Re: [PATCH] intel_th: Fix error handling in intel_th_output_open
From: kernel test robot
Date: Tue Nov 11 2025 - 10:11:49 EST
Hi Ma,
kernel test robot noticed the following build warnings:
[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on linus/master v6.18-rc5 next-20251111]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Ma-Ke/intel_th-Fix-error-handling-in-intel_th_output_open/20251111-104412
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20251111024204.12299-1-make24%40iscas.ac.cn
patch subject: [PATCH] intel_th: Fix error handling in intel_th_output_open
config: x86_64-buildonly-randconfig-002-20251111 (https://download.01.org/0day-ci/archive/20251111/202511112222.vMmKmHbd-lkp@xxxxxxxxx/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251111/202511112222.vMmKmHbd-lkp@xxxxxxxxx/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511112222.vMmKmHbd-lkp@xxxxxxxxx/
All warnings (new ones prefixed by >>):
>> drivers/hwtracing/intel_th/core.c:818:6: warning: variable 'err' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
818 | if (!fops)
| ^~~~~
drivers/hwtracing/intel_th/core.c:836:9: note: uninitialized use occurs here
836 | return err;
| ^~~
drivers/hwtracing/intel_th/core.c:818:2: note: remove the 'if' if its condition is always false
818 | if (!fops)
| ^~~~~~~~~~
819 | goto out_put_device;
| ~~~~~~~~~~~~~~~~~~~
drivers/hwtracing/intel_th/core.c:813:6: warning: variable 'err' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
813 | if (!dev || !dev->driver)
| ^~~~~~~~~~~~~~~~~~~~
drivers/hwtracing/intel_th/core.c:836:9: note: uninitialized use occurs here
836 | return err;
| ^~~
drivers/hwtracing/intel_th/core.c:813:2: note: remove the 'if' if its condition is always false
813 | if (!dev || !dev->driver)
| ^~~~~~~~~~~~~~~~~~~~~~~~~
814 | goto out_no_device;
| ~~~~~~~~~~~~~~~~~~
>> drivers/hwtracing/intel_th/core.c:813:6: warning: variable 'err' is used uninitialized whenever '||' condition is true [-Wsometimes-uninitialized]
813 | if (!dev || !dev->driver)
| ^~~~
drivers/hwtracing/intel_th/core.c:836:9: note: uninitialized use occurs here
836 | return err;
| ^~~
drivers/hwtracing/intel_th/core.c:813:6: note: remove the '||' if its condition is always false
813 | if (!dev || !dev->driver)
| ^~~~~~~
drivers/hwtracing/intel_th/core.c:810:9: note: initialize the variable 'err' to silence this warning
810 | int err;
| ^
| = 0
3 warnings generated.
vim +818 drivers/hwtracing/intel_th/core.c
39f4034693b7c7 Alexander Shishkin 2015-09-22 804
39f4034693b7c7 Alexander Shishkin 2015-09-22 805 static int intel_th_output_open(struct inode *inode, struct file *file)
39f4034693b7c7 Alexander Shishkin 2015-09-22 806 {
39f4034693b7c7 Alexander Shishkin 2015-09-22 807 const struct file_operations *fops;
39f4034693b7c7 Alexander Shishkin 2015-09-22 808 struct intel_th_driver *thdrv;
39f4034693b7c7 Alexander Shishkin 2015-09-22 809 struct device *dev;
39f4034693b7c7 Alexander Shishkin 2015-09-22 810 int err;
39f4034693b7c7 Alexander Shishkin 2015-09-22 811
4495dfdd6193d9 Suzuki K Poulose 2019-07-23 812 dev = bus_find_device_by_devt(&intel_th_bus, inode->i_rdev);
39f4034693b7c7 Alexander Shishkin 2015-09-22 @813 if (!dev || !dev->driver)
b54f5a424fbe0f Ma Ke 2025-11-11 814 goto out_no_device;
39f4034693b7c7 Alexander Shishkin 2015-09-22 815
39f4034693b7c7 Alexander Shishkin 2015-09-22 816 thdrv = to_intel_th_driver(dev->driver);
39f4034693b7c7 Alexander Shishkin 2015-09-22 817 fops = fops_get(thdrv->fops);
39f4034693b7c7 Alexander Shishkin 2015-09-22 @818 if (!fops)
b54f5a424fbe0f Ma Ke 2025-11-11 819 goto out_put_device;
39f4034693b7c7 Alexander Shishkin 2015-09-22 820
39f4034693b7c7 Alexander Shishkin 2015-09-22 821 replace_fops(file, fops);
39f4034693b7c7 Alexander Shishkin 2015-09-22 822
39f4034693b7c7 Alexander Shishkin 2015-09-22 823 file->private_data = to_intel_th_device(dev);
39f4034693b7c7 Alexander Shishkin 2015-09-22 824
39f4034693b7c7 Alexander Shishkin 2015-09-22 825 if (file->f_op->open) {
39f4034693b7c7 Alexander Shishkin 2015-09-22 826 err = file->f_op->open(inode, file);
b54f5a424fbe0f Ma Ke 2025-11-11 827 if (err)
b54f5a424fbe0f Ma Ke 2025-11-11 828 goto out_put_device;
39f4034693b7c7 Alexander Shishkin 2015-09-22 829 }
39f4034693b7c7 Alexander Shishkin 2015-09-22 830
39f4034693b7c7 Alexander Shishkin 2015-09-22 831 return 0;
b54f5a424fbe0f Ma Ke 2025-11-11 832
b54f5a424fbe0f Ma Ke 2025-11-11 833 out_put_device:
b54f5a424fbe0f Ma Ke 2025-11-11 834 put_device(dev);
b54f5a424fbe0f Ma Ke 2025-11-11 835 out_no_device:
b54f5a424fbe0f Ma Ke 2025-11-11 @836 return err;
39f4034693b7c7 Alexander Shishkin 2015-09-22 837 }
39f4034693b7c7 Alexander Shishkin 2015-09-22 838
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