[PATCH v6 09/33] objtool: check: Support data in text section
From: Chen Zhongjin <hidden>
Date: 2022-06-23 01:53:03
Also in:
linux-arch, linux-arm-kernel, linux-kbuild, live-patching, lkml
Subsystem:
objtool, the rest · Maintainers:
Josh Poimboeuf, Peter Zijlstra, Linus Torvalds
Arm64 assembly code can mix code and data in text sections through the use of SYM_DATA_*() macros. Skip the content of these symbols when decoding instructions of text sections. Signed-off-by: Julien Thierry <redacted> Signed-off-by: Chen Zhongjin <redacted> --- tools/objtool/check.c | 14 ++++++++++++-- tools/objtool/elf.c | 14 ++++++++++++++ tools/objtool/include/objtool/elf.h | 1 + 3 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index c0feb6db7c6d..f19ea3fc1e6b 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c@@ -359,7 +359,7 @@ static int decode_instructions(struct objtool_file *file) { struct section *sec; struct symbol *func; - unsigned long offset; + unsigned long offset, next_offset; struct instruction *insn; int ret;
@@ -377,7 +377,15 @@ static int decode_instructions(struct objtool_file *file) !strcmp(sec->name, ".entry.text")) sec->noinstr = true; - for (offset = 0; offset < sec->sh.sh_size; offset += insn->len) { + for (offset = 0; offset < sec->sh.sh_size; offset = next_offset) { + struct symbol *obj_sym = find_object_containing(sec, offset); + + if (obj_sym) { + /* This is data in the middle of text section, skip it */ + next_offset = obj_sym->offset + obj_sym->len; + continue; + } + insn = malloc(sizeof(*insn)); if (!insn) { WARN("malloc failed");
@@ -410,6 +418,8 @@ static int decode_instructions(struct objtool_file *file) hash_add(file->insn_hash, &insn->hash, sec_offset_hash(sec, insn->offset)); list_add_tail(&insn->list, &file->insn_list); nr_insns++; + + next_offset = offset + insn->len; } list_for_each_entry(func, &sec->symbol_list, list) {
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index c25e957c1e52..d7304e39f6b6 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c@@ -236,6 +236,20 @@ struct symbol *find_func_containing(struct section *sec, unsigned long offset) return NULL; } +struct symbol *find_object_containing(const struct section *sec, unsigned long offset) +{ + struct rb_node *node; + + rb_for_each(node, &offset, &sec->symbol_tree, symbol_by_offset) { + struct symbol *s = rb_entry(node, struct symbol, node); + + if (s->type == STT_OBJECT) + return s; + } + + return NULL; +} + struct symbol *find_symbol_by_name(const struct elf *elf, const char *name) { struct symbol *sym;
diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
index adebfbc2b518..8b0896935af1 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h@@ -167,6 +167,7 @@ struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, uns struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec, unsigned long offset, unsigned int len); struct symbol *find_func_containing(struct section *sec, unsigned long offset); +struct symbol *find_object_containing(const struct section *sec, unsigned long offset); #define for_each_sec(file, sec) \ list_for_each_entry(sec, &file->elf->sections, list)
--
2.17.1