diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2009-04-03 01:58:38 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-04-03 04:05:02 +0200 |
| commit | 52ee2dfdd4f51cf422ea6a96a0846dc94244aa37 (patch) | |
| tree | e15753e01d2c2fbe980edc45f78a9ae77d2cf891 /kernel/sys.c | |
| parent | pids: improve get_task_pid() to fix the unsafe sys_wait4()->task_pgrp() (diff) | |
| download | linux-52ee2dfdd4f51cf422ea6a96a0846dc94244aa37.tar.xz linux-52ee2dfdd4f51cf422ea6a96a0846dc94244aa37.zip | |
pids: refactor vnr/nr_ns helpers to make them safe
Inho, the safety rules for vnr/nr_ns helpers are horrible and buggy.
task_pid_nr_ns(task) needs rcu/tasklist depending on task == current.
As for "special" pids, vnr/nr_ns helpers always need rcu. However, if
task != current, they are unsafe even under rcu lock, we can't trust
task->group_leader without the special checks.
And almost every helper has a callsite which needs a fix.
Also, it is a bit annoying that the implementations of, say,
task_pgrp_vnr() and task_pgrp_nr_ns() are not "symmetrical".
This patch introduces the new helper, __task_pid_nr_ns(), which is always
safe to use, and turns all other helpers into the trivial wrappers.
After this I'll send another patch which converts task_tgid_xxx() as well,
they're are a bit special.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/sys.c')
0 files changed, 0 insertions, 0 deletions