[PATCH] scsi: qla4xxx: avoid freeing unallocated dma memory

From: Arnd Bergmann
Date: Fri Mar 22 2019 - 10:25:52 EST


Clang -Wuninitialized notices that on is_qla40XX we never allocate
any DMA memory in get_fw_boot_info() but attempt to free it anyway:

drivers/scsi/qla4xxx/ql4_os.c:5915:7: error: variable 'buf_dma' is used uninitialized whenever 'if' condition is false
[-Werror,-Wsometimes-uninitialized]
if (!(val & 0x07)) {
^~~~~~~~~~~~~
drivers/scsi/qla4xxx/ql4_os.c:5985:47: note: uninitialized use occurs here
dma_free_coherent(&ha->pdev->dev, size, buf, buf_dma);
^~~~~~~
drivers/scsi/qla4xxx/ql4_os.c:5915:3: note: remove the 'if' if its condition is always true
if (!(val & 0x07)) {
^~~~~~~~~~~~~~~~~~~
drivers/scsi/qla4xxx/ql4_os.c:5885:20: note: initialize the variable 'buf_dma' to silence this warning
dma_addr_t buf_dma;
^
= 0

Skip the call to dma_free_coherent() here.

Fixes: 2a991c215978 ("[SCSI] qla4xxx: Boot from SAN support for open-iscsi")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/scsi/qla4xxx/ql4_os.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index 16a18d5d856f..daa884fa43f4 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -5928,7 +5928,7 @@ static int get_fw_boot_info(struct scsi_qla_host *ha, uint16_t ddb_index[])
val = rd_nvram_byte(ha, sec_addr);
if (val & BIT_7)
ddb_index[1] = (val & 0x7f);
-
+ goto exit_boot_info;
} else if (is_qla80XX(ha)) {
buf = dma_alloc_coherent(&ha->pdev->dev, size,
&buf_dma, GFP_KERNEL);
--
2.20.0