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: Kees Cook <keescook@chromium.org>
Reviewed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230817235859.49846-8-keescook@chromium.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Kees Cook 2023-08-17 16:58:45 -07:00 committed by Vinod Koul
parent b9fe0bd590
commit 04b5433b8c

View file

@ -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;