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authorEric W. Biederman <ebiederm@xmission.com>2006-10-02 02:17:27 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-02 07:57:15 -0700
commit43fa1adb9334bf4585cd53144eb5911488f85bc7 (patch)
tree64be64424e7db15e1872077f900870895ccac85b /fs/fcntl.c
parenta03fcb730b4fe7da14ca4405f23dbde717b1d2b9 (diff)
downloadlinux-linaro-43fa1adb9334bf4585cd53144eb5911488f85bc7.tar.gz
[PATCH] file: Add locking to f_getown
This has been needed for a long time, but now with the advent of a reference counted struct pid there are real consequences for getting this wrong. Someone I think it was Oleg Nesterov pointed out that this construct was missing locking, when I introduced struct pid. After taking time to review the locking construct already present I figured out which lock needs to be taken. The other paths that access f_owner.pid take either the f_owner read or the write lock. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/fcntl.c')
-rw-r--r--fs/fcntl.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c
index e7c66a1bf83..e4f26165f12 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -305,9 +305,11 @@ void f_delown(struct file *filp)
pid_t f_getown(struct file *filp)
{
pid_t pid;
+ read_lock(&filp->f_owner.lock);
pid = pid_nr(filp->f_owner.pid);
if (filp->f_owner.pid_type == PIDTYPE_PGID)
pid = -pid;
+ read_unlock(&filp->f_owner.lock);
return pid;
}