tree: https://gitee.com/openeuler/kernel.git openEuler-1.0-LTS head: d5c3ef07e625af7ba8aded2f507f092bceab3cbc commit: 4cdb60f56180d6ef7c10bd0e50ddda96ebc9f783 [1291/1291] svm: implement unpin pages to dec refcount config: arm64-randconfig-r063-20241113 (https://download.01.org/0day-ci/archive/20241114/202411142057.pcqq5uGT-lkp@i...) compiler: aarch64-linux-gcc (GCC) 14.2.0

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@intel.com | Closes: https://lore.kernel.org/oe-kbuild-all/202411142057.pcqq5uGT-lkp@intel.com/

cocci warnings: (new ones prefixed by >>)

...

drivers/char/svm.c:312:17-38: WARNING: atomic_dec_and_test variation before object free at line 335.

vim +312 drivers/char/svm.c

304 305 static void svm_remove_sdma(struct svm_process *process, 306 struct svm_sdma *sdma, bool try_rm) 307 { 308 int null_count = 0; 309 310 mutex_lock(&process->mutex); 311

312 if (try_rm && (!atomic64_dec_and_test(&sdma->ref))) {

313 mutex_unlock(&process->mutex); 314 return; 315 } 316 317 rb_erase(&sdma->node, &process->sdma_list); 318 RB_CLEAR_NODE(&sdma->node); 319 mutex_unlock(&process->mutex); 320 321 while (sdma->nr_pages--) { 322 if (sdma->pages[sdma->nr_pages] == NULL) { 323 pr_err("null pointer, nr_pages:%d.\n", sdma->nr_pages); 324 null_count++; 325 continue; 326 } 327 328 put_page(sdma->pages[sdma->nr_pages]); 329 } 330 331 if (null_count) 332 dump_stack(); 333 334 kfree(sdma->pages);

335 kfree(sdma);

336 } 337