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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2016-03-09 00:06:54 -0600 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-03-09 10:48:08 +0100 |
| commit | d8d1b2cb58540b0cf572be4715167c473193888e (patch) | |
| tree | ca57817439709d3607c8bc71e477ec438a123c81 /tools | |
| parent | d435fb5ef74c31909ca58f93aa87ad09b17bbe9a (diff) | |
| download | linux-d8d1b2cb58540b0cf572be4715167c473193888e.tar.gz linux-d8d1b2cb58540b0cf572be4715167c473193888e.tar.bz2 linux-d8d1b2cb58540b0cf572be4715167c473193888e.zip | |
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.GA20956@gmail.com
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/382de77ccaaa8cd79b27a155c3d109ebd4ce0219.1457502970.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/objtool/builtin-check.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 51da270758f0..fe248044415b 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++; |