From ada543af3bfe3d953986eca118601b9612382c13 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Fri, 1 Apr 2022 11:28:45 -0700 Subject: [PATCH] mm, kasan: fix __GFP_BITS_SHIFT definition breaking LOCKDEP KASAN changes that added new GFP flags mistakenly updated __GFP_BITS_SHIFT as the total number of GFP bits instead of as a shift used to define __GFP_BITS_MASK. This broke LOCKDEP, as __GFP_BITS_MASK now gets the 25th bit enabled instead of the 28th for __GFP_NOLOCKDEP. Update __GFP_BITS_SHIFT to always count KASAN GFP bits. In the future, we could handle all combinations of KASAN and LOCKDEP to occupy as few bits as possible. For now, we have enough GFP bits to be inefficient in this quick fix. Link: https://lkml.kernel.org/r/462ff52742a1fcc95a69778685737f723ee4dfb3.1648400273.git.andreyknvl@google.com Fixes: 9353ffa6e9e9 ("kasan, page_alloc: allow skipping memory init for HW_TAGS") Fixes: 53ae233c30a6 ("kasan, page_alloc: allow skipping unpoisoning for HW_TAGS") Fixes: f49d9c5bb15c ("kasan, mm: only define ___GFP_SKIP_KASAN_POISON with HW_TAGS") Signed-off-by: Andrey Konovalov Reported-by: Sebastian Andrzej Siewior Tested-by: Sebastian Andrzej Siewior Acked-by: Vlastimil Babka Cc: Marco Elver Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/gfp.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 0fa17fb..761f8f18 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -264,9 +264,7 @@ struct vm_area_struct; #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP) /* Room for N __GFP_FOO bits */ -#define __GFP_BITS_SHIFT (24 + \ - 3 * IS_ENABLED(CONFIG_KASAN_HW_TAGS) + \ - IS_ENABLED(CONFIG_LOCKDEP)) +#define __GFP_BITS_SHIFT (27 + IS_ENABLED(CONFIG_LOCKDEP)) #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1)) /** -- 2.7.4