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-rw-r--r--tools/objtool/check.c183
1 files changed, 94 insertions, 89 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 5e5388a38e2a..1f4154f9b04b 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -433,8 +433,7 @@ reachable:
static int create_static_call_sections(struct objtool_file *file)
{
- struct section *sec, *reloc_sec;
- struct reloc *reloc;
+ struct section *sec;
struct static_call_site *site;
struct instruction *insn;
struct symbol *key_sym;
@@ -452,7 +451,7 @@ static int create_static_call_sections(struct objtool_file *file)
return 0;
idx = 0;
- list_for_each_entry(insn, &file->static_call_list, static_call_node)
+ list_for_each_entry(insn, &file->static_call_list, call_node)
idx++;
sec = elf_create_section(file->elf, ".static_call_sites", SHF_WRITE,
@@ -460,36 +459,18 @@ static int create_static_call_sections(struct objtool_file *file)
if (!sec)
return -1;
- reloc_sec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
- if (!reloc_sec)
- return -1;
-
idx = 0;
- list_for_each_entry(insn, &file->static_call_list, static_call_node) {
+ 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' */
- reloc = malloc(sizeof(*reloc));
-
- if (!reloc) {
- perror("malloc");
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(struct static_call_site),
+ R_X86_64_PC32,
+ insn->sec, insn->offset))
return -1;
- }
- memset(reloc, 0, sizeof(*reloc));
-
- insn_to_reloc_sym_addend(insn->sec, insn->offset, reloc);
- if (!reloc->sym) {
- WARN_FUNC("static call tramp: missing containing symbol",
- insn->sec, insn->offset);
- return -1;
- }
-
- reloc->type = R_X86_64_PC32;
- reloc->offset = idx * sizeof(struct static_call_site);
- reloc->sec = reloc_sec;
- elf_add_reloc(file->elf, reloc);
/* find key symbol */
key_name = strdup(insn->call_dest->name);
@@ -526,32 +507,21 @@ static int create_static_call_sections(struct objtool_file *file)
free(key_name);
/* populate reloc for 'key' */
- reloc = malloc(sizeof(*reloc));
- if (!reloc) {
- perror("malloc");
+ 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))
return -1;
- }
- memset(reloc, 0, sizeof(*reloc));
- reloc->sym = key_sym;
- reloc->addend = is_sibling_call(insn) ? STATIC_CALL_SITE_TAIL : 0;
- reloc->type = R_X86_64_PC32;
- reloc->offset = idx * sizeof(struct static_call_site) + 4;
- reloc->sec = reloc_sec;
- elf_add_reloc(file->elf, reloc);
idx++;
}
- if (elf_rebuild_reloc_section(file->elf, reloc_sec))
- return -1;
-
return 0;
}
static int create_mcount_loc_sections(struct objtool_file *file)
{
- struct section *sec, *reloc_sec;
- struct reloc *reloc;
+ struct section *sec;
unsigned long *loc;
struct instruction *insn;
int idx;
@@ -574,49 +544,21 @@ static int create_mcount_loc_sections(struct objtool_file *file)
if (!sec)
return -1;
- reloc_sec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
- if (!reloc_sec)
- return -1;
-
idx = 0;
list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node) {
loc = (unsigned long *)sec->data->d_buf + idx;
memset(loc, 0, sizeof(unsigned long));
- reloc = malloc(sizeof(*reloc));
- if (!reloc) {
- perror("malloc");
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(unsigned long),
+ R_X86_64_64,
+ insn->sec, insn->offset))
return -1;
- }
- memset(reloc, 0, sizeof(*reloc));
-
- if (insn->sec->sym) {
- reloc->sym = insn->sec->sym;
- reloc->addend = insn->offset;
- } else {
- reloc->sym = find_symbol_containing(insn->sec, insn->offset);
-
- if (!reloc->sym) {
- WARN("missing symbol for insn at offset 0x%lx\n",
- insn->offset);
- return -1;
- }
-
- reloc->addend = insn->offset - reloc->sym->offset;
- }
-
- reloc->type = R_X86_64_64;
- reloc->offset = idx * sizeof(unsigned long);
- reloc->sec = reloc_sec;
- elf_add_reloc(file->elf, reloc);
idx++;
}
- if (elf_rebuild_reloc_section(file->elf, reloc_sec))
- return -1;
-
return 0;
}
@@ -850,6 +792,30 @@ static int add_ignore_alternatives(struct objtool_file *file)
return 0;
}
+__weak bool arch_is_retpoline(struct symbol *sym)
+{
+ return false;
+}
+
+#define NEGATIVE_RELOC ((void *)-1L)
+
+static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn)
+{
+ if (insn->reloc == NEGATIVE_RELOC)
+ return NULL;
+
+ if (!insn->reloc) {
+ insn->reloc = find_reloc_by_dest_range(file->elf, insn->sec,
+ insn->offset, insn->len);
+ if (!insn->reloc) {
+ insn->reloc = NEGATIVE_RELOC;
+ return NULL;
+ }
+ }
+
+ return insn->reloc;
+}
+
/*
* Find the destination instructions for all jumps.
*/
@@ -864,16 +830,14 @@ static int add_jump_destinations(struct objtool_file *file)
if (!is_static_jump(insn))
continue;
- reloc = find_reloc_by_dest_range(file->elf, insn->sec,
- insn->offset, insn->len);
+ reloc = insn_reloc(file, insn);
if (!reloc) {
dest_sec = insn->sec;
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);
- } else if (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21) ||
- !strncmp(reloc->sym->name, "__x86_retpoline_", 16)) {
+ } else if (arch_is_retpoline(reloc->sym)) {
/*
* Retpoline jumps are really dynamic jumps in
* disguise, so convert them accordingly.
@@ -883,13 +847,16 @@ static int add_jump_destinations(struct objtool_file *file)
else
insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL;
+ list_add_tail(&insn->call_node,
+ &file->retpoline_call_list);
+
insn->retpoline_safe = true;
continue;
} else if (insn->func) {
/* internal or external sibling call (with reloc) */
insn->call_dest = reloc->sym;
if (insn->call_dest->static_call_tramp) {
- list_add_tail(&insn->static_call_node,
+ list_add_tail(&insn->call_node,
&file->static_call_list);
}
continue;
@@ -951,7 +918,7 @@ static int add_jump_destinations(struct objtool_file *file)
/* internal sibling call (without reloc) */
insn->call_dest = insn->jump_dest->func;
if (insn->call_dest->static_call_tramp) {
- list_add_tail(&insn->static_call_node,
+ list_add_tail(&insn->call_node,
&file->static_call_list);
}
}
@@ -995,8 +962,7 @@ static int add_call_destinations(struct objtool_file *file)
if (insn->type != INSN_CALL)
continue;
- reloc = find_reloc_by_dest_range(file->elf, insn->sec,
- insn->offset, insn->len);
+ reloc = insn_reloc(file, insn);
if (!reloc) {
dest_off = arch_jump_destination(insn);
insn->call_dest = find_call_destination(insn->sec, dest_off);
@@ -1026,9 +992,29 @@ static int add_call_destinations(struct objtool_file *file)
dest_off);
return -1;
}
+
+ } else if (arch_is_retpoline(reloc->sym)) {
+ /*
+ * Retpoline calls are really dynamic calls in
+ * disguise, so convert them accordingly.
+ */
+ insn->type = INSN_CALL_DYNAMIC;
+ insn->retpoline_safe = true;
+
+ list_add_tail(&insn->call_node,
+ &file->retpoline_call_list);
+
+ remove_insn_ops(insn);
+ continue;
+
} else
insn->call_dest = reloc->sym;
+ if (insn->call_dest && insn->call_dest->static_call_tramp) {
+ list_add_tail(&insn->call_node,
+ &file->static_call_list);
+ }
+
/*
* Many compilers cannot disable KCOV with a function attribute
* so they need a little help, NOP out any KCOV calls from noinstr
@@ -1175,8 +1161,7 @@ static int handle_group_alt(struct objtool_file *file,
* alternatives code can adjust the relative offsets
* accordingly.
*/
- alt_reloc = find_reloc_by_dest_range(file->elf, insn->sec,
- insn->offset, insn->len);
+ alt_reloc = insn_reloc(file, insn);
if (alt_reloc &&
!arch_support_alt_relocation(special_alt, insn, alt_reloc)) {
@@ -1751,6 +1736,11 @@ static void mark_rodata(struct objtool_file *file)
file->rodata = found;
}
+__weak int arch_rewrite_retpolines(struct objtool_file *file)
+{
+ return 0;
+}
+
static int decode_sections(struct objtool_file *file)
{
int ret;
@@ -1772,10 +1762,17 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
+ /*
+ * Must be before add_{jump_call}_destination.
+ */
ret = read_static_call_tramps(file);
if (ret)
return ret;
+ /*
+ * Must be before add_special_section_alts() as that depends on
+ * jump_dest being set.
+ */
ret = add_jump_destinations(file);
if (ret)
return ret;
@@ -1784,6 +1781,10 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
+ /*
+ * Must be before add_call_destination(); it changes INSN_CALL to
+ * INSN_JUMP.
+ */
ret = read_intra_function_calls(file);
if (ret)
return ret;
@@ -1808,6 +1809,15 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
+ /*
+ * Must be after add_special_section_alts(), since this will emit
+ * alternatives. Must be after add_{jump,call}_destination(), since
+ * those create the call insn lists.
+ */
+ ret = arch_rewrite_retpolines(file);
+ if (ret)
+ return ret;
+
return 0;
}
@@ -2746,11 +2756,6 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
if (dead_end_function(file, insn->call_dest))
return 0;
- if (insn->type == INSN_CALL && insn->call_dest->static_call_tramp) {
- list_add_tail(&insn->static_call_node,
- &file->static_call_list);
- }
-
break;
case INSN_JUMP_CONDITIONAL:
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-30 22:16:08 +0300