From mboxrd@z Thu Jan 1 00:00:00 1970 From: Logan Gunthorpe Date: Fri, 23 Jul 2021 17:50:08 +0000 Subject: [PATCH v2 21/21] dma-mapping: Disallow .map_sg operations from returning zero on error Message-Id: <20210723175008.22410-22-logang@deltatee.com> List-Id: References: <20210723175008.22410-1-logang@deltatee.com> In-Reply-To: <20210723175008.22410-1-logang@deltatee.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, iommu@lists.linux-foundation.org, linux-parisc@vger.kernel.org, xen-devel@lists.xenproject.org Cc: Christoph Hellwig , Marek Szyprowski , Robin Murphy , Stephen Bates , Martin Oliveira , Logan Gunthorpe Now that all the .map_sg operations have been converted to returning proper error codes, drop the code to handle a zero return value, add a warning if a zero is returned and update the comment for the map_sg operation. Signed-off-by: Logan Gunthorpe --- kernel/dma/mapping.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index b8dc8b1cb402..86a8a421344a 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -194,6 +194,9 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, else ents = ops->map_sg(dev, sg, nents, dir, attrs); + if (WARN_ON_ONCE(ents = 0)) + return -EIO; + if (ents > 0) debug_dma_map_sg(dev, sg, nents, ents, dir); @@ -259,9 +262,7 @@ int dma_map_sgtable(struct device *dev, struct sg_table *sgt, int nents; nents = __dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); - if (nents = 0) - return -EIO; - else if (nents < 0) { + if (nents < 0) { if (WARN_ON_ONCE(nents != -EINVAL && nents != -ENOMEM && nents != -EIO)) return -EIO; -- 2.20.1