[PATCH AUTOSEL 4.9 13/13] kmemleak: increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE default to 16K

[Sasha Levin]

From: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>

[ Upstream commit b751c52bb587ae66f773b15204ef7a147467f4c7 ]

The current default value (400) is too low on many systems (e.g.  some
ARM64 platform takes up 1000+ entries).

syzbot uses 16000 as default value, and has proved to be enough on beefy
configurations, so let's pick that value.

This consumes more RAM on boot (each entry is 160 bytes, so in total
~2.5MB of RAM), but the memory would later be freed (early_log is
__initdata).

Link: http://lkml.kernel.org/r/20190730154027.101525-1-drinkcat@xxxxxxxxxxxx
Signed-off-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>
Suggested-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Acked-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
Cc: Uladzislau Rezki <urezki@xxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 lib/Kconfig.debug | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 4f561860bf41e..bc5ff3a53d4a6 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -535,7 +535,7 @@ config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
 	int "Maximum kmemleak early log entries"
 	depends on DEBUG_KMEMLEAK
 	range 200 40000
-	default 400
+	default 16000
 	help
 	  Kmemleak must track all the memory allocations to avoid
 	  reporting false positives. Since memory may be allocated or
-- 
2.20.1