[PATCH 14/15] isci: avoid gcc-10 zero-length-bounds warning

From: Arnd Bergmann
Date: Thu Apr 30 2020 - 17:34:13 EST


gcc-10 warns about accesses to zero-length arrays:

drivers/scsi/isci/task.h:125:31: error: array subscript 0 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[0]'} [-Werror=zero-length-bounds]
125 | tmf->resp.resp_iu.resp_data[0],
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
include/linux/dynamic_debug.h:143:2: note: in expansion of macro '__dynamic_func_call'
143 | __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
| ^~~~~~~~~~~~~~~~~~~
include/linux/dynamic_debug.h:157:2: note: in expansion of macro '_dynamic_func_call'
157 | _dynamic_func_call(fmt,__dynamic_dev_dbg, \
| ^~~~~~~~~~~~~~~~~~
include/linux/dev_printk.h:115:2: note: in expansion of macro 'dynamic_dev_dbg'
115 | dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
| ^~~~~~~~~~~~~~~
drivers/scsi/isci/task.h:111:3: note: in expansion of macro 'dev_dbg'
111 | dev_dbg(&ihost->pdev->dev,
| ^~~~~~~
In file included from include/scsi/libsas.h:15,
from drivers/scsi/isci/task.c:59:
include/scsi/sas.h:326:9: note: while referencing 'resp_data'
326 | u8 resp_data[0];
| ^~~~~~~~~

This instance is not a bug, so just work around the warning by
adding a temporary pointer.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/scsi/isci/task.h | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/isci/task.h b/drivers/scsi/isci/task.h
index 8f4531f22ac2..2d556d7b5292 100644
--- a/drivers/scsi/isci/task.h
+++ b/drivers/scsi/isci/task.h
@@ -98,6 +98,8 @@ struct isci_tmf {

static inline void isci_print_tmf(struct isci_host *ihost, struct isci_tmf *tmf)
{
+ u8 *resp = tmf->resp.resp_iu.resp_data;
+
if (SAS_PROTOCOL_SATA == tmf->proto)
dev_dbg(&ihost->pdev->dev,
"%s: status = %x\n"
@@ -122,10 +124,7 @@ static inline void isci_print_tmf(struct isci_host *ihost, struct isci_tmf *tmf)
tmf->resp.resp_iu.datapres,
tmf->resp.resp_iu.status,
be32_to_cpu(tmf->resp.resp_iu.response_data_len),
- tmf->resp.resp_iu.resp_data[0],
- tmf->resp.resp_iu.resp_data[1],
- tmf->resp.resp_iu.resp_data[2],
- tmf->resp.resp_iu.resp_data[3]);
+ resp[0], resp[1], resp[2], resp[3]);
}


--
2.26.0