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 <[email protected]>
Reported-by: Fengguang Wu <[email protected]>
Acked-by: Abylay Ospan <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Mauro Carvalho Chehab <[email protected]>
Cc: Kozlov Sergey <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index ab76b99adc857fb38c2e4677b6ab34d6a01fa786..1d1521c26302a2510e873d49a8b6bb525f399d66 100644 (file)
--- a/lib/Kconfig.debug
+++ b/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