Commit-ID: d8d1b2cb58540b0cf572be4715167c473193888e Gitweb: http://git.kernel.org/tip/d8d1b2cb58540b0cf572be4715167c473193888e Author: Josh Poimboeuf <jpoim...@redhat.com> AuthorDate: Wed, 9 Mar 2016 00:06:54 -0600 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 9 Mar 2016 10:48:08 +0100
objtool: Fix false positive warnings related to sibling calls With some configs [1], objtool prints a bunch of false positive warnings like: arch/x86/events/core.o: warning: objtool: x86_del_exclusive()+0x0: frame pointer state mismatch For some reason this config has a bunch of sibling calls. When objtool follows a sibling call jump, it attempts to compare the frame pointer state. But it also accidentally compares the FENTRY state, resulting in a false positive warning. [1] https://lkml.kernel.org/r/20160308154909.ga20...@gmail.com Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Andy Lutomirski <l...@kernel.org> Cc: Arnaldo Carvalho de Melo <a...@infradead.org> Cc: Arnaldo Carvalho de Melo <a...@kernel.org> Cc: Bernd Petrovitsch <be...@petrovitsch.priv.at> Cc: Borislav Petkov <b...@alien8.de> Cc: Chris J Arges <chris.j.ar...@canonical.com> Cc: Jiri Slaby <jsl...@suse.cz> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Michal Marek <mma...@suse.cz> Cc: Namhyung Kim <namhy...@gmail.com> Cc: Pedro Alves <pal...@redhat.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: live-patch...@vger.kernel.org Link: http://lkml.kernel.org/r/382de77ccaaa8cd79b27a155c3d109ebd4ce0219.1457502970.git.jpoim...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- tools/objtool/builtin-check.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 51da270..fe24804 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -729,6 +729,11 @@ static bool has_valid_stack_frame(struct instruction *insn) (insn->state & STATE_FP_SETUP); } +static unsigned int frame_state(unsigned long state) +{ + return (state & (STATE_FP_SAVED | STATE_FP_SETUP)); +} + /* * Follow the branch starting at the given instruction, and recursively follow * any other branches (jumps). Meanwhile, track the frame pointer state at @@ -756,7 +761,7 @@ static int validate_branch(struct objtool_file *file, while (1) { if (insn->visited) { - if (insn->state != state) { + if (frame_state(insn->state) != frame_state(state)) { WARN_FUNC("frame pointer state mismatch", sec, insn->offset); warnings++;
