Message ID | 20240220-slab-cleanup-flags-v1-3-e657e373944a@suse.cz |
---|---|
State | New |
Headers |
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Series |
cleanup of SLAB_ flags
|
|
Commit Message
Vlastimil Babka
Feb. 20, 2024, 4:58 p.m. UTC
The SLAB_KASAN flag prevents merging of caches in some configurations,
which is handled in a rather complicated way via kasan_never_merge().
Since we now have a generic SLAB_NO_MERGE flag, we can instead use it
for KASAN caches in addition to SLAB_KASAN in those configurations,
and simplify the SLAB_NEVER_MERGE handling.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
include/linux/kasan.h | 6 ------
mm/kasan/generic.c | 16 ++++------------
mm/slab_common.c | 2 +-
3 files changed, 5 insertions(+), 19 deletions(-)
Comments
> The SLAB_KASAN flag prevents merging of caches in some configurations, > which is handled in a rather complicated way via kasan_never_merge(). > Since we now have a generic SLAB_NO_MERGE flag, we can instead use it > for KASAN caches in addition to SLAB_KASAN in those configurations, > and simplify the SLAB_NEVER_MERGE handling. > > Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Ran a rough test with build and bootup with CONFIG_KASAN_GENERIC enabled, feel free to add Tested-by: Xiongwei Song <xiongwei.song@windriver.com> Thanks, Xiongwei > --- > include/linux/kasan.h | 6 ------ > mm/kasan/generic.c | 16 ++++------------ > mm/slab_common.c | 2 +- > 3 files changed, 5 insertions(+), 19 deletions(-) > > diff --git a/include/linux/kasan.h b/include/linux/kasan.h > index dbb06d789e74..70d6a8f6e25d 100644 > --- a/include/linux/kasan.h > +++ b/include/linux/kasan.h > @@ -429,7 +429,6 @@ struct kasan_cache { > }; > > size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object); > -slab_flags_t kasan_never_merge(void); > void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, > slab_flags_t *flags); > > @@ -446,11 +445,6 @@ static inline size_t kasan_metadata_size(struct kmem_cache > *cache, > { > return 0; > } > -/* And thus nothing prevents cache merging. */ > -static inline slab_flags_t kasan_never_merge(void) > -{ > - return 0; > -} > /* And no cache-related metadata initialization is required. */ > static inline void kasan_cache_create(struct kmem_cache *cache, > unsigned int *size, > diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c > index df6627f62402..d8b78d273b9f 100644 > --- a/mm/kasan/generic.c > +++ b/mm/kasan/generic.c > @@ -334,14 +334,6 @@ DEFINE_ASAN_SET_SHADOW(f3); > DEFINE_ASAN_SET_SHADOW(f5); > DEFINE_ASAN_SET_SHADOW(f8); > > -/* Only allow cache merging when no per-object metadata is present. */ > -slab_flags_t kasan_never_merge(void) > -{ > - if (!kasan_requires_meta()) > - return 0; > - return SLAB_KASAN; > -} > - > /* > * Adaptive redzone policy taken from the userspace AddressSanitizer runtime. > * For larger allocations larger redzones are used. > @@ -372,13 +364,13 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned > int *size, > /* > * SLAB_KASAN is used to mark caches that are sanitized by KASAN > * and that thus have per-object metadata. > - * Currently this flag is used in two places: > + * Currently this flag is used in one place: > * 1. In slab_ksize() to account for per-object metadata when > * calculating the size of the accessible memory within the object. > - * 2. In slab_common.c via kasan_never_merge() to prevent merging of > - * caches with per-object metadata. > + * Additionally, we use SLAB_NO_MERGE to prevent merging of caches > + * with per-object metadata. > */ > - *flags |= SLAB_KASAN; > + *flags |= SLAB_KASAN | SLAB_NO_MERGE; > > ok_size = *size; > > diff --git a/mm/slab_common.c b/mm/slab_common.c > index 238293b1dbe1..7cfa2f1ce655 100644 > --- a/mm/slab_common.c > +++ b/mm/slab_common.c > @@ -50,7 +50,7 @@ static DECLARE_WORK(slab_caches_to_rcu_destroy_work, > */ > #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ > SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \ > - SLAB_FAILSLAB | SLAB_NO_MERGE | kasan_never_merge()) > + SLAB_FAILSLAB | SLAB_NO_MERGE) > > #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \ > SLAB_CACHE_DMA32 | SLAB_ACCOUNT) > > -- > 2.43.1
On 2024/2/21 00:58, Vlastimil Babka wrote: > The SLAB_KASAN flag prevents merging of caches in some configurations, > which is handled in a rather complicated way via kasan_never_merge(). > Since we now have a generic SLAB_NO_MERGE flag, we can instead use it > for KASAN caches in addition to SLAB_KASAN in those configurations, > and simplify the SLAB_NEVER_MERGE handling. > > Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Thanks! > --- > include/linux/kasan.h | 6 ------ > mm/kasan/generic.c | 16 ++++------------ > mm/slab_common.c | 2 +- > 3 files changed, 5 insertions(+), 19 deletions(-) > > diff --git a/include/linux/kasan.h b/include/linux/kasan.h > index dbb06d789e74..70d6a8f6e25d 100644 > --- a/include/linux/kasan.h > +++ b/include/linux/kasan.h > @@ -429,7 +429,6 @@ struct kasan_cache { > }; > > size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object); > -slab_flags_t kasan_never_merge(void); > void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, > slab_flags_t *flags); > > @@ -446,11 +445,6 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache, > { > return 0; > } > -/* And thus nothing prevents cache merging. */ > -static inline slab_flags_t kasan_never_merge(void) > -{ > - return 0; > -} > /* And no cache-related metadata initialization is required. */ > static inline void kasan_cache_create(struct kmem_cache *cache, > unsigned int *size, > diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c > index df6627f62402..d8b78d273b9f 100644 > --- a/mm/kasan/generic.c > +++ b/mm/kasan/generic.c > @@ -334,14 +334,6 @@ DEFINE_ASAN_SET_SHADOW(f3); > DEFINE_ASAN_SET_SHADOW(f5); > DEFINE_ASAN_SET_SHADOW(f8); > > -/* Only allow cache merging when no per-object metadata is present. */ > -slab_flags_t kasan_never_merge(void) > -{ > - if (!kasan_requires_meta()) > - return 0; > - return SLAB_KASAN; > -} > - > /* > * Adaptive redzone policy taken from the userspace AddressSanitizer runtime. > * For larger allocations larger redzones are used. > @@ -372,13 +364,13 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, > /* > * SLAB_KASAN is used to mark caches that are sanitized by KASAN > * and that thus have per-object metadata. > - * Currently this flag is used in two places: > + * Currently this flag is used in one place: > * 1. In slab_ksize() to account for per-object metadata when > * calculating the size of the accessible memory within the object. > - * 2. In slab_common.c via kasan_never_merge() to prevent merging of > - * caches with per-object metadata. > + * Additionally, we use SLAB_NO_MERGE to prevent merging of caches > + * with per-object metadata. > */ > - *flags |= SLAB_KASAN; > + *flags |= SLAB_KASAN | SLAB_NO_MERGE; > > ok_size = *size; > > diff --git a/mm/slab_common.c b/mm/slab_common.c > index 238293b1dbe1..7cfa2f1ce655 100644 > --- a/mm/slab_common.c > +++ b/mm/slab_common.c > @@ -50,7 +50,7 @@ static DECLARE_WORK(slab_caches_to_rcu_destroy_work, > */ > #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ > SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \ > - SLAB_FAILSLAB | SLAB_NO_MERGE | kasan_never_merge()) > + SLAB_FAILSLAB | SLAB_NO_MERGE) > > #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \ > SLAB_CACHE_DMA32 | SLAB_ACCOUNT) >
On Tue, Feb 20, 2024 at 5:58 PM Vlastimil Babka <vbabka@suse.cz> wrote: > > The SLAB_KASAN flag prevents merging of caches in some configurations, > which is handled in a rather complicated way via kasan_never_merge(). > Since we now have a generic SLAB_NO_MERGE flag, we can instead use it > for KASAN caches in addition to SLAB_KASAN in those configurations, > and simplify the SLAB_NEVER_MERGE handling. > > Signed-off-by: Vlastimil Babka <vbabka@suse.cz> > --- > include/linux/kasan.h | 6 ------ > mm/kasan/generic.c | 16 ++++------------ > mm/slab_common.c | 2 +- > 3 files changed, 5 insertions(+), 19 deletions(-) > > diff --git a/include/linux/kasan.h b/include/linux/kasan.h > index dbb06d789e74..70d6a8f6e25d 100644 > --- a/include/linux/kasan.h > +++ b/include/linux/kasan.h > @@ -429,7 +429,6 @@ struct kasan_cache { > }; > > size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object); > -slab_flags_t kasan_never_merge(void); > void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, > slab_flags_t *flags); > > @@ -446,11 +445,6 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache, > { > return 0; > } > -/* And thus nothing prevents cache merging. */ > -static inline slab_flags_t kasan_never_merge(void) > -{ > - return 0; > -} > /* And no cache-related metadata initialization is required. */ > static inline void kasan_cache_create(struct kmem_cache *cache, > unsigned int *size, > diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c > index df6627f62402..d8b78d273b9f 100644 > --- a/mm/kasan/generic.c > +++ b/mm/kasan/generic.c > @@ -334,14 +334,6 @@ DEFINE_ASAN_SET_SHADOW(f3); > DEFINE_ASAN_SET_SHADOW(f5); > DEFINE_ASAN_SET_SHADOW(f8); > > -/* Only allow cache merging when no per-object metadata is present. */ > -slab_flags_t kasan_never_merge(void) > -{ > - if (!kasan_requires_meta()) > - return 0; > - return SLAB_KASAN; > -} > - > /* > * Adaptive redzone policy taken from the userspace AddressSanitizer runtime. > * For larger allocations larger redzones are used. > @@ -372,13 +364,13 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, > /* > * SLAB_KASAN is used to mark caches that are sanitized by KASAN > * and that thus have per-object metadata. > - * Currently this flag is used in two places: > + * Currently this flag is used in one place: > * 1. In slab_ksize() to account for per-object metadata when > * calculating the size of the accessible memory within the object. > - * 2. In slab_common.c via kasan_never_merge() to prevent merging of > - * caches with per-object metadata. Let's reword this to: SLAB_KASAN is used to mark caches that are sanitized by KASAN and that thus have per-object metadata. Currently, this flag is used in slab_ksize() to account for per-object metadata when calculating the size of the accessible memory within the object. > + * Additionally, we use SLAB_NO_MERGE to prevent merging of caches > + * with per-object metadata. > */ > - *flags |= SLAB_KASAN; > + *flags |= SLAB_KASAN | SLAB_NO_MERGE; > > ok_size = *size; > > diff --git a/mm/slab_common.c b/mm/slab_common.c > index 238293b1dbe1..7cfa2f1ce655 100644 > --- a/mm/slab_common.c > +++ b/mm/slab_common.c > @@ -50,7 +50,7 @@ static DECLARE_WORK(slab_caches_to_rcu_destroy_work, > */ > #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ > SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \ > - SLAB_FAILSLAB | SLAB_NO_MERGE | kasan_never_merge()) > + SLAB_FAILSLAB | SLAB_NO_MERGE) > > #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \ > SLAB_CACHE_DMA32 | SLAB_ACCOUNT) > > -- > 2.43.1 > Otherwise, looks good to me. Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Thanks!
diff --git a/include/linux/kasan.h b/include/linux/kasan.h index dbb06d789e74..70d6a8f6e25d 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -429,7 +429,6 @@ struct kasan_cache { }; size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object); -slab_flags_t kasan_never_merge(void); void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, slab_flags_t *flags); @@ -446,11 +445,6 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache, { return 0; } -/* And thus nothing prevents cache merging. */ -static inline slab_flags_t kasan_never_merge(void) -{ - return 0; -} /* And no cache-related metadata initialization is required. */ static inline void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index df6627f62402..d8b78d273b9f 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -334,14 +334,6 @@ DEFINE_ASAN_SET_SHADOW(f3); DEFINE_ASAN_SET_SHADOW(f5); DEFINE_ASAN_SET_SHADOW(f8); -/* Only allow cache merging when no per-object metadata is present. */ -slab_flags_t kasan_never_merge(void) -{ - if (!kasan_requires_meta()) - return 0; - return SLAB_KASAN; -} - /* * Adaptive redzone policy taken from the userspace AddressSanitizer runtime. * For larger allocations larger redzones are used. @@ -372,13 +364,13 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, /* * SLAB_KASAN is used to mark caches that are sanitized by KASAN * and that thus have per-object metadata. - * Currently this flag is used in two places: + * Currently this flag is used in one place: * 1. In slab_ksize() to account for per-object metadata when * calculating the size of the accessible memory within the object. - * 2. In slab_common.c via kasan_never_merge() to prevent merging of - * caches with per-object metadata. + * Additionally, we use SLAB_NO_MERGE to prevent merging of caches + * with per-object metadata. */ - *flags |= SLAB_KASAN; + *flags |= SLAB_KASAN | SLAB_NO_MERGE; ok_size = *size; diff --git a/mm/slab_common.c b/mm/slab_common.c index 238293b1dbe1..7cfa2f1ce655 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -50,7 +50,7 @@ static DECLARE_WORK(slab_caches_to_rcu_destroy_work, */ #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \ - SLAB_FAILSLAB | SLAB_NO_MERGE | kasan_never_merge()) + SLAB_FAILSLAB | SLAB_NO_MERGE) #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \ SLAB_CACHE_DMA32 | SLAB_ACCOUNT)