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: Kees Cook <keescook@chromium.org>
Reviewed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230817235859.49846-18-keescook@chromium.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Kees Cook 2023-08-17 16:58:55 -07:00 committed by Vinod Koul
parent 5f240e0cdb
commit b85178611c

View File

@ -124,7 +124,7 @@ struct omap_desc {
uint32_t csdp; /* CSDP value */ uint32_t csdp; /* CSDP value */
unsigned sglen; unsigned sglen;
struct omap_sg sg[]; struct omap_sg sg[] __counted_by(sglen);
}; };
enum { 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); d = kzalloc(struct_size(d, sg, sglen), GFP_ATOMIC);
if (!d) if (!d)
return NULL; return NULL;
d->sglen = sglen;
d->dir = dir; d->dir = dir;
d->dev_addr = dev_addr; 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 */ /* Release the dma_pool entries if one allocation failed */
if (ll_failed) { if (ll_failed) {
for (i = 0; i < d->sglen; i++) { for (i = 0; i < d->sglen; i++) {