The patch titled
Subject: exit: wait: cleanup the ptrace_reparented() checks
has been added to the -mm tree. Its filename is
exit-wait-cleanup-the-ptrace_reparented-checks.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/exit-wait-cleanup-the-ptrace_reparented-checks.patch
echo and later at
echo http://ozlabs.org/~akpm/mmotm/broken-out/exit-wait-cleanup-the-ptrace_reparented-checks.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Subject: exit: wait: cleanup the ptrace_reparented() checks
Now that EXIT_DEAD is the terminal state we can kill "int traced" variable
and check "state == EXIT_DEAD" instead to cleanup the code. In
particular, this way it is clear that the check obviously doesn't need
tasklist_lock.
Also fix the type of "unsigned long state", "long" was always wrong
although this doesn't matter because cmpxchg/xchg uses typeof(*ptr).
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Aaron Tomlin <atomlin@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Sterling Alexander <stalexan@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/exit.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff -puN kernel/exit.c~exit-wait-cleanup-the-ptrace_reparented-checks kernel/exit.c
--- a/kernel/exit.c~exit-wait-cleanup-the-ptrace_reparented-checks
+++ a/kernel/exit.c
@@ -973,8 +973,7 @@ static int wait_noreap_copyout(struct wa
*/
static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
{
- unsigned long state;
- int retval, status, traced;
+ int state, retval, status;
pid_t pid = task_pid_vnr(p);
uid_t uid = from_kuid_munged(current_user_ns(), task_uid(p));
struct siginfo __user *infop;
@@ -997,19 +996,18 @@ static int wait_task_zombie(struct wait_
}
return wait_noreap_copyout(wo, p, pid, uid, why, status);
}
-
- traced = ptrace_reparented(p);
/*
* Move the task's state to DEAD/TRACE, only one thread can do this.
*/
- state = traced && thread_group_leader(p) ? EXIT_TRACE : EXIT_DEAD;
+ state = ptrace_reparented(p) && thread_group_leader(p) ?
+ EXIT_TRACE : EXIT_DEAD;
if (cmpxchg(&p->exit_state, EXIT_ZOMBIE, state) != EXIT_ZOMBIE)
return 0;
+
/*
- * It can be ptraced but not reparented, check
- * thread_group_leader() to filter out sub-threads.
+ * Check thread_group_leader() to exclude the traced sub-threads.
*/
- if (likely(!traced) && thread_group_leader(p)) {
+ if (state == EXIT_DEAD && thread_group_leader(p)) {
struct signal_struct *psig;
struct signal_struct *sig;
unsigned long maxrss;
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
mmfs-introduce-helpers-around-the-i_mmap_mutex.patch
mm-use-new-helper-functions-around-the-i_mmap_mutex.patch
mm-convert-i_mmap_mutex-to-rwsem.patch
mm-rmap-share-the-i_mmap_rwsem.patch
uprobes-share-the-i_mmap_rwsem.patch
mm-xip-share-the-i_mmap_rwsem.patch
mm-memory-failure-share-the-i_mmap_rwsem.patch
mm-nommu-share-the-i_mmap_rwsem.patch
mm-memoryc-share-the-i_mmap_rwsem.patch
remove-unnecessary-is_valid_nodemask.patch
proc-task_state-read-cred-group_info-outside-of-task_lock.patch
proc-task_state-deuglify-the-max_fds-calculation.patch
proc-task_state-move-the-main-seq_printf-outside-of-rcu_read_lock.patch
proc-task_state-ptrace_parent-doesnt-need-pid_alive-check.patch
sched_show_task-fix-unsafe-usage-of-real_parent.patch
exit-reparent-use-ptrace_entry-rather-than-sibling-for-exit_dead-tasks.patch
exit-reparent-cleanup-the-changing-of-parent.patch
exit-reparent-cleanup-the-changing-of-parent-fix.patch
exit-reparent-cleanup-the-usage-of-reparent_leader.patch
exit-ptrace-shift-reap-dead-code-from-exit_ptrace-to-forget_original_parent.patch
usermodehelper-dont-use-clone_vfork-for-____call_usermodehelper.patch
usermodehelper-kill-the-kmod_thread_locker-logic.patch
exit-wait-cleanup-the-ptrace_reparented-checks.patch
exit-wait-cleanup-the-ptrace_reparented-checks-fix.patch
exit-wait-dont-use-zombie-real_parent.patch
exit-wait-drop-tasklist_lock-before-psig-c-accounting.patch
exit-release_task-fix-the-comment-about-group-leader-accounting.patch
exit-proc-dont-try-to-flush-proc-tgid-task-tgid.patch
exit-reparent-fix-the-dead-parent-pr_set_child_subreaper-reparenting.patch
exit-reparent-fix-the-cross-namespace-pr_set_child_subreaper-reparenting.patch
exit-reparent-s-while_each_thread-for_each_thread-in-find_new_reaper.patch
exit-reparent-document-the-has_child_subreaper-checks.patch
exit-reparent-introduce-find_child_reaper.patch
exit-reparent-introduce-find_alive_thread.patch
linux-next.patch
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