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author | Namhyung Kim <namhyung@kernel.org> | 2024-03-19 08:51:13 +0300 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2024-03-21 16:41:29 +0300 |
commit | b3c95109c131fcc959d2473e7c384d8cc62d23d0 (patch) | |
tree | 75e22c1ee75fde09d5ac3eea0f779feead8981f0 /tools/perf/util | |
parent | eb9190afaed6afd5ed54bb0a3269eec338663858 (diff) | |
download | linux-b3c95109c131fcc959d2473e7c384d8cc62d23d0.tar.xz |
perf annotate-data: Add stack canary type
When the stack protector is enabled, compiler would generate code to
check stack overflow with a special value called 'stack carary' at
runtime. On x86_64, GCC hard-codes the stack canary as %gs:40.
While there's a definition of fixed_percpu_data in asm/processor.h,
it seems that the header is not included everywhere and many places
it cannot find the type info. As it's in the well-known location (at
%gs:40), let's add a pseudo stack canary type to handle it specially.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240319055115.4063940-22-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util')
-rw-r--r-- | tools/perf/util/annotate-data.c | 46 | ||||
-rw-r--r-- | tools/perf/util/annotate-data.h | 1 | ||||
-rw-r--r-- | tools/perf/util/annotate.c | 25 |
3 files changed, 72 insertions, 0 deletions
diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c index bd10a576cfbf..633fe125fcd8 100644 --- a/tools/perf/util/annotate-data.c +++ b/tools/perf/util/annotate-data.c @@ -30,6 +30,7 @@ enum type_state_kind { TSR_KIND_PERCPU_BASE, TSR_KIND_CONST, TSR_KIND_POINTER, + TSR_KIND_CANARY, }; #define pr_debug_dtp(fmt, ...) \ @@ -62,6 +63,9 @@ static void pr_debug_type_name(Dwarf_Die *die, enum type_state_kind kind) pr_info(" pointer"); /* it also prints the type info */ break; + case TSR_KIND_CANARY: + pr_info(" stack canary\n"); + return; case TSR_KIND_TYPE: default: break; @@ -676,6 +680,15 @@ static void update_insn_state_x86(struct type_state *state, */ var_addr = src->offset; + if (var_addr == 40) { + tsr->kind = TSR_KIND_CANARY; + tsr->ok = true; + + pr_debug_dtp("mov [%x] stack canary -> reg%d\n", + insn_offset, dst->reg1); + return; + } + if (!get_global_var_type(cu_die, dloc, ip, var_addr, &offset, &type_die) || !die_get_member_type(&type_die, offset, &type_die)) { @@ -991,6 +1004,16 @@ static void delete_var_types(struct die_var_type *var_types) } } +/* should match to is_stack_canary() in util/annotate.c */ +static void setup_stack_canary(struct data_loc_info *dloc) +{ + if (arch__is(dloc->arch, "x86")) { + dloc->op->segment = INSN_SEG_X86_GS; + dloc->op->imm = true; + dloc->op->offset = 40; + } +} + /* It's at the target address, check if it has a matching type */ static bool check_matching_type(struct type_state *state, struct data_loc_info *dloc, int reg, @@ -1038,6 +1061,11 @@ static bool check_matching_type(struct type_state *state, if (stack == NULL) return false; + if (stack->kind == TSR_KIND_CANARY) { + setup_stack_canary(dloc); + return false; + } + *type_die = stack->type; /* Update the type offset from the start of slot */ dloc->type_offset -= stack->offset; @@ -1062,6 +1090,11 @@ static bool check_matching_type(struct type_state *state, if (stack == NULL) return false; + if (stack->kind == TSR_KIND_CANARY) { + setup_stack_canary(dloc); + return false; + } + *type_die = stack->type; /* Update the type offset from the start of slot */ dloc->type_offset -= fboff + stack->offset; @@ -1102,6 +1135,19 @@ static bool check_matching_type(struct type_state *state, return true; } + if (state->regs[reg].ok && state->regs[reg].kind == TSR_KIND_CANARY) { + pr_debug_dtp(" stack canary\n"); + + /* + * This is a saved value of the stack canary which will be handled + * in the outer logic when it returns failure here. Pretend it's + * from the stack canary directly. + */ + setup_stack_canary(dloc); + + return false; + } + if (map__dso(dloc->ms->map)->kernel && arch__is(dloc->arch, "x86")) { u64 addr; int offset; diff --git a/tools/perf/util/annotate-data.h b/tools/perf/util/annotate-data.h index ae0f87aed804..1b5a152163b5 100644 --- a/tools/perf/util/annotate-data.h +++ b/tools/perf/util/annotate-data.h @@ -73,6 +73,7 @@ struct annotated_data_type { extern struct annotated_data_type unknown_type; extern struct annotated_data_type stackop_type; +extern struct annotated_data_type canary_type; /** * struct data_loc_info - Data location information diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c index e4121acb4f88..64e54ff1aa1d 100644 --- a/tools/perf/util/annotate.c +++ b/tools/perf/util/annotate.c @@ -118,6 +118,13 @@ struct annotated_data_type stackop_type = { }, }; +struct annotated_data_type canary_type = { + .self = { + .type_name = (char *)"(stack canary)", + .children = LIST_HEAD_INIT(canary_type.self.children), + }, +}; + static int arch__grow_instructions(struct arch *arch) { struct ins *new_instructions; @@ -3803,6 +3810,18 @@ static bool is_stack_operation(struct arch *arch, struct disasm_line *dl) return false; } +static bool is_stack_canary(struct arch *arch, struct annotated_op_loc *loc) +{ + /* On x86_64, %gs:40 is used for stack canary */ + if (arch__is(arch, "x86")) { + if (loc->segment == INSN_SEG_X86_GS && loc->imm && + loc->offset == 40) + return true; + } + + return false; +} + u64 annotate_calc_pcrel(struct map_symbol *ms, u64 ip, int offset, struct disasm_line *dl) { @@ -3929,6 +3948,12 @@ retry: } mem_type = find_data_type(&dloc); + + if (mem_type == NULL && is_stack_canary(arch, op_loc)) { + mem_type = &canary_type; + dloc.type_offset = 0; + } + if (mem_type) istat->good++; else |