Commit 97b59826 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Ma Wupeng
Browse files

bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS 

stable inclusion
from stable-v6.6.30
commit 15aa09d6d84629eb5296de30ac0aa19a33512f16
bugzilla: https://gitee.com/openeuler/kernel/issues/I9MPZ8

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=15aa09d6d84629eb5296de30ac0aa19a33512f16



--------------------------------

commit 5af385f5f4cddf908f663974847a4083b2ff2c79 upstream.

bits_per() rounds up to the next power of two when passed a power of
two.  This causes crashes on some machines and configurations.

Reported-by: default avatarМихаил Новоселов <m.novosyolov@rosalinux.ru>
Tested-by: default avatarИльфат Гаптрахманов <i.gaptrakhmanov@rosalinux.ru>
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/3347
Link: https://lore.kernel.org/all/1c978cf1-2934-4e66-e4b3-e81b04cb3571@rosalinux.ru/


Fixes: f2d5dcb48f7b (bounds: support non-power-of-two CONFIG_NR_CPUS)
Cc:  <stable@vger.kernel.org>
Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
parent 1071f32d

kernel/bounds.c

+1 −1
Original line number Diff line number Diff line
@@ -19,7 +19,7 @@ int main(void) 
	DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS);

	DEFINE(MAX_NR_ZONES, __MAX_NR_ZONES);

#ifdef CONFIG_SMP

	DEFINE(NR_CPUS_BITS, bits_per(CONFIG_NR_CPUS));

	DEFINE(NR_CPUS_BITS, order_base_2(CONFIG_NR_CPUS));

#endif

	DEFINE(SPINLOCK_SIZE, sizeof(spinlock_t));

#ifdef CONFIG_LRU_GEN