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@xxxxxxxxxx> Cc: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx> Cc: dmaengine@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- drivers/dma/ti/omap-dma.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/dma/ti/omap-dma.c b/drivers/dma/ti/omap-dma.c index cf96cf915c0c..11ac3fc0a52a 100644 --- a/drivers/dma/ti/omap-dma.c +++ b/drivers/dma/ti/omap-dma.c @@ -124,7 +124,7 @@ struct omap_desc { uint32_t csdp; /* CSDP value */ unsigned sglen; - struct omap_sg sg[]; + struct omap_sg sg[] __counted_by(sglen); }; 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); if (!d) return NULL; + d->sglen = sglen; d->dir = dir; 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 */ if (ll_failed) { for (i = 0; i < d->sglen; i++) { -- 2.34.1
