dmaengine: hisilicon: Annotate struct hisi_dma_dev with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct hisi_dma_dev.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Vinod Koul <vkoul@kernel.org>
Cc: Zhou Wang <wangzhou1@hisilicon.com>
Cc: Jie Hai <haijie1@huawei.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230817235859.49846-5-keescook@chromium.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/hisi_dma.c b/drivers/dma/hisi_dma.c
index c1350a36fddd995c3144176b91affb5f87350ff5..4c47bff81064015a9f737eb8dfff632ae8386d56 100644 (file)
--- a/drivers/dma/hisi_dma.c
+++ b/drivers/dma/hisi_dma.c
@@ -163,7 +163,7 @@ struct hisi_dma_dev {
        u32 chan_depth;
        enum hisi_dma_reg_layout reg_layout;
        void __iomem *queue_base; /* queue region start of register */
-       struct hisi_dma_chan chan[];
+       struct hisi_dma_chan chan[] __counted_by(chan_num);
 };
 
 #ifdef CONFIG_DEBUG_FS