[PATCH] scsi: gdth: Only call dma_free_coherent when buf is not NULL in ioc_general

Nathan Chancellor
2019-03-07T23:18:39Z

When building with -Wsometimes-uninitialized, Clang warns:

drivers/scsi/gdth.c:3662:6: warning: variable 'paddr' is used
uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]

Don't attempt to call dma_free_coherent when buf is NULL (meaning that
we never called dma_alloc_coherent and initialized paddr), which avoids
this warning.

Link: https://github.com/ClangBuiltLinux/linux/issues/402
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
drivers/scsi/gdth.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/gdth.c b/drivers/scsi/gdth.c
index e7f1dd4f3b66..0ca9b4393770 100644
--- a/drivers/scsi/gdth.c
+++ b/drivers/scsi/gdth.c
@@ -3697,8 +3697,9 @@ static int ioc_general(void __user *arg, char *cmnd)

rval = 0;
out_free_buf:
- dma_free_coherent(&ha->pdev->dev, gen.data_len + gen.sense_len, buf,
- paddr);
+ if (buf)
+ dma_free_coherent(&ha->pdev->dev, gen.data_len + gen.sense_len,
+ buf, paddr);
return rval;
}

--
2.21.0