From: Andrey Konovalov <andreyknvl@google.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Dmitry Vyukov <dvyukov@google.com>,
Alexander Potapenko <glider@google.com>,
Marco Elver <elver@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Will Deacon <will.deacon@arm.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Peter Collingbourne <pcc@google.com>,
Evgenii Stepanov <eugenis@google.com>,
Branislav Rankov <Branislav.Rankov@arm.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
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 03/12] kasan: optimize large kmalloc poisoning
Date: Mon, 1 Feb 2021 20:43:27 +0100 [thread overview]
Message-ID: <8fdbf86842f4eaf2458ecd23d0844058dbc2c7a2.1612208222.git.andreyknvl@google.com> (raw)
In-Reply-To: <cover.1612208222.git.andreyknvl@google.com>
Similarly to kasan_kmalloc(), kasan_kmalloc_large() doesn't need
to unpoison the object as it as already unpoisoned by alloc_pages()
(or by ksize() for krealloc()).
This patch changes kasan_kmalloc_large() to only poison the redzone.
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
mm/kasan/common.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 128cb330ca73..a7eb553c8e91 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -494,7 +494,6 @@ EXPORT_SYMBOL(__kasan_kmalloc);
void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
gfp_t flags)
{
- struct page *page;
unsigned long redzone_start;
unsigned long redzone_end;
@@ -504,12 +503,23 @@ void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
if (unlikely(ptr == NULL))
return NULL;
- page = virt_to_page(ptr);
+ /*
+ * The object has already been unpoisoned by kasan_alloc_pages() for
+ * alloc_pages() or by ksize() for krealloc().
+ */
+
+ /*
+ * The redzone has byte-level precision for the generic mode.
+ * Partially poison the last object granule to cover the unaligned
+ * part of the redzone.
+ */
+ if (IS_ENABLED(CONFIG_KASAN_GENERIC))
+ kasan_poison_last_granule(ptr, size);
+
+ /* Poison the aligned part of the redzone. */
redzone_start = round_up((unsigned long)(ptr + size),
KASAN_GRANULE_SIZE);
- redzone_end = (unsigned long)ptr + page_size(page);
-
- kasan_unpoison(ptr, size);
+ redzone_end = (unsigned long)ptr + page_size(virt_to_page(ptr));
kasan_poison((void *)redzone_start, redzone_end - redzone_start,
KASAN_PAGE_REDZONE);
--
2.30.0.365.g02bc693789-goog
next prev parent reply other threads:[~2021-02-01 19:43 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-01 19:43 [PATCH 00/12] kasan: optimizations and fixes for HW_TAGS Andrey Konovalov
2021-02-01 19:43 ` [PATCH 01/12] kasan, mm: don't save alloc stacks twice Andrey Konovalov
2021-02-02 16:06 ` Marco Elver
2021-02-02 18:01 ` Andrey Konovalov
2021-02-02 18:40 ` Marco Elver
2021-02-01 19:43 ` [PATCH 02/12] kasan, mm: optimize kmalloc poisoning Andrey Konovalov
2021-02-02 16:25 ` Marco Elver
2021-02-02 17:15 ` Andrey Konovalov
2021-02-02 17:39 ` Marco Elver
2021-02-01 19:43 ` Andrey Konovalov [this message]
2021-02-02 16:57 ` [PATCH 03/12] kasan: optimize large " Marco Elver
2021-02-01 19:43 ` [PATCH 04/12] kasan: clean up setting free info in kasan_slab_free Andrey Konovalov
2021-02-02 17:03 ` Marco Elver
2021-02-01 19:43 ` [PATCH 05/12] kasan: unify large kfree checks Andrey Konovalov
2021-02-03 12:13 ` Marco Elver
2021-02-01 19:43 ` [PATCH 06/12] kasan: rework krealloc tests Andrey Konovalov
2021-02-03 14:48 ` Marco Elver
2021-02-01 19:43 ` [PATCH 07/12] kasan, mm: remove krealloc side-effect Andrey Konovalov
2021-02-03 15:10 ` Marco Elver
2021-02-01 19:43 ` [PATCH 08/12] kasan, mm: optimize krealloc poisoning Andrey Konovalov
2021-02-03 14:34 ` Marco Elver
2021-02-01 19:43 ` [PATCH 09/12] kasan: ensure poisoning size alignment Andrey Konovalov
2021-02-03 15:31 ` Marco Elver
2021-02-01 19:43 ` [PATCH 10/12] arm64: kasan: simplify and inline MTE functions Andrey Konovalov
2021-02-01 22:44 ` Andrew Morton
2021-02-04 12:39 ` Vincenzo Frascino
2021-02-02 15:42 ` Catalin Marinas
2021-02-02 18:04 ` Andrey Konovalov
2021-02-04 12:37 ` Vincenzo Frascino
2021-02-01 19:43 ` [PATCH 11/12] kasan: always inline HW_TAGS helper functions Andrey Konovalov
2021-02-03 15:51 ` Marco Elver
2021-02-01 19:43 ` [PATCH 12/12] arm64: kasan: export MTE symbols for KASAN tests Andrey Konovalov
2021-02-02 10:46 ` Will Deacon
2021-02-02 13:42 ` Andrey Konovalov
2021-02-02 15:43 ` Catalin Marinas
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