From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
[ Upstream commit 1f9a1b74942485a0a29e7c4a9a9f2fe8aea17766 ]
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@xxxxxxxxxx>
Link: https://lore.kernel.org/r/31f5833e2e4f01e3d755889ac77e3661e906c09f.1611263461.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/objtool/arch/x86/special.c | 2 +-
tools/objtool/check.c | 3 ++-
tools/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 fd4af88c0ea52..151b13d0a2676 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 2e154f00ccec2..48e22e3c6f186 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -789,7 +789,8 @@ 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/check.h b/tools/objtool/check.h
index 5ec00a4b891b6..2804848e628e3 100644
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -54,6 +54,17 @@ 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);
--
2.27.0
