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authorJosh Poimboeuf <jpoimboe@redhat.com>2017-08-11 20:24:15 +0300
committerIngo Molnar <mingo@kernel.org>2017-08-21 17:06:05 +0300
commitee97638b5737cc0dba2f12a3bdcda761656b7c01 (patch)
tree7304c38918d60253c789cadd2cb3a8dbea96dd8c /tools/objtool/check.c
parentfa2016a8e7d846b306e431646d250500e1da0c33 (diff)
downloadlinux-ee97638b5737cc0dba2f12a3bdcda761656b7c01.tar.xz
objtool: Fix objtool fallthrough detection with function padding
When GCC adds NOP padding between functions, those NOPs aren't associated with a function symbol, which breaks objtool's detection of a function falling through to another function. Instead it shows confusing errors like: drivers/mtd/chips/cfi_util.o: warning: objtool: cfi_qry_mode_on()+0x8b: return with modified stack frame drivers/mtd/chips/cfi_util.o: warning: objtool: cfi_qry_mode_on()+0x0: stack state mismatch: cfa1=-4-32 cfa2=7+8 drivers/mtd/chips/cfi_cmdset_0002.o: warning: objtool: fixup_use_fwh_lock()+0x8: unknown stack-related register move drivers/mtd/chips/cfi_cmdset_0002.o: warning: objtool: fixup_use_fwh_lock()+0x0: stack state mismatch: cfa1=6+16 cfa2=7+8 drivers/mtd/chips/cfi_cmdset_0002.o: warning: objtool: do_otp_write()+0xa: unsupported stack pointer realignment drivers/mtd/chips/cfi_cmdset_0002.o: warning: objtool: do_otp_write()+0x0: stack state mismatch: cfa1=-4-40 cfa2=7+8 Reported-by: kbuild test robot <fengguang.wu@intel.com> 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/43e7aae9a7a7710cd6df597fa9dc501da4ba0602.1502472193.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/objtool/check.c')
-rw-r--r--tools/objtool/check.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 17375925e7aa..3dffeb944523 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1536,15 +1536,15 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
while (1) {
next_insn = next_insn_same_sec(file, insn);
- if (file->c_file && insn->func) {
- if (func && func != insn->func) {
- WARN("%s() falls through to next function %s()",
- func->name, insn->func->name);
- return 1;
- }
+
+ if (file->c_file && func && insn->func && func != insn->func) {
+ WARN("%s() falls through to next function %s()",
+ func->name, insn->func->name);
+ return 1;
}
- func = insn->func;
+ if (insn->func)
+ func = insn->func;
if (func && insn->ignore) {
WARN_FUNC("BUG: why am I validating an ignored function?",