On 7/1/22 9:39 AM, Nathan Chancellor wrote:
On Fri, Jul 01, 2022 at 08:48:11AM -0600, Shuah Khan wrote:
On 7/1/22 2:59 AM, Greg Kroah-Hartman wrote:
All warnings (new ones prefixed by >>):
if (!ucr->rsp_buf)drivers/misc/cardreader/rtsx_usb.c:639:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
^~~~~~~~~~~~~
drivers/misc/cardreader/rtsx_usb.c:678:9: note: uninitialized use occurs here
return ret;
^~~
drivers/misc/cardreader/rtsx_usb.c:639:2: note: remove the 'if' if its condition is always false
if (!ucr->rsp_buf)
^~~~~~~~~~~~~~~~~~
drivers/misc/cardreader/rtsx_usb.c:622:9: note: initialize the variable 'ret' to silence this warning
int ret;
^
= 0
1 warning generated.
Odd, gcc doesn't show this for me. Shuah, can you send a follow-on
patch to fix this? The warning does look correct.
gcc didn't complain when I compiled either. I will send a follow-on patch.
Unfortunately, GCC won't warn for most uninitialized variables by
default after 5.7, which included commit 78a5255ffb6a ("Stop the ad-hoc
games with -Wno-maybe-initialized"). They will potentially show up at
W=2 or with an explicit KCFLAGS=-Wmaybe-uninitialized (it does in this
case):
Thank you.
| drivers/misc/cardreader/rtsx_usb.c: In function ‘rtsx_usb_probe’:
| drivers/misc/cardreader/rtsx_usb.c:678:16: error: ‘ret’ may be used uninitialized [-Werror=maybe-uninitialized]
| 678 | return ret;
| | ^~~
| drivers/misc/cardreader/rtsx_usb.c:622:13: note: ‘ret’ was declared here
| 622 | int ret;
| | ^~~
| cc1: all warnings being treated as errors
This is a bug and a good find. ret should have been set
in the if (!ucr->rsp_buf) before going to error handling.
I wonder if it would have been flagged if ret were to be
initialized to 0. Something to experiment.