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From:   Julia Lawall <Julia.Lawall@inria.fr>
To:     Sumit Semwal <sumit.semwal@linaro.org>
Cc:     keescook@chromium.org, kernel-janitors@vger.kernel.org,
        Benjamin Gaignard <benjamin.gaignard@collabora.com>,
        Liam Mark <lmark@codeaurora.org>,
        Laura Abbott <labbott@redhat.com>,
        Brian Starkey <Brian.Starkey@arm.com>,
        John Stultz <jstultz@google.com>,
        =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>,
        linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
        linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org
Subject: [PATCH 06/26] dma-buf: system_heap: use array_size
Date:   Fri, 23 Jun 2023 23:14:37 +0200
Message-Id: <20230623211457.102544-7-Julia.Lawall@inria.fr>
In-Reply-To: <20230623211457.102544-1-Julia.Lawall@inria.fr>
References: <20230623211457.102544-1-Julia.Lawall@inria.fr>
MIME-Version: 1.0
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Use array_size to protect against multiplication overflows.

The changes were done using the following Coccinelle semantic patch:

// <smpl>
@@
    size_t e1,e2;
    expression COUNT;
    identifier alloc = {vmalloc,vzalloc,kvmalloc,kvzalloc};
@@

(
      alloc(
-           (e1) * (e2)
+           array_size(e1, e2)
      ,...)
|
      alloc(
-           (e1) * (COUNT)
+           array_size(COUNT, e1)
      ,...)
)
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

---
 drivers/dma-buf/heaps/system_heap.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
index ee7059399e9c..fb7867599874 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -221,7 +221,7 @@ static void *system_heap_do_vmap(struct system_heap_buffer *buffer)
 {
 	struct sg_table *table = &buffer->sg_table;
 	int npages = PAGE_ALIGN(buffer->len) / PAGE_SIZE;
-	struct page **pages = vmalloc(sizeof(struct page *) * npages);
+	struct page **pages = vmalloc(array_size(npages, sizeof(struct page *)));
 	struct page **tmp = pages;
 	struct sg_page_iter piter;
 	void *vaddr;