[PATCH v2 4/9] objtool: Add symbol iteration helpers

From: Josh Poimboeuf
Date: Wed Apr 12 2023 - 15:04:01 EST


Add [sec_]for_each_sym() and use them.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
tools/objtool/check.c | 98 ++++++++++++-----------------
tools/objtool/elf.c | 2 +-
tools/objtool/include/objtool/elf.h | 9 +++
3 files changed, 51 insertions(+), 58 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index de0d0234527d..d1d47baa252c 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -470,7 +470,7 @@ static int decode_instructions(struct objtool_file *file)

// printf("%s: last chunk used: %d\n", sec->name, (int)idx);

- list_for_each_entry(func, &sec->symbol_list, list) {
+ sec_for_each_sym(sec, func) {
if (func->type != STT_NOTYPE && func->type != STT_FUNC)
continue;

@@ -924,7 +924,7 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file)

static int create_cfi_sections(struct objtool_file *file)
{
- struct section *sec, *s;
+ struct section *sec;
struct symbol *sym;
unsigned int *loc;
int idx;
@@ -937,19 +937,14 @@ static int create_cfi_sections(struct objtool_file *file)
}

idx = 0;
- for_each_sec(file, s) {
- if (!s->text)
+ for_each_sym(file, sym) {
+ if (sym->type != STT_FUNC)
continue;

- list_for_each_entry(sym, &s->symbol_list, list) {
- if (sym->type != STT_FUNC)
- continue;
-
- if (strncmp(sym->name, "__cfi_", 6))
- continue;
+ if (strncmp(sym->name, "__cfi_", 6))
+ continue;

- idx++;
- }
+ idx++;
}

sec = elf_create_section(file->elf, ".cfi_sites", 0, sizeof(unsigned int), idx);
@@ -957,28 +952,23 @@ static int create_cfi_sections(struct objtool_file *file)
return -1;

idx = 0;
- for_each_sec(file, s) {
- if (!s->text)
+ for_each_sym(file, sym) {
+ if (sym->type != STT_FUNC)
continue;

- list_for_each_entry(sym, &s->symbol_list, list) {
- if (sym->type != STT_FUNC)
- continue;
-
- if (strncmp(sym->name, "__cfi_", 6))
- continue;
+ if (strncmp(sym->name, "__cfi_", 6))
+ continue;

- loc = (unsigned int *)sec->data->d_buf + idx;
- memset(loc, 0, sizeof(unsigned int));
+ 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,
- s, sym->offset))
- return -1;
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(unsigned int),
+ R_X86_64_PC32,
+ sym->sec, sym->offset))
+ return -1;

- idx++;
- }
+ idx++;
}

return 0;
@@ -2205,23 +2195,20 @@ static int add_func_jump_tables(struct objtool_file *file,
*/
static int add_jump_table_alts(struct objtool_file *file)
{
- struct section *sec;
struct symbol *func;
int ret;

if (!file->rodata)
return 0;

- for_each_sec(file, sec) {
- list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->type != STT_FUNC)
- continue;
+ for_each_sym(file, func) {
+ if (func->type != STT_FUNC)
+ continue;

- mark_func_jump_tables(file, func);
- ret = add_func_jump_tables(file, func);
- if (ret)
- return ret;
- }
+ mark_func_jump_tables(file, func);
+ ret = add_func_jump_tables(file, func);
+ if (ret)
+ return ret;
}

return 0;
@@ -2533,30 +2520,27 @@ static bool is_profiling_func(const char *name)

static int classify_symbols(struct objtool_file *file)
{
- struct section *sec;
struct symbol *func;

- for_each_sec(file, sec) {
- list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->bind != STB_GLOBAL)
- continue;
+ for_each_sym(file, func) {
+ if (func->bind != STB_GLOBAL)
+ continue;

- if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
- strlen(STATIC_CALL_TRAMP_PREFIX_STR)))
- func->static_call_tramp = true;
+ if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
+ strlen(STATIC_CALL_TRAMP_PREFIX_STR)))
+ func->static_call_tramp = true;

- if (arch_is_retpoline(func))
- func->retpoline_thunk = true;
+ if (arch_is_retpoline(func))
+ func->retpoline_thunk = true;

- if (arch_is_rethunk(func))
- func->return_thunk = true;
+ if (arch_is_rethunk(func))
+ func->return_thunk = true;

- if (arch_ftrace_match(func->name))
- func->fentry = true;
+ if (arch_ftrace_match(func->name))
+ func->fentry = true;

- if (is_profiling_func(func->name))
- func->profiling_func = true;
- }
+ if (is_profiling_func(func->name))
+ func->profiling_func = true;
}

return 0;
@@ -4222,7 +4206,7 @@ static int validate_section(struct objtool_file *file, struct section *sec)
struct symbol *func;
int warnings = 0;

- list_for_each_entry(func, &sec->symbol_list, list) {
+ sec_for_each_sym(sec, func) {
if (func->type != STT_FUNC)
continue;

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 6806ce01d933..500e92979a31 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -474,7 +474,7 @@ static int read_symbols(struct elf *elf)

/* Create parent/child links for any cold subfunctions */
list_for_each_entry(sec, &elf->sections, list) {
- list_for_each_entry(sym, &sec->symbol_list, list) {
+ sec_for_each_sym(sec, sym) {
char pname[MAX_NAME_LEN + 1];
size_t pnamelen;
if (sym->type != STT_FUNC)
diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
index a668173a5869..78e2d0fc21ca 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -189,4 +189,13 @@ struct symbol *find_func_containing(struct section *sec, unsigned long offset);
#define for_each_sec(file, sec) \
list_for_each_entry(sec, &file->elf->sections, list)

+#define sec_for_each_sym(sec, sym) \
+ list_for_each_entry(sym, &sec->symbol_list, list)
+
+#define for_each_sym(file, sym) \
+ for (struct section *__sec, *__fake = (struct section *)1; \
+ __fake; __fake = NULL) \
+ for_each_sec(file, __sec) \
+ sec_for_each_sym(__sec, sym)
+
#endif /* _OBJTOOL_ELF_H */
--
2.39.2