| Message ID | 20230817235859.49846-19-keescook@chromium.org |
|---|---|
| State | Handled Elsewhere |
| 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 uniphier_xdmac_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: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> > Cc: Masami Hiramatsu <mhiramat@kernel.org> > Cc: dmaengine@vger.kernel.org > Cc: linux-arm-kernel@lists.infradead.org > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Thanks -- Gustavo > --- > drivers/dma/uniphier-xdmac.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/dma/uniphier-xdmac.c b/drivers/dma/uniphier-xdmac.c > index 290836b7e1be..dd51522879a7 100644 > --- a/drivers/dma/uniphier-xdmac.c > +++ b/drivers/dma/uniphier-xdmac.c > @@ -80,7 +80,7 @@ struct uniphier_xdmac_desc { > unsigned int nr_node; > unsigned int cur_node; > enum dma_transfer_direction dir; > - struct uniphier_xdmac_desc_node nodes[]; > + struct uniphier_xdmac_desc_node nodes[] __counted_by(nr_node); > }; > > struct uniphier_xdmac_chan { > @@ -295,6 +295,7 @@ uniphier_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst, > xd = kzalloc(struct_size(xd, nodes, nr), GFP_NOWAIT); > if (!xd) > return NULL; > + xd->nr_node = nr; > > for (i = 0; i < nr; i++) { > burst_size = min_t(size_t, len, XDMAC_MAX_WORD_SIZE); > @@ -309,7 +310,6 @@ uniphier_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst, > } > > xd->dir = DMA_MEM_TO_MEM; > - xd->nr_node = nr; > xd->cur_node = 0; > > return vchan_tx_prep(vc, &xd->vd, flags); > @@ -351,6 +351,7 @@ uniphier_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, > xd = kzalloc(struct_size(xd, nodes, sg_len), GFP_NOWAIT); > if (!xd) > return NULL; > + xd->nr_node = sg_len; > > for_each_sg(sgl, sg, sg_len, i) { > xd->nodes[i].src = (direction == DMA_DEV_TO_MEM) > @@ -385,7 +386,6 @@ uniphier_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, > } > > xd->dir = direction; > - xd->nr_node = sg_len; > xd->cur_node = 0; > > return vchan_tx_prep(vc, &xd->vd, flags);
diff --git a/drivers/dma/uniphier-xdmac.c b/drivers/dma/uniphier-xdmac.c index 290836b7e1be..dd51522879a7 100644 --- a/drivers/dma/uniphier-xdmac.c +++ b/drivers/dma/uniphier-xdmac.c @@ -80,7 +80,7 @@ struct uniphier_xdmac_desc { unsigned int nr_node; unsigned int cur_node; enum dma_transfer_direction dir; - struct uniphier_xdmac_desc_node nodes[]; + struct uniphier_xdmac_desc_node nodes[] __counted_by(nr_node); }; struct uniphier_xdmac_chan { @@ -295,6 +295,7 @@ uniphier_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst, xd = kzalloc(struct_size(xd, nodes, nr), GFP_NOWAIT); if (!xd) return NULL; + xd->nr_node = nr; for (i = 0; i < nr; i++) { burst_size = min_t(size_t, len, XDMAC_MAX_WORD_SIZE); @@ -309,7 +310,6 @@ uniphier_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst, } xd->dir = DMA_MEM_TO_MEM; - xd->nr_node = nr; xd->cur_node = 0; return vchan_tx_prep(vc, &xd->vd, flags); @@ -351,6 +351,7 @@ uniphier_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, xd = kzalloc(struct_size(xd, nodes, sg_len), GFP_NOWAIT); if (!xd) return NULL; + xd->nr_node = sg_len; for_each_sg(sgl, sg, sg_len, i) { xd->nodes[i].src = (direction == DMA_DEV_TO_MEM) @@ -385,7 +386,6 @@ uniphier_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, } xd->dir = direction; - xd->nr_node = sg_len; xd->cur_node = 0; return vchan_tx_prep(vc, &xd->vd, flags);
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 uniphier_xdmac_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: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: dmaengine@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/dma/uniphier-xdmac.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)