From: Andrey Konovalov <andreyknvl@google.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Dmitry Vyukov <dvyukov@google.com>,
Alexander Potapenko <glider@google.com>,
Marco Elver <elver@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>,
Kostya Serebryany <kcc@google.com>,
Peter Collingbourne <pcc@google.com>,
Serban Constantinescu <serbanc@google.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Elena Petrova <lenaptr@google.com>,
Branislav Rankov <Branislav.Rankov@arm.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
Andrew Morton <akpm@linux-foundation.org>,
kasan-dev@googlegroups.com,
linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH RFC v2 16/21] kasan: optimize poisoning in kmalloc and krealloc
Date: Thu, 22 Oct 2020 15:19:08 +0200 [thread overview]
Message-ID: <ce573435398f21d3e604f104c29ba65eca70d9e7.1603372719.git.andreyknvl@google.com> (raw)
In-Reply-To: <cover.1603372719.git.andreyknvl@google.com>
Since kasan_kmalloc() always follows kasan_slab_alloc(), there's no need
to reunpoison the object data, only to poison the redzone.
This requires changing kasan annotation for early SLUB cache to
kasan_slab_alloc(). Otherwise kasan_kmalloc() doesn't untag the object.
This doesn't do any functional changes, as kmem_cache_node->object_size
is equal to sizeof(struct kmem_cache_node).
Similarly for kasan_krealloc(), as it's called after ksize(), which
already unpoisoned the object, there's no need to do it again.
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Link: https://linux-review.googlesource.com/id/I4083d3b55605f70fef79bca9b90843c4390296f2
---
mm/kasan/common.c | 31 +++++++++++++++++++++----------
mm/slub.c | 3 +--
2 files changed, 22 insertions(+), 12 deletions(-)
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index c5ec60e1a4d2..a581937c2a44 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -360,8 +360,14 @@ static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object,
if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || IS_ENABLED(CONFIG_KASAN_HW_TAGS))
tag = assign_tag(cache, object, false, keep_tag);
- /* Tag is ignored in set_tag without CONFIG_KASAN_SW/HW_TAGS */
- kasan_unpoison_memory(set_tag(object, tag), size);
+ /*
+ * Don't unpoison the object when keeping the tag. Tag is kept for:
+ * 1. krealloc(), and then the memory has already been unpoisoned via ksize();
+ * 2. kmalloc(), and then the memory has already been unpoisoned by kasan_kmalloc().
+ * Tag is ignored in set_tag() without CONFIG_KASAN_SW/HW_TAGS.
+ */
+ if (!keep_tag)
+ kasan_unpoison_memory(set_tag(object, tag), size);
kasan_poison_memory((void *)redzone_start, redzone_end - redzone_start,
KASAN_KMALLOC_REDZONE);
@@ -384,10 +390,9 @@ void * __must_check __kasan_kmalloc(struct kmem_cache *cache, const void *object
}
EXPORT_SYMBOL(__kasan_kmalloc);
-void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
- gfp_t flags)
+static void * __must_check ____kasan_kmalloc_large(struct page *page, const void *ptr,
+ size_t size, gfp_t flags, bool realloc)
{
- struct page *page;
unsigned long redzone_start;
unsigned long redzone_end;
@@ -397,18 +402,24 @@ void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
if (unlikely(ptr == NULL))
return NULL;
- page = virt_to_page(ptr);
- redzone_start = round_up((unsigned long)(ptr + size),
- KASAN_GRANULE_SIZE);
+ redzone_start = round_up((unsigned long)(ptr + size), KASAN_GRANULE_SIZE);
redzone_end = (unsigned long)ptr + page_size(page);
- kasan_unpoison_memory(ptr, size);
+ /* ksize() in __do_krealloc() already unpoisoned the memory. */
+ if (!realloc)
+ kasan_unpoison_memory(ptr, size);
kasan_poison_memory((void *)redzone_start, redzone_end - redzone_start,
KASAN_PAGE_REDZONE);
return (void *)ptr;
}
+void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
+ gfp_t flags)
+{
+ return ____kasan_kmalloc_large(virt_to_page(ptr), ptr, size, flags, false);
+}
+
void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flags)
{
struct page *page;
@@ -419,7 +430,7 @@ void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flag
page = virt_to_head_page(object);
if (unlikely(!PageSlab(page)))
- return __kasan_kmalloc_large(object, size, flags);
+ return ____kasan_kmalloc_large(page, object, size, flags, true);
else
return ____kasan_kmalloc(page->slab_cache, object, size,
flags, true);
diff --git a/mm/slub.c b/mm/slub.c
index 1d3f2355df3b..afb035b0bf2d 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3535,8 +3535,7 @@ static void early_kmem_cache_node_alloc(int node)
init_object(kmem_cache_node, n, SLUB_RED_ACTIVE);
init_tracking(kmem_cache_node, n);
#endif
- n = kasan_kmalloc(kmem_cache_node, n, sizeof(struct kmem_cache_node),
- GFP_KERNEL);
+ n = kasan_slab_alloc(kmem_cache_node, n, GFP_KERNEL);
page->freelist = get_freepointer(kmem_cache_node, n);
page->inuse = 1;
page->frozen = 0;
--
2.29.0.rc1.297.gfa9743e501-goog
next prev parent reply other threads:[~2020-10-22 13:20 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-22 13:18 [PATCH RFC v2 00/21] kasan: hardware tag-based mode for production use on arm64 Andrey Konovalov
2020-10-22 13:18 ` [PATCH RFC v2 01/21] kasan: simplify quarantine_put call site Andrey Konovalov
2020-10-27 12:40 ` Dmitry Vyukov
2020-10-22 13:18 ` [PATCH RFC v2 02/21] kasan: rename get_alloc/free_info Andrey Konovalov
2020-10-27 12:40 ` Dmitry Vyukov
2020-10-22 13:18 ` [PATCH RFC v2 03/21] kasan: introduce set_alloc_info Andrey Konovalov
2020-10-27 12:41 ` Dmitry Vyukov
2020-10-22 13:18 ` [PATCH RFC v2 04/21] kasan: unpoison stack only with CONFIG_KASAN_STACK Andrey Konovalov
2020-10-27 12:44 ` Dmitry Vyukov
2020-10-27 12:45 ` Dmitry Vyukov
2020-10-29 19:57 ` Andrey Konovalov
2020-11-16 10:59 ` Dmitry Vyukov
2020-11-16 11:50 ` Marco Elver
2020-11-16 12:16 ` Catalin Marinas
2020-11-16 12:19 ` Dmitry Vyukov
2020-11-16 12:45 ` Vincenzo Frascino
2020-11-16 13:50 ` Andrey Konovalov
2020-11-16 14:50 ` Vincenzo Frascino
2020-10-22 13:18 ` [PATCH RFC v2 05/21] kasan: allow VMAP_STACK for HW_TAGS mode Andrey Konovalov
2020-10-27 12:49 ` Dmitry Vyukov
2020-10-29 20:00 ` Andrey Konovalov
2020-10-22 13:18 ` [PATCH RFC v2 06/21] kasan: mark kasan_init_tags as __init Andrey Konovalov
2020-10-28 10:08 ` Dmitry Vyukov
2020-10-29 20:08 ` Andrey Konovalov
2020-10-22 13:18 ` [PATCH RFC v2 07/21] kasan, arm64: move initialization message Andrey Konovalov
2020-10-28 10:55 ` Dmitry Vyukov
2020-10-29 20:14 ` Andrey Konovalov
2020-11-03 15:33 ` Andrey Konovalov
2020-10-22 13:19 ` [PATCH RFC v2 08/21] kasan: remove __kasan_unpoison_stack Andrey Konovalov
2020-10-28 10:57 ` Dmitry Vyukov
2020-10-22 13:19 ` [PATCH RFC v2 09/21] kasan: inline kasan_reset_tag for tag-based modes Andrey Konovalov
2020-10-28 11:05 ` Dmitry Vyukov
2020-10-30 16:19 ` Andrey Konovalov
2020-10-22 13:19 ` [PATCH RFC v2 10/21] kasan: inline random_tag for HW_TAGS Andrey Konovalov
2020-10-28 11:08 ` Dmitry Vyukov
2020-10-30 15:48 ` Andrey Konovalov
2020-10-30 16:07 ` Andrey Konovalov
2020-10-22 13:19 ` [PATCH RFC v2 11/21] kasan: inline kasan_poison_memory and check_invalid_free Andrey Konovalov
2020-10-28 11:29 ` Dmitry Vyukov
2020-10-22 13:19 ` [PATCH RFC v2 12/21] kasan: inline and rename kasan_unpoison_memory Andrey Konovalov
2020-10-28 11:36 ` Dmitry Vyukov
2020-10-30 16:34 ` Andrey Konovalov
2020-10-30 17:46 ` Dmitry Vyukov
2020-10-22 13:19 ` [PATCH RFC v2 13/21] arm64: kasan: Add cpu_supports_tags helper Andrey Konovalov
2020-10-28 11:38 ` Dmitry Vyukov
2020-10-22 13:19 ` [PATCH RFC v2 14/21] kasan: add and integrate kasan boot parameters Andrey Konovalov
2020-10-22 18:50 ` Marco Elver
2020-10-22 20:28 ` Andrey Konovalov
2020-10-28 12:27 ` Dmitry Vyukov
2020-10-30 19:30 ` Andrey Konovalov
2020-10-30 14:45 ` Marco Elver
2020-10-30 19:30 ` Andrey Konovalov
2020-10-22 13:19 ` [PATCH RFC v2 15/21] kasan: check kasan_enabled in annotations Andrey Konovalov
2020-10-28 16:47 ` Dmitry Vyukov
2020-10-30 19:47 ` Andrey Konovalov
2020-10-22 13:19 ` Andrey Konovalov [this message]
2020-10-28 16:55 ` [PATCH RFC v2 16/21] kasan: optimize poisoning in kmalloc and krealloc Dmitry Vyukov
2020-11-02 15:17 ` Andrey Konovalov
2020-10-22 13:19 ` [PATCH RFC v2 17/21] kasan: simplify kasan_poison_kfree Andrey Konovalov
2020-10-28 16:57 ` Dmitry Vyukov
2020-10-22 13:19 ` [PATCH RFC v2 18/21] kasan: rename kasan_poison_kfree Andrey Konovalov
2020-10-28 16:58 ` Dmitry Vyukov
2020-10-22 13:19 ` [PATCH RFC v2 19/21] kasan: don't round_up too much Andrey Konovalov
2020-10-28 17:01 ` Dmitry Vyukov
2020-10-22 13:19 ` [PATCH RFC v2 20/21] kasan: simplify assign_tag and set_tag calls Andrey Konovalov
2020-10-28 17:03 ` Dmitry Vyukov
2020-10-22 13:19 ` [PATCH RFC v2 21/21] kasan: clarify comment in __kasan_kfree_large Andrey Konovalov
2020-10-28 17:04 ` Dmitry Vyukov
2020-10-22 15:15 ` [PATCH RFC v2 00/21] kasan: hardware tag-based mode for production use on arm64 Dmitry Vyukov
2020-10-22 17:00 ` Andrey Konovalov
2020-10-22 18:29 ` Kostya Serebryany
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=ce573435398f21d3e604f104c29ba65eca70d9e7.1603372719.git.andreyknvl@google.com \
--to=andreyknvl@google.com \
--cc=Branislav.Rankov@arm.com \
--cc=akpm@linux-foundation.org \
--cc=aryabinin@virtuozzo.com \
--cc=catalin.marinas@arm.com \
--cc=dvyukov@google.com \
--cc=elver@google.com \
--cc=eugenis@google.com \
--cc=glider@google.com \
--cc=kasan-dev@googlegroups.com \
--cc=kcc@google.com \
--cc=kevin.brodsky@arm.com \
--cc=lenaptr@google.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=pcc@google.com \
--cc=serbanc@google.com \
--cc=vincenzo.frascino@arm.com \
--cc=will.deacon@arm.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;
as well as URLs for NNTP newsgroup(s).