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![Matthew Wilcox (Oracle)](/assets/img/avatar_default.png)
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: Михаил Новоселов <m.novosyolov@rosalinux.ru>
Tested-by: Ильфат 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: f2d5dcb48f
(bounds: support non-power-of-two CONFIG_NR_CPUS)
Cc: <stable@vger.kernel.org>
Signed-off-by: Matthew 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: Linus Torvalds <torvalds@linux-foundation.org>
36 lines
950 B
C
36 lines
950 B
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Generate definitions needed by the preprocessor.
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* This code generates raw asm output which is post-processed
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* to extract and format the required data.
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*/
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#define __GENERATING_BOUNDS_H
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/* Include headers that define the enum constants of interest */
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#include <linux/page-flags.h>
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#include <linux/mmzone.h>
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#include <linux/kbuild.h>
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#include <linux/log2.h>
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#include <linux/spinlock_types.h>
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int main(void)
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{
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/* The enum constants to put into include/generated/bounds.h */
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DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS);
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DEFINE(MAX_NR_ZONES, __MAX_NR_ZONES);
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#ifdef CONFIG_SMP
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DEFINE(NR_CPUS_BITS, order_base_2(CONFIG_NR_CPUS));
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#endif
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DEFINE(SPINLOCK_SIZE, sizeof(spinlock_t));
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#ifdef CONFIG_LRU_GEN
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DEFINE(LRU_GEN_WIDTH, order_base_2(MAX_NR_GENS + 1));
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DEFINE(__LRU_REFS_WIDTH, MAX_NR_TIERS - 2);
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#else
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DEFINE(LRU_GEN_WIDTH, 0);
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DEFINE(__LRU_REFS_WIDTH, 0);
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#endif
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/* End of constants */
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return 0;
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}
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