The patch titled
Subject: kasan: introduce kasan_mempool_unpoison_pages
has been added to the -mm mm-unstable branch. Its filename is
kasan-introduce-kasan_mempool_unpoison_pages.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kasan-introduce-kasan_mempool_unpoison_pages.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: kasan: introduce kasan_mempool_unpoison_pages
Date: Tue, 19 Dec 2023 23:28:51 +0100
Introduce and document a new kasan_mempool_unpoison_pages hook to be used
by the mempool code instead of kasan_unpoison_pages.
This hook is not functionally different from kasan_unpoison_pages, but
using it improves the mempool code readability.
Link: https://lkml.kernel.org/r/239bd9af6176f2cc59f5c25893eb36143184daff.1703024586.git.andreyknvl@xxxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Alexander Lobakin <alobakin@xxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Breno Leitao <leitao@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/kasan.h | 25 +++++++++++++++++++++++++
mm/kasan/common.c | 6 ++++++
2 files changed, 31 insertions(+)
--- a/include/linux/kasan.h~kasan-introduce-kasan_mempool_unpoison_pages
+++ a/include/linux/kasan.h
@@ -225,6 +225,9 @@ bool __kasan_mempool_poison_pages(struct
* This function is similar to kasan_mempool_poison_object() but operates on
* page allocations.
*
+ * Before the poisoned allocation can be reused, it must be unpoisoned via
+ * kasan_mempool_unpoison_pages().
+ *
* Return: true if the allocation can be safely reused; false otherwise.
*/
static __always_inline bool kasan_mempool_poison_pages(struct page *page,
@@ -235,6 +238,27 @@ static __always_inline bool kasan_mempoo
return true;
}
+void __kasan_mempool_unpoison_pages(struct page *page, unsigned int order,
+ unsigned long ip);
+/**
+ * kasan_mempool_unpoison_pages - Unpoison a mempool page allocation.
+ * @page: Pointer to the page allocation.
+ * @order: Order of the allocation.
+ *
+ * This function is intended for kernel subsystems that cache page allocations
+ * to reuse them instead of freeing them back to page_alloc (e.g. mempool).
+ *
+ * This function unpoisons a page allocation that was previously poisoned by
+ * kasan_mempool_poison_pages() without zeroing the allocation's memory. For
+ * the tag-based modes, this function assigns a new tag to the allocation.
+ */
+static __always_inline void kasan_mempool_unpoison_pages(struct page *page,
+ unsigned int order)
+{
+ if (kasan_enabled())
+ __kasan_mempool_unpoison_pages(page, order, _RET_IP_);
+}
+
bool __kasan_mempool_poison_object(void *ptr, unsigned long ip);
/**
* kasan_mempool_poison_object - Check and poison a mempool slab allocation.
@@ -353,6 +377,7 @@ static inline bool kasan_mempool_poison_
{
return true;
}
+static inline void kasan_mempool_unpoison_pages(struct page *page, unsigned int order) {}
static inline bool kasan_mempool_poison_object(void *ptr)
{
return true;
--- a/mm/kasan/common.c~kasan-introduce-kasan_mempool_unpoison_pages
+++ a/mm/kasan/common.c
@@ -449,6 +449,12 @@ bool __kasan_mempool_poison_pages(struct
return true;
}
+void __kasan_mempool_unpoison_pages(struct page *page, unsigned int order,
+ unsigned long ip)
+{
+ __kasan_unpoison_pages(page, order, false);
+}
+
bool __kasan_mempool_poison_object(void *ptr, unsigned long ip)
{
struct folio *folio;
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
kasan-rename-kasan_slab_free_mempool-to-kasan_mempool_poison_object.patch
kasan-move-kasan_mempool_poison_object.patch
kasan-document-kasan_mempool_poison_object.patch
kasan-add-return-value-for-kasan_mempool_poison_object.patch
kasan-introduce-kasan_mempool_unpoison_object.patch
kasan-introduce-kasan_mempool_poison_pages.patch
kasan-introduce-kasan_mempool_unpoison_pages.patch
kasan-clean-up-__kasan_mempool_poison_object.patch
kasan-save-free-stack-traces-for-slab-mempools.patch
kasan-clean-up-and-rename-____kasan_kmalloc.patch
kasan-introduce-poison_kmalloc_large_redzone.patch
kasan-save-alloc-stack-traces-for-mempool.patch
mempool-skip-slub_debug-poisoning-when-kasan-is-enabled.patch
mempool-use-new-mempool-kasan-hooks.patch
mempool-introduce-mempool_use_prealloc_only.patch
kasan-add-mempool-tests.patch
kasan-rename-pagealloc-tests.patch
kasan-reorder-tests.patch
kasan-rename-and-document-kasan_unpoison_object_data.patch
skbuff-use-mempool-kasan-hooks.patch
io_uring-use-mempool-kasan-hook.patch
