Hi Andrea, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on linux/master] [also build test WARNING on linus/master hnaz-linux-mm/master v5.11-rc2 next-20210104] [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] url: https://github.com/0day-ci/linux/commits/Andrea-Arcangeli/page_count-can-t-be-used-to-decide-when-wp_page_copy/20210108-040616 base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 09162bc32c880a791c6c0668ce0745cf7958f576 compiler: nds32le-linux-gcc (GCC) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> "cppcheck warnings: (new ones prefixed by >>)" >> fs/proc/task_mmu.c:1248:33: warning: Uninitialized variable: tmp [uninitvar] for (vma = mm->mmap; vma != tmp; ^ vim +1248 fs/proc/task_mmu.c 1183 1184 static ssize_t clear_refs_write(struct file *file, const char __user *buf, 1185 size_t count, loff_t *ppos) 1186 { 1187 struct task_struct *task; 1188 char buffer[PROC_NUMBUF]; 1189 struct mm_struct *mm; 1190 struct vm_area_struct *vma; 1191 enum clear_refs_types type; 1192 int itype; 1193 int rv; 1194 1195 memset(buffer, 0, sizeof(buffer)); 1196 if (count > sizeof(buffer) - 1) 1197 count = sizeof(buffer) - 1; 1198 if (copy_from_user(buffer, buf, count)) 1199 return -EFAULT; 1200 rv = kstrtoint(strstrip(buffer), 10, &itype); 1201 if (rv < 0) 1202 return rv; 1203 type = (enum clear_refs_types)itype; 1204 if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST) 1205 return -EINVAL; 1206 1207 task = get_proc_task(file_inode(file)); 1208 if (!task) 1209 return -ESRCH; 1210 mm = get_task_mm(task); 1211 if (mm) { 1212 struct mmu_notifier_range range; 1213 struct clear_refs_private cp = { 1214 .type = type, 1215 }; 1216 1217 if (type == CLEAR_REFS_MM_HIWATER_RSS) { 1218 if (mmap_write_lock_killable(mm)) { 1219 count = -EINTR; 1220 goto out_mm; 1221 } 1222 1223 /* 1224 * Writing 5 to /proc/pid/clear_refs resets the peak 1225 * resident set size to this mm's current rss value. 1226 */ 1227 reset_mm_hiwater_rss(mm); 1228 mmap_write_unlock(mm); 1229 goto out_mm; 1230 } 1231 1232 if (mmap_read_lock_killable(mm)) { 1233 count = -EINTR; 1234 goto out_mm; 1235 } 1236 if (type == CLEAR_REFS_SOFT_DIRTY) { 1237 for (vma = mm->mmap; vma; vma = vma->vm_next) { 1238 struct vm_area_struct *tmp; 1239 if (!(vma->vm_flags & VM_SOFTDIRTY)) { 1240 inc_wrprotect_tlb_flush_pending(vma); 1241 continue; 1242 } 1243 1244 /* 1245 * Rollback wrprotect_tlb_flush_pending before 1246 * releasing the mmap_lock. 1247 */ > 1248 for (vma = mm->mmap; vma != tmp; 1249 vma = vma->vm_next) 1250 dec_wrprotect_tlb_flush_pending(vma); 1251 1252 mmap_read_unlock(mm); 1253 if (mmap_write_lock_killable(mm)) { 1254 count = -EINTR; 1255 goto out_mm; 1256 } 1257 for (vma = mm->mmap; vma; vma = vma->vm_next) { 1258 vma->vm_flags &= ~VM_SOFTDIRTY; 1259 vma_set_page_prot(vma); 1260 inc_wrprotect_tlb_flush_pending(vma); 1261 } 1262 mmap_write_downgrade(mm); 1263 break; 1264 } 1265 1266 inc_tlb_flush_pending(mm); 1267 mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY, 1268 0, NULL, mm, 0, -1UL); 1269 mmu_notifier_invalidate_range_start(&range); 1270 } 1271 walk_page_range(mm, 0, mm->highest_vm_end, &clear_refs_walk_ops, 1272 &cp); 1273 if (type == CLEAR_REFS_SOFT_DIRTY) { 1274 mmu_notifier_invalidate_range_end(&range); 1275 flush_tlb_mm(mm); 1276 for (vma = mm->mmap; vma; vma = vma->vm_next) 1277 dec_wrprotect_tlb_flush_pending(vma); 1278 dec_tlb_flush_pending(mm); 1279 } 1280 mmap_read_unlock(mm); 1281 out_mm: 1282 mmput(mm); 1283 } 1284 put_task_struct(task); 1285 1286 return count; 1287 } 1288 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
