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| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2010-03-05 22:42:56 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-03-06 20:26:33 +0100 |
| commit | 9728e5d6e6c432ee8487c63ce6e479e2474d9945 (patch) | |
| tree | 2cd7e9a9102649a36d52cbac918f045dcfaa08f2 /kernel/async.c | |
| parent | panic: fix panic_timeout accuracy when running on a hypervisor (diff) | |
| download | linux-9728e5d6e6c432ee8487c63ce6e479e2474d9945.tar.xz linux-9728e5d6e6c432ee8487c63ce6e479e2474d9945.zip | |
kernel/pid.c: update comment on find_task_by_pid_ns
tasklist_lock does protect the task and its pid, it can't go away. The
problem is that find_pid_ns() itself is unsafe without rcu lock, it can
race with copy_process()->free_pid(any_pid).
Protecting copy_process()->free_pid(any_pid) with tasklist_lock would make
it possible to call find_task_by_pid_ns() under tasklist safely, but we
don't do so because we are trying to get rid of the read_lock sites of
tasklist_lock.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/async.c')
0 files changed, 0 insertions, 0 deletions