path: root/tools/objtool
diff options
authorJosh Poimboeuf <jpoimboe@redhat.com>2017-07-27 15:56:54 -0500
committerIngo Molnar <mingo@kernel.org>2017-07-28 08:33:32 +0200
commit0e2bb2bc14b3df754b0a86e87cd8923df0701a1b (patch)
tree5b8ad66eabab70d8c1360d1edaebc5af23051db8 /tools/objtool
parent649ea4d5a624f061a111b1f1cb0e47cfdc3ac21b (diff)
objtool: Skip unreachable warnings for 'alt' instructions
When a whitelisted function uses one of the ALTERNATIVE macros, it produces false positive warnings like: arch/x86/kvm/vmx.o: warning: objtool: .altinstr_replacement+0x0: unreachable instruction arch/x86/kvm/svm.o: warning: objtool: .altinstr_replacement+0x6e: unreachable instruction There's no easy way to whitelist alternative instructions, so instead just skip any 'unreachable' warnings associated with them. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a5d0a8c60155f03b36a31fac871e12cf75f35fd0.1501188854.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/objtool')
1 files changed, 6 insertions, 1 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index d07bf4a62b45..4f0c4aea8f6f 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1746,8 +1746,13 @@ static bool ignore_unreachable_insn(struct instruction *insn)
* Ignore any unused exceptions. This can happen when a whitelisted
* function has an exception table entry.
+ *
+ * Also ignore alternative replacement instructions. This can happen
+ * when a whitelisted function uses one of the ALTERNATIVE macros.
- if (!strcmp(insn->sec->name, ".fixup"))
+ if (!strcmp(insn->sec->name, ".fixup") ||
+ !strcmp(insn->sec->name, ".altinstr_replacement") ||
+ !strcmp(insn->sec->name, ".altinstr_aux"))
return true;