Implement event notifiers for syscalls

[lttng-modules.git] / src / lttng-events.c

diff --git a/src/lttng-events.c b/src/lttng-events.c
index 41fea8500c550b63634237b0569a63dc192f46a9..176c38326bc6f8bff15e96e2bf57f14bbcca4676 100644 (file)
--- a/src/lttng-events.c
+++ b/src/lttng-events.c
@@ -329,6 +329,9 @@ void lttng_event_notifier_group_destroy(
 
        mutex_lock(&sessions_mutex);
 
+       ret = lttng_syscalls_unregister_event_notifier(event_notifier_group);
+       WARN_ON(ret);
+
        list_for_each_entry_safe(event_notifier, tmpevent_notifier,
                        &event_notifier_group->event_notifiers_head, list) {
                ret = _lttng_event_notifier_unregister(event_notifier);
@@ -612,13 +615,13 @@ int lttng_event_notifier_enable(struct lttng_event_notifier *event_notifier)
        }
        switch (event_notifier->instrumentation) {
        case LTTNG_KERNEL_TRACEPOINT:
+       case LTTNG_KERNEL_SYSCALL:
                ret = -EINVAL;
                break;
        case LTTNG_KERNEL_KPROBE:
        case LTTNG_KERNEL_UPROBE:
                WRITE_ONCE(event_notifier->enabled, 1);
                break;
-       case LTTNG_KERNEL_SYSCALL:
        case LTTNG_KERNEL_FUNCTION:
        case LTTNG_KERNEL_NOOP:
        case LTTNG_KERNEL_KRETPROBE:
@@ -642,13 +645,13 @@ int lttng_event_notifier_disable(struct lttng_event_notifier *event_notifier)
        }
        switch (event_notifier->instrumentation) {
        case LTTNG_KERNEL_TRACEPOINT:
+       case LTTNG_KERNEL_SYSCALL:
                ret = -EINVAL;
                break;
        case LTTNG_KERNEL_KPROBE:
        case LTTNG_KERNEL_UPROBE:
                WRITE_ONCE(event_notifier->enabled, 0);
                break;
-       case LTTNG_KERNEL_SYSCALL:
        case LTTNG_KERNEL_FUNCTION:
        case LTTNG_KERNEL_NOOP:
        case LTTNG_KERNEL_KRETPROBE:
@@ -1009,12 +1012,12 @@ struct lttng_event_notifier *_lttng_event_notifier_create(
                break;
        case LTTNG_KERNEL_KPROBE:
        case LTTNG_KERNEL_UPROBE:
+       case LTTNG_KERNEL_SYSCALL:
                event_name = event_notifier_param->event.name;
                break;
        case LTTNG_KERNEL_KRETPROBE:
        case LTTNG_KERNEL_FUNCTION:
        case LTTNG_KERNEL_NOOP:
-       case LTTNG_KERNEL_SYSCALL:
        default:
                WARN_ON_ONCE(1);
                ret = -EINVAL;
@@ -1086,6 +1089,20 @@ struct lttng_event_notifier *_lttng_event_notifier_create(
                ret = try_module_get(event_notifier->desc->owner);
                WARN_ON_ONCE(!ret);
                break;
+       case LTTNG_KERNEL_NOOP:
+       case LTTNG_KERNEL_SYSCALL:
+               /*
+                * Needs to be explicitly enabled after creation, since
+                * we may want to apply filters.
+                */
+               event_notifier->enabled = 0;
+               event_notifier->registered = 0;
+               event_notifier->desc = event_desc;
+               if (!event_notifier->desc) {
+                       ret = -EINVAL;
+                       goto register_error;
+               }
+               break;
        case LTTNG_KERNEL_UPROBE:
                /*
                 * Needs to be explicitly enabled after creation, since
@@ -1111,8 +1128,6 @@ struct lttng_event_notifier *_lttng_event_notifier_create(
                break;
        case LTTNG_KERNEL_KRETPROBE:
        case LTTNG_KERNEL_FUNCTION:
-       case LTTNG_KERNEL_NOOP:
-       case LTTNG_KERNEL_SYSCALL:
        default:
                WARN_ON_ONCE(1);
                ret = -EINVAL;
@@ -1257,11 +1272,13 @@ void register_event_notifier(struct lttng_event_notifier *event_notifier)
                                                  desc->event_notifier_callback,
                                                  event_notifier);
                break;
+       case LTTNG_KERNEL_SYSCALL:
+               ret = lttng_syscall_filter_enable_event_notifier(event_notifier);
+               break;
        case LTTNG_KERNEL_KPROBE:
        case LTTNG_KERNEL_UPROBE:
                ret = 0;
                break;
-       case LTTNG_KERNEL_SYSCALL:
        case LTTNG_KERNEL_KRETPROBE:
        case LTTNG_KERNEL_FUNCTION:
        case LTTNG_KERNEL_NOOP:
@@ -1297,9 +1314,11 @@ int _lttng_event_notifier_unregister(
                lttng_uprobes_unregister_event_notifier(event_notifier);
                ret = 0;
                break;
+       case LTTNG_KERNEL_SYSCALL:
+               ret = lttng_syscall_filter_disable_event_notifier(event_notifier);
+               break;
        case LTTNG_KERNEL_KRETPROBE:
        case LTTNG_KERNEL_FUNCTION:
-       case LTTNG_KERNEL_SYSCALL:
        case LTTNG_KERNEL_NOOP:
        default:
                WARN_ON_ONCE(1);
@@ -1357,14 +1376,15 @@ void _lttng_event_notifier_destroy(struct lttng_event_notifier *event_notifier)
                module_put(event_notifier->desc->owner);
                lttng_kprobes_destroy_event_notifier_private(event_notifier);
                break;
+       case LTTNG_KERNEL_NOOP:
+       case LTTNG_KERNEL_SYSCALL:
+               break;
        case LTTNG_KERNEL_UPROBE:
                module_put(event_notifier->desc->owner);
                lttng_uprobes_destroy_event_notifier_private(event_notifier);
                break;
        case LTTNG_KERNEL_KRETPROBE:
        case LTTNG_KERNEL_FUNCTION:
-       case LTTNG_KERNEL_NOOP:
-       case LTTNG_KERNEL_SYSCALL:
        default:
                WARN_ON_ONCE(1);
        }
@@ -1647,7 +1667,6 @@ int lttng_match_enabler_name(const char *desc_name,
        return 1;
 }
 
-static
 int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
                struct lttng_enabler *enabler)
 {
@@ -1901,6 +1920,17 @@ void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_ena
        WARN_ON_ONCE(ret);
 }
 
+static
+void lttng_create_syscall_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
+{
+       int ret;
+
+       ret = lttng_syscalls_register_event_notifier(event_notifier_enabler, NULL);
+       WARN_ON_ONCE(ret);
+       ret = lttng_syscals_create_matching_event_notifiers(event_notifier_enabler, NULL);
+       WARN_ON_ONCE(ret);
+}
+
 /*
  * Create struct lttng_event if it is missing and present in the list of
  * tracepoint probes.
@@ -1995,6 +2025,9 @@ void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler
        case LTTNG_KERNEL_TRACEPOINT:
                lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler);
                break;
+       case LTTNG_KERNEL_SYSCALL:
+               lttng_create_syscall_event_notifier_if_missing(event_notifier_enabler);
+               break;
        default:
                WARN_ON_ONCE(1);
                break;