user/sven/linux.git/kernel/exit.c, branch v2.6.31.2

headers: mnt_namespace.h redux

2009-07-08T16:31:56Z

Fix various silly problems wrt mnt_namespace.h: - exit_mnt_ns() isn't used, remove it - done that, sched.h and nsproxy.h inclusions aren't needed - mount.h inclusion was need for vfsmount_lock, but no longer - remove mnt_namespace.h inclusion from files which don't use anything from mnt_namespace.h Signed-off-by: Alexey Dobriyan Signed-off-by: Linus Torvalds

ptrace: wait_task_zombie: do not account traced sub-threads

2009-06-19T23:46:06Z

The bug is ancient. If we trace the sub-thread of our natural child and this sub-thread exits, we update parent->signal->cxxx fields. But we should not do this until the whole thread-group exits, otherwise we account this thread (and all other live threads) twice. Add the task_detached() check. No need to check thread_group_empty(), wait_consider_task()->delay_group_leader() already did this. Signed-off-by: Oleg Nesterov Cc: Peter Zijlstra Acked-by: Roland McGrath Cc: Stanislaw Gruszka Cc: Vitaly Mayatskikh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: exit.c reorder wait_opts to remove padding on 64 bit builds

2009-06-18T20:03:53Z

Reorder struct wait_opts to remove 8 bytes of alignment padding on 64 bit builds. Signed-off-by: Richard Kennedy Cc: Oleg Nesterov Cc: Ingo Molnar Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

do_wait: fix the theoretical race with stop/trace/cont

2009-06-18T20:03:53Z

do_wait: current->state = TASK_INTERRUPTIBLE; read_lock(&tasklist_lock); ... search for the task to reap ... In theory, the ->state changing can leak into the critical section. Since the child can change its status under read_lock(tasklist) in parallel (finish_stop/ptrace_stop), we can miss the wakeup if __wake_up_parent() sees us in TASK_RUNNING state. Add the barrier. Also, use __set_current_state() to set TASK_RUNNING. Signed-off-by: Oleg Nesterov Cc: Ingo Molnar Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

do_wait: kill the old BUG_ON, use while_each_thread()

2009-06-18T20:03:53Z

do_wait() does BUG_ON(tsk->signal != current->signal), this looks like a raher obsolete check. At least, I don't think do_wait() is the best place to verify that all threads have the same ->signal. Remove it. Also, change the code to use while_each_thread(). Signed-off-by: Oleg Nesterov Cc: Ingo Molnar Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

do_wait: simplify retval/tsk_result/notask_error mess

2009-06-18T20:03:53Z

Now that we don't pass &retval down to other helpers we can simplify the code more. - kill tsk_result, just use retval - add the "notask" label right after the main loop, and s/got end/goto notask/ after the fastpath pid check. This way we don't need to initialize retval before this check and the code becomes a bit more clean, if this pid has no attached tasks we should just skip the list search. Signed-off-by: Oleg Nesterov Cc: Ingo Molnar Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

introduce "struct wait_opts" to simplify do_wait() patches

2009-06-18T20:03:52Z

Introduce "struct wait_opts" which holds the parameters for misc helpers in do_wait() pathes. This adds 13 lines to kernel/exit.c, but saves 256 bytes from .o and imho makes the code much more readable. This patch temporary uglifies rusage/siginfo code a little bit, will be addressed by further cleanups. Signed-off-by: Oleg Nesterov Reviewed-by: Ingo Molnar Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

shift "ptrace implies WUNTRACED" from ptrace_do_wait() to wait_task_stopped()

2009-06-18T20:03:52Z

No functional changes, preparation for the next patch. ptrace_do_wait() adds WUNTRACED to options for wait_task_stopped() which should always accept the stopped tracee, even if do_wait() was called without WUNTRACED. Change wait_task_stopped() to check "ptrace || WUNTRACED" instead. This makes the code more explicit, and "int options" argument becomes const in do_wait() pathes. Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

wait_task_zombie: do not use thread_group_cputime()

2009-06-18T20:03:52Z

There is no reason for thread_group_cputime() in wait_task_zombie(), there must be no other threads. This call was previously needed to collect the per-cpu data which we do not have any longer. Signed-off-by: Oleg Nesterov Cc: Peter Zijlstra Acked-by: Roland McGrath Cc: Stanislaw Gruszka Cc: Vitaly Mayatskikh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ptrace: wait_task_zombie: s/->parent/->real_parent/

2009-06-18T20:03:51Z

Change wait_task_zombie() to use ->real_parent instead of ->parent. We could even use current afaics, but ->real_parent is more clean. We know that the child is not ptrace_reparented() and thus they are equal. But we should avoid using task_struct->parent, we are going to remove it. Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds