The patch titled Subject: proc: task_state: ptrace_parent() doesn't need pid_alive() check has been added to the -mm tree. Its filename is proc-task_state-ptrace_parent-doesnt-need-pid_alive-check.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/proc-task_state-ptrace_parent-doesnt-need-pid_alive-check.patch echo and later at echo http://ozlabs.org/~akpm/mmotm/broken-out/proc-task_state-ptrace_parent-doesnt-need-pid_alive-check.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** 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: proc: task_state: ptrace_parent() doesn't need pid_alive() check p->ptrace != 0 means that release_task(p) was not called, so pid_alive() buys nothing and we can remove this check. Other callers already use it directly without additional checks. Note: with or without this patch ptrace_parent() can return the pointer to the freed task, this will be explained/fixed later. Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Aaron Tomlin <atomlin@xxxxxxxxxx> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>, Cc: Sterling Alexander <stalexan@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Roland McGrath <roland@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/array.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff -puN fs/proc/array.c~proc-task_state-ptrace_parent-doesnt-need-pid_alive-check fs/proc/array.c --- a/fs/proc/array.c~proc-task_state-ptrace_parent-doesnt-need-pid_alive-check +++ a/fs/proc/array.c @@ -157,19 +157,18 @@ static inline void task_state(struct seq struct user_namespace *user_ns = seq_user_ns(m); struct group_info *group_info; int g; + struct task_struct *tracer; const struct cred *cred; - pid_t ppid, tpid, tgid, ngid; + pid_t ppid, tpid = 0, tgid, ngid; unsigned int max_fds = 0; rcu_read_lock(); ppid = pid_alive(p) ? task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0; - tpid = 0; - if (pid_alive(p)) { - struct task_struct *tracer = ptrace_parent(p); - if (tracer) - tpid = task_pid_nr_ns(tracer, ns); - } + + tracer = ptrace_parent(p); + if (tracer) + tpid = task_pid_nr_ns(tracer, ns); tgid = task_tgid_nr_ns(p, ns); ngid = task_numa_group_id(p); _ 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 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-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 linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html