Commit b8517861 authored by Kees Cook's avatar Kees Cook Committed by Vinod Koul
Browse files

dmaengine: ti: omap-dma: Annotate struct omap_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 omap_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: Peter Ujfalusi <peter.ujfalusi@gmail.com>
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/20230817235859.49846-18-keescook@chromium.org


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 5f240e0c

drivers/dma/ti/omap-dma.c

+2 −3
Original line number Diff line number Diff line
@@ -124,7 +124,7 @@ struct omap_desc { 
	uint32_t csdp;		/* CSDP value */



	unsigned sglen;

	struct omap_sg sg[];

	struct omap_sg sg[] __counted_by(sglen);

};



enum {
@@ -1005,6 +1005,7 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg( 
	d = kzalloc(struct_size(d, sg, sglen), GFP_ATOMIC);

	if (!d)

		return NULL;

	d->sglen = sglen;



	d->dir = dir;

	d->dev_addr = dev_addr;
@@ -1120,8 +1121,6 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg( 
		}

	}



	d->sglen = sglen;



	/* Release the dma_pool entries if one allocation failed */

	if (ll_failed) {

		for (i = 0; i < d->sglen; i++) {