Commit fd1cb31a authored by Kees Cook's avatar Kees Cook Committed by Vinod Koul
Browse files

dmaengine: moxart-dma: Annotate struct moxart_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 moxart_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/20230817235859.49846-6-keescook@chromium.org


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 7d4b8218

drivers/dma/moxart-dma.c

+2 −3
Original line number Diff line number Diff line
@@ -124,7 +124,7 @@ struct moxart_desc { 
	unsigned int			dma_cycles;

	struct virt_dma_desc		vd;

	uint8_t				es;

	struct moxart_sg		sg[];

	struct moxart_sg		sg[] __counted_by(sglen);

};



struct moxart_chan {
@@ -309,6 +309,7 @@ static struct dma_async_tx_descriptor *moxart_prep_slave_sg( 
	d = kzalloc(struct_size(d, sg, sg_len), GFP_ATOMIC);

	if (!d)

		return NULL;

	d->sglen = sg_len;



	d->dma_dir = dir;

	d->dev_addr = dev_addr;
@@ -319,8 +320,6 @@ static struct dma_async_tx_descriptor *moxart_prep_slave_sg( 
		d->sg[i].len = sg_dma_len(sgent);

	}



	d->sglen = sg_len;



	ch->error = 0;



	return vchan_tx_prep(&ch->vc, &d->vd, tx_flags);