Linus,
Please pull the latest objtool/urgent git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git objtool-urgent-2021-06-12
# HEAD: 2d49b721dc18c113d5221f4cf5a6104eb66cb7f2 objtool: Only rewrite unconditional retpoline thunk calls
Two objtool fixes:
- fix a bug that corrupts the code by mistakenly rewriting
conditional jumps,
- and fix another bug generating an incorrect ELF symbol table
during retpoline rewriting.
Thanks,
Ingo
------------------>
Peter Zijlstra (2):
objtool: Fix .symtab_shndx handling for elf_create_undef_symbol()
objtool: Only rewrite unconditional retpoline thunk calls
tools/objtool/arch/x86/decode.c | 4 ++++
tools/objtool/elf.c | 25 ++++++++++++++++++++++++-
2 files changed, 28 insertions(+), 1 deletion(-)
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 24295d39713b..523aa4157f80 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -747,6 +747,10 @@ int arch_rewrite_retpolines(struct objtool_file *file)
list_for_each_entry(insn, &file->retpoline_call_list, call_node) {
+ if (insn->type != INSN_JUMP_DYNAMIC &&
+ insn->type != INSN_CALL_DYNAMIC)
+ continue;
+
if (!strcmp(insn->sec->name, ".text.__x86.indirect_thunk"))
continue;
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 743c2e9d0f56..41bca1d13d8e 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -717,7 +717,7 @@ static int elf_add_string(struct elf *elf, struct section *strtab, char *str)
struct symbol *elf_create_undef_symbol(struct elf *elf, const char *name)
{
- struct section *symtab;
+ struct section *symtab, *symtab_shndx;
struct symbol *sym;
Elf_Data *data;
Elf_Scn *s;
@@ -769,6 +769,29 @@ struct symbol *elf_create_undef_symbol(struct elf *elf, const char *name)
symtab->len += data->d_size;
symtab->changed = true;
+ symtab_shndx = find_section_by_name(elf, ".symtab_shndx");
+ if (symtab_shndx) {
+ s = elf_getscn(elf->elf, symtab_shndx->idx);
+ if (!s) {
+ WARN_ELF("elf_getscn");
+ return NULL;
+ }
+
+ data = elf_newdata(s);
+ if (!data) {
+ WARN_ELF("elf_newdata");
+ return NULL;
+ }
+
+ data->d_buf = &sym->sym.st_size; /* conveniently 0 */
+ data->d_size = sizeof(Elf32_Word);
+ data->d_align = 4;
+ data->d_type = ELF_T_WORD;
+
+ symtab_shndx->len += 4;
+ symtab_shndx->changed = true;
+ }
+
sym->sec = find_section_by_index(elf, 0);
elf_add_symbol(elf, sym);
The pull request you sent on Sat, 12 Jun 2021 14:37:46 +0200:
> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git objtool-urgent-2021-06-12
has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/768895fb774d7af32d17cf3a455b0bd6df272f14
Thank you!
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