a93c..04b4152be206 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -958,7 +958,7 @@ static int create_mcount_loc_sections(struct objtool_file *file) if (!reloc) return -1; - reloc->type = addr_size == 8 ? R_ABS64 : R_ABS32; + set_reloc_type(reloc, addr_size == 8 ? R_ABS64 : R_ABS32); idx++; } @@ -1354,7 +1354,7 @@ static void annotate_call_site(struct objtool_file *file, */ if (opts.hack_noinstr && insn->sec->noinstr && sym->profiling_func) { if (reloc) { - reloc->type = R_NONE; + set_reloc_type(reloc, R_NONE); elf_write_reloc(file->elf, reloc); } @@ -1383,7 +1383,7 @@ static void annotate_call_site(struct objtool_file *file, WARN_INSN(insn, "tail call to __fentry__ !?!?"); if (opts.mnop) { if (reloc) { - reloc->type = R_NONE; + set_reloc_type(reloc, R_NONE); elf_write_reloc(file->elf, reloc); } @@ -1865,7 +1865,7 @@ static int handle_jump_alt(struct objtool_file *file, struct reloc *reloc = insn_reloc(file, orig_insn); if (reloc) { - reloc->type = R_NONE; + set_reloc_type(reloc, R_NONE); elf_write_reloc(file->elf, reloc); } elf_write_insn(file->elf, orig_insn->sec, @@ -4277,7 +4277,8 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn continue; off = reloc->sym->offset; - if (reloc->type == R_X86_64_PC32 || reloc->type == R_X86_64_PLT32) + if (reloc_type(reloc) == R_X86_64_PC32 || + reloc_type(reloc) == R_X86_64_PLT32) off += arch_dest_reloc_offset(reloc->addend); else off += reloc->addend; diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 2b45460225d1..be9d24dcdf56 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -541,6 +541,7 @@ static int elf_update_sym_relocs(struct elf *elf, struct symbol *sym) struct reloc *reloc; list_for_each_entry(reloc, &sym->reloc_list, sym_reloc_entry) { + reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc_type(reloc)); if (elf_write_reloc(elf, reloc)) return -1; } @@ -831,11 +832,11 @@ static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, } reloc->sec = rsec; - reloc->type = type; reloc->sym = sym; reloc->addend = addend; reloc->rel.r_offset = offset; + reloc->rel.r_info = GELF_R_INFO(sym->idx, type); if (elf_write_reloc(elf, reloc)) return NULL; @@ -910,7 +911,6 @@ static int read_reloc(struct section *rsec, int i, struct reloc *reloc) return -1; } - reloc->type = GELF_R_TYPE(reloc->rel.r_info); reloc->addend = rela ? reloc->rela.r_addend : 0; return 0; @@ -1231,8 +1231,6 @@ int elf_write_reloc(struct elf *elf, struct reloc *reloc) struct section *rsec = reloc->sec; int ret; - reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - if (rsec->sh.sh_type == SHT_RELA) { reloc->rela.r_addend = reloc->addend; ret = gelf_update_rela(rsec->data, reloc_idx(reloc), &reloc->rela); diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 2070860a099e..41d2149f8bb8 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -76,7 +76,6 @@ struct reloc { struct symbol *sym; struct list_head sym_reloc_entry; s64 addend; - unsigned int type; bool jump_table_start; }; @@ -208,6 +207,16 @@ static inline unsigned long reloc_offset(struct reloc *reloc) return reloc->rel.r_offset; } +static inline unsigned int reloc_type(struct reloc *reloc) +{ + return GELF_R_TYPE(reloc->rel.r_info); +} + +static inline void set_reloc_type(struct reloc *reloc, int type) +{ + reloc->rel.r_info = GELF_R_INFO(GELF_R_SYM(reloc->rel.r_info), type); +} + #define for_each_sec(file, sec) \ list_for_each_entry(sec, &file->elf->sections, list) -- cgit v1.2.3 From 0696b6e314dbe4bd2f24d5e749469f57ea095a9f Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:08 -0700 Subject: objtool: Get rid of reloc->addend Get the addend from the embedded GElf_Rel[a] struct. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 42.10G - After: peak heap memory consumption: 40.37G Link: https://lore.kernel.org/r/ad2354f95d9ddd86094e3f7687acfa0750657784.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/arch/x86/decode.c | 4 +-- tools/objtool/arch/x86/special.c | 2 +- tools/objtool/check.c | 69 +++++++++++++++++++++---------------- tools/objtool/elf.c | 10 ++---- tools/objtool/include/objtool/elf.h | 6 +++- tools/objtool/special.c | 4 +-- 6 files changed, 53 insertions(+), 42 deletions(-) diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index ffb12e83b238..2e1caabecb18 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -623,11 +623,11 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec if (!immr || strcmp(immr->sym->name, "pv_ops")) break; - idx = (immr->addend + 8) / sizeof(void *); + idx = (reloc_addend(immr) + 8) / sizeof(void *); func = disp->sym; if (disp->sym->type == STT_SECTION) - func = find_symbol_by_offset(disp->sym->sec, disp->addend); + func = find_symbol_by_offset(disp->sym->sec, reloc_addend(disp)); if (!func) { WARN("no func for pv_ops[]"); return -1; diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c index 1a54a249cb50..65f48f35b97e 100644 --- a/tools/objtool/arch/x86/special.c +++ b/tools/objtool/arch/x86/special.c @@ -105,7 +105,7 @@ struct reloc *arch_find_switch_table(struct objtool_file *file, !text_reloc->sym->sec->rodata) return NULL; - table_offset = text_reloc->addend; + table_offset = reloc_addend(text_reloc); table_sec = text_reloc->sym->sec; if (reloc_type(text_reloc) == R_X86_64_PC32) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 04b4152be206..745487dda432 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -509,7 +509,8 @@ static int add_pv_ops(struct objtool_file *file, const char *symname) func = reloc->sym; if (func->type == STT_SECTION) - func = find_symbol_by_offset(reloc->sym->sec, reloc->addend); + func = find_symbol_by_offset(reloc->sym->sec, + reloc_addend(reloc)); idx = (reloc_offset(reloc) - sym->offset) / sizeof(unsigned long); @@ -583,6 +584,7 @@ static int add_dead_ends(struct objtool_file *file) struct section *rsec; struct reloc *reloc; struct instruction *insn; + s64 addend; /* * Check for manually annotated dead ends. @@ -592,23 +594,27 @@ static int add_dead_ends(struct objtool_file *file) goto reachable; for_each_reloc(rsec, reloc) { + if (reloc->sym->type != STT_SECTION) { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + + addend = reloc_addend(reloc); + + insn = find_insn(file, reloc->sym->sec, addend); if (insn) insn = prev_insn_same_sec(file, insn); - else if (reloc->addend == reloc->sym->sec->sh.sh_size) { + else if (addend == reloc->sym->sec->sh.sh_size) { insn = find_last_insn(file, reloc->sym->sec); if (!insn) { WARN("can't find unreachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, reloc->addend); + reloc->sym->sec->name, addend); return -1; } } else { WARN("can't find unreachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, reloc->addend); + reloc->sym->sec->name, addend); return -1; } @@ -627,23 +633,27 @@ reachable: return 0; for_each_reloc(rsec, reloc) { + if (reloc->sym->type != STT_SECTION) { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + + addend = reloc_addend(reloc); + + insn = find_insn(file, reloc->sym->sec, addend); if (insn) insn = prev_insn_same_sec(file, insn); - else if (reloc->addend == reloc->sym->sec->sh.sh_size) { + else if (addend == reloc->sym->sec->sh.sh_size) { insn = find_last_insn(file, reloc->sym->sec); if (!insn) { WARN("can't find reachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, reloc->addend); + reloc->sym->sec->name, addend); return -1; } } else { WARN("can't find reachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, reloc->addend); + reloc->sym->sec->name, addend); return -1; } @@ -1026,7 +1036,7 @@ static void add_ignores(struct objtool_file *file) break; case STT_SECTION: - func = find_func_by_offset(reloc->sym->sec, reloc->addend); + func = find_func_by_offset(reloc->sym->sec, reloc_addend(reloc)); if (!func) continue; break; @@ -1266,7 +1276,7 @@ static int add_ignore_alternatives(struct objtool_file *file) return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("bad .discard.ignore_alts entry"); return -1; @@ -1542,7 +1552,7 @@ static int add_jump_destinations(struct objtool_file *file) dest_off = arch_jump_destination(insn); } else if (reloc->sym->type == STT_SECTION) { dest_sec = reloc->sym->sec; - dest_off = arch_dest_reloc_offset(reloc->addend); + dest_off = arch_dest_reloc_offset(reloc_addend(reloc)); } else if (reloc->sym->retpoline_thunk) { add_retpoline_call(file, insn); continue; @@ -1559,7 +1569,7 @@ static int add_jump_destinations(struct objtool_file *file) } else if (reloc->sym->sec->idx) { dest_sec = reloc->sym->sec; dest_off = reloc->sym->sym.st_value + - arch_dest_reloc_offset(reloc->addend); + arch_dest_reloc_offset(reloc_addend(reloc)); } else { /* non-func asm code jumping to another file */ continue; @@ -1676,7 +1686,7 @@ static int add_call_destinations(struct objtool_file *file) } } else if (reloc->sym->type == STT_SECTION) { - dest_off = arch_dest_reloc_offset(reloc->addend); + dest_off = arch_dest_reloc_offset(reloc_addend(reloc)); dest = find_call_destination(reloc->sym->sec, dest_off); if (!dest) { WARN_INSN(insn, "can't find call dest symbol at %s+0x%lx", @@ -2003,10 +2013,10 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn, /* Detect function pointers from contiguous objects: */ if (reloc->sym->sec == pfunc->sec && - reloc->addend == pfunc->offset) + reloc_addend(reloc) == pfunc->offset) break; - dest_insn = find_insn(file, reloc->sym->sec, reloc->addend); + dest_insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!dest_insn) break; @@ -2067,7 +2077,7 @@ static struct reloc *find_jump_table(struct objtool_file *file, table_reloc = arch_find_switch_table(file, insn); if (!table_reloc) continue; - dest_insn = find_insn(file, table_reloc->sym->sec, table_reloc->addend); + dest_insn = find_insn(file, table_reloc->sym->sec, reloc_addend(table_reloc)); if (!dest_insn || !insn_func(dest_insn) || insn_func(dest_insn)->pfunc != func) continue; @@ -2203,7 +2213,7 @@ static int read_unwind_hints(struct objtool_file *file) return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("can't find insn for unwind_hints[%d]", i); return -1; @@ -2271,7 +2281,8 @@ static int read_noendbr_hints(struct objtool_file *file) return 0; for_each_reloc(rsec, reloc) { - insn = find_insn(file, reloc->sym->sec, reloc->sym->offset + reloc->addend); + insn = find_insn(file, reloc->sym->sec, + reloc->sym->offset + reloc_addend(reloc)); if (!insn) { WARN("bad .discard.noendbr entry"); return -1; @@ -2299,7 +2310,7 @@ static int read_retpoline_hints(struct objtool_file *file) return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("bad .discard.retpoline_safe entry"); return -1; @@ -2335,7 +2346,7 @@ static int read_instr_hints(struct objtool_file *file) return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("bad .discard.instr_end entry"); return -1; @@ -2354,7 +2365,7 @@ static int read_instr_hints(struct objtool_file *file) return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("bad .discard.instr_begin entry"); return -1; @@ -2382,7 +2393,7 @@ static int read_validate_unret_hints(struct objtool_file *file) return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("bad .discard.instr_end entry"); return -1; @@ -2413,7 +2424,7 @@ static int read_intra_function_calls(struct objtool_file *file) return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("bad .discard.intra_function_call entry"); return -1; @@ -3317,7 +3328,7 @@ static inline const char *call_dest_name(struct instruction *insn) reloc = insn_reloc(NULL, insn); if (reloc && !strcmp(reloc->sym->name, "pv_ops")) { - idx = (reloc->addend / sizeof(void *)); + idx = (reloc_addend(reloc) / sizeof(void *)); snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx); return pvname; } @@ -3335,7 +3346,7 @@ static bool pv_call_dest(struct objtool_file *file, struct instruction *insn) if (!reloc || strcmp(reloc->sym->name, "pv_ops")) return false; - idx = (arch_dest_reloc_offset(reloc->addend) / sizeof(void *)); + idx = (arch_dest_reloc_offset(reloc_addend(reloc)) / sizeof(void *)); if (file->pv_ops[idx].clean) return true; @@ -4279,9 +4290,9 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn off = reloc->sym->offset; if (reloc_type(reloc) == R_X86_64_PC32 || reloc_type(reloc) == R_X86_64_PLT32) - off += arch_dest_reloc_offset(reloc->addend); + off += arch_dest_reloc_offset(reloc_addend(reloc)); else - off += reloc->addend; + off += reloc_addend(reloc); dest = find_insn(file, reloc->sym->sec, off); if (!dest) @@ -4338,7 +4349,7 @@ static int validate_ibt_data_reloc(struct objtool_file *file, struct instruction *dest; dest = find_insn(file, reloc->sym->sec, - reloc->sym->offset + reloc->addend); + reloc->sym->offset + reloc_addend(reloc)); if (!dest) return 0; diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index be9d24dcdf56..16e019a1762c 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -833,10 +833,10 @@ static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, reloc->sec = rsec; reloc->sym = sym; - reloc->addend = addend; reloc->rel.r_offset = offset; reloc->rel.r_info = GELF_R_INFO(sym->idx, type); + reloc->rela.r_addend = addend; if (elf_write_reloc(elf, reloc)) return NULL; @@ -911,8 +911,6 @@ static int read_reloc(struct section *rsec, int i, struct reloc *reloc) return -1; } - reloc->addend = rela ? reloc->rela.r_addend : 0; - return 0; } @@ -1231,12 +1229,10 @@ int elf_write_reloc(struct elf *elf, struct reloc *reloc) struct section *rsec = reloc->sec; int ret; - if (rsec->sh.sh_type == SHT_RELA) { - reloc->rela.r_addend = reloc->addend; + if (rsec->sh.sh_type == SHT_RELA) ret = gelf_update_rela(rsec->data, reloc_idx(reloc), &reloc->rela); - } else { + else ret = gelf_update_rel(rsec->data, reloc_idx(reloc), &reloc->rel); - } if (!ret) { WARN_ELF("gelf_update_rela"); diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 41d2149f8bb8..be08b32a93ee 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -75,7 +75,6 @@ struct reloc { struct section *sec; struct symbol *sym; struct list_head sym_reloc_entry; - s64 addend; bool jump_table_start; }; @@ -217,6 +216,11 @@ static inline void set_reloc_type(struct reloc *reloc, int type) reloc->rel.r_info = GELF_R_INFO(GELF_R_SYM(reloc->rel.r_info), type); } +static inline s64 reloc_addend(struct reloc *reloc) +{ + return reloc->rela.r_addend; +} + #define for_each_sec(file, sec) \ list_for_each_entry(sec, &file->elf->sections, list) diff --git a/tools/objtool/special.c b/tools/objtool/special.c index baa85c31526b..91b1950f5bd8 100644 --- a/tools/objtool/special.c +++ b/tools/objtool/special.c @@ -62,7 +62,7 @@ static void reloc_to_sec_off(struct reloc *reloc, struct section **sec, unsigned long *off) { *sec = reloc->sym->sec; - *off = reloc->sym->offset + reloc->addend; + *off = reloc->sym->offset + reloc_addend(reloc); } static int get_alt_entry(struct elf *elf, const struct special_entry *entry, @@ -126,7 +126,7 @@ static int get_alt_entry(struct elf *elf, const struct special_entry *entry, sec, offset + entry->key); return -1; } - alt->key_addend = key_reloc->addend; + alt->key_addend = reloc_addend(key_reloc); } return 0; -- cgit v1.2.3 From be2f0b1e12644c956a347d7fde93c2ffe9cdb1af Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:09 -0700 Subject: objtool: Get rid of reloc->jump_table_start Rework the jump table logic slightly so 'jump_table_start' is no longer needed. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 40.37G - After: peak heap memory consumption: 38.64G Link: https://lore.kernel.org/r/e1602ed8a6171ada3cfac0bd8449892ec82bd188.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 35 +++++++++++++++++++++++------------ tools/objtool/include/objtool/elf.h | 1 - 2 files changed, 23 insertions(+), 13 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 745487dda432..7fb6467178cb 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1989,13 +1989,14 @@ out: } static int add_jump_table(struct objtool_file *file, struct instruction *insn, - struct reloc *table) + struct reloc *next_table) { - struct reloc *reloc = table; - struct instruction *dest_insn; - struct alternative *alt; struct symbol *pfunc = insn_func(insn)->pfunc; + struct reloc *table = insn_jump_table(insn); + struct instruction *dest_insn; unsigned int prev_offset = 0; + struct reloc *reloc = table; + struct alternative *alt; /* * Each @reloc is a switch table relocation which points to the target @@ -2004,7 +2005,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn, for_each_reloc_from(table->sec, reloc) { /* Check for the end of the table: */ - if (reloc != table && reloc->jump_table_start) + if (reloc != table && reloc == next_table) break; /* Make sure the table entries are consecutive: */ @@ -2119,29 +2120,39 @@ static void mark_func_jump_tables(struct objtool_file *file, continue; reloc = find_jump_table(file, func, insn); - if (reloc) { - reloc->jump_table_start = true; + if (reloc) insn->_jump_table = reloc; - } } } static int add_func_jump_tables(struct objtool_file *file, struct symbol *func) { - struct instruction *insn; - int ret; + struct instruction *insn, *insn_t1 = NULL, *insn_t2; + int ret = 0; func_for_each_insn(file, func, insn) { if (!insn_jump_table(insn)) continue; - ret = add_jump_table(file, insn, insn_jump_table(insn)); + if (!insn_t1) { + insn_t1 = insn; + continue; + } + + insn_t2 = insn; + + ret = add_jump_table(file, insn_t1, insn_jump_table(insn_t2)); if (ret) return ret; + + insn_t1 = insn_t2; } - return 0; + if (insn_t1) + ret = add_jump_table(file, insn_t1, NULL); + + return ret; } /* diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index be08b32a93ee..60686f746c9e 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -75,7 +75,6 @@ struct reloc { struct section *sec; struct symbol *sym; struct list_head sym_reloc_entry; - bool jump_table_start; }; struct elf { -- cgit v1.2.3 From 890f10a433f51f95eccaec13d46dde769ccc113b Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:10 -0700 Subject: objtool: Shrink reloc->sym_reloc_entry Convert it to a singly-linked list. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 38.64G - After: peak heap memory consumption: 36.89G Link: https://lore.kernel.org/r/a51f0a6f9bbf2494d5a3a449807307e78a940988.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/elf.c | 9 +++++---- tools/objtool/include/objtool/elf.h | 4 ++-- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 16e019a1762c..4b0de0e56068 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -356,7 +356,6 @@ static void elf_add_symbol(struct elf *elf, struct symbol *sym) struct rb_node *pnode; struct symbol *iter; - INIT_LIST_HEAD(&sym->reloc_list); INIT_LIST_HEAD(&sym->pv_target); sym->alias = sym; @@ -540,7 +539,7 @@ static int elf_update_sym_relocs(struct elf *elf, struct symbol *sym) { struct reloc *reloc; - list_for_each_entry(reloc, &sym->reloc_list, sym_reloc_entry) { + for (reloc = sym->relocs; reloc; reloc = reloc->sym_next_reloc) { reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc_type(reloc)); if (elf_write_reloc(elf, reloc)) return -1; @@ -841,8 +840,9 @@ static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, if (elf_write_reloc(elf, reloc)) return NULL; - list_add_tail(&reloc->sym_reloc_entry, &sym->reloc_list); elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); + reloc->sym_next_reloc = sym->relocs; + sym->relocs = reloc; return reloc; } @@ -960,8 +960,9 @@ static int read_relocs(struct elf *elf) return -1; } - list_add_tail(&reloc->sym_reloc_entry, &sym->reloc_list); elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); + reloc->sym_next_reloc = sym->relocs; + sym->relocs = reloc; nr_reloc++; } diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 60686f746c9e..7b808ac3156c 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -63,7 +63,7 @@ struct symbol { u8 profiling_func : 1; u8 warned : 1; struct list_head pv_target; - struct list_head reloc_list; + struct reloc *relocs; }; struct reloc { @@ -74,7 +74,7 @@ struct reloc { }; struct section *sec; struct symbol *sym; - struct list_head sym_reloc_entry; + struct reloc *sym_next_reloc; }; struct elf { -- cgit v1.2.3 From 02b54001066364aee72bc4c802b42a96c6e0dc1f Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:11 -0700 Subject: objtool: Shrink elf hash nodes Instead of using hlist for the 'struct elf' hashes, use a custom single-linked list scheme. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 36.89G - After: peak heap memory consumption: 35.12G Link: https://lore.kernel.org/r/6e8cd305ed22e743c30d6e72cfdc1be20fb94cd4.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/elf.c | 52 +++++++++++++++++++++++++++++++------ tools/objtool/include/objtool/elf.h | 24 ++++++++++------- 2 files changed, 58 insertions(+), 18 deletions(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 4b0de0e56068..04038b1324cf 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -32,16 +32,52 @@ static inline u32 str_hash(const char *str) #define __elf_table(name) (elf->name##_hash) #define __elf_bits(name) (elf->name##_bits) -#define elf_hash_add(name, node, key) \ - hlist_add_head(node, &__elf_table(name)[hash_min(key, __elf_bits(name))]) +#define __elf_table_entry(name, key) \ + __elf_table(name)[hash_min(key, __elf_bits(name))] + +#define elf_hash_add(name, node, key) \ +({ \ + struct elf_hash_node *__node = node; \ + __node->next = __elf_table_entry(name, key); \ + __elf_table_entry(name, key) = __node; \ +}) + +static inline void __elf_hash_del(struct elf_hash_node *node, + struct elf_hash_node **head) +{ + struct elf_hash_node *cur, *prev; -#define elf_hash_for_each_possible(name, obj, member, key) \ - hlist_for_each_entry(obj, &__elf_table(name)[hash_min(key, __elf_bits(name))], member) + if (node == *head) { + *head = node->next; + return; + } + + for (prev = NULL, cur = *head; cur; prev = cur, cur = cur->next) { + if (cur == node) { + prev->next = cur->next; + break; + } + } +} + +#define elf_hash_del(name, node, key) \ + __elf_hash_del(node, &__elf_table_entry(name, key)) + +#define elf_list_entry(ptr, type, member) \ +({ \ + typeof(ptr) __ptr = (ptr); \ + __ptr ? container_of(__ptr, type, member) : NULL; \ +}) + +#define elf_hash_for_each_possible(name, obj, member, key) \ + for (obj = elf_list_entry(__elf_table_entry(name, key), typeof(*obj), member); \ + obj; \ + obj = elf_list_entry(obj->member.next, typeof(*(obj)), member)) #define elf_alloc_hash(name, size) \ ({ \ __elf_bits(name) = max(10, ilog2(size)); \ - __elf_table(name) = mmap(NULL, sizeof(struct hlist_head) << __elf_bits(name), \ + __elf_table(name) = mmap(NULL, sizeof(struct elf_hash_node *) << __elf_bits(name), \ PROT_READ|PROT_WRITE, \ MAP_PRIVATE|MAP_ANON, -1, 0); \ if (__elf_table(name) == (void *)-1L) { \ @@ -713,10 +749,10 @@ __elf_create_symbol(struct elf *elf, struct symbol *sym) first_non_local = symtab->sh.sh_info; old = find_symbol_by_index(elf, first_non_local); if (old) { - old->idx = new_idx; - hlist_del(&old->hash); - elf_hash_add(symbol, &old->hash, old->idx); + elf_hash_del(symbol, &old->hash, old->idx); + elf_hash_add(symbol, &old->hash, new_idx); + old->idx = new_idx; if (elf_update_symbol(elf, symtab, symtab_shndx, old)) { WARN("elf_update_symbol move"); diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 7b808ac3156c..03a9040f696c 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -26,10 +26,14 @@ #define ELF_C_READ_MMAP ELF_C_READ #endif +struct elf_hash_node { + struct elf_hash_node *next; +}; + struct section { struct list_head list; - struct hlist_node hash; - struct hlist_node name_hash; + struct elf_hash_node hash; + struct elf_hash_node name_hash; GElf_Shdr sh; struct rb_root_cached symbol_tree; struct list_head symbol_list; @@ -45,8 +49,8 @@ struct section { struct symbol { struct list_head list; struct rb_node node; - struct hlist_node hash; - struct hlist_node name_hash; + struct elf_hash_node hash; + struct elf_hash_node name_hash; GElf_Sym sym; struct section *sec; char *name; @@ -67,7 +71,7 @@ struct symbol { }; struct reloc { - struct hlist_node hash; + struct elf_hash_node hash; union { GElf_Rela rela; GElf_Rel rel; @@ -93,11 +97,11 @@ struct elf { int section_name_bits; int reloc_bits; - struct hlist_head *symbol_hash; - struct hlist_head *symbol_name_hash; - struct hlist_head *section_hash; - struct hlist_head *section_name_hash; - struct hlist_head *reloc_hash; + struct elf_hash_node **symbol_hash; + struct elf_hash_node **symbol_name_hash; + struct elf_hash_node **section_hash; + struct elf_hash_node **section_name_hash; + struct elf_hash_node **reloc_hash; struct section *section_data; struct symbol *symbol_data; -- cgit v1.2.3 From ec24b927c1fbfc91cf7a48276d9fd92072b17d3b Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:12 -0700 Subject: objtool: Get rid of reloc->rel[a] Get the relocation entry info from the underlying rsec->data. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 35.12G - After: peak heap memory consumption: 29.93G Link: https://lore.kernel.org/r/2be32323de6d8cc73179ee0ff14b71f4e7cefaa0.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 20 +++----- tools/objtool/elf.c | 60 +++-------------------- tools/objtool/include/objtool/elf.h | 94 ++++++++++++++++++++++++++++++++----- 3 files changed, 96 insertions(+), 78 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 7fb6467178cb..47ff130a9460 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -968,7 +968,7 @@ static int create_mcount_loc_sections(struct objtool_file *file) if (!reloc) return -1; - set_reloc_type(reloc, addr_size == 8 ? R_ABS64 : R_ABS32); + set_reloc_type(file->elf, reloc, addr_size == 8 ? R_ABS64 : R_ABS32); idx++; } @@ -1363,10 +1363,8 @@ static void annotate_call_site(struct objtool_file *file, * noinstr text. */ if (opts.hack_noinstr && insn->sec->noinstr && sym->profiling_func) { - if (reloc) { - set_reloc_type(reloc, R_NONE); - elf_write_reloc(file->elf, reloc); - } + if (reloc) + set_reloc_type(file->elf, reloc, R_NONE); elf_write_insn(file->elf, insn->sec, insn->offset, insn->len, @@ -1392,10 +1390,8 @@ static void annotate_call_site(struct objtool_file *file, if (sibling) WARN_INSN(insn, "tail call to __fentry__ !?!?"); if (opts.mnop) { - if (reloc) { - set_reloc_type(reloc, R_NONE); - elf_write_reloc(file->elf, reloc); - } + if (reloc) + set_reloc_type(file->elf, reloc, R_NONE); elf_write_insn(file->elf, insn->sec, insn->offset, insn->len, @@ -1874,10 +1870,8 @@ static int handle_jump_alt(struct objtool_file *file, if (opts.hack_jump_label && special_alt->key_addend & 2) { struct reloc *reloc = insn_reloc(file, orig_insn); - if (reloc) { - set_reloc_type(reloc, R_NONE); - elf_write_reloc(file->elf, reloc); - } + if (reloc) + set_reloc_type(file->elf, reloc, R_NONE); elf_write_insn(file->elf, orig_insn->sec, orig_insn->offset, orig_insn->len, arch_nop_insn(orig_insn->len)); diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 04038b1324cf..54d182ddc4bb 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -575,11 +575,8 @@ static int elf_update_sym_relocs(struct elf *elf, struct symbol *sym) { struct reloc *reloc; - for (reloc = sym->relocs; reloc; reloc = reloc->sym_next_reloc) { - reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc_type(reloc)); - if (elf_write_reloc(elf, reloc)) - return -1; - } + for (reloc = sym->relocs; reloc; reloc = reloc->sym_next_reloc) + set_reloc_sym(elf, reloc, reloc->sym->idx); return 0; } @@ -869,12 +866,10 @@ static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, reloc->sec = rsec; reloc->sym = sym; - reloc->rel.r_offset = offset; - reloc->rel.r_info = GELF_R_INFO(sym->idx, type); - reloc->rela.r_addend = addend; - - if (elf_write_reloc(elf, reloc)) - return NULL; + set_reloc_offset(elf, reloc, offset); + set_reloc_sym(elf, reloc, sym->idx); + set_reloc_type(elf, reloc, type); + set_reloc_addend(elf, reloc, addend); elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); reloc->sym_next_reloc = sym->relocs; @@ -932,24 +927,6 @@ struct reloc *elf_init_reloc_data_sym(struct elf *elf, struct section *sec, elf_data_rela_type(elf)); } -static int read_reloc(struct section *rsec, int i, struct reloc *reloc) -{ - bool rela = rsec->sh.sh_type == SHT_RELA; - void *retp; - - if (rela) - retp = gelf_getrela(rsec->data, i, &reloc->rela); - else - retp = gelf_getrel(rsec->data, i, &reloc->rel); - - if (!retp) { - WARN_ELF("gelf_getrela"); - return -1; - } - - return 0; -} - static int read_relocs(struct elf *elf) { unsigned long nr_reloc, max_reloc = 0; @@ -984,11 +961,8 @@ static int read_relocs(struct elf *elf) for (i = 0; i < sec_num_entries(rsec); i++) { reloc = &rsec->relocs[i]; - if (read_reloc(rsec, i, reloc)) - return -1; - reloc->sec = rsec; - symndx = GELF_R_SYM(reloc->rel.r_info); + symndx = reloc_sym(reloc); reloc->sym = sym = find_symbol_by_index(elf, symndx); if (!reloc->sym) { WARN("can't find reloc entry symbol %d for %s", @@ -1261,26 +1235,6 @@ int elf_write_insn(struct elf *elf, struct section *sec, return 0; } -int elf_write_reloc(struct elf *elf, struct reloc *reloc) -{ - struct section *rsec = reloc->sec; - int ret; - - if (rsec->sh.sh_type == SHT_RELA) - ret = gelf_update_rela(rsec->data, reloc_idx(reloc), &reloc->rela); - else - ret = gelf_update_rel(rsec->data, reloc_idx(reloc), &reloc->rel); - - if (!ret) { - WARN_ELF("gelf_update_rela"); - return -1; - } - - mark_sec_changed(elf, rsec, true); - - return 0; -} - /* * When Elf_Scn::sh_size is smaller than the combined Elf_Data::d_size * do you: diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 03a9040f696c..c532d70864dc 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -72,10 +72,6 @@ struct symbol { struct reloc { struct elf_hash_node hash; - union { - GElf_Rela rela; - GElf_Rel rel; - }; struct section *sec; struct symbol *sym; struct reloc *sym_next_reloc; @@ -132,7 +128,6 @@ struct reloc *elf_init_reloc_data_sym(struct elf *elf, struct section *sec, int elf_write_insn(struct elf *elf, struct section *sec, unsigned long offset, unsigned int len, const char *insn); -int elf_write_reloc(struct elf *elf, struct reloc *reloc); int elf_write(struct elf *elf); void elf_close(struct elf *elf); @@ -204,24 +199,99 @@ static inline unsigned int reloc_idx(struct reloc *reloc) return reloc - reloc->sec->relocs; } -static inline unsigned long reloc_offset(struct reloc *reloc) +static inline void *reloc_rel(struct reloc *reloc) { - return reloc->rel.r_offset; + struct section *rsec = reloc->sec; + + return rsec->data->d_buf + (reloc_idx(reloc) * rsec->sh.sh_entsize); } -static inline unsigned int reloc_type(struct reloc *reloc) +static inline bool is_32bit_reloc(struct reloc *reloc) { - return GELF_R_TYPE(reloc->rel.r_info); + /* + * Elf32_Rel: 8 bytes + * Elf32_Rela: 12 bytes + * Elf64_Rel: 16 bytes + * Elf64_Rela: 24 bytes + */ + return reloc->sec->sh.sh_entsize < 16; } -static inline void set_reloc_type(struct reloc *reloc, int type) +#define __get_reloc_field(reloc, field) \ +({ \ + is_32bit_reloc(reloc) ? \ + ((Elf32_Rela *)reloc_rel(reloc))->field : \ + ((Elf64_Rela *)reloc_rel(reloc))->field; \ +}) + +#define __set_reloc_field(reloc, field, val) \ +({ \ + if (is_32bit_reloc(reloc)) \ + ((Elf32_Rela *)reloc_rel(reloc))->field = val; \ + else \ + ((Elf64_Rela *)reloc_rel(reloc))->field = val; \ +}) + +static inline u64 reloc_offset(struct reloc *reloc) { - reloc->rel.r_info = GELF_R_INFO(GELF_R_SYM(reloc->rel.r_info), type); + return __get_reloc_field(reloc, r_offset); +} + +static inline void set_reloc_offset(struct elf *elf, struct reloc *reloc, u64 offset) +{ + __set_reloc_field(reloc, r_offset, offset); + mark_sec_changed(elf, reloc->sec, true); } static inline s64 reloc_addend(struct reloc *reloc) { - return reloc->rela.r_addend; + return __get_reloc_field(reloc, r_addend); +} + +static inline void set_reloc_addend(struct elf *elf, struct reloc *reloc, s64 addend) +{ + __set_reloc_field(reloc, r_addend, addend); + mark_sec_changed(elf, reloc->sec, true); +} + + +static inline unsigned int reloc_sym(struct reloc *reloc) +{ + u64 info = __get_reloc_field(reloc, r_info); + + return is_32bit_reloc(reloc) ? + ELF32_R_SYM(info) : + ELF64_R_SYM(info); +} + +static inline unsigned int reloc_type(struct reloc *reloc) +{ + u64 info = __get_reloc_field(reloc, r_info); + + return is_32bit_reloc(reloc) ? + ELF32_R_TYPE(info) : + ELF64_R_TYPE(info); +} + +static inline void set_reloc_sym(struct elf *elf, struct reloc *reloc, unsigned int sym) +{ + u64 info = is_32bit_reloc(reloc) ? + ELF32_R_INFO(sym, reloc_type(reloc)) : + ELF64_R_INFO(sym, reloc_type(reloc)); + + __set_reloc_field(reloc, r_info, info); + + mark_sec_changed(elf, reloc->sec, true); +} +static inline void set_reloc_type(struct elf *elf, struct reloc *reloc, unsigned int type) +{ + u64 info = is_32bit_reloc(reloc) ? + ELF32_R_INFO(reloc_sym(reloc), type) : + ELF64_R_INFO(reloc_sym(reloc), type); + + __set_reloc_field(reloc, r_info, info); + + mark_sec_changed(elf, reloc->sec, true); } #define for_each_sec(file, sec) \ -- cgit v1.2.3 From d93b5935fd47007597aed5105a902a10204bc30e Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:13 -0700 Subject: objtool: Free insns when done Free the decoded instructions as they're no longer needed after this point. This frees up a big chunk of heap, which will come handy when skipping the reading of DWARF section data. Link: https://lore.kernel.org/r/4d4bca1a0f869de020dac80d91f9acbf6df77eab.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 47ff130a9460..8936a05f0e5a 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -4596,6 +4596,34 @@ static int disas_warned_funcs(struct objtool_file *file) return 0; } +struct insn_chunk { + void *addr; + struct insn_chunk *next; +}; + +/* + * Reduce peak RSS usage by freeing insns memory before writing the ELF file, + * which can trigger more allocations for .debug_* sections whose data hasn't + * been read yet. + */ +static void free_insns(struct objtool_file *file) +{ + struct instruction *insn; + struct insn_chunk *chunks = NULL, *chunk; + + for_each_insn(file, insn) { + if (!insn->idx) { + chunk = malloc(sizeof(*chunk)); + chunk->addr = insn; + chunk->next = chunks; + chunks = chunk; + } + } + + for (chunk = chunks; chunk; chunk = chunk->next) + free(chunk->addr); +} + int check(struct objtool_file *file) { int ret, warnings = 0; @@ -4742,6 +4770,8 @@ int check(struct objtool_file *file) warnings += ret; } + free_insns(file); + if (opts.verbose) disas_warned_funcs(file); -- cgit v1.2.3 From b4c96ef0add5b701eb37be9830a98610e1d9b4a3 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 30 May 2023 10:21:14 -0700 Subject: objtool: Skip reading DWARF section data Objtool doesn't use DWARF at all, and the DWARF sections' data take up a lot of memory. Skip reading them. Note this only skips the DWARF base sections, not the rela sections. The relas are needed because their symbol references may need to be reindexed if any local symbols get added by elf_create_symbol(). Also note the DWARF data will eventually be read by libelf anyway, when writing the object file. But that's fine, the goal here is to reduce *peak* memory usage, and the previous patch (which freed insn memory) gave some breathing room. So the allocation gets shifted to a later time, resulting in lower peak memory usage. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 29.93G - After: peak heap memory consumption: 25.47G Link: https://lore.kernel.org/r/52a9698835861dd35f2ec35c49f96d0bb39fb177.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/elf.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 54d182ddc4bb..d420b5d2e2b6 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -300,6 +300,11 @@ struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, uns return find_reloc_by_dest_range(elf, sec, offset, 1); } +static bool is_dwarf_section(struct section *sec) +{ + return !strncmp(sec->name, ".debug_", 7); +} + static int read_sections(struct elf *elf) { Elf_Scn *s = NULL; @@ -350,7 +355,7 @@ static int read_sections(struct elf *elf) return -1; } - if (sec->sh.sh_size != 0) { + if (sec->sh.sh_size != 0 && !is_dwarf_section(sec)) { sec->data = elf_getdata(s, NULL); if (!sec->data) { WARN_ELF("elf_getdata"); -- cgit v1.2.3 From 301cf77e21317b3465c5e2bb0188df24bbf1c2e2 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 9 Jun 2023 11:04:53 +0200 Subject: x86/orc: Make the is_callthunk() definition depend on CONFIG_BPF_JIT=y MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Recent commit: 020126239b8f Revert "x86/orc: Make it callthunk aware" Made the only user of is_callthunk() depend on CONFIG_BPF_JIT=y, while the definition of the helper function is unconditional. Move is_callthunk() inside the #ifdef block. Addresses this build failure: arch/x86/kernel/callthunks.c:296:13: error: ‘is_callthunk’ defined but not used [-Werror=unused-function] Signed-off-by: Ingo Molnar Cc: Josh Poimboeuf Cc: linux-kernel@vger.kernel.org Cc: Peter Zijlstra --- arch/x86/kernel/callthunks.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/callthunks.c b/arch/x86/kernel/callthunks.c index 8e0a9b637e23..fcb8eeaf65b1 100644 --- a/arch/x86/kernel/callthunks.c +++ b/arch/x86/kernel/callthunks.c @@ -293,6 +293,7 @@ void *callthunks_translate_call_dest(void *dest) return target ? : dest; } +#ifdef CONFIG_BPF_JIT static bool is_callthunk(void *addr) { unsigned int tmpl_size = SKL_TMPL_SIZE; @@ -306,7 +307,6 @@ static bool is_callthunk(void *addr) return !bcmp((void *)(dest - tmpl_size), tmpl, tmpl_size); } -#ifdef CONFIG_BPF_JIT int x86_call_depth_emit_accounting(u8 **pprog, void *func) { unsigned int tmpl_size = SKL_TMPL_SIZE; -- cgit v1.2.3