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authorGuillem Jover <guillem.jover@nokia.com>2006-12-06 23:32:24 -0500
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-07 11:39:21 -0500
commit8fb4fc68ca391862b061b3d358a288ccf6abed39 (patch)
tree5fb67541fb76957260879812d6d21ead6c4e6852
parent3b17979bda74493633364c2c263b452b7788e350 (diff)
[PATCH] Allow user processes to raise their oom_adj value
Currently a user process cannot rise its own oom_adj value (i.e. unprotecting itself from the OOM killer). As this value is stored in the task structure it gets inherited and the unprivileged childs will be unable to rise it. The EPERM will be handled by the generic proc fs layer, as only processes with the proper caps or the owner of the process will be able to write to the file. So we allow only the processes with CAP_SYS_RESOURCE to lower the value, otherwise it will get an EACCES which seems more appropriate than EPERM. Signed-off-by: Guillem Jover <guillem.jover@nokia.com> Acked-by: Andrea Arcangeli <andrea@novell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--fs/proc/base.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 795319c54f72..05ace70d051a 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -683,8 +683,6 @@ static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
683 char buffer[PROC_NUMBUF], *end; 683 char buffer[PROC_NUMBUF], *end;
684 int oom_adjust; 684 int oom_adjust;
685 685
686 if (!capable(CAP_SYS_RESOURCE))
687 return -EPERM;
688 memset(buffer, 0, sizeof(buffer)); 686 memset(buffer, 0, sizeof(buffer));
689 if (count > sizeof(buffer) - 1) 687 if (count > sizeof(buffer) - 1)
690 count = sizeof(buffer) - 1; 688 count = sizeof(buffer) - 1;
@@ -699,6 +697,10 @@ static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
699 task = get_proc_task(file->f_dentry->d_inode); 697 task = get_proc_task(file->f_dentry->d_inode);
700 if (!task) 698 if (!task)
701 return -ESRCH; 699 return -ESRCH;
700 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) {
701 put_task_struct(task);
702 return -EACCES;
703 }
702 task->oomkilladj = oom_adjust; 704 task->oomkilladj = oom_adjust;
703 put_task_struct(task); 705 put_task_struct(task);
704 if (end - buffer == 0) 706 if (end - buffer == 0)