The patch titled tracehook: TIF_NOTIFY_RESUME has been removed from the -mm tree. Its filename was tracehook-tif_notify_resume.patch This patch was dropped because it was merged into mainline or a subsystem tree 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> Reviewed-by: Ingo Molnar <mingo@xxxxxxx> 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 tracehook-syscall.patch tracehook-config_have_arch_tracehook.patch x86-tracehook_signal_handler.patch x86-tracehook-syscall.patch x86-tracehook-asm-syscallh.patch x86-signals-use-asm-syscallh.patch x86-tracehook-tif_notify_resume.patch x86-tracehook-config_have_arch_tracehook.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