Re: [PATCH v2] misc: new driver sram_uapi for user level SRAM access

From: kbuild test robot
Date: Mon May 04 2020 - 11:23:47 EST


Hi Wang,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on arm-soc/for-next linus/master linux/master v5.7-rc3 next-20200501]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url: https://github.com/0day-ci/linux/commits/Wang-Wenhu/misc-new-driver-sram_uapi-for-user-level-SRAM-access/20200421-105427
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git ae83d0b416db002fe95601e7f97f64b59514d936
config: microblaze-allyesconfig (attached as .config)
compiler: microblaze-linux-gcc (GCC) 9.3.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day GCC_VERSION=9.3.0 make.cross ARCH=microblaze

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@xxxxxxxxx>

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

drivers/misc/sram_uapi.c: In function 'sram_uapi_ioctl':
>> drivers/misc/sram_uapi.c:100:6: warning: 'type' may be used uninitialized in this function [-Wmaybe-uninitialized]
100 | if (cur->type == type) {
| ^
drivers/misc/sram_uapi.c:188:8: note: 'type' was declared here
188 | __u32 type;
| ^~~~

vim +/type +100 drivers/misc/sram_uapi.c

93
94 static struct sram_api *get_sram_api_from_type(__u32 type)
95 {
96 struct sram_api *cur;
97
98 mutex_lock(&sram_list_lock);
99 list_for_each_entry(cur, &sram_list, list) {
> 100 if (cur->type == type) {
101 kref_get(&cur->kref);
102 mutex_unlock(&sram_list_lock);
103 return cur;
104 }
105 }
106 mutex_unlock(&sram_list_lock);
107
108 return NULL;
109 }
110

---
0-DAY CI Kernel Test Service, Intel Corporation
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