This stops a process after an event has been triggered a given number of times. For example:
[[ -d /sys/kernel/debug/tracing ]] || \ mount -t debugfs none /sys/kernel/debug echo "p:myevent $(which myapp):0x700" > /sys/kernel/debug/tracing/uprobe_events echo 1 > /sys/kernel/debug/tracing/events/uprobes/myevent/enable echo 'signal:3' > /sys/kernel/debug/tracing/events/uprobes/myevent/trigger myapp myapp myapp & Here, the 0x700 offset is the entry to main(). On the third invocation of the program, the process is stopped. Signed-off-by: Christopher Covington <[email protected]> --- include/linux/ftrace_event.h | 1 + kernel/trace/trace_events_trigger.c | 73 +++++++++++++++++++++++++++++++++++++ 2 files changed, 74 insertions(+) diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index cff3106..7bca0df 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -402,6 +402,7 @@ enum event_trigger_type { ETT_SNAPSHOT = (1 << 1), ETT_STACKTRACE = (1 << 2), ETT_EVENT_ENABLE = (1 << 3), + ETT_SIGNAL = (1 << 4), }; extern void destroy_preds(struct ftrace_event_file *file); diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 4747b47..d0599fa 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -1042,6 +1042,78 @@ static __init int register_trigger_stacktrace_cmd(void) static __init int register_trigger_stacktrace_cmd(void) { return 0; } #endif /* CONFIG_STACKTRACE */ +//ifdef CONFIG_TRACER_SIGNAL +static void +signal_trigger(struct event_trigger_data *data) +{ + force_sig(SIGSTOP, current); +} + +static void +signal_count_trigger(struct event_trigger_data *data) +{ + switch(data->count) { + case 0: + return; + case 1: + signal_trigger(data); + // fall through + default: + (data->count)--; + } +} + +static int +signal_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + return event_trigger_print("signal", m, (void *)data->count, + data->filter_str); +} + +static struct event_trigger_ops signal_trigger_ops = { + .func = signal_trigger, + .print = signal_trigger_print, + .init = event_trigger_init, + .free = event_trigger_free, +}; + +static struct event_trigger_ops signal_count_trigger_ops = { + .func = signal_count_trigger, + .print = signal_trigger_print, + .init = event_trigger_init, + .free = event_trigger_free, +}; + +static struct event_trigger_ops * +signal_get_trigger_ops(char *cmd, char *param) +{ + return param ? &signal_count_trigger_ops : &signal_trigger_ops; +} + +static struct event_command trigger_signal_cmd = { + .name = "signal", + .trigger_type = ETT_SIGNAL, + .func = event_trigger_callback, + .reg = register_trigger, + .unreg = unregister_trigger, + .get_trigger_ops = signal_get_trigger_ops, + .set_filter = set_trigger_filter, +}; + +static __init int register_trigger_signal_cmd(void) +{ + int ret; + + ret = register_event_command(&trigger_signal_cmd); + WARN_ON(ret < 0); + + return ret; +} +/* else +static __init int register_trigger_signal_cmd(void) { return 0; } +endif CONFIG_TRACER_SIGNAL */ + static __init void unregister_trigger_traceon_traceoff_cmds(void) { unregister_event_command(&trigger_traceon_cmd); @@ -1432,6 +1504,7 @@ __init int register_trigger_cmds(void) register_trigger_snapshot_cmd(); register_trigger_stacktrace_cmd(); register_trigger_enable_disable_cmds(); + register_trigger_signal_cmd(); return 0; } -- Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by the Linux Foundation. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
