4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Arnd Bergmann <[email protected]> commit b334e19ae9381f12a7521976883022385d2b7eef upstream. In commit a76bcf557ef4 ("Kbuild: enable -Wmaybe-uninitialized warning for "make W=1""), I reverted another change that happened to fix a problem with old compilers, and now we get this report again with old compilers (prior to gcc-4.8) and GCOV enabled: cc1: warnings being treated as errors drivers/gpu/drm/i915/intel_ringbuffer.c: In function 'intel_ring_setup_status_page': drivers/gpu/drm/i915/intel_ringbuffer.c:438: error: 'mmio.reg' may be used uninitialized in this function At top level: >> cc1: error: unrecognized command line option "-Wno-maybe-uninitialized" The problem is that we turn off the warning conditionally in a number of places as we should, but one of them does it unconditionally. Instead, change it to call cc-disable-warning as we do elsewhere. The original patch that caused it was merged into linux-4.7, then 4.8 removed the change and 4.9 brought it back, so we probably want a backport to 4.9 once this is merged. Use a ':=' assignment instead of '=' to force the cc-disable-warning call to only be evaluated once instead of every time. Fixes: a76bcf557ef4 ("Kbuild: enable -Wmaybe-uninitialized warning for "make W=1"") Fixes: e72e2dfe7c16 ("gcov: disable -Wmaybe-uninitialized warning") Reported-by: kbuild test robot <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]> Signed-off-by: Masahiro Yamada <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/Makefile +++ b/Makefile @@ -370,7 +370,7 @@ LDFLAGS_MODULE = CFLAGS_KERNEL = AFLAGS_KERNEL = LDFLAGS_vmlinux = -CFLAGS_GCOV = -fprofile-arcs -ftest-coverage -fno-tree-loop-im -Wno-maybe-uninitialized +CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,) CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,)
