From: John Stultz <john.stultz@linaro.org>
To: guangming.cao@mediatek.com
Cc: benjamin.gaignard@linaro.org, bo.song@mediatek.com,
christian.koenig@amd.com, dri-devel@lists.freedesktop.org,
jianjiao.zeng@mediatek.com, labbott@redhat.com,
libo.kang@mediatek.com, linaro-mm-sig@lists.linaro.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
linux-mediatek@lists.infradead.org, lmark@codeaurora.org,
matthias.bgg@gmail.com, michael.j.ruhl@intel.com,
mingyuan.ma@mediatek.com, sumit.semwal@linaro.org,
wsd_upstream@mediatek.com, yf.wang@mediatek.com,
caoguangming34@gmail.com
Subject: Re: [PATCH v4] dma-buf: system_heap: Add a size check for allocation
Date: Wed, 19 Jan 2022 19:48:55 -0800 [thread overview]
Message-ID: <CALAqxLW5uEZCGHGk3rYoiOGzN5XMKb39JzoPB1iEX9k3UsiT-A@mail.gmail.com> (raw)
In-Reply-To: <20220120033450.90164-1-guangming.cao@mediatek.com>
On Wed, Jan 19, 2022 at 7:34 PM <guangming.cao@mediatek.com> wrote:
>
> From: Guangming <Guangming.Cao@mediatek.com>
>
> Add a size check for allocation since the allocation size should be
> always less than the total DRAM size on system heap.
> And it can prevent consuming too much time for invalid allocations.
>
> Signed-off-by: Guangming <Guangming.Cao@mediatek.com>
> ---
> drivers/dma-buf/heaps/system_heap.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
> index 23a7e74ef966..bd6f255620e2 100644
> --- a/drivers/dma-buf/heaps/system_heap.c
> +++ b/drivers/dma-buf/heaps/system_heap.c
> @@ -347,6 +347,13 @@ static struct dma_buf *system_heap_allocate(struct dma_heap *heap,
> struct page *page, *tmp_page;
> int i, ret = -ENOMEM;
>
> + /*
> + * Size check. The "len" should be less than totalram since system_heap
> + * memory is comes from system. Adding check here can prevent consuming
> + * too much time for invalid allocations.
> + */
> + if (len >> PAGE_SHIFT > totalram_pages())
> + return -EINVAL;
Thanks so much for revising and sending this along! It looks good to me.
Acked-by: John Stultz <john.stultz@linaro.org>
thanks again
-john
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next prev parent reply other threads:[~2022-01-20 3:49 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-17 9:41 [PATCH] dma-buf: dma-heap: Add a size limitation for allocation guangming.cao
2021-12-27 9:51 ` [PATCH v2] dma-buf: dma-heap: Add a size check " guangming.cao
2022-01-03 18:57 ` John Stultz
2022-01-04 7:47 ` Christian König
2022-01-04 8:44 ` Guangming.Cao
2022-01-05 6:36 ` guangming.cao
2022-01-13 10:50 ` Sumit Semwal
2022-01-13 12:34 ` [PATCH v3] " guangming.cao
2022-01-13 12:57 ` Ruhl, Michael J
2022-01-13 13:00 ` Ruhl, Michael J
2022-01-13 13:05 ` Christian König
2022-01-13 23:26 ` John Stultz
2022-01-14 7:16 ` Christian König
2022-01-14 12:05 ` Guangming.Cao
2022-01-15 1:17 ` John Stultz
2022-01-19 9:59 ` Guangming.Cao
2022-01-19 20:37 ` John Stultz
2022-01-20 3:34 ` [PATCH v4] dma-buf: system_heap: " guangming.cao
2022-01-20 3:48 ` John Stultz [this message]
2022-01-20 7:08 ` [PATCH v5] " guangming.cao
2022-01-20 8:27 ` Christian König
2022-01-20 8:52 ` [PATCH v6] " guangming.cao
2022-01-20 10:00 ` [PATCH v6 RESEND] " guangming.cao
2022-01-20 10:22 ` Christian König
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