| Message ID | 20190620062622.9979-1-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | scsi: mvumi: fix build warning | expand |
On 6/19/19 11:26 PM, Ming Lei wrote: > The local variable 'sg' should be initialized in the failure path of > mvumi_make_sgl(), otherwise the following build warning is triggered: > > In file included from include/linux/pci-dma-compat.h:8, > from include/linux/pci.h:2408, > from drivers/scsi/mvumi.c:13: > drivers/scsi/mvumi.c: In function 'mvumi_queue_command': > include/linux/dma-mapping.h:608:34: warning: 'sg' may be used uninitialized in this function > +[-Wmaybe-uninitialized] > #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0) > ^~~~~~~~~~~~~~~~~~ > drivers/scsi/mvumi.c:192:22: note: 'sg' was declared here > struct scatterlist *sg; > ^~ > Fixed it by removing the local variable reference in failure path. Reviewed-by: Bart Van Assche <bvanassche@acm.org>
On Thu, 2019-06-20 at 14:26 +0800, Ming Lei wrote: > The local variable 'sg' should be initialized in the failure path of > mvumi_make_sgl(), otherwise the following build warning is triggered: > > In file included from include/linux/pci-dma-compat.h:8, > from include/linux/pci.h:2408, > from drivers/scsi/mvumi.c:13: > drivers/scsi/mvumi.c: In function 'mvumi_queue_command': > include/linux/dma-mapping.h:608:34: warning: 'sg' may be used > uninitialized in this function > +[-Wmaybe-uninitialized] > #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, > r, 0) > ^~~~~~~~~~~~~~~~~~ > drivers/scsi/mvumi.c:192:22: note: 'sg' was declared here > struct scatterlist *sg; > ^~ > Fixed it by removing the local variable reference in failure path. > > Cc: Christoph Hellwig <hch@lst.de> > Cc: Bart Van Assche <bvanassche@acm.org> > Cc: Ewan D. Milne <emilne@redhat.com> > Fixes: 350d66a72adc ("scsi: mvumi: use sg helper to iterate over > scatterlist") > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > drivers/scsi/mvumi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/scsi/mvumi.c b/drivers/scsi/mvumi.c > index 0022cd31500a..53f3563aca22 100644 > --- a/drivers/scsi/mvumi.c > +++ b/drivers/scsi/mvumi.c > @@ -217,7 +217,7 @@ static int mvumi_make_sgl(struct mvumi_hba *mhba, > struct scsi_cmnd *scmd, > dev_err(&mhba->pdev->dev, > "sg count[0x%x] is bigger than max > sg[0x%x].\n", > *sg_count, mhba->max_sge); > - dma_unmap_sg(&mhba->pdev->dev, sg, sgnum, > + dma_unmap_sg(&mhba->pdev->dev, scsi_sglist(scmd), > sgnum, > scmd->sc_data_direction); > return -1; > } I think this is a serious enough problem for mvumi that it needs folding with comment into the original path. I believe it will cause an oops when this code path is hit otherwise, right? James
Ming, > The local variable 'sg' should be initialized in the failure path of > mvumi_make_sgl(), otherwise the following build warning is triggered: Rolled this fix into the mvumi commit. Thanks!
diff --git a/drivers/scsi/mvumi.c b/drivers/scsi/mvumi.c index 0022cd31500a..53f3563aca22 100644 --- a/drivers/scsi/mvumi.c +++ b/drivers/scsi/mvumi.c @@ -217,7 +217,7 @@ static int mvumi_make_sgl(struct mvumi_hba *mhba, struct scsi_cmnd *scmd, dev_err(&mhba->pdev->dev, "sg count[0x%x] is bigger than max sg[0x%x].\n", *sg_count, mhba->max_sge); - dma_unmap_sg(&mhba->pdev->dev, sg, sgnum, + dma_unmap_sg(&mhba->pdev->dev, scsi_sglist(scmd), sgnum, scmd->sc_data_direction); return -1; }
The local variable 'sg' should be initialized in the failure path of mvumi_make_sgl(), otherwise the following build warning is triggered: In file included from include/linux/pci-dma-compat.h:8, from include/linux/pci.h:2408, from drivers/scsi/mvumi.c:13: drivers/scsi/mvumi.c: In function 'mvumi_queue_command': include/linux/dma-mapping.h:608:34: warning: 'sg' may be used uninitialized in this function +[-Wmaybe-uninitialized] #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0) ^~~~~~~~~~~~~~~~~~ drivers/scsi/mvumi.c:192:22: note: 'sg' was declared here struct scatterlist *sg; ^~ Fixed it by removing the local variable reference in failure path. Cc: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Ewan D. Milne <emilne@redhat.com> Fixes: 350d66a72adc ("scsi: mvumi: use sg helper to iterate over scatterlist") Signed-off-by: Ming Lei <ming.lei@redhat.com> --- drivers/scsi/mvumi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)