The patch titled ptrace: simplify ptrace_stop()->sigkill_pending() path has been removed from the -mm tree. Its filename was ptrace-simplify-ptrace_stop-sigkill_pending-path.patch This patch was dropped because an updated version will be merged The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: ptrace: simplify ptrace_stop()->sigkill_pending() path From: Oleg Nesterov <oleg@xxxxxxxxxx> 1. SIGKILL can't be blocked, remove this check from sigkill_pending(). 2. When ptrace_stop() sees sigkill_pending() == T, it can just return. Kill "int killed" and simplify the code. This also is more correct, the tracer shouldn't see us in TASK_TRACED if we are not going to stop. I strongly believe this code needs further changes. We should do the "was this task killed" check unconditionally, currently it depends on arch_ptrace_stop_needed(). On the other hand, sigkill_pending() isn't very clever. If the task was killed tkill(SIGKILL), the signal can be already dequeued if the caller is do_exit(). Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Roland McGrath <roland@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/signal.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff -puN kernel/signal.c~ptrace-simplify-ptrace_stop-sigkill_pending-path kernel/signal.c --- a/kernel/signal.c~ptrace-simplify-ptrace_stop-sigkill_pending-path +++ a/kernel/signal.c @@ -1496,9 +1496,8 @@ static inline int may_ptrace_stop(void) */ static int sigkill_pending(struct task_struct *tsk) { - return ((sigismember(&tsk->pending.signal, SIGKILL) || - sigismember(&tsk->signal->shared_pending.signal, SIGKILL)) && - !unlikely(sigismember(&tsk->blocked, SIGKILL))); + return sigismember(&tsk->pending.signal, SIGKILL) || + sigismember(&tsk->signal->shared_pending.signal, SIGKILL); } /* @@ -1514,8 +1513,6 @@ static int sigkill_pending(struct task_s */ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info) { - int killed = 0; - if (arch_ptrace_stop_needed(exit_code, info)) { /* * The arch code has something special to do before a @@ -1531,7 +1528,8 @@ static void ptrace_stop(int exit_code, i spin_unlock_irq(¤t->sighand->siglock); arch_ptrace_stop(exit_code, info); spin_lock_irq(¤t->sighand->siglock); - killed = sigkill_pending(current); + if (sigkill_pending(current)) + return; } /* @@ -1548,7 +1546,7 @@ static void ptrace_stop(int exit_code, i __set_current_state(TASK_TRACED); spin_unlock_irq(¤t->sighand->siglock); read_lock(&tasklist_lock); - if (!unlikely(killed) && may_ptrace_stop()) { + if (may_ptrace_stop()) { do_notify_parent_cldstop(current, CLD_TRAPPED); read_unlock(&tasklist_lock); schedule(); _ Patches currently in -mm which might be from oleg@xxxxxxxxxx are linux-next.patch migrate_timers-add-comment-use-spinlock_irq.patch pm-introduce-new-interfaces-schedule_work_on-and-queue_work_on.patch pm-introduce-new-interfaces-schedule_work_on-and-queue_work_on-cleanup.patch posix-timers-timer_delete-remove-the-bogus-it_process-=-null-check.patch posix-timers-release_posix_timer-kill-the-bogus-put_task_struct-it_process.patch signals-collect_signal-remove-the-unneeded-sigismember-check.patch signals-collect_signal-simplify-the-still_pending-logic.patch signals-change-collect_signal-to-return-void.patch __exit_signal-dont-take-rcu-lock.patch signals-dequeue_signal-dont-check-signal_group_exit-when-setting-signal_stop_dequeued.patch signals-do_signal_stop-kill-the-signal_unkillable-check.patch coredump-zap_threads-comments-use-while_each_thread.patch signals-make-siginfo_t-si_utime-si_sstime-report-times-in-user_hz-not-hz.patch kernel-signalc-change-vars-pid-and-tgid-types-to-pid_t.patch include-asm-ptraceh-userspace-headers-cleanup.patch ptrace-give-more-respect-to-sigkill.patch ptrace-simplify-ptrace_stop-sigkill_pending-path.patch introduce-pf_kthread-flag.patch kill-pf_borrowed_mm-in-favour-of-pf_kthread.patch coredump-zap_threads-must-skip-kernel-threads.patch coredump-elf_core_dump-skip-kernel-threads.patch coredump-turn-mm-core_startup_done-into-the-pointer-to-struct-core_state.patch coredump-move-mm-core_waiters-into-struct-core_state.patch coredump-simplify-core_state-nr_threads-calculation.patch coredump-turn-core_state-nr_threads-into-atomic_t.patch workqueues-insert_work-use-list_head-instead-of-int-tail.patch workqueues-implement-flush_work.patch workqueues-schedule_on_each_cpu-use-flush_work.patch workqueues-make-get_online_cpus-useable-for-work-func.patch workqueues-make-get_online_cpus-useable-for-work-func-fix.patch s390-topology-dont-use-kthread-for-arch_reinit_sched_domains.patch workqueues-lockdep-annotations-for-flush_work.patch workqueues-queue_work-can-use-queue_work_on.patch workqueues-schedule_on_each_cpu-can-use-schedule_work_on.patch pidns-remove-now-unused-kill_proc-function.patch pidns-remove-now-unused-find_pid-function.patch pidns-remove-find_task_by_pid-unused-for-a-long-time.patch distinct-tgid-tid-i-o-statistics.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