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From:   andrey.konovalov@linux.dev
To:     Marco Elver <elver@google.com>,
        Alexander Potapenko <glider@google.com>
Cc:     Andrey Konovalov <andreyknvl@gmail.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        kasan-dev@googlegroups.com, Evgenii Stepanov <eugenis@google.com>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH RFC 03/20] kasan: document kasan_mempool_poison_object
Date:   Mon,  6 Nov 2023 21:10:12 +0100
Message-Id: <e0c319c2033685fc25765af45d5b75224c15721e.1699297309.git.andreyknvl@google.com>
In-Reply-To: <cover.1699297309.git.andreyknvl@google.com>
References: <cover.1699297309.git.andreyknvl@google.com>
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From: Andrey Konovalov <andreyknvl@google.com>

Add documentation comment for kasan_mempool_poison_object.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 include/linux/kasan.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 0d1f925c136d..bbf6e2fa4ffd 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -213,6 +213,24 @@ static __always_inline void * __must_check kasan_krealloc(const void *object,
 }
 
 void __kasan_mempool_poison_object(void *ptr, unsigned long ip);
+/**
+ * kasan_mempool_poison_object - Check and poison a mempool slab allocation.
+ * @ptr: Pointer to the slab allocation.
+ *
+ * This function is intended for kernel subsystems that cache slab allocations
+ * to reuse them instead of freeing them back to the slab allocator (e.g.
+ * mempool).
+ *
+ * This function poisons a slab allocation without initializing its memory and
+ * without putting it into the quarantine (for the Generic mode).
+ *
+ * This function also performs checks to detect double-free and invalid-free
+ * bugs and reports them.
+ *
+ * This function operates on all slab allocations including large kmalloc
+ * allocations (the ones returned by kmalloc_large() or by kmalloc() with the
+ * size > KMALLOC_MAX_SIZE).
+ */
 static __always_inline void kasan_mempool_poison_object(void *ptr)
 {
 	if (kasan_enabled())
-- 
2.25.1