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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2017-08-11 20:24:15 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-08-21 17:06:05 +0300 |
| commit | ee97638b5737cc0dba2f12a3bdcda761656b7c01 (patch) | |
| tree | 7304c38918d60253c789cadd2cb3a8dbea96dd8c /tools/objtool | |
| parent | fa2016a8e7d846b306e431646d250500e1da0c33 (diff) | |
| download | linux-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')
| -rw-r--r-- | tools/objtool/check.c | 14 |
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?", |