linux-stable/tools/objtool
Josh Poimboeuf 867ac9d737 objtool: Fix gcov check for older versions of GCC
Objtool tries to silence 'unreachable instruction' warnings when it
detects gcov is enabled, because gcov produces a lot of unreachable
instructions and they don't really matter.

However, the 0-day bot is still reporting some unreachable instruction
warnings with CONFIG_GCOV_KERNEL=y on GCC 4.6.4.

As it turns out, objtool's gcov detection doesn't work with older
versions of GCC because they don't create a bunch of symbols with the
'gcov.' prefix like newer versions of GCC do.

Move the gcov check out of objtool and instead just create a new
'--no-unreachable' flag which can be passed in by the kernel Makefile
when CONFIG_GCOV_KERNEL is defined.

Also rename the 'nofp' variable to 'no_fp' for consistency with the new
'no_unreachable' variable.

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>
Fixes: 9cfffb1168 ("objtool: Skip all "unreachable instruction" warnings for gcov kernels")
Link: http://lkml.kernel.org/r/c243dc78eb2ffdabb6e927844dea39b6033cd395.1500939244.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-25 11:12:45 +02:00
..
arch/x86 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-03 12:40:46 -07:00
Documentation objtool: Add ORC unwind table generation 2017-07-18 10:57:43 +02:00
.gitignore objtool: Add 'fixdep' to objtool/.gitignore 2016-07-27 11:07:11 +02:00
arch.h objtool: Implement stack validation 2.0 2017-06-30 10:19:19 +02:00
Build objtool: Add ORC unwind table generation 2017-07-18 10:57:43 +02:00
builtin-check.c objtool: Fix gcov check for older versions of GCC 2017-07-25 11:12:45 +02:00
builtin-orc.c objtool: Fix gcov check for older versions of GCC 2017-07-25 11:12:45 +02:00
builtin.h objtool: Add ORC unwind table generation 2017-07-18 10:57:43 +02:00
cfi.h objtool: Implement stack validation 2.0 2017-06-30 10:19:19 +02:00
check.c objtool: Fix gcov check for older versions of GCC 2017-07-25 11:12:45 +02:00
check.h objtool: Fix gcov check for older versions of GCC 2017-07-25 11:12:45 +02:00
elf.c objtool: Add ORC unwind table generation 2017-07-18 10:57:43 +02:00
elf.h objtool: Add ORC unwind table generation 2017-07-18 10:57:43 +02:00
Makefile objtool, x86: Add facility for asm code to provide unwind hints 2017-07-18 10:57:44 +02:00
objtool.c objtool: Add ORC unwind table generation 2017-07-18 10:57:43 +02:00
orc.h objtool: Add ORC unwind table generation 2017-07-18 10:57:43 +02:00
orc_dump.c objtool: Add ORC unwind table generation 2017-07-18 10:57:43 +02:00
orc_gen.c objtool: Add ORC unwind table generation 2017-07-18 10:57:43 +02:00
orc_types.h objtool, x86: Add facility for asm code to provide unwind hints 2017-07-18 10:57:44 +02:00
special.c objtool: Implement stack validation 2.0 2017-06-30 10:19:19 +02:00
special.h
warn.h objtool: Implement stack validation 2.0 2017-06-30 10:19:19 +02:00