The patch titled
oom: rewrite error handling for oom_adj and oom_score_adj tunables
has been added to the -mm tree. Its filename is
oom-rewrite-error-handling-for-oom_adj-and-oom_score_adj-tunables.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: oom: rewrite error handling for oom_adj and oom_score_adj tunables
From: David Rientjes <rientjes@xxxxxxxxxx>
It's better to use proper error handling in oom_adjust_write() and
oom_score_adj_write() instead of duplicating the locking order on various
exit paths.
Suggested-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Ying Han <yinghan@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/base.c | 83 +++++++++++++++++++++++++++--------------------
1 file changed, 48 insertions(+), 35 deletions(-)
diff -puN fs/proc/base.c~oom-rewrite-error-handling-for-oom_adj-and-oom_score_adj-tunables fs/proc/base.c
--- a/fs/proc/base.c~oom-rewrite-error-handling-for-oom_adj-and-oom_score_adj-tunables
+++ a/fs/proc/base.c
@@ -1025,36 +1025,39 @@ static ssize_t oom_adjust_write(struct f
memset(buffer, 0, sizeof(buffer));
if (count > sizeof(buffer) - 1)
count = sizeof(buffer) - 1;
- if (copy_from_user(buffer, buf, count))
- return -EFAULT;
+ if (copy_from_user(buffer, buf, count)) {
+ err = -EFAULT;
+ goto out;
+ }
err = strict_strtol(strstrip(buffer), 0, &oom_adjust);
if (err)
- return -EINVAL;
+ goto out;
if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
- oom_adjust != OOM_DISABLE)
- return -EINVAL;
+ oom_adjust != OOM_DISABLE) {
+ err = -EINVAL;
+ goto out;
+ }
task = get_proc_task(file->f_path.dentry->d_inode);
- if (!task)
- return -ESRCH;
+ if (!task) {
+ err = -ESRCH;
+ goto out;
+ }
if (!lock_task_sighand(task, &flags)) {
- put_task_struct(task);
- return -ESRCH;
+ err = -ESRCH;
+ goto err_task_struct;
}
if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
- unlock_task_sighand(task, &flags);
- put_task_struct(task);
- return -EACCES;
+ err = -EACCES;
+ goto err_sighand;
}
task_lock(task);
if (!task->mm) {
- task_unlock(task);
- unlock_task_sighand(task, &flags);
- put_task_struct(task);
- return -EINVAL;
+ err = -EINVAL;
+ goto err_task_lock;
}
if (oom_adjust != task->signal->oom_adj) {
@@ -1082,11 +1085,14 @@ static ssize_t oom_adjust_write(struct f
else
task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
-OOM_DISABLE;
+err_task_lock:
task_unlock(task);
+err_sighand:
unlock_task_sighand(task, &flags);
+err_task_struct:
put_task_struct(task);
-
- return count;
+out:
+ return err < 0 ? err : count;
}
static const struct file_operations proc_oom_adjust_operations = {
@@ -1127,36 +1133,39 @@ static ssize_t oom_score_adj_write(struc
memset(buffer, 0, sizeof(buffer));
if (count > sizeof(buffer) - 1)
count = sizeof(buffer) - 1;
- if (copy_from_user(buffer, buf, count))
- return -EFAULT;
+ if (copy_from_user(buffer, buf, count)) {
+ err = -EFAULT;
+ goto out;
+ }
err = strict_strtol(strstrip(buffer), 0, &oom_score_adj);
if (err)
- return -EINVAL;
+ goto out;
if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
- oom_score_adj > OOM_SCORE_ADJ_MAX)
- return -EINVAL;
+ oom_score_adj > OOM_SCORE_ADJ_MAX) {
+ err = -EINVAL;
+ goto out;
+ }
task = get_proc_task(file->f_path.dentry->d_inode);
- if (!task)
- return -ESRCH;
+ if (!task) {
+ err = -ESRCH;
+ goto out;
+ }
if (!lock_task_sighand(task, &flags)) {
- put_task_struct(task);
- return -ESRCH;
+ err = -ESRCH;
+ goto err_task_struct;
}
if (oom_score_adj < task->signal->oom_score_adj &&
!capable(CAP_SYS_RESOURCE)) {
- unlock_task_sighand(task, &flags);
- put_task_struct(task);
- return -EACCES;
+ err = -EACCES;
+ goto err_sighand;
}
task_lock(task);
if (!task->mm) {
- task_unlock(task);
- unlock_task_sighand(task, &flags);
- put_task_struct(task);
- return -EINVAL;
+ err = -EINVAL;
+ goto err_task_lock;
}
if (oom_score_adj != task->signal->oom_score_adj) {
if (oom_score_adj == OOM_SCORE_ADJ_MIN)
@@ -1174,10 +1183,14 @@ static ssize_t oom_score_adj_write(struc
else
task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
OOM_SCORE_ADJ_MAX;
+err_task_lock:
task_unlock(task);
+err_sighand:
unlock_task_sighand(task, &flags);
+err_task_struct:
put_task_struct(task);
- return count;
+out:
+ return err < 0 ? err : count;
}
static const struct file_operations proc_oom_score_adj_operations = {
_
Patches currently in -mm which might be from rientjes@xxxxxxxxxx are
linux-next.patch
oom-add-per-mm-oom-disable-count.patch
oom-avoid-killing-a-task-if-a-thread-sharing-its-mm-cannot-be-killed.patch
oom-kill-all-threads-sharing-oom-killed-tasks-mm.patch
oom-kill-all-threads-sharing-oom-killed-tasks-mm-fix.patch
oom-kill-all-threads-sharing-oom-killed-tasks-mm-fix-fix.patch
oom-rewrite-error-handling-for-oom_adj-and-oom_score_adj-tunables.patch
jbd-remove-dependency-on-__gfp_nofail.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
