linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: andrey.konovalov@linux.dev
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>,
	Marco Elver <elver@google.com>,
	Alexander Potapenko <glider@google.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Andrey Ryabinin <ryabinin.a.a@gmail.com>,
	kasan-dev@googlegroups.com, Peter Collingbourne <pcc@google.com>,
	Evgenii Stepanov <eugenis@google.com>,
	Florian Mayer <fmayer@google.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH mm v3 18/34] kasan: only define kasan_cache_create for Generic mode
Date: Mon,  5 Sep 2022 23:05:33 +0200	[thread overview]
Message-ID: <61faa2aa1906e2d02c97d00ddf99ce8911dda095.1662411799.git.andreyknvl@google.com> (raw)
In-Reply-To: <cover.1662411799.git.andreyknvl@google.com>

From: Andrey Konovalov <andreyknvl@google.com>

Right now, kasan_cache_create() assigns SLAB_KASAN for all KASAN modes
and then sets up metadata-related cache parameters for the Generic mode.

SLAB_KASAN is used in two places:

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.

Both cases are only relevant when per-object metadata is present, which
is only the case with the Generic mode.

Thus, assign SLAB_KASAN and define kasan_cache_create() only for the
Generic mode.

Also update the SLAB_KASAN-related comment.

Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 include/linux/kasan.h | 18 ++++++------------
 include/linux/slab.h  |  2 +-
 mm/kasan/common.c     | 16 ----------------
 mm/kasan/generic.c    | 17 ++++++++++++++++-
 4 files changed, 23 insertions(+), 30 deletions(-)

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index a212c2e3f32d..d811b3d7d2a1 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -128,15 +128,6 @@ static __always_inline void kasan_unpoison_pages(struct page *page,
 		__kasan_unpoison_pages(page, order, init);
 }
 
-void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
-				slab_flags_t *flags);
-static __always_inline void kasan_cache_create(struct kmem_cache *cache,
-				unsigned int *size, slab_flags_t *flags)
-{
-	if (kasan_enabled())
-		__kasan_cache_create(cache, size, flags);
-}
-
 void __kasan_cache_create_kmalloc(struct kmem_cache *cache);
 static __always_inline void kasan_cache_create_kmalloc(struct kmem_cache *cache)
 {
@@ -260,9 +251,6 @@ static inline void kasan_poison_pages(struct page *page, unsigned int order,
 				      bool init) {}
 static inline void kasan_unpoison_pages(struct page *page, unsigned int order,
 					bool init) {}
-static inline void kasan_cache_create(struct kmem_cache *cache,
-				      unsigned int *size,
-				      slab_flags_t *flags) {}
 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,
@@ -316,6 +304,8 @@ static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
 
 size_t kasan_metadata_size(struct kmem_cache *cache);
 slab_flags_t kasan_never_merge(void);
+void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
+			slab_flags_t *flags);
 
 void kasan_cache_shrink(struct kmem_cache *cache);
 void kasan_cache_shutdown(struct kmem_cache *cache);
@@ -334,6 +324,10 @@ 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,
+				      slab_flags_t *flags) {}
 
 static inline void kasan_cache_shrink(struct kmem_cache *cache) {}
 static inline void kasan_cache_shutdown(struct kmem_cache *cache) {}
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 0fefdf528e0d..1c6b7362e82b 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -106,7 +106,7 @@
 # define SLAB_ACCOUNT		0
 #endif
 
-#ifdef CONFIG_KASAN
+#ifdef CONFIG_KASAN_GENERIC
 #define SLAB_KASAN		((slab_flags_t __force)0x08000000U)
 #else
 #define SLAB_KASAN		0
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index c2690e938030..8efa63190951 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -110,22 +110,6 @@ void __kasan_poison_pages(struct page *page, unsigned int order, bool init)
 			     KASAN_PAGE_FREE, init);
 }
 
-void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
-			  slab_flags_t *flags)
-{
-	/*
-	 * SLAB_KASAN is used to mark caches as ones that are sanitized by
-	 * KASAN. Currently this flag is used in two places:
-	 * 1. In slab_ksize() when calculating the size of the accessible
-	 *    memory within the object.
-	 * 2. In slab_common.c to prevent merging of sanitized caches.
-	 */
-	*flags |= SLAB_KASAN;
-
-	if (kasan_requires_meta())
-		kasan_init_cache_meta(cache, size);
-}
-
 void __kasan_cache_create_kmalloc(struct kmem_cache *cache)
 {
 	cache->kasan_info.is_kmalloc = true;
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 25333bf3c99f..f6bef347de87 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -352,11 +352,26 @@ static inline unsigned int optimal_redzone(unsigned int object_size)
 		object_size <= (1 << 16) - 1024 ? 1024 : 2048;
 }
 
-void kasan_init_cache_meta(struct kmem_cache *cache, unsigned int *size)
+void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
+			  slab_flags_t *flags)
 {
 	unsigned int ok_size;
 	unsigned int optimal_size;
 
+	if (!kasan_requires_meta())
+		return;
+
+	/*
+	 * 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:
+	 * 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.
+	 */
+	*flags |= SLAB_KASAN;
+
 	ok_size = *size;
 
 	/* Add alloc meta into redzone. */
-- 
2.25.1



  parent reply	other threads:[~2022-09-05 21:09 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-05 21:05 [PATCH mm v3 00/34] kasan: switch tag-based modes to stack ring from per-object metadata andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 01/34] kasan: check KASAN_NO_FREE_META in __kasan_metadata_size andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 02/34] kasan: rename kasan_set_*_info to kasan_save_*_info andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 03/34] kasan: move is_kmalloc check out of save_alloc_info andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 04/34] kasan: split save_alloc_info implementations andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 05/34] kasan: drop CONFIG_KASAN_TAGS_IDENTIFY andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 06/34] kasan: introduce kasan_print_aux_stacks andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 07/34] kasan: introduce kasan_get_alloc_track andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 08/34] kasan: introduce kasan_init_object_meta andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 09/34] kasan: clear metadata functions for tag-based modes andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 10/34] kasan: move kasan_get_*_meta to generic.c andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 11/34] kasan: introduce kasan_requires_meta andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 12/34] kasan: introduce kasan_init_cache_meta andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 13/34] kasan: drop CONFIG_KASAN_GENERIC check from kasan_init_cache_meta andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 14/34] kasan: only define kasan_metadata_size for Generic mode andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 15/34] kasan: only define kasan_never_merge " andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 16/34] kasan: only define metadata offsets " andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 17/34] kasan: only define metadata structs " andrey.konovalov
2022-09-05 21:05 ` andrey.konovalov [this message]
2022-09-05 21:05 ` [PATCH mm v3 19/34] kasan: pass tagged pointers to kasan_save_alloc/free_info andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 20/34] kasan: move kasan_get_alloc/free_track definitions andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 21/34] kasan: cosmetic changes in report.c andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 22/34] kasan: use virt_addr_valid in kasan_addr_to_page/slab andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 23/34] kasan: use kasan_addr_to_slab in print_address_description andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 24/34] kasan: make kasan_addr_to_page static andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 25/34] kasan: simplify print_report andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 26/34] kasan: introduce complete_report_info andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 27/34] kasan: fill in cache and object in complete_report_info andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 28/34] kasan: rework function arguments in report.c andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 29/34] kasan: introduce kasan_complete_mode_report_info andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 30/34] kasan: implement stack ring for tag-based modes andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 31/34] kasan: support kasan.stacktrace for SW_TAGS andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 32/34] kasan: dynamically allocate stack ring entries andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 33/34] kasan: better identify bug types for tag-based modes andrey.konovalov
2022-09-05 21:05 ` [PATCH mm v3 34/34] kasan: add another use-after-free test andrey.konovalov
2022-09-11 11:50 ` [PATCH mm v3 00/34] kasan: switch tag-based modes to stack ring from per-object metadata Andrey Konovalov
2022-09-12  9:39   ` Marco Elver
2022-09-12 20:06     ` Andrew Morton
2022-09-19  8:07       ` Yu Zhao
2022-09-20 18:59         ` Andrey Konovalov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=61faa2aa1906e2d02c97d00ddf99ce8911dda095.1662411799.git.andreyknvl@google.com \
    --to=andrey.konovalov@linux.dev \
    --cc=akpm@linux-foundation.org \
    --cc=andreyknvl@gmail.com \
    --cc=andreyknvl@google.com \
    --cc=dvyukov@google.com \
    --cc=elver@google.com \
    --cc=eugenis@google.com \
    --cc=fmayer@google.com \
    --cc=glider@google.com \
    --cc=kasan-dev@googlegroups.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=pcc@google.com \
    --cc=ryabinin.a.a@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox