Hi Tze-nan,
kernel test robot noticed the following build warnings:
[auto build test WARNING on linus/master] [also build test WARNING on rostedt-trace/for-next v6.3-rc5 next-20230406] [cannot apply to rostedt-trace/for-next-urgent] [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/Tze-nan-Wu/ring-buffer-Preven... patch link: https://lore.kernel.org/r/20230408052226.25268-1-Tze-nan.Wu%40mediatek.com patch subject: [PATCH] ring-buffer: Prevent inconsistent operation on cpu_buffer->resize_disabled config: x86_64-randconfig-a002-20230403 (https://download.01.org/0day-ci/archive/20230408/202304081615.eiaqpbV8-lkp@i...) compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/intel-lab-lkp/linux/commit/d404bc0af0a4bde3aa20704642d69a... git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Tze-nan-Wu/ring-buffer-Prevent-inconsistent-operation-on-cpu_buffer-resize_disabled/20230408-132502 git checkout d404bc0af0a4bde3aa20704642d69a78bdc154f8 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash kernel/trace/
If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot lkp@intel.com | Link: https://lore.kernel.org/oe-kbuild-all/202304081615.eiaqpbV8-lkp@intel.com/
All warnings (new ones prefixed by >>):
kernel/trace/ring_buffer.c:5359:15: warning: variable 'reset_online_mask' is uninitialized when used here [-Wuninitialized]
cpumask_copy(reset_online_mask, cpu_online_mask); ^~~~~~~~~~~~~~~~~ kernel/trace/ring_buffer.c:5353:33: note: initialize the variable 'reset_online_mask' to silence this warning cpumask_var_t reset_online_mask; ^ = NULL 1 warning generated.
vim +/reset_online_mask +5359 kernel/trace/ring_buffer.c
5344 5345 /** 5346 * ring_buffer_reset_online_cpus - reset a ring buffer per CPU buffer 5347 * @buffer: The ring buffer to reset a per cpu buffer of 5348 * @cpu: The CPU buffer to be reset 5349 */ 5350 void ring_buffer_reset_online_cpus(struct trace_buffer *buffer) 5351 { 5352 struct ring_buffer_per_cpu *cpu_buffer; 5353 cpumask_var_t reset_online_mask; 5354 int cpu; 5355 5356 /* prevent another thread from changing buffer sizes */ 5357 mutex_lock(&buffer->mutex); 5358
5359 cpumask_copy(reset_online_mask, cpu_online_mask);
5360 5361 for_each_cpu_and(cpu, buffer->cpumask, reset_online_mask) { 5362 cpu_buffer = buffer->buffers[cpu]; 5363 5364 atomic_inc(&cpu_buffer->resize_disabled); 5365 atomic_inc(&cpu_buffer->record_disabled); 5366 } 5367 5368 /* Make sure all commits have finished */ 5369 synchronize_rcu(); 5370 5371 for_each_cpu_and(cpu, buffer->cpumask, reset_online_mask) { 5372 cpu_buffer = buffer->buffers[cpu]; 5373 5374 reset_disabled_cpu_buffer(cpu_buffer); 5375 5376 atomic_dec(&cpu_buffer->record_disabled); 5377 atomic_dec(&cpu_buffer->resize_disabled); 5378 } 5379 5380 mutex_unlock(&buffer->mutex); 5381 } 5382