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author | David Rientjes <rientjes@google.com> | 2010-10-26 14:21:25 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-26 16:52:05 -0700 |
commit | 723548bff1dde9ab6bdb23f4bb92277c4da49473 (patch) | |
tree | 7c4b97cb80003caae19a849e9ffb490be943bbf2 /fs/proc | |
parent | 1e99bad0d9c12a4aaa60cd812c84ef152564bcf5 (diff) | |
download | kernel_samsung_smdk4412-723548bff1dde9ab6bdb23f4bb92277c4da49473.zip kernel_samsung_smdk4412-723548bff1dde9ab6bdb23f4bb92277c4da49473.tar.gz kernel_samsung_smdk4412-723548bff1dde9ab6bdb23f4bb92277c4da49473.tar.bz2 |
oom: rewrite error handling for oom_adj and oom_score_adj tunables
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@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc')
-rw-r--r-- | fs/proc/base.c | 83 |
1 files changed, 48 insertions, 35 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 6e50c8e..34d11ac 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1023,36 +1023,39 @@ static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 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) { @@ -1080,11 +1083,14 @@ static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 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 = { @@ -1125,36 +1131,39 @@ static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 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) @@ -1172,10 +1181,14 @@ static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 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 = { |