Commit 04b5433b authored by Kees Cook's avatar Kees Cook Committed by Vinod Koul
Browse files

dmaengine: sa11x0: Annotate struct sa11x0_dma_desc 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 sa11x0_dma_desc.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

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



Cc: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatar"Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230817235859.49846-8-keescook@chromium.org


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent b9fe0bd5

drivers/dma/sa11x0-dma.c

+3 −3
Original line number Diff line number Diff line
@@ -78,7 +78,7 @@ struct sa11x0_dma_desc { 
	bool			cyclic;



	unsigned		sglen;

	struct sa11x0_dma_sg	sg[];

	struct sa11x0_dma_sg	sg[] __counted_by(sglen);

};



struct sa11x0_dma_phy;
@@ -558,6 +558,7 @@ static struct dma_async_tx_descriptor *sa11x0_dma_prep_slave_sg( 
		dev_dbg(chan->device->dev, "vchan %p: kzalloc failed\n", &c->vc);

		return NULL;

	}

	txd->sglen = j;



	j = 0;

	for_each_sg(sg, sgent, sglen, i) {
@@ -593,7 +594,6 @@ static struct dma_async_tx_descriptor *sa11x0_dma_prep_slave_sg( 


	txd->ddar = c->ddar;

	txd->size = size;

	txd->sglen = j;



	dev_dbg(chan->device->dev, "vchan %p: txd %p: size %zu nr %u\n",

		&c->vc, &txd->vd, txd->size, txd->sglen);
@@ -628,6 +628,7 @@ static struct dma_async_tx_descriptor *sa11x0_dma_prep_dma_cyclic( 
		dev_dbg(chan->device->dev, "vchan %p: kzalloc failed\n", &c->vc);

		return NULL;

	}

	txd->sglen = sglen;



	for (i = k = 0; i < size / period; i++) {

		size_t tlen, len = period;
@@ -653,7 +654,6 @@ static struct dma_async_tx_descriptor *sa11x0_dma_prep_dma_cyclic( 


	txd->ddar = c->ddar;

	txd->size = size;

	txd->sglen = sglen;

	txd->cyclic = 1;

	txd->period = sgperiod;