c/r: prctl: less paranoid prctl_set_mm_exe_file()
authorKonstantin Khlebnikov <khlebnikov@openvz.org>
Wed, 11 Jul 2012 21:02:11 +0000 (14:02 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 11 Jul 2012 23:04:43 +0000 (16:04 -0700)
commit4229fb1dc6843c49a14bb098719f8a696cdc44f8
treeb4c8bd028870c42487a168842f43a15d09d4a4d0
parenta4e08d001f2e50bb8b3c4eebadcf08e5535f02ee
c/r: prctl: less paranoid prctl_set_mm_exe_file()

"no other files mapped" requirement from my previous patch (c/r: prctl:
update prctl_set_mm_exe_file() after mm->num_exe_file_vmas removal) is too
paranoid, it forbids operation even if there mapped one shared-anon vma.

Let's check that current mm->exe_file already unmapped, in this case
exe_file symlink already outdated and its changing is reasonable.

Plus, this patch fixes exit code in case operation success.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Reported-by: Cyrill Gorcunov <gorcunov@openvz.org>
Tested-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/sys.c