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Patch "Kbuild: use cc-disable-warning consistently for maybe-uninitialized" has been added to the 4.10-stable tree

PATCH [email protected] 1 participant 1 message Apr 10, 2017

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This is a note to let you know that I've just added the patch titled

Kbuild: use cc-disable-warning consistently for maybe-uninitialized

to the 4.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
kbuild-use-cc-disable-warning-consistently-for-maybe-uninitialized.patch
and it can be found in the queue-4.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

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From b334e19ae9381f12a7521976883022385d2b7eef Mon Sep 17 00:00:00 2001

From: Arnd Bergmann <[email protected]>
Date: Fri, 13 Jan 2017 16:40:01 +0100
Subject: Kbuild: use cc-disable-warning consistently for maybe-uninitialized

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:

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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")
---
 Makefile |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Makefile +1 -1
@@ -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,)
 
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.10/kbuild-use-cc-disable-warning-consistently-for-maybe-uninitialized.patch