Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
mm: fix clear_refs_write locking
Turning page table entries read-only requires the mmap_sem held for
writing.
So stop doing the odd games with turning things from read locks to write
locks and back. Just get the write lock.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+9
-23
+9
-23
fs/proc/task_mmu.c
+9
-23
fs/proc/task_mmu.c
···
1215
1215
.type = type,
1216
1216
};
1217
1217
1218
+
if (mmap_write_lock_killable(mm)) {
1219
+
count = -EINTR;
1220
+
goto out_mm;
1221
+
}
1218
1222
if (type == CLEAR_REFS_MM_HIWATER_RSS) {
1219
-
if (mmap_write_lock_killable(mm)) {
1220
-
count = -EINTR;
1221
-
goto out_mm;
1222
-
}
1223
-
1224
1223
/*
1225
1224
* Writing 5 to /proc/pid/clear_refs resets the peak
1226
1225
* resident set size to this mm's current rss value.
1227
1226
*/
1228
1227
reset_mm_hiwater_rss(mm);
1229
-
mmap_write_unlock(mm);
1230
-
goto out_mm;
1228
+
goto out_unlock;
1231
1229
}
1232
1230
1233
-
if (mmap_read_lock_killable(mm)) {
1234
-
count = -EINTR;
1235
-
goto out_mm;
1236
-
}
1237
1231
tlb_gather_mmu(&tlb, mm, 0, -1);
1238
1232
if (type == CLEAR_REFS_SOFT_DIRTY) {
1239
1233
for (vma = mm->mmap; vma; vma = vma->vm_next) {
1240
1234
if (!(vma->vm_flags & VM_SOFTDIRTY))
1241
1235
continue;
1242
-
mmap_read_unlock(mm);
1243
-
if (mmap_write_lock_killable(mm)) {
1244
-
count = -EINTR;
1245
-
goto out_mm;
1246
-
}
1247
-
for (vma = mm->mmap; vma; vma = vma->vm_next) {
1248
-
vma->vm_flags &= ~VM_SOFTDIRTY;
1249
-
vma_set_page_prot(vma);
1250
-
}
1251
-
mmap_write_downgrade(mm);
1252
-
break;
1236
+
vma->vm_flags &= ~VM_SOFTDIRTY;
1237
+
vma_set_page_prot(vma);
1253
1238
}
1254
1239
1255
1240
mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
···
1246
1261
if (type == CLEAR_REFS_SOFT_DIRTY)
1247
1262
mmu_notifier_invalidate_range_end(&range);
1248
1263
tlb_finish_mmu(&tlb, 0, -1);
1249
-
mmap_read_unlock(mm);
1264
+
out_unlock:
1265
+
mmap_write_unlock(mm);
1250
1266
out_mm:
1251
1267
mmput(mm);
1252
1268
}