The patch titled tracehook: TIF_NOTIFY_RESUME has been added to the -mm tree. Its filename is tracehook-tif_notify_resume.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 *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: tracehook: TIF_NOTIFY_RESUME From: Roland McGrath <roland@xxxxxxxxxx> This adds tracehook.h inlines to enable a new arch feature in support of user debugging/tracing. This is not used yet, but it lays the groundwork for a debugger to be able to wrangle a task that's possibly running, without interrupting its syscalls in progress. Each arch should define TIF_NOTIFY_RESUME, and in their entry.S code treat it much like TIF_SIGPENDING. That is, it causes you to take the slow path when returning to user mode, where you get the full user-mode state accessible as for signal handling or ptrace. The arch code should check TIF_NOTIFY_RESUME after handling TIF_SIGPENDING. When it's set, clear it and then call tracehook_notify_resume(). In future, tracing code will call set_notify_resume() when it wants to get a callback in tracehook_notify_resume(). Signed-off-by: Roland McGrath <roland@xxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/tracehook.h | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff -puN include/linux/tracehook.h~tracehook-tif_notify_resume include/linux/tracehook.h --- a/include/linux/tracehook.h~tracehook-tif_notify_resume +++ a/include/linux/tracehook.h @@ -537,4 +537,38 @@ static inline void tracehook_report_deat { } +#ifdef TIF_NOTIFY_RESUME +/** + * set_notify_resume - cause tracehook_notify_resume() to be called + * @task: task that will call tracehook_notify_resume() + * + * Calling this arranges that @task will call tracehook_notify_resume() + * before returning to user mode. If it's already running in user mode, + * it will enter the kernel and call tracehook_notify_resume() soon. + * If it's blocked, it will not be woken. + */ +static inline void set_notify_resume(struct task_struct *task) +{ + if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_RESUME)) + kick_process(task); +} + +/** + * tracehook_notify_resume - report when about to return to user mode + * @regs: user-mode registers of @current task + * + * This is called when %TIF_NOTIFY_RESUME has been set. Now we are + * about to return to user mode, and the user state in @regs can be + * inspected or adjusted. The caller in arch code has cleared + * %TIF_NOTIFY_RESUME before the call. If the flag gets set again + * asynchronously, this will be called again before we return to + * user mode. + * + * Called without locks. + */ +static inline void tracehook_notify_resume(struct pt_regs *regs) +{ +} +#endif /* TIF_NOTIFY_RESUME */ + #endif /* <linux/tracehook.h> */ _ Patches currently in -mm which might be from roland@xxxxxxxxxx are origin.patch execve-filename-document-and-export-via-auxiliary-vector.patch flag-parameters-paccept-fix.patch flag-parameters-paccept-fix-flag-parameters-arch-specific-sock_nonblock.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 __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 ptrace-do_wait-reorganization.patch ptrace-ptrace-children-revamp.patch ptrace-do_wait-return-security_task_wait-error-code-in-place-of-echild.patch ptrace-fix-dangling-zombie-when-new-parent-ignores-children.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 coredump-make-mm-core_state-visible-to-core_dump.patch coredump-construct-the-list-of-coredumping-threads-at-startup-time.patch coredump-elf_core_dump-use-core_state-dumper-list.patch coredump-elf_fdpic_core_dump-use-core_state-dumper-list.patch coredump-kill-mm-core_done.patch coredump-binfmt_elf_fdpic-dont-use-sub-threads-mm.patch coredump-exit_mm-clear-mm-first-then-play-with-core_state.patch coredump-exit_mm-clear-mm-first-then-play-with-core_state-checkpatch-fixes.patch tracehook-add-linux-tracehookh.patch tracehook-exec.patch tracehook-unexport-ptrace_notify.patch tracehook-exit.patch tracehook-clone.patch tracehook-vfork-done.patch tracehook-release_task.patch tracehook-tracehook_tracer_task.patch tracehook-tracehook_expect_breakpoints.patch tracehook-tracehook_signal_handler.patch tracehook-tracehook_consider_ignored_signal.patch tracehook-tracehook_consider_fatal_signal.patch tracehook-syscall.patch tracehook-get_signal_to_deliver.patch tracehook-job-control.patch tracehook-death.patch tracehook-force-signal_pending.patch tracehook-tif_notify_resume.patch tracehook-asm-syscallh.patch tracehook-config_have_arch_tracehook.patch tracehook-wait_task_inactive.patch task_current_syscall.patch proc-pid-syscall.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