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 84ffd28332e9b5b02a1cafed7d83f82e9249cff3..176c38326bc6f8bff15e96e2bf57f14bbcca4676 100644 (file)
--- a/src/lttng-events.c
+++ b/src/lttng-events.c
@@ -280,7 +280,7 @@ void lttng_session_destroy(struct lttng_session *session)
        mutex_lock(&sessions_mutex);
        WRITE_ONCE(session->active, 0);
        list_for_each_entry(chan, &session->chan, list) {
-               ret = lttng_syscalls_unregister(chan);
+               ret = lttng_syscalls_unregister_event(chan);
                WARN_ON(ret);
        }
        list_for_each_entry(event, &session->events, list) {
@@ -289,7 +289,7 @@ void lttng_session_destroy(struct lttng_session *session)
        }
        synchronize_trace();    /* Wait for in-flight events to complete */
        list_for_each_entry(chan, &session->chan, list) {
-               ret = lttng_syscalls_destroy(chan);
+               ret = lttng_syscalls_destroy_event(chan);
                WARN_ON(ret);
        }
        list_for_each_entry_safe(event_enabler, tmp_event_enabler,
@@ -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);
@@ -612,14 +615,14 @@ 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_UPROBE:
        case LTTNG_KERNEL_NOOP:
        case LTTNG_KERNEL_KRETPROBE:
        default:
@@ -642,14 +645,14 @@ 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_UPROBE:
        case LTTNG_KERNEL_NOOP:
        case LTTNG_KERNEL_KRETPROBE:
        default:
@@ -958,7 +961,7 @@ struct lttng_event *_lttng_event_create(struct lttng_channel *chan,
                 */
                smp_wmb();
 
-               ret = lttng_uprobes_register(event_param->name,
+               ret = lttng_uprobes_register_event(event_param->name,
                                event_param->u.uprobe.fd,
                                event);
                if (ret)
@@ -1008,13 +1011,13 @@ struct lttng_event_notifier *_lttng_event_notifier_create(
                event_name = event_desc->name;
                break;
        case LTTNG_KERNEL_KPROBE:
+       case LTTNG_KERNEL_UPROBE:
+       case LTTNG_KERNEL_SYSCALL:
                event_name = event_notifier_param->event.name;
                break;
-       case LTTNG_KERNEL_UPROBE:
        case LTTNG_KERNEL_KRETPROBE:
        case LTTNG_KERNEL_FUNCTION:
        case LTTNG_KERNEL_NOOP:
-       case LTTNG_KERNEL_SYSCALL:
        default:
                WARN_ON_ONCE(1);
                ret = -EINVAL;
@@ -1086,11 +1089,45 @@ 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
+                * we may want to apply filters.
+                */
+               event_notifier->enabled = 0;
+               event_notifier->registered = 1;
+
+               /*
+                * Populate lttng_event_notifier structure before
+                * event_notifier registration.
+                */
+               smp_wmb();
+
+               ret = lttng_uprobes_register_event_notifier(
+                               event_notifier_param->event.name,
+                               event_notifier_param->event.u.uprobe.fd,
+                               event_notifier);
+               if (ret)
+                       goto register_error;
+               ret = try_module_get(event_notifier->desc->owner);
+               WARN_ON_ONCE(!ret);
+               break;
        case LTTNG_KERNEL_KRETPROBE:
        case LTTNG_KERNEL_FUNCTION:
-       case LTTNG_KERNEL_NOOP:
-       case LTTNG_KERNEL_SYSCALL:
        default:
                WARN_ON_ONCE(1);
                ret = -EINVAL;
@@ -1157,7 +1194,7 @@ void register_event(struct lttng_event *event)
                                                  event);
                break;
        case LTTNG_KERNEL_SYSCALL:
-               ret = lttng_syscall_filter_enable(event->chan, event);
+               ret = lttng_syscall_filter_enable_event(event->chan, event);
                break;
        case LTTNG_KERNEL_KPROBE:
        case LTTNG_KERNEL_UPROBE:
@@ -1200,13 +1237,13 @@ int _lttng_event_unregister(struct lttng_event *event)
                ret = 0;
                break;
        case LTTNG_KERNEL_SYSCALL:
-               ret = lttng_syscall_filter_disable(event->chan, event);
+               ret = lttng_syscall_filter_disable_event(event->chan, event);
                break;
        case LTTNG_KERNEL_NOOP:
                ret = 0;
                break;
        case LTTNG_KERNEL_UPROBE:
-               lttng_uprobes_unregister(event);
+               lttng_uprobes_unregister_event(event);
                ret = 0;
                break;
        case LTTNG_KERNEL_FUNCTION:     /* Fall-through */
@@ -1235,11 +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_UPROBE:
        case LTTNG_KERNEL_KRETPROBE:
        case LTTNG_KERNEL_FUNCTION:
        case LTTNG_KERNEL_NOOP:
@@ -1271,11 +1310,16 @@ int _lttng_event_notifier_unregister(
                lttng_kprobes_unregister_event_notifier(event_notifier);
                ret = 0;
                break;
+       case LTTNG_KERNEL_UPROBE:
+               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:
-       case LTTNG_KERNEL_UPROBE:
        default:
                WARN_ON_ONCE(1);
        }
@@ -1307,7 +1351,7 @@ void _lttng_event_destroy(struct lttng_event *event)
                break;
        case LTTNG_KERNEL_UPROBE:
                module_put(event->desc->owner);
-               lttng_uprobes_destroy_private(event);
+               lttng_uprobes_destroy_event_private(event);
                break;
        case LTTNG_KERNEL_FUNCTION:     /* Fall-through */
        default:
@@ -1332,11 +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_KRETPROBE:
-       case LTTNG_KERNEL_FUNCTION:
        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:
        default:
                WARN_ON_ONCE(1);
        }
@@ -1619,7 +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)
 {
@@ -1869,7 +1916,18 @@ void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_ena
 {
        int ret;
 
-       ret = lttng_syscalls_register(event_enabler->chan, NULL);
+       ret = lttng_syscalls_register_event(event_enabler->chan, NULL);
+       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);
 }
 
@@ -1967,6 +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;
@@ -2163,7 +2224,7 @@ int lttng_event_add_callsite(struct lttng_event *event,
 
        switch (event->instrumentation) {
        case LTTNG_KERNEL_UPROBE:
-               return lttng_uprobes_add_callsite(event, callsite);
+               return lttng_uprobes_event_add_callsite(event, callsite);
        default:
                return -EINVAL;
        }
@@ -2270,6 +2331,19 @@ error:
        return ret;
 }
 
+int lttng_event_notifier_add_callsite(struct lttng_event_notifier *event_notifier,
+               struct lttng_kernel_event_callsite __user *callsite)
+{
+
+       switch (event_notifier->instrumentation) {
+       case LTTNG_KERNEL_UPROBE:
+               return lttng_uprobes_event_notifier_add_callsite(event_notifier,
+                               callsite);
+       default:
+               return -EINVAL;
+       }
+}
+
 int lttng_event_notifier_enabler_attach_context(
                struct lttng_event_notifier_enabler *event_notifier_enabler,
                struct lttng_kernel_context *context_param)