diff options
| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2021-01-21 15:29:18 -0600 |
|---|---|---|
| committer | Josh Poimboeuf <jpoimboe@redhat.com> | 2021-01-26 11:11:59 -0600 |
| commit | 1f9a1b74942485a0a29e7c4a9a9f2fe8aea17766 (patch) | |
| tree | fed5d10db74d928885cbac6c194893a21ca34556 /tools/objtool | |
| parent | 6f567c9300a5ebd7b18c26dda1c8d6ffbdd0debd (diff) | |
objtool: Fix retpoline detection in asm code
The JMP_NOSPEC macro branches to __x86_retpoline_*() rather than the
__x86_indirect_thunk_*() wrappers used by C code. Detect jumps to
__x86_retpoline_*() as retpoline dynamic jumps.
Presumably this doesn't trigger a user-visible bug. I only found it
when testing vmlinux.o validation.
Fixes: 39b735332cb8 ("objtool: Detect jumps to retpoline thunks")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/31f5833e2e4f01e3d755889ac77e3661e906c09f.1611263461.git.jpoimboe@redhat.com
Diffstat (limited to 'tools/objtool')
| -rw-r--r-- | tools/objtool/arch/x86/special.c | 2 | ||||
| -rw-r--r-- | tools/objtool/check.c | 3 | ||||
| -rw-r--r-- | tools/objtool/include/objtool/check.h | 11 |
3 files changed, 14 insertions, 2 deletions
diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c index b4bd3505fc94..e707d9bcd161 100644 --- a/tools/objtool/arch/x86/special.c +++ b/tools/objtool/arch/x86/special.c @@ -48,7 +48,7 @@ bool arch_support_alt_relocation(struct special_alt *special_alt, * replacement group. */ return insn->offset == special_alt->new_off && - (insn->type == INSN_CALL || is_static_jump(insn)); + (insn->type == INSN_CALL || is_jump(insn)); } /* diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 3bdd946c2027..081572170f6b 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -785,7 +785,8 @@ static int add_jump_destinations(struct objtool_file *file) dest_sec = reloc->sym->sec; dest_off = reloc->sym->sym.st_value + arch_dest_reloc_offset(reloc->addend); - } else if (strstr(reloc->sym->name, "_indirect_thunk_")) { + } else if (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21) || + !strncmp(reloc->sym->name, "__x86_retpoline_", 16)) { /* * Retpoline jumps are really dynamic jumps in * disguise, so convert them accordingly. diff --git a/tools/objtool/include/objtool/check.h b/tools/objtool/include/objtool/check.h index f4e041fbdab2..b408636c0201 100644 --- a/tools/objtool/include/objtool/check.h +++ b/tools/objtool/include/objtool/check.h @@ -68,6 +68,17 @@ static inline bool is_static_jump(struct instruction *insn) insn->type == INSN_JUMP_UNCONDITIONAL; } +static inline bool is_dynamic_jump(struct instruction *insn) +{ + return insn->type == INSN_JUMP_DYNAMIC || + insn->type == INSN_JUMP_DYNAMIC_CONDITIONAL; +} + +static inline bool is_jump(struct instruction *insn) +{ + return is_static_jump(insn) || is_dynamic_jump(insn); +} + struct instruction *find_insn(struct objtool_file *file, struct section *sec, unsigned long offset); |