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| author | Andrey Konovalov <andreyknvl@google.com> | 2022-03-25 04:11:29 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-25 05:06:47 +0300 |
| commit | 9353ffa6e9e90d2b6348209cf2b95a8ffee18711 (patch) | |
| tree | a60f59aac1953b77a338e672c1ff2f5ebd6b0c1e /include/linux | |
| parent | 53ae233c30a623ff44ff2f83854e92530c5d9fc2 (diff) | |
| download | linux-9353ffa6e9e90d2b6348209cf2b95a8ffee18711.tar.xz | |
kasan, page_alloc: allow skipping memory init for HW_TAGS
Add a new GFP flag __GFP_SKIP_ZERO that allows to skip memory
initialization. The flag is only effective with HW_TAGS KASAN.
This flag will be used by vmalloc code for page_alloc allocations backing
vmalloc() mappings in a following patch. The reason to skip memory
initialization for these pages in page_alloc is because vmalloc code will
be initializing them instead.
With the current implementation, when __GFP_SKIP_ZERO is provided,
__GFP_ZEROTAGS is ignored. This doesn't matter, as these two flags are
never provided at the same time. However, if this is changed in the
future, this particular implementation detail can be changed as well.
Link: https://lkml.kernel.org/r/0d53efeff345de7d708e0baa0d8829167772521e.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/gfp.h | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 688a39fde43e..0fa17fb85de5 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -55,14 +55,16 @@ struct vm_area_struct; #define ___GFP_ACCOUNT 0x400000u #define ___GFP_ZEROTAGS 0x800000u #ifdef CONFIG_KASAN_HW_TAGS -#define ___GFP_SKIP_KASAN_UNPOISON 0x1000000u -#define ___GFP_SKIP_KASAN_POISON 0x2000000u +#define ___GFP_SKIP_ZERO 0x1000000u +#define ___GFP_SKIP_KASAN_UNPOISON 0x2000000u +#define ___GFP_SKIP_KASAN_POISON 0x4000000u #else +#define ___GFP_SKIP_ZERO 0 #define ___GFP_SKIP_KASAN_UNPOISON 0 #define ___GFP_SKIP_KASAN_POISON 0 #endif #ifdef CONFIG_LOCKDEP -#define ___GFP_NOLOCKDEP 0x4000000u +#define ___GFP_NOLOCKDEP 0x8000000u #else #define ___GFP_NOLOCKDEP 0 #endif @@ -239,9 +241,10 @@ struct vm_area_struct; * %__GFP_ZERO returns a zeroed page on success. * * %__GFP_ZEROTAGS zeroes memory tags at allocation time if the memory itself - * is being zeroed (either via __GFP_ZERO or via init_on_alloc). This flag is - * intended for optimization: setting memory tags at the same time as zeroing - * memory has minimal additional performace impact. + * is being zeroed (either via __GFP_ZERO or via init_on_alloc, provided that + * __GFP_SKIP_ZERO is not set). This flag is intended for optimization: setting + * memory tags at the same time as zeroing memory has minimal additional + * performace impact. * * %__GFP_SKIP_KASAN_UNPOISON makes KASAN skip unpoisoning on page allocation. * Only effective in HW_TAGS mode. @@ -253,6 +256,7 @@ struct vm_area_struct; #define __GFP_COMP ((__force gfp_t)___GFP_COMP) #define __GFP_ZERO ((__force gfp_t)___GFP_ZERO) #define __GFP_ZEROTAGS ((__force gfp_t)___GFP_ZEROTAGS) +#define __GFP_SKIP_ZERO ((__force gfp_t)___GFP_SKIP_ZERO) #define __GFP_SKIP_KASAN_UNPOISON ((__force gfp_t)___GFP_SKIP_KASAN_UNPOISON) #define __GFP_SKIP_KASAN_POISON ((__force gfp_t)___GFP_SKIP_KASAN_POISON) @@ -261,7 +265,7 @@ struct vm_area_struct; /* Room for N __GFP_FOO bits */ #define __GFP_BITS_SHIFT (24 + \ - 2 * IS_ENABLED(CONFIG_KASAN_HW_TAGS) + \ + 3 * IS_ENABLED(CONFIG_KASAN_HW_TAGS) + \ IS_ENABLED(CONFIG_LOCKDEP)) #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1)) |