The patch titled
Subject: lib/Kconfig.debug: disable -Wframe-larger-than warnings with KASAN=y
has been added to the -mm tree. Its filename is
disable-wframe-larger-than-warnings-with-kasan=y.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/disable-wframe-larger-than-warnings-with-kasan%3Dy.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/disable-wframe-larger-than-warnings-with-kasan%3Dy.patch
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------------------------------------------------------
From: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Subject: lib/Kconfig.debug: disable -Wframe-larger-than warnings with KASAN=y
When the kernel compiled with KASAN=y, GCC adds redzones for each variable
on stack. This enlarges function's stack frame and causes:
'warning: the frame size of X bytes is larger than Y bytes'
The worst case I've seen for now is following:
../net/wireless/nl80211.c: In function `nl80211_send_wiphy':
../net/wireless/nl80211.c:1731:1: warning: the frame size of 5448 bytes is larger than 2048 bytes [-Wframe-larger-than=]
}
That kind of warning becomes useless with KASAN=y. It doesn't necessarily
indicate that there is some problem in the code, thus we should turn it
off.
(The KASAN=y stack size in increased from 16k to 32k for this reason)
Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Reported-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Acked-by: Abylay Ospan <aospan@xxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx>
Cc: Kozlov Sergey <serjk@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/Kconfig.debug | 1 +
1 file changed, 1 insertion(+)
diff -puN lib/Kconfig.debug~disable-wframe-larger-than-warnings-with-kasan=y lib/Kconfig.debug
--- a/lib/Kconfig.debug~disable-wframe-larger-than-warnings-with-kasan=y
+++ a/lib/Kconfig.debug
@@ -197,6 +197,7 @@ config ENABLE_MUST_CHECK
config FRAME_WARN
int "Warn for stack frames larger than (needs gcc 4.4)"
range 0 8192
+ default 0 if KASAN
default 1024 if !64BIT
default 2048 if 64BIT
help
_
Patches currently in -mm which might be from aryabinin@xxxxxxxxxxxxx are
disable-wframe-larger-than-warnings-with-kasan=y.patch
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