Commit-ID: 0e2bb2bc14b3df754b0a86e87cd8923df0701a1b Gitweb: http://git.kernel.org/tip/0e2bb2bc14b3df754b0a86e87cd8923df0701a1b Author: Josh Poimboeuf <jpoim...@redhat.com> AuthorDate: Thu, 27 Jul 2017 15:56:54 -0500 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Fri, 28 Jul 2017 08:33:32 +0200
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 <a...@arndb.de> Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/a5d0a8c60155f03b36a31fac871e12cf75f35fd0.1501188854.git.jpoim...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- tools/objtool/check.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index d07bf4a..4f0c4ae 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; /*
