Re: [PATCH 3/4] scsi: qla2xxx: avoid printf format warning

From: Himanshu Madhani
Date: Wed Mar 06 2019 - 12:29:46 EST




ïOn 3/4/19, 11:39 AM, "Arnd Bergmann" <arnd@xxxxxxxx> wrote:

Depending on the target architecture and configuration, both phys_addr_t
and dma_addr_t may be smaller than 'long long', so we get a warning when
printing either of them using the %llx format string:

drivers/scsi/qla2xxx/qla_iocb.c: In function 'qla24xx_walk_and_build_prot_sglist':
drivers/scsi/qla2xxx/qla_iocb.c:1140:46: error: format '%llx' expects argument of type 'long long unsigned int', but argument 6 has type 'dma_addr_t' {aka 'unsigned int'} [-Werror=format=]
"%s: page boundary crossing (phys=%llx len=%x)\n",
~~~^
%x
__func__, sle_phys, sg->length);
~~~~~~~~
drivers/scsi/qla2xxx/qla_iocb.c:1180:29: error: format '%llx' expects argument of type 'long long unsigned int', but argument 7 has type 'dma_addr_t' {aka 'unsigned int'} [-Werror=format=]
"%s: sg[%x] (phys=%llx sglen=%x) ldma_sg_len: %x dif_bundl_len: %x ldma_needed: %x\n",
~~~^

There are special %pad and %pap format strings in Linux that we could use here,
but since the driver already does 64-bit arithmetic on the values, using a
plain 'u64' seems more consistent here.

Note: A possible related issue may be that the driver possibly checks the
wrong kind of overflow: when an IOMMU is in use, buffers that cross a 32-bit
boundary in physical addresses would still be mapped into dma addresses
within the low 4GB space, so I suspect that we actually want to check
sg_dma_address() instead of sg_phys() here.

Fixes: 50b812755e97 ("scsi: qla2xxx: Fix DMA error when the DIF sg buffer crosses 4GB boundary")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/scsi/qla2xxx/qla_iocb.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_iocb.c b/drivers/scsi/qla2xxx/qla_iocb.c
index 63f8e3c19841..456a41d2e2c6 100644
--- a/drivers/scsi/qla2xxx/qla_iocb.c
+++ b/drivers/scsi/qla2xxx/qla_iocb.c
@@ -1132,7 +1132,7 @@ qla24xx_walk_and_build_prot_sglist(struct qla_hw_data *ha, srb_t *sp,
/* if initiator doing write or target doing read */
if (direction_to_device) {
for_each_sg(sgl, sg, tot_dsds, i) {
- dma_addr_t sle_phys = sg_phys(sg);
+ u64 sle_phys = sg_phys(sg);

/* If SGE addr + len flips bits in upper 32-bits */
if (MSD(sle_phys + sg->length) ^ MSD(sle_phys)) {
@@ -1178,7 +1178,7 @@ qla24xx_walk_and_build_prot_sglist(struct qla_hw_data *ha, srb_t *sp,

ql_dbg(ql_dbg_tgt + ql_dbg_verbose, vha, 0xe023,
"%s: sg[%x] (phys=%llx sglen=%x) ldma_sg_len: %x dif_bundl_len: %x ldma_needed: %x\n",
- __func__, i, sg_phys(sg), sglen, ldma_sg_len,
+ __func__, i, (u64)sg_phys(sg), sglen, ldma_sg_len,
difctx->dif_bundl_len, ldma_needed);

while (sglen) {
--
2.20.0

Looks good

Acked-by: Himanshu Madhani <hmadhani@xxxxxxxxxxx>