* [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro
@ 2022-11-21 13:50 Feng Tang
2022-11-21 13:50 ` [PATCH -next 2/2] mm/kasan: simplify is_kmalloc check Feng Tang
2022-11-21 20:19 ` [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro Andrew Morton
0 siblings, 2 replies; 11+ messages in thread
From: Feng Tang @ 2022-11-21 13:50 UTC (permalink / raw)
To: Andrew Morton, Vlastimil Babka, Christoph Lameter, Pekka Enberg,
David Rientjes, Joonsoo Kim, Roman Gushchin, Hyeonggon Yoo,
Andrey Konovalov, Dmitry Vyukov, Andrey Ryabinin,
Alexander Potapenko, Vincenzo Frascino
Cc: linux-mm, kasan-dev, linux-kernel, Feng Tang
commit 6edf2576a6cc ("mm/slub: enable debugging memory wasting of
kmalloc") introduces 'SLAB_KMALLOC' bit specifying whether a
kmem_cache is a kmalloc cache for slab/slub (slob doesn't have
dedicated kmalloc caches).
Add a helper macro for other components like kasan to simplify code.
Signed-off-by: Feng Tang <feng.tang@intel.com>
---
include/linux/slab.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 1c670c16c737..ee6499088ad3 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -758,6 +758,12 @@ extern void kvfree_sensitive(const void *addr, size_t len);
unsigned int kmem_cache_size(struct kmem_cache *s);
+#ifndef CONFIG_SLOB
+#define is_kmalloc_cache(s) ((s)->flags & SLAB_KMALLOC)
+#else
+#define is_kmalloc_cache(s) (false)
+#endif
+
/**
* kmalloc_size_roundup - Report allocation bucket size for the given size
*
--
2.34.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH -next 2/2] mm/kasan: simplify is_kmalloc check
2022-11-21 13:50 [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro Feng Tang
@ 2022-11-21 13:50 ` Feng Tang
2022-11-21 14:13 ` Feng Tang
2022-11-21 15:15 ` Andrey Konovalov
2022-11-21 20:19 ` [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro Andrew Morton
1 sibling, 2 replies; 11+ messages in thread
From: Feng Tang @ 2022-11-21 13:50 UTC (permalink / raw)
To: Andrew Morton, Vlastimil Babka, Christoph Lameter, Pekka Enberg,
David Rientjes, Joonsoo Kim, Roman Gushchin, Hyeonggon Yoo,
Andrey Konovalov, Dmitry Vyukov, Andrey Ryabinin,
Alexander Potapenko, Vincenzo Frascino
Cc: linux-mm, kasan-dev, linux-kernel, Feng Tang
Use new is_kmalloc_cache() to simplify the code of checking whether
a kmem_cache is a kmalloc cache.
Signed-off-by: Feng Tang <feng.tang@intel.com>
---
include/linux/kasan.h | 9 ---------
mm/kasan/common.c | 9 ++-------
mm/slab_common.c | 1 -
3 files changed, 2 insertions(+), 17 deletions(-)
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index dff604912687..fc46f5d6f404 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -102,7 +102,6 @@ struct kasan_cache {
int alloc_meta_offset;
int free_meta_offset;
#endif
- bool is_kmalloc;
};
void __kasan_unpoison_range(const void *addr, size_t size);
@@ -129,13 +128,6 @@ static __always_inline bool kasan_unpoison_pages(struct page *page,
return false;
}
-void __kasan_cache_create_kmalloc(struct kmem_cache *cache);
-static __always_inline void kasan_cache_create_kmalloc(struct kmem_cache *cache)
-{
- if (kasan_enabled())
- __kasan_cache_create_kmalloc(cache);
-}
-
void __kasan_poison_slab(struct slab *slab);
static __always_inline void kasan_poison_slab(struct slab *slab)
{
@@ -252,7 +244,6 @@ static inline void kasan_poison_pages(struct page *page, unsigned int order,
bool init) {}
static inline bool kasan_unpoison_pages(struct page *page, unsigned int order,
bool init) { return false; }
-static inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) {}
static inline void kasan_poison_slab(struct slab *slab) {}
static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
void *object) {}
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 1f30080a7a4c..f7e0e5067e7a 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -122,11 +122,6 @@ void __kasan_poison_pages(struct page *page, unsigned int order, bool init)
KASAN_PAGE_FREE, init);
}
-void __kasan_cache_create_kmalloc(struct kmem_cache *cache)
-{
- cache->kasan_info.is_kmalloc = true;
-}
-
void __kasan_poison_slab(struct slab *slab)
{
struct page *page = slab_page(slab);
@@ -326,7 +321,7 @@ void * __must_check __kasan_slab_alloc(struct kmem_cache *cache,
kasan_unpoison(tagged_object, cache->object_size, init);
/* Save alloc info (if possible) for non-kmalloc() allocations. */
- if (kasan_stack_collection_enabled() && !cache->kasan_info.is_kmalloc)
+ if (kasan_stack_collection_enabled() && is_kmalloc_cache(cache))
kasan_save_alloc_info(cache, tagged_object, flags);
return tagged_object;
@@ -372,7 +367,7 @@ static inline void *____kasan_kmalloc(struct kmem_cache *cache,
* Save alloc info (if possible) for kmalloc() allocations.
* This also rewrites the alloc info when called from kasan_krealloc().
*/
- if (kasan_stack_collection_enabled() && cache->kasan_info.is_kmalloc)
+ if (kasan_stack_collection_enabled() && is_kmalloc_cache(cache))
kasan_save_alloc_info(cache, (void *)object, flags);
/* Keep the tag that was set by kasan_slab_alloc(). */
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 8276022f0da4..a5480d67f391 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -663,7 +663,6 @@ struct kmem_cache *__init create_kmalloc_cache(const char *name,
create_boot_cache(s, name, size, flags | SLAB_KMALLOC, useroffset,
usersize);
- kasan_cache_create_kmalloc(s);
list_add(&s->list, &slab_caches);
s->refcount = 1;
return s;
--
2.34.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH -next 2/2] mm/kasan: simplify is_kmalloc check
2022-11-21 13:50 ` [PATCH -next 2/2] mm/kasan: simplify is_kmalloc check Feng Tang
@ 2022-11-21 14:13 ` Feng Tang
2022-11-21 15:15 ` Andrey Konovalov
1 sibling, 0 replies; 11+ messages in thread
From: Feng Tang @ 2022-11-21 14:13 UTC (permalink / raw)
To: Andrew Morton, Vlastimil Babka, Christoph Lameter, Pekka Enberg,
David Rientjes, Joonsoo Kim, Roman Gushchin, Hyeonggon Yoo,
Andrey Konovalov, Dmitry Vyukov, Andrey Ryabinin,
Alexander Potapenko, Vincenzo Frascino
Cc: linux-mm, kasan-dev, linux-kernel
On Mon, Nov 21, 2022 at 09:50:24PM +0800, Tang, Feng wrote:
> Use new is_kmalloc_cache() to simplify the code of checking whether
> a kmem_cache is a kmalloc cache.
>
> Signed-off-by: Feng Tang <feng.tang@intel.com>
> ---
> include/linux/kasan.h | 9 ---------
> mm/kasan/common.c | 9 ++-------
> mm/slab_common.c | 1 -
> 3 files changed, 2 insertions(+), 17 deletions(-)
>
> diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> index dff604912687..fc46f5d6f404 100644
> --- a/include/linux/kasan.h
> +++ b/include/linux/kasan.h
> @@ -102,7 +102,6 @@ struct kasan_cache {
> int alloc_meta_offset;
> int free_meta_offset;
> #endif
> - bool is_kmalloc;
> };
>
> void __kasan_unpoison_range(const void *addr, size_t size);
> @@ -129,13 +128,6 @@ static __always_inline bool kasan_unpoison_pages(struct page *page,
> return false;
> }
>
> -void __kasan_cache_create_kmalloc(struct kmem_cache *cache);
> -static __always_inline void kasan_cache_create_kmalloc(struct kmem_cache *cache)
> -{
> - if (kasan_enabled())
> - __kasan_cache_create_kmalloc(cache);
> -}
> -
> void __kasan_poison_slab(struct slab *slab);
> static __always_inline void kasan_poison_slab(struct slab *slab)
> {
> @@ -252,7 +244,6 @@ static inline void kasan_poison_pages(struct page *page, unsigned int order,
> bool init) {}
> static inline bool kasan_unpoison_pages(struct page *page, unsigned int order,
> bool init) { return false; }
> -static inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) {}
> static inline void kasan_poison_slab(struct slab *slab) {}
> static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
> void *object) {}
> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> index 1f30080a7a4c..f7e0e5067e7a 100644
> --- a/mm/kasan/common.c
> +++ b/mm/kasan/common.c
> @@ -122,11 +122,6 @@ void __kasan_poison_pages(struct page *page, unsigned int order, bool init)
> KASAN_PAGE_FREE, init);
> }
>
> -void __kasan_cache_create_kmalloc(struct kmem_cache *cache)
> -{
> - cache->kasan_info.is_kmalloc = true;
> -}
> -
> void __kasan_poison_slab(struct slab *slab)
> {
> struct page *page = slab_page(slab);
> @@ -326,7 +321,7 @@ void * __must_check __kasan_slab_alloc(struct kmem_cache *cache,
> kasan_unpoison(tagged_object, cache->object_size, init);
>
> /* Save alloc info (if possible) for non-kmalloc() allocations. */
> - if (kasan_stack_collection_enabled() && !cache->kasan_info.is_kmalloc)
> + if (kasan_stack_collection_enabled() && is_kmalloc_cache(cache))
Sorry, it should be:
- if (kasan_stack_collection_enabled() && !cache->kasan_info.is_kmalloc)
+ if (kasan_stack_collection_enabled() && !is_kmalloc_cache(cache))
Thanks,
Feng
> kasan_save_alloc_info(cache, tagged_object, flags);
>
> return tagged_object;
> @@ -372,7 +367,7 @@ static inline void *____kasan_kmalloc(struct kmem_cache *cache,
> * Save alloc info (if possible) for kmalloc() allocations.
> * This also rewrites the alloc info when called from kasan_krealloc().
> */
> - if (kasan_stack_collection_enabled() && cache->kasan_info.is_kmalloc)
> + if (kasan_stack_collection_enabled() && is_kmalloc_cache(cache))
> kasan_save_alloc_info(cache, (void *)object, flags);
>
> /* Keep the tag that was set by kasan_slab_alloc(). */
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index 8276022f0da4..a5480d67f391 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -663,7 +663,6 @@ struct kmem_cache *__init create_kmalloc_cache(const char *name,
>
> create_boot_cache(s, name, size, flags | SLAB_KMALLOC, useroffset,
> usersize);
> - kasan_cache_create_kmalloc(s);
> list_add(&s->list, &slab_caches);
> s->refcount = 1;
> return s;
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH -next 2/2] mm/kasan: simplify is_kmalloc check
2022-11-21 13:50 ` [PATCH -next 2/2] mm/kasan: simplify is_kmalloc check Feng Tang
2022-11-21 14:13 ` Feng Tang
@ 2022-11-21 15:15 ` Andrey Konovalov
2022-11-22 6:53 ` Feng Tang
1 sibling, 1 reply; 11+ messages in thread
From: Andrey Konovalov @ 2022-11-21 15:15 UTC (permalink / raw)
To: Feng Tang
Cc: Andrew Morton, Vlastimil Babka, Christoph Lameter, Pekka Enberg,
David Rientjes, Joonsoo Kim, Roman Gushchin, Hyeonggon Yoo,
Dmitry Vyukov, Andrey Ryabinin, Alexander Potapenko,
Vincenzo Frascino, linux-mm, kasan-dev, linux-kernel
On Mon, Nov 21, 2022 at 2:53 PM Feng Tang <feng.tang@intel.com> wrote:
>
> Use new is_kmalloc_cache() to simplify the code of checking whether
> a kmem_cache is a kmalloc cache.
>
> Signed-off-by: Feng Tang <feng.tang@intel.com>
Hi Feng,
Nice simplification!
> ---
> include/linux/kasan.h | 9 ---------
> mm/kasan/common.c | 9 ++-------
> mm/slab_common.c | 1 -
> 3 files changed, 2 insertions(+), 17 deletions(-)
>
> diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> index dff604912687..fc46f5d6f404 100644
> --- a/include/linux/kasan.h
> +++ b/include/linux/kasan.h
> @@ -102,7 +102,6 @@ struct kasan_cache {
> int alloc_meta_offset;
> int free_meta_offset;
> #endif
> - bool is_kmalloc;
> };
We can go even further here, and only define the kasan_cache struct
and add the kasan_info field to kmem_cache when CONFIG_KASAN_GENERIC
is enabled.
>
> void __kasan_unpoison_range(const void *addr, size_t size);
> @@ -129,13 +128,6 @@ static __always_inline bool kasan_unpoison_pages(struct page *page,
> return false;
> }
>
> -void __kasan_cache_create_kmalloc(struct kmem_cache *cache);
> -static __always_inline void kasan_cache_create_kmalloc(struct kmem_cache *cache)
> -{
> - if (kasan_enabled())
> - __kasan_cache_create_kmalloc(cache);
> -}
> -
> void __kasan_poison_slab(struct slab *slab);
> static __always_inline void kasan_poison_slab(struct slab *slab)
> {
> @@ -252,7 +244,6 @@ static inline void kasan_poison_pages(struct page *page, unsigned int order,
> bool init) {}
> static inline bool kasan_unpoison_pages(struct page *page, unsigned int order,
> bool init) { return false; }
> -static inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) {}
> static inline void kasan_poison_slab(struct slab *slab) {}
> static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
> void *object) {}
> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> index 1f30080a7a4c..f7e0e5067e7a 100644
> --- a/mm/kasan/common.c
> +++ b/mm/kasan/common.c
> @@ -122,11 +122,6 @@ void __kasan_poison_pages(struct page *page, unsigned int order, bool init)
> KASAN_PAGE_FREE, init);
> }
>
> -void __kasan_cache_create_kmalloc(struct kmem_cache *cache)
> -{
> - cache->kasan_info.is_kmalloc = true;
> -}
> -
> void __kasan_poison_slab(struct slab *slab)
> {
> struct page *page = slab_page(slab);
> @@ -326,7 +321,7 @@ void * __must_check __kasan_slab_alloc(struct kmem_cache *cache,
> kasan_unpoison(tagged_object, cache->object_size, init);
>
> /* Save alloc info (if possible) for non-kmalloc() allocations. */
> - if (kasan_stack_collection_enabled() && !cache->kasan_info.is_kmalloc)
> + if (kasan_stack_collection_enabled() && is_kmalloc_cache(cache))
> kasan_save_alloc_info(cache, tagged_object, flags);
>
> return tagged_object;
> @@ -372,7 +367,7 @@ static inline void *____kasan_kmalloc(struct kmem_cache *cache,
> * Save alloc info (if possible) for kmalloc() allocations.
> * This also rewrites the alloc info when called from kasan_krealloc().
> */
> - if (kasan_stack_collection_enabled() && cache->kasan_info.is_kmalloc)
> + if (kasan_stack_collection_enabled() && is_kmalloc_cache(cache))
> kasan_save_alloc_info(cache, (void *)object, flags);
>
> /* Keep the tag that was set by kasan_slab_alloc(). */
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index 8276022f0da4..a5480d67f391 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -663,7 +663,6 @@ struct kmem_cache *__init create_kmalloc_cache(const char *name,
>
> create_boot_cache(s, name, size, flags | SLAB_KMALLOC, useroffset,
> usersize);
> - kasan_cache_create_kmalloc(s);
> list_add(&s->list, &slab_caches);
> s->refcount = 1;
> return s;
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro
2022-11-21 13:50 [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro Feng Tang
2022-11-21 13:50 ` [PATCH -next 2/2] mm/kasan: simplify is_kmalloc check Feng Tang
@ 2022-11-21 20:19 ` Andrew Morton
2022-11-22 5:30 ` Feng Tang
1 sibling, 1 reply; 11+ messages in thread
From: Andrew Morton @ 2022-11-21 20:19 UTC (permalink / raw)
To: Feng Tang
Cc: Vlastimil Babka, Christoph Lameter, Pekka Enberg, David Rientjes,
Joonsoo Kim, Roman Gushchin, Hyeonggon Yoo, Andrey Konovalov,
Dmitry Vyukov, Andrey Ryabinin, Alexander Potapenko,
Vincenzo Frascino, linux-mm, kasan-dev, linux-kernel
On Mon, 21 Nov 2022 21:50:23 +0800 Feng Tang <feng.tang@intel.com> wrote:
> +#ifndef CONFIG_SLOB
> +#define is_kmalloc_cache(s) ((s)->flags & SLAB_KMALLOC)
> +#else
> +#define is_kmalloc_cache(s) (false)
> +#endif
Could be implemented as a static inline C function, yes?
If so, that's always best. For (silly) example, consider the behaviour
of
x = is_kmalloc_cache(s++);
with and without CONFIG_SLOB.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro
2022-11-21 20:19 ` [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro Andrew Morton
@ 2022-11-22 5:30 ` Feng Tang
2022-11-22 23:17 ` Andrew Morton
2022-11-23 9:21 ` Vlastimil Babka
0 siblings, 2 replies; 11+ messages in thread
From: Feng Tang @ 2022-11-22 5:30 UTC (permalink / raw)
To: Andrew Morton
Cc: Vlastimil Babka, Christoph Lameter, Pekka Enberg, David Rientjes,
Joonsoo Kim, Roman Gushchin, Hyeonggon Yoo, Andrey Konovalov,
Dmitry Vyukov, Andrey Ryabinin, Alexander Potapenko,
Vincenzo Frascino, linux-mm, kasan-dev, linux-kernel
On Mon, Nov 21, 2022 at 12:19:38PM -0800, Andrew Morton wrote:
> On Mon, 21 Nov 2022 21:50:23 +0800 Feng Tang <feng.tang@intel.com> wrote:
>
> > +#ifndef CONFIG_SLOB
> > +#define is_kmalloc_cache(s) ((s)->flags & SLAB_KMALLOC)
> > +#else
> > +#define is_kmalloc_cache(s) (false)
> > +#endif
>
> Could be implemented as a static inline C function, yes?
Right, I also did try inline function first, and met compilation error:
"
./include/linux/slab.h: In function ‘is_kmalloc_cache’:
./include/linux/slab.h:159:18: error: invalid use of undefined type ‘struct kmem_cache’
159 | return (s->flags & SLAB_KMALLOC);
| ^~
"
The reason is 'struct kmem_cache' definition for slab/slub/slob sit
separately in slab_def.h, slub_def.h and mm/slab.h, and they are not
included in this 'include/linux/slab.h'. So I chose the macro way.
Btw, I've worked on some patches related with sl[auo]b recently, and
really felt the pain when dealing with 3 allocators, on both reading
code and writing patches. And I really like the idea of fading away
SLOB as the first step :)
> If so, that's always best. For (silly) example, consider the behaviour
> of
>
> x = is_kmalloc_cache(s++);
>
> with and without CONFIG_SLOB.
Another solution I can think of is putting the implementation into
slab_common.c, like the below?
Thanks,
Feng
---
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 067f0e80be9e..e4fcdbfb3477 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -149,6 +149,17 @@
struct list_lru;
struct mem_cgroup;
+
+#ifndef CONFIG_SLOB
+extern bool is_kmalloc_cache(struct kmem_cache *s);
+#else
+static inline bool is_kmalloc_cache(struct kmem_cache *s)
+{
+ return false;
+}
+#endif
+
/*
* struct kmem_cache related prototypes
*/
diff --git a/mm/slab_common.c b/mm/slab_common.c
index a5480d67f391..860e804b7c0a 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -77,6 +77,13 @@ __setup_param("slub_merge", slub_merge, setup_slab_merge, 0);
__setup("slab_nomerge", setup_slab_nomerge);
__setup("slab_merge", setup_slab_merge);
+#ifndef CONFIG_SLOB
+bool is_kmalloc_cache(struct kmem_cache *s)
+{
+ return (s->flags & SLAB_KMALLOC);
+}
+#endif
+
/*
* Determine the size of a slab object
*/
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH -next 2/2] mm/kasan: simplify is_kmalloc check
2022-11-21 15:15 ` Andrey Konovalov
@ 2022-11-22 6:53 ` Feng Tang
2022-11-22 9:57 ` Andrey Konovalov
0 siblings, 1 reply; 11+ messages in thread
From: Feng Tang @ 2022-11-22 6:53 UTC (permalink / raw)
To: Andrey Konovalov
Cc: Andrew Morton, Vlastimil Babka, Christoph Lameter, Pekka Enberg,
David Rientjes, Joonsoo Kim, Roman Gushchin, Hyeonggon Yoo,
Dmitry Vyukov, Andrey Ryabinin, Alexander Potapenko,
Vincenzo Frascino, linux-mm, kasan-dev, linux-kernel
On Mon, Nov 21, 2022 at 04:15:32PM +0100, Andrey Konovalov wrote:
> On Mon, Nov 21, 2022 at 2:53 PM Feng Tang <feng.tang@intel.com> wrote:
> >
> > Use new is_kmalloc_cache() to simplify the code of checking whether
> > a kmem_cache is a kmalloc cache.
> >
> > Signed-off-by: Feng Tang <feng.tang@intel.com>
>
> Hi Feng,
>
> Nice simplification!
>
> > ---
> > include/linux/kasan.h | 9 ---------
> > mm/kasan/common.c | 9 ++-------
> > mm/slab_common.c | 1 -
> > 3 files changed, 2 insertions(+), 17 deletions(-)
> >
> > diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> > index dff604912687..fc46f5d6f404 100644
> > --- a/include/linux/kasan.h
> > +++ b/include/linux/kasan.h
> > @@ -102,7 +102,6 @@ struct kasan_cache {
> > int alloc_meta_offset;
> > int free_meta_offset;
> > #endif
> > - bool is_kmalloc;
> > };
>
> We can go even further here, and only define the kasan_cache struct
> and add the kasan_info field to kmem_cache when CONFIG_KASAN_GENERIC
> is enabled.
Good idea. thanks!
I mainly checked the kasan_cache related code, and make an add-on
patch below, please let me know if my understanding is wrong or I
missed anything.
Thanks,
Feng
---
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 0ac6505367ee..f2e41290094e 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -96,14 +96,6 @@ static inline bool kasan_has_integrated_init(void)
}
#ifdef CONFIG_KASAN
-
-struct kasan_cache {
-#ifdef CONFIG_KASAN_GENERIC
- int alloc_meta_offset;
- int free_meta_offset;
-#endif
-};
-
void __kasan_unpoison_range(const void *addr, size_t size);
static __always_inline void kasan_unpoison_range(const void *addr, size_t size)
{
@@ -293,6 +285,11 @@ static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
#ifdef CONFIG_KASAN_GENERIC
+struct kasan_cache {
+ int alloc_meta_offset;
+ int free_meta_offset;
+};
+
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,
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index f0ffad6a3365..39f7f1f95de2 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -72,7 +72,7 @@ struct kmem_cache {
int obj_offset;
#endif /* CONFIG_DEBUG_SLAB */
-#ifdef CONFIG_KASAN
+#ifdef CONFIG_KASAN_GENERIC
struct kasan_cache kasan_info;
#endif
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index f9c68a9dac04..4e7cdada4bbb 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -132,7 +132,7 @@ struct kmem_cache {
unsigned int *random_seq;
#endif
-#ifdef CONFIG_KASAN
+#ifdef CONFIG_KASAN_GENERIC
struct kasan_cache kasan_info;
#endif
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH -next 2/2] mm/kasan: simplify is_kmalloc check
2022-11-22 6:53 ` Feng Tang
@ 2022-11-22 9:57 ` Andrey Konovalov
0 siblings, 0 replies; 11+ messages in thread
From: Andrey Konovalov @ 2022-11-22 9:57 UTC (permalink / raw)
To: Feng Tang
Cc: Andrew Morton, Vlastimil Babka, Christoph Lameter, Pekka Enberg,
David Rientjes, Joonsoo Kim, Roman Gushchin, Hyeonggon Yoo,
Dmitry Vyukov, Andrey Ryabinin, Alexander Potapenko,
Vincenzo Frascino, linux-mm, kasan-dev, linux-kernel
On Tue, Nov 22, 2022 at 7:56 AM Feng Tang <feng.tang@intel.com> wrote:
>
> On Mon, Nov 21, 2022 at 04:15:32PM +0100, Andrey Konovalov wrote:
> > On Mon, Nov 21, 2022 at 2:53 PM Feng Tang <feng.tang@intel.com> wrote:
> > >
> > > Use new is_kmalloc_cache() to simplify the code of checking whether
> > > a kmem_cache is a kmalloc cache.
> > >
> > > Signed-off-by: Feng Tang <feng.tang@intel.com>
> >
> > Hi Feng,
> >
> > Nice simplification!
> >
> > > ---
> > > include/linux/kasan.h | 9 ---------
> > > mm/kasan/common.c | 9 ++-------
> > > mm/slab_common.c | 1 -
> > > 3 files changed, 2 insertions(+), 17 deletions(-)
> > >
> > > diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> > > index dff604912687..fc46f5d6f404 100644
> > > --- a/include/linux/kasan.h
> > > +++ b/include/linux/kasan.h
> > > @@ -102,7 +102,6 @@ struct kasan_cache {
> > > int alloc_meta_offset;
> > > int free_meta_offset;
> > > #endif
> > > - bool is_kmalloc;
> > > };
> >
> > We can go even further here, and only define the kasan_cache struct
> > and add the kasan_info field to kmem_cache when CONFIG_KASAN_GENERIC
> > is enabled.
>
> Good idea. thanks!
>
> I mainly checked the kasan_cache related code, and make an add-on
> patch below, please let me know if my understanding is wrong or I
> missed anything.
>
> Thanks,
> Feng
>
> ---
> diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> index 0ac6505367ee..f2e41290094e 100644
> --- a/include/linux/kasan.h
> +++ b/include/linux/kasan.h
> @@ -96,14 +96,6 @@ static inline bool kasan_has_integrated_init(void)
> }
>
> #ifdef CONFIG_KASAN
> -
> -struct kasan_cache {
> -#ifdef CONFIG_KASAN_GENERIC
> - int alloc_meta_offset;
> - int free_meta_offset;
> -#endif
> -};
> -
> void __kasan_unpoison_range(const void *addr, size_t size);
> static __always_inline void kasan_unpoison_range(const void *addr, size_t size)
> {
> @@ -293,6 +285,11 @@ static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
>
> #ifdef CONFIG_KASAN_GENERIC
>
> +struct kasan_cache {
> + int alloc_meta_offset;
> + int free_meta_offset;
> +};
> +
> 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,
> diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
> index f0ffad6a3365..39f7f1f95de2 100644
> --- a/include/linux/slab_def.h
> +++ b/include/linux/slab_def.h
> @@ -72,7 +72,7 @@ struct kmem_cache {
> int obj_offset;
> #endif /* CONFIG_DEBUG_SLAB */
>
> -#ifdef CONFIG_KASAN
> +#ifdef CONFIG_KASAN_GENERIC
> struct kasan_cache kasan_info;
> #endif
>
> diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
> index f9c68a9dac04..4e7cdada4bbb 100644
> --- a/include/linux/slub_def.h
> +++ b/include/linux/slub_def.h
> @@ -132,7 +132,7 @@ struct kmem_cache {
> unsigned int *random_seq;
> #endif
>
> -#ifdef CONFIG_KASAN
> +#ifdef CONFIG_KASAN_GENERIC
> struct kasan_cache kasan_info;
> #endif
Yes, this looks good.
Please resend as a v2 and I'll give a Reviewed-by.
Thanks!
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro
2022-11-22 5:30 ` Feng Tang
@ 2022-11-22 23:17 ` Andrew Morton
2022-11-23 9:21 ` Vlastimil Babka
1 sibling, 0 replies; 11+ messages in thread
From: Andrew Morton @ 2022-11-22 23:17 UTC (permalink / raw)
To: Feng Tang
Cc: Vlastimil Babka, Christoph Lameter, Pekka Enberg, David Rientjes,
Joonsoo Kim, Roman Gushchin, Hyeonggon Yoo, Andrey Konovalov,
Dmitry Vyukov, Andrey Ryabinin, Alexander Potapenko,
Vincenzo Frascino, linux-mm, kasan-dev, linux-kernel
On Tue, 22 Nov 2022 13:30:19 +0800 Feng Tang <feng.tang@intel.com> wrote:
> > If so, that's always best. For (silly) example, consider the behaviour
> > of
> >
> > x = is_kmalloc_cache(s++);
> >
> > with and without CONFIG_SLOB.
>
> Another solution I can think of is putting the implementation into
> slab_common.c, like the below?
I'm not sure that's much of an improvement on the macro :(
How about we go with the macro and avoid the
expression-with-side-effects gotcha (and the potential CONFIG_SLOB=n
unused-variable gotcha)? That would involve evaluating the arg within
the CONFIG_SLOB=y version of the macro.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro
2022-11-22 5:30 ` Feng Tang
2022-11-22 23:17 ` Andrew Morton
@ 2022-11-23 9:21 ` Vlastimil Babka
2022-11-23 12:17 ` Feng Tang
1 sibling, 1 reply; 11+ messages in thread
From: Vlastimil Babka @ 2022-11-23 9:21 UTC (permalink / raw)
To: Feng Tang, Andrew Morton
Cc: Christoph Lameter, Pekka Enberg, David Rientjes, Joonsoo Kim,
Roman Gushchin, Hyeonggon Yoo, Andrey Konovalov, Dmitry Vyukov,
Andrey Ryabinin, Alexander Potapenko, Vincenzo Frascino,
linux-mm, kasan-dev, linux-kernel
On 11/22/22 06:30, Feng Tang wrote:
> On Mon, Nov 21, 2022 at 12:19:38PM -0800, Andrew Morton wrote:
>> On Mon, 21 Nov 2022 21:50:23 +0800 Feng Tang <feng.tang@intel.com> wrote:
>>
>> > +#ifndef CONFIG_SLOB
>> > +#define is_kmalloc_cache(s) ((s)->flags & SLAB_KMALLOC)
>> > +#else
>> > +#define is_kmalloc_cache(s) (false)
>> > +#endif
>>
>> Could be implemented as a static inline C function, yes?
>
> Right, I also did try inline function first, and met compilation error:
>
> "
> ./include/linux/slab.h: In function ‘is_kmalloc_cache’:
> ./include/linux/slab.h:159:18: error: invalid use of undefined type ‘struct kmem_cache’
> 159 | return (s->flags & SLAB_KMALLOC);
> | ^~
> "
>
> The reason is 'struct kmem_cache' definition for slab/slub/slob sit
> separately in slab_def.h, slub_def.h and mm/slab.h, and they are not
> included in this 'include/linux/slab.h'. So I chose the macro way.
You could try mm/slab.h instead, below the slub_def.h includes there.
is_kmalloc_cache(s) shouldn't have random consumers in the kernel anyway.
It's fine if kasan includes it, as it's intertwined with slab a lot anyway.
> Btw, I've worked on some patches related with sl[auo]b recently, and
> really felt the pain when dealing with 3 allocators, on both reading
> code and writing patches. And I really like the idea of fading away
> SLOB as the first step :)
Can't agree more :)
>> If so, that's always best. For (silly) example, consider the behaviour
>> of
>>
>> x = is_kmalloc_cache(s++);
>>
>> with and without CONFIG_SLOB.
>
> Another solution I can think of is putting the implementation into
> slab_common.c, like the below?
The overhead of function call between compilation units (sans LTO) is not
worth it.
> Thanks,
> Feng
>
> ---
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index 067f0e80be9e..e4fcdbfb3477 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -149,6 +149,17 @@
>
> struct list_lru;
> struct mem_cgroup;
> +
> +#ifndef CONFIG_SLOB
> +extern bool is_kmalloc_cache(struct kmem_cache *s);
> +#else
> +static inline bool is_kmalloc_cache(struct kmem_cache *s)
> +{
> + return false;
> +}
> +#endif
> +
> /*
> * struct kmem_cache related prototypes
> */
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index a5480d67f391..860e804b7c0a 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -77,6 +77,13 @@ __setup_param("slub_merge", slub_merge, setup_slab_merge, 0);
> __setup("slab_nomerge", setup_slab_nomerge);
> __setup("slab_merge", setup_slab_merge);
>
> +#ifndef CONFIG_SLOB
> +bool is_kmalloc_cache(struct kmem_cache *s)
> +{
> + return (s->flags & SLAB_KMALLOC);
> +}
> +#endif
> +
> /*
> * Determine the size of a slab object
> */
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro
2022-11-23 9:21 ` Vlastimil Babka
@ 2022-11-23 12:17 ` Feng Tang
0 siblings, 0 replies; 11+ messages in thread
From: Feng Tang @ 2022-11-23 12:17 UTC (permalink / raw)
To: Vlastimil Babka, Andrew Morton
Cc: Christoph Lameter, Pekka Enberg, David Rientjes, Joonsoo Kim,
Roman Gushchin, Hyeonggon Yoo, Andrey Konovalov, Dmitry Vyukov,
Andrey Ryabinin, Alexander Potapenko, Vincenzo Frascino,
linux-mm, kasan-dev, linux-kernel
On Wed, Nov 23, 2022 at 10:21:03AM +0100, Vlastimil Babka wrote:
> On 11/22/22 06:30, Feng Tang wrote:
> > On Mon, Nov 21, 2022 at 12:19:38PM -0800, Andrew Morton wrote:
> >> On Mon, 21 Nov 2022 21:50:23 +0800 Feng Tang <feng.tang@intel.com> wrote:
> >>
> >> > +#ifndef CONFIG_SLOB
> >> > +#define is_kmalloc_cache(s) ((s)->flags & SLAB_KMALLOC)
> >> > +#else
> >> > +#define is_kmalloc_cache(s) (false)
> >> > +#endif
> >>
> >> Could be implemented as a static inline C function, yes?
> >
> > Right, I also did try inline function first, and met compilation error:
> >
> > "
> > ./include/linux/slab.h: In function ‘is_kmalloc_cache’:
> > ./include/linux/slab.h:159:18: error: invalid use of undefined type ‘struct kmem_cache’
> > 159 | return (s->flags & SLAB_KMALLOC);
> > | ^~
> > "
> >
> > The reason is 'struct kmem_cache' definition for slab/slub/slob sit
> > separately in slab_def.h, slub_def.h and mm/slab.h, and they are not
> > included in this 'include/linux/slab.h'. So I chose the macro way.
>
> You could try mm/slab.h instead, below the slub_def.h includes there.
> is_kmalloc_cache(s) shouldn't have random consumers in the kernel anyway.
> It's fine if kasan includes it, as it's intertwined with slab a lot anyway.
Good suggestion! thanks! This can address Andrew's concern and also
avoid extra cost.
And yes, besides sanity code like kasan/kfence, rare code will care
whether other kmem_cache is a kmalloc cache or not. And kasan code
already includes "../slab.h".
> > Btw, I've worked on some patches related with sl[auo]b recently, and
> > really felt the pain when dealing with 3 allocators, on both reading
> > code and writing patches. And I really like the idea of fading away
> > SLOB as the first step :)
>
> Can't agree more :)
>
> >> If so, that's always best. For (silly) example, consider the behaviour
> >> of
> >>
> >> x = is_kmalloc_cache(s++);
> >>
> >> with and without CONFIG_SLOB.
> >
> > Another solution I can think of is putting the implementation into
> > slab_common.c, like the below?
>
> The overhead of function call between compilation units (sans LTO) is not
> worth it.
Yes. Will send out the v2 patches.
Thanks,
Feng
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2022-11-23 12:20 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-11-21 13:50 [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro Feng Tang
2022-11-21 13:50 ` [PATCH -next 2/2] mm/kasan: simplify is_kmalloc check Feng Tang
2022-11-21 14:13 ` Feng Tang
2022-11-21 15:15 ` Andrey Konovalov
2022-11-22 6:53 ` Feng Tang
2022-11-22 9:57 ` Andrey Konovalov
2022-11-21 20:19 ` [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro Andrew Morton
2022-11-22 5:30 ` Feng Tang
2022-11-22 23:17 ` Andrew Morton
2022-11-23 9:21 ` Vlastimil Babka
2022-11-23 12:17 ` Feng Tang
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