Refactoring: event notifier create: use enablers

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ib75cc8d0336f74af96455fd04c0a967db9013633

diff --git a/include/lttng/events-internal.h b/include/lttng/events-internal.h
index 873adc31201238d2506538ba5e26df15d5aafe0c..30f56e150b7355f94d36697a7a2e869a4a4b324e 100644 (file)
--- a/include/lttng/events-internal.h
+++ b/include/lttng/events-internal.h
@@ -250,6 +250,7 @@ struct lttng_event_notifier_enabler {
        struct lttng_event_enabler_common parent;
        uint64_t error_counter_index;
        struct list_head node;  /* List of event_notifier enablers */
+       bool published;         /* published in group list. */
        struct lttng_event_notifier_group *group;
 
        /* head list of struct lttng_kernel_bytecode_node */
@@ -780,9 +781,11 @@ void lttng_event_enabler_session_add(struct lttng_kernel_session *session,
                struct lttng_event_recorder_enabler *event_enabler);
 
 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
-               struct lttng_event_notifier_group *event_notifier_group,
                enum lttng_enabler_format_type format_type,
-               struct lttng_kernel_abi_event_notifier *event_notifier_param);
+               struct lttng_kernel_abi_event_notifier *event_notifier_param,
+               struct lttng_event_notifier_group *event_notifier_group);
+void lttng_event_notifier_enabler_group_add(struct lttng_event_notifier_group *event_notifier_group,
+               struct lttng_event_notifier_enabler *event_notifier_enabler);
 int lttng_event_notifier_enabler_attach_capture_bytecode(
                struct lttng_event_notifier_enabler *event_notifier_enabler,
                struct lttng_kernel_abi_capture_bytecode __user *bytecode);
@@ -1015,20 +1018,10 @@ struct lttng_kernel_event_recorder *lttng_event_compat_old_create(struct lttng_k
                struct lttng_kernel_abi_old_event *old_event_param,
                const struct lttng_kernel_event_desc *internal_desc);
 
-struct lttng_kernel_event_notifier *lttng_event_notifier_create(
-                               const struct lttng_kernel_event_desc *event_notifier_desc,
-                               uint64_t id,
-                               uint64_t error_counter_idx,
-                               struct lttng_event_notifier_group *event_notifier_group,
-                               struct lttng_kernel_abi_event_notifier *event_notifier_param,
-                               enum lttng_kernel_abi_instrumentation itype);
-struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
-                               const struct lttng_kernel_event_desc *event_notifier_desc,
-                               uint64_t id,
-                               uint64_t error_counter_idx,
-                               struct lttng_event_notifier_group *event_notifier_group,
-                               struct lttng_kernel_abi_event_notifier *event_notifier_param,
-                               enum lttng_kernel_abi_instrumentation itype);
+struct lttng_kernel_event_notifier *lttng_event_notifier_create(struct lttng_event_notifier_enabler *event_enabler,
+                               const struct lttng_kernel_event_desc *event_notifier_desc);
+struct lttng_kernel_event_notifier *_lttng_event_notifier_create(struct lttng_event_notifier_enabler *event_enabler,
+                               const struct lttng_kernel_event_desc *event_notifier_desc);
 
 int lttng_channel_enable(struct lttng_kernel_channel_common *channel);
 int lttng_channel_disable(struct lttng_kernel_channel_common *channel);

diff --git a/src/lttng-abi.c b/src/lttng-abi.c
index 63cce39c8c97c3f3f9e8028c15c4bb2bd553cd71..1f0939815262e5e2209d6c3e208a1c113c4b3acc 100644 (file)
--- a/src/lttng-abi.c
+++ b/src/lttng-abi.c
@@ -2132,15 +2132,17 @@ int lttng_abi_create_event_notifier(struct file *event_notifier_group_file,
                         * we create the special star globbing enabler.
                         */
                        enabler = lttng_event_notifier_enabler_create(
-                                       event_notifier_group,
                                        LTTNG_ENABLER_FORMAT_STAR_GLOB,
-                                       event_notifier_param);
+                                       event_notifier_param,
+                                       event_notifier_group);
                } else {
                        enabler = lttng_event_notifier_enabler_create(
-                                       event_notifier_group,
                                        LTTNG_ENABLER_FORMAT_NAME,
-                                       event_notifier_param);
+                                       event_notifier_param,
+                                       event_notifier_group);
                }
+               if (enabler)
+                       lttng_event_notifier_enabler_group_add(event_notifier_group, enabler);
                priv = enabler;
                break;
        }
@@ -2152,18 +2154,17 @@ int lttng_abi_create_event_notifier(struct file *event_notifier_group_file,
        case LTTNG_KERNEL_ABI_UPROBE:
        {
                struct lttng_kernel_event_notifier *event_notifier;
+               struct lttng_event_notifier_enabler *event_notifier_enabler;
 
-               /*
-                * We tolerate no failure path after event notifier creation.
-                * It will stay invariant for the rest of the session.
-                */
-               event_notifier = lttng_event_notifier_create(NULL,
-                               event_notifier_param->event.token,
-                               event_notifier_param->error_counter_index,
-                               event_notifier_group,
-                               event_notifier_param,
-                               event_notifier_param->event.instrumentation);
+               event_notifier_enabler = lttng_event_notifier_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
+                               event_notifier_param, event_notifier_group);
+               if (!event_notifier_enabler) {
+                       ret = -ENOMEM;
+                       goto event_notifier_error;
+               }
+               event_notifier = lttng_event_notifier_create(event_notifier_enabler, NULL);
                WARN_ON_ONCE(!event_notifier);
+               lttng_event_enabler_destroy(&event_notifier_enabler->parent);
                if (IS_ERR(event_notifier)) {
                        ret = PTR_ERR(event_notifier);
                        goto event_notifier_error;

diff --git a/src/lttng-events.c b/src/lttng-events.c
index 9f9e89471afb840b110fe7a4c4d7de0bcb2348ca..78ee916f0258283b2f92b29f932d4508af6c05b2 100644 (file)
--- a/src/lttng-events.c
+++ b/src/lttng-events.c
@@ -1151,13 +1151,13 @@ full:
        return ERR_PTR(ret);
 }
 
-struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
-               const struct lttng_kernel_event_desc *event_desc,
-               uint64_t token, uint64_t error_counter_index,
-               struct lttng_event_notifier_group *event_notifier_group,
-               struct lttng_kernel_abi_event_notifier *event_notifier_param,
-               enum lttng_kernel_abi_instrumentation itype)
+struct lttng_kernel_event_notifier *_lttng_event_notifier_create(struct lttng_event_notifier_enabler *event_enabler,
+               const struct lttng_kernel_event_desc *event_desc)
 {
+       struct lttng_event_notifier_group *event_notifier_group = event_enabler->group;
+       struct lttng_kernel_abi_event *event_param = &event_enabler->parent.event_param;
+       uint64_t token = event_enabler->parent.user_token;
+       enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
        struct lttng_kernel_event_notifier *event_notifier;
        struct lttng_kernel_event_notifier_private *event_notifier_priv;
        struct lttng_counter *error_counter;
@@ -1175,7 +1175,7 @@ struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
        case LTTNG_KERNEL_ABI_UPROBE:
                lttng_fallthrough;
        case LTTNG_KERNEL_ABI_SYSCALL:
-               event_name = event_notifier_param->event.name;
+               event_name = event_param->name;
                break;
 
        case LTTNG_KERNEL_ABI_KRETPROBE:
@@ -1220,8 +1220,8 @@ struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
        event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
 
        event_notifier->priv->group = event_notifier_group;
-       event_notifier->priv->parent.user_token = token;
-       event_notifier->priv->error_counter_index = error_counter_index;
+       event_notifier->priv->parent.user_token = event_enabler->parent.user_token;
+       event_notifier->priv->error_counter_index = event_enabler->error_counter_index;
        event_notifier->priv->num_captures = 0;
        event_notifier->priv->parent.instrumentation = itype;
        event_notifier->notification_send = lttng_event_notifier_notification_send;
@@ -1256,10 +1256,10 @@ struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
                 * registration.
                 */
                smp_wmb();
-               ret = lttng_kprobes_register_event(event_notifier_param->event.u.kprobe.symbol_name,
-                               event_notifier_param->event.u.kprobe.symbol_name,
-                               event_notifier_param->event.u.kprobe.offset,
-                               event_notifier_param->event.u.kprobe.addr,
+               ret = lttng_kprobes_register_event(event_param->u.kprobe.symbol_name,
+                               event_param->u.kprobe.symbol_name,
+                               event_param->u.kprobe.offset,
+                               event_param->u.kprobe.addr,
                                &event_notifier->parent);
                if (ret) {
                        ret = -EINVAL;
@@ -1277,7 +1277,7 @@ struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
                event_notifier->parent.enabled = 0;
                event_notifier->priv->parent.registered = 0;
                event_notifier->priv->parent.desc = event_desc;
-               switch (event_notifier_param->event.u.syscall.entryexit) {
+               switch (event_param->u.syscall.entryexit) {
                case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
                        ret = -EINVAL;
                        goto register_error;
@@ -1288,7 +1288,7 @@ struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
                        event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
                        break;
                }
-               switch (event_notifier_param->event.u.syscall.abi) {
+               switch (event_param->u.syscall.abi) {
                case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
                        ret = -EINVAL;
                        goto register_error;
@@ -1320,8 +1320,8 @@ struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
                 */
                smp_wmb();
 
-               ret = lttng_uprobes_register_event(event_notifier_param->event.name,
-                               event_notifier_param->event.u.uprobe.fd,
+               ret = lttng_uprobes_register_event(event_param->name,
+                               event_param->u.uprobe.fd,
                                &event_notifier->parent);
                if (ret)
                        goto register_error;
@@ -1418,19 +1418,13 @@ struct lttng_kernel_event_recorder *lttng_kernel_event_recorder_create(struct lt
        return event;
 }
 
-struct lttng_kernel_event_notifier *lttng_event_notifier_create(
-               const struct lttng_kernel_event_desc *event_desc,
-               uint64_t id, uint64_t error_counter_index,
-               struct lttng_event_notifier_group *event_notifier_group,
-               struct lttng_kernel_abi_event_notifier *event_notifier_param,
-               enum lttng_kernel_abi_instrumentation itype)
+struct lttng_kernel_event_notifier *lttng_event_notifier_create(struct lttng_event_notifier_enabler *event_enabler,
+               const struct lttng_kernel_event_desc *event_desc)
 {
        struct lttng_kernel_event_notifier *event_notifier;
 
        mutex_lock(&sessions_mutex);
-       event_notifier = _lttng_event_notifier_create(event_desc, id,
-               error_counter_index, event_notifier_group,
-               event_notifier_param, itype);
+       event_notifier = _lttng_event_notifier_create(event_enabler, event_desc);
        mutex_unlock(&sessions_mutex);
        return event_notifier;
 }
@@ -2156,11 +2150,7 @@ void lttng_create_tracepoint_event_notifier_if_missing(struct lttng_event_notifi
                        /*
                         * We need to create a event_notifier for this event probe.
                         */
-                       event_notifier = _lttng_event_notifier_create(desc,
-                               event_notifier_enabler->parent.user_token,
-                               event_notifier_enabler->error_counter_index,
-                               event_notifier_group, NULL,
-                               LTTNG_KERNEL_ABI_TRACEPOINT);
+                       event_notifier = _lttng_event_notifier_create(event_notifier_enabler, desc);
                        if (IS_ERR(event_notifier)) {
                                printk(KERN_INFO "Unable to create event_notifier %s\n",
                                        probe_desc->event_desc[i]->event_name);
@@ -2545,8 +2535,9 @@ void lttng_event_enabler_destroy(struct lttng_event_enabler_common *event_enable
                struct lttng_event_notifier_enabler *event_notifier_enabler =
                        container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
 
-               list_del(&event_notifier_enabler->node);
                lttng_enabler_destroy(event_enabler);
+               if (event_notifier_enabler->published)
+                       list_del(&event_notifier_enabler->node);
                kfree(event_notifier_enabler);
                break;
        }
@@ -2556,9 +2547,9 @@ void lttng_event_enabler_destroy(struct lttng_event_enabler_common *event_enable
 }
 
 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
-               struct lttng_event_notifier_group *event_notifier_group,
                enum lttng_enabler_format_type format_type,
-               struct lttng_kernel_abi_event_notifier *event_notifier_param)
+               struct lttng_kernel_abi_event_notifier *event_notifier_param,
+               struct lttng_event_notifier_group *event_notifier_group)
 {
        struct lttng_event_notifier_enabler *event_notifier_enabler;
 
@@ -2580,14 +2571,17 @@ struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
        event_notifier_enabler->parent.enabled = 0;
        event_notifier_enabler->parent.user_token = event_notifier_param->event.token;
        event_notifier_enabler->group = event_notifier_group;
+       return event_notifier_enabler;
+}
 
+void lttng_event_notifier_enabler_group_add(struct lttng_event_notifier_group *event_notifier_group,
+               struct lttng_event_notifier_enabler *event_notifier_enabler)
+{
        mutex_lock(&sessions_mutex);
        list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
+       event_notifier_enabler->published = true;
        lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
-
        mutex_unlock(&sessions_mutex);
-
-       return event_notifier_enabler;
 }
 
 int lttng_event_notifier_enabler_enable(

diff --git a/src/lttng-syscalls.c b/src/lttng-syscalls.c
index ff14dbbb0998782de88d72feae3aeef86c82f711..360f12b4b28a9d203e384230f5e8dd466158a650 100644 (file)
--- a/src/lttng-syscalls.c
+++ b/src/lttng-syscalls.c
@@ -898,12 +898,16 @@ int create_unknown_event_notifier(
        event_notifier_param.event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 
        event_notifier_param.event.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
+       event_notifier_param.event.token = user_token;
        event_notifier_param.event.u.syscall.abi = abi;
        event_notifier_param.event.u.syscall.entryexit = entryexit;
+       event_notifier_param.error_counter_index = error_counter_index;
 
-       event_notifier = _lttng_event_notifier_create(desc, user_token,
-               error_counter_index, group, &event_notifier_param,
-               event_notifier_param.event.instrumentation);
+       event_notifier_enabler = lttng_event_notifier_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
+                       &event_notifier_param, group);
+       WARN_ON_ONCE(!event_notifier_enabler);
+       event_notifier = _lttng_event_notifier_create(event_notifier_enabler, desc);
+       lttng_event_enabler_destroy(&event_notifier_enabler->parent);
        if (IS_ERR(event_notifier)) {
                printk(KERN_INFO "Unable to create unknown notifier %s\n",
                        desc->event_name);
@@ -918,19 +922,20 @@ end:
 }
 
 static int create_matching_event_notifiers(
-               struct lttng_event_notifier_enabler *event_notifier_enabler,
+               struct lttng_event_notifier_enabler *syscall_event_notifier_enabler,
                const struct trace_syscall_entry *table,
                size_t table_len, enum sc_type type)
 {
-       struct lttng_event_notifier_group *group = event_notifier_enabler->group;
+       struct lttng_event_notifier_group *group = syscall_event_notifier_enabler->group;
        const struct lttng_kernel_event_desc *desc;
-       uint64_t user_token = event_notifier_enabler->parent.user_token;
-       uint64_t error_counter_index = event_notifier_enabler->error_counter_index;
+       uint64_t user_token = syscall_event_notifier_enabler->parent.user_token;
+       uint64_t error_counter_index = syscall_event_notifier_enabler->error_counter_index;
        unsigned int i;
        int ret = 0;
 
        /* iterate over all syscall and create event_notifier that match */
        for (i = 0; i < table_len; i++) {
+               struct lttng_event_notifier_enabler *event_notifier_enabler;
                struct lttng_kernel_event_notifier_private *event_notifier_priv;
                struct lttng_kernel_event_notifier *event_notifier;
                struct lttng_kernel_abi_event_notifier event_notifier_param;
@@ -944,7 +949,7 @@ static int create_matching_event_notifiers(
                }
 
                if (!lttng_desc_match_enabler(desc,
-                               lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
+                               lttng_event_notifier_enabler_as_enabler(syscall_event_notifier_enabler)))
                        continue;
 
                /*
@@ -954,7 +959,7 @@ static int create_matching_event_notifiers(
                        LTTNG_EVENT_HT_SIZE, desc->event_name);
                lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
                        if (event_notifier_priv->parent.desc == desc
-                               && event_notifier_priv->parent.user_token == event_notifier_enabler->parent.user_token)
+                               && event_notifier_priv->parent.user_token == syscall_event_notifier_enabler->parent.user_token)
                                found = 1;
                }
                if (found)
@@ -983,10 +988,14 @@ static int create_matching_event_notifiers(
                        LTTNG_KERNEL_ABI_SYM_NAME_LEN - strlen(event_notifier_param.event.name) - 1);
                event_notifier_param.event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
                event_notifier_param.event.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
-
-               event_notifier = _lttng_event_notifier_create(desc, user_token,
-                       error_counter_index, group, &event_notifier_param,
-                       event_notifier_param.event.instrumentation);
+               event_notifier_param.event.token = user_token;
+               event_notifier_param.error_counter_index = error_counter_index;
+
+               event_notifier_enabler = lttng_event_notifier_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
+                               &event_notifier_param, group);
+               WARN_ON_ONCE(!event_notifier_enabler);
+               event_notifier = _lttng_event_notifier_create(event_notifier_enabler, desc);
+               lttng_event_enabler_destroy(&event_notifier_enabler->parent);
                if (IS_ERR(event_notifier)) {
                        printk(KERN_INFO "Unable to create event_notifier %s\n",
                                desc->event_name);