| Message ID | 20230817235859.49846-8-keescook@chromium.org |
|---|---|
| State | Accepted |
| Commit | 04b5433b8c0e1b014f081f4bf79767bbc207a7b0 |
| Headers | show |
| Series | dmaengine: Annotate with __counted_by | expand |
On 8/17/23 17:58, Kees Cook wrote: > 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> Thanks -- Gustavo > --- > drivers/dma/sa11x0-dma.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/dma/sa11x0-dma.c b/drivers/dma/sa11x0-dma.c > index a29c13cae716..e5849622f198 100644 > --- a/drivers/dma/sa11x0-dma.c > +++ b/drivers/dma/sa11x0-dma.c > @@ -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; >
diff --git a/drivers/dma/sa11x0-dma.c b/drivers/dma/sa11x0-dma.c index a29c13cae716..e5849622f198 100644 --- a/drivers/dma/sa11x0-dma.c +++ b/drivers/dma/sa11x0-dma.c @@ -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;
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> --- drivers/dma/sa11x0-dma.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)