Use event enabler for event recorder creation for all instrumentation types

Remove special-cases for uprobes, kprobes, kretprobes and use a
temporary event enabler to hold relevant information for event recorder
creation.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ib353a67d1554c345ba71d31c5632ded3b33b2a92

diff --git a/include/lttng/events-internal.h b/include/lttng/events-internal.h
index ca2190c4d33330d76dbdd8cd41a0fbcc6d2b43ae..cfbde70f00e1f5032f6e1b955dd39ac6d5cdae48 100644 (file)
--- a/include/lttng/events-internal.h
+++ b/include/lttng/events-internal.h
@@ -221,7 +221,8 @@ struct lttng_enabler {
 
 struct lttng_event_enabler {
        struct lttng_enabler base;
-       struct list_head node;  /* per-session list of enablers */
+       struct list_head node;          /* per-session list of enablers */
+       bool published;                 /* published in per-session list. */
        struct lttng_kernel_channel_buffer *chan;
 };
 
@@ -779,6 +780,9 @@ struct lttng_event_enabler *lttng_event_enabler_create(
                enum lttng_enabler_format_type format_type,
                struct lttng_kernel_abi_event *event_param,
                struct lttng_kernel_channel_buffer *chan);
+void lttng_event_enabler_session_add(struct lttng_kernel_session *session,
+               struct lttng_event_enabler *event_enabler);
+void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler);
 
 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler);
 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler);
@@ -1096,14 +1100,10 @@ struct lttng_kernel_channel_buffer *lttng_global_channel_create(struct lttng_ker
                                       unsigned int read_timer_interval);
 
 void lttng_metadata_channel_destroy(struct lttng_kernel_channel_buffer *chan);
-struct lttng_kernel_event_recorder *lttng_kernel_event_recorder_create(struct lttng_kernel_channel_buffer *chan,
-                               struct lttng_kernel_abi_event *event_param,
-                               const struct lttng_kernel_event_desc *event_desc,
-                               enum lttng_kernel_abi_instrumentation itype);
-struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_kernel_channel_buffer *chan,
-                               struct lttng_kernel_abi_event *event_param,
-                               const struct lttng_kernel_event_desc *event_desc,
-                               enum lttng_kernel_abi_instrumentation itype);
+struct lttng_kernel_event_recorder *lttng_kernel_event_recorder_create(struct lttng_event_enabler *event_enabler,
+                               const struct lttng_kernel_event_desc *event_desc);
+struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_event_enabler *event_enabler,
+                               const struct lttng_kernel_event_desc *event_desc);
 struct lttng_kernel_event_recorder *lttng_event_compat_old_create(struct lttng_kernel_channel_buffer *chan,
                struct lttng_kernel_abi_old_event *old_event_param,
                const struct lttng_kernel_event_desc *internal_desc);

diff --git a/src/lttng-abi.c b/src/lttng-abi.c
index eac1afd11a83b50caa6495251d70b44dc838e1af..72dc06034fe2f5b6c2e90f039b457e829a3551ef 100644 (file)
--- a/src/lttng-abi.c
+++ b/src/lttng-abi.c
@@ -1900,6 +1900,8 @@ int lttng_abi_create_event(struct file *channel_file,
                        event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
                                event_param, channel);
                }
+               if (event_enabler)
+                       lttng_event_enabler_session_add(channel->parent.session, event_enabler);
                priv = event_enabler;
                break;
        }
@@ -1911,14 +1913,21 @@ int lttng_abi_create_event(struct file *channel_file,
        case LTTNG_KERNEL_ABI_UPROBE:
        {
                struct lttng_kernel_event_recorder *event;
+               struct lttng_event_enabler *event_enabler;
 
+               event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
+                               event_param, channel);
+               if (!event_enabler) {
+                       ret = -ENOMEM;
+                       goto event_error;
+               }
                /*
                 * We tolerate no failure path after event creation. It
                 * will stay invariant for the rest of the session.
                 */
-               event = lttng_kernel_event_recorder_create(channel, event_param,
-                               NULL, event_param->instrumentation);
+               event = lttng_kernel_event_recorder_create(event_enabler, NULL);
                WARN_ON_ONCE(!event);
+               lttng_event_enabler_destroy(event_enabler);
                if (IS_ERR(event)) {
                        ret = PTR_ERR(event);
                        goto event_error;

diff --git a/src/lttng-events.c b/src/lttng-events.c
index 230e393446735edcfaef947c274a39faa0d6f891..02c62b0cefaa269aa15a9b4c3e17f806d33ac163 100644 (file)
--- a/src/lttng-events.c
+++ b/src/lttng-events.c
@@ -66,7 +66,6 @@ static struct kmem_cache *event_notifier_private_cache;
 
 static void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session);
 static void lttng_session_sync_event_enablers(struct lttng_kernel_session *session);
-static void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler);
 static void lttng_event_notifier_enabler_destroy(struct lttng_event_notifier_enabler *event_notifier_enabler);
 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
 
@@ -860,11 +859,12 @@ void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
  * Supports event creation while tracing session is active.
  * Needs to be called with sessions mutex held.
  */
-struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_kernel_channel_buffer *chan,
-                               struct lttng_kernel_abi_event *event_param,
-                               const struct lttng_kernel_event_desc *event_desc,
-                               enum lttng_kernel_abi_instrumentation itype)
+struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_event_enabler *event_enabler,
+                               const struct lttng_kernel_event_desc *event_desc)
 {
+       struct lttng_kernel_channel_buffer *chan = event_enabler->chan;
+       struct lttng_kernel_abi_event *event_param = &event_enabler->base.event_param;
+       enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
        struct lttng_kernel_session *session = chan->parent.session;
        struct lttng_kernel_event_recorder *event_recorder;
        struct lttng_kernel_event_recorder_private *event_recorder_priv;
@@ -1395,15 +1395,13 @@ int lttng_kernel_counter_clear(struct lttng_counter *counter,
        return counter->ops->counter_clear(counter->counter, dim_indexes);
 }
 
-struct lttng_kernel_event_recorder *lttng_kernel_event_recorder_create(struct lttng_kernel_channel_buffer *chan,
-                               struct lttng_kernel_abi_event *event_param,
-                               const struct lttng_kernel_event_desc *event_desc,
-                               enum lttng_kernel_abi_instrumentation itype)
+struct lttng_kernel_event_recorder *lttng_kernel_event_recorder_create(struct lttng_event_enabler *event_enabler,
+                               const struct lttng_kernel_event_desc *event_desc)
 {
        struct lttng_kernel_event_recorder *event;
 
        mutex_lock(&sessions_mutex);
-       event = _lttng_kernel_event_recorder_create(chan, event_param, event_desc, itype);
+       event = _lttng_kernel_event_recorder_create(event_enabler, event_desc);
        mutex_unlock(&sessions_mutex);
        return event;
 }
@@ -2160,8 +2158,7 @@ void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_
                         * We need to create an event for this
                         * event probe.
                         */
-                       event_recorder = _lttng_kernel_event_recorder_create(event_enabler->chan,
-                                       NULL, desc, LTTNG_KERNEL_ABI_TRACEPOINT);
+                       event_recorder = _lttng_kernel_event_recorder_create(event_enabler, desc);
                        if (!event_recorder) {
                                printk(KERN_INFO "LTTng: Unable to create event %s\n",
                                        probe_desc->event_desc[i]->event_name);
@@ -2492,11 +2489,17 @@ struct lttng_event_enabler *lttng_event_enabler_create(
        event_enabler->chan = chan;
        /* ctx left NULL */
        event_enabler->base.enabled = 0;
+       return event_enabler;
+}
+
+void lttng_event_enabler_session_add(struct lttng_kernel_session *session,
+               struct lttng_event_enabler *event_enabler)
+{
        mutex_lock(&sessions_mutex);
-       list_add(&event_enabler->node, &event_enabler->chan->parent.session->priv->enablers_head);
-       lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
+       list_add(&event_enabler->node, &session->priv->enablers_head);
+       event_enabler->published = true;
+       lttng_session_lazy_sync_event_enablers(session);
        mutex_unlock(&sessions_mutex);
-       return event_enabler;
 }
 
 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
@@ -2590,12 +2593,12 @@ void lttng_enabler_destroy(struct lttng_enabler *enabler)
        }
 }
 
-static
 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
 {
        lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
 
-       list_del(&event_enabler->node);
+       if (event_enabler->published)
+               list_del(&event_enabler->node);
        kfree(event_enabler);
 }
 

diff --git a/src/lttng-syscalls.c b/src/lttng-syscalls.c
index bd836c001d658257e5bf529d61a3cbeabc84a168..25db7f61a8532e5ee339d7acd7ec18365c30309e 100644 (file)
--- a/src/lttng-syscalls.c
+++ b/src/lttng-syscalls.c
@@ -613,16 +613,17 @@ void syscall_exit_event_notifier_probe(void *__data, struct pt_regs *regs,
  */
 static
 int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *table, size_t table_len,
-       struct hlist_head *chan_table, struct lttng_event_enabler *event_enabler,
+       struct hlist_head *chan_table, struct lttng_event_enabler *syscall_event_enabler,
        enum sc_type type)
 {
-       struct lttng_kernel_channel_buffer *chan = event_enabler->chan;
+       struct lttng_kernel_channel_buffer *chan = syscall_event_enabler->chan;
        struct lttng_kernel_session *session = chan->parent.session;
        unsigned int i;
 
        /* Allocate events for each syscall matching enabler, insert into table */
        for (i = 0; i < table_len; i++) {
                const struct lttng_kernel_event_desc *desc = table[i].desc;
+               struct lttng_event_enabler *event_enabler;
                struct lttng_kernel_abi_event ev;
                struct lttng_kernel_event_recorder_private *event_recorder_priv;
                struct lttng_kernel_event_recorder *event_recorder;
@@ -634,7 +635,7 @@ int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *tabl
                        continue;
                }
                if (lttng_desc_match_enabler(desc,
-                               lttng_event_enabler_as_enabler(event_enabler)) <= 0)
+                               lttng_event_enabler_as_enabler(syscall_event_enabler)) <= 0)
                        continue;
                /*
                 * Check if already created.
@@ -644,7 +645,7 @@ int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *tabl
                        desc->event_name);
                lttng_hlist_for_each_entry(event_recorder_priv, head, hlist) {
                        if (event_recorder_priv->parent.desc == desc
-                               && event_recorder_priv->pub->chan == event_enabler->chan)
+                               && event_recorder_priv->pub->chan == chan)
                                found = true;
                }
                if (found)
@@ -673,8 +674,13 @@ int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *tabl
                strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1);
                ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
                ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
-               event_recorder = _lttng_kernel_event_recorder_create(chan, &ev, desc, ev.instrumentation);
+               event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
+               if (!event_enabler) {
+                       return -ENOMEM;
+               }
+               event_recorder = _lttng_kernel_event_recorder_create(event_enabler, desc);
                WARN_ON_ONCE(!event_recorder);
+               lttng_event_enabler_destroy(event_enabler);
                if (IS_ERR(event_recorder)) {
                        /*
                         * If something goes wrong in event registration
@@ -692,9 +698,9 @@ int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *tabl
 /*
  * Should be called with sessions lock held.
  */
-int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler)
+int lttng_syscalls_register_event(struct lttng_event_enabler *syscall_event_enabler)
 {
-       struct lttng_kernel_channel_buffer *chan = event_enabler->chan;
+       struct lttng_kernel_channel_buffer *chan = syscall_event_enabler->chan;
        struct lttng_kernel_abi_event ev;
        int ret;
 
@@ -737,6 +743,7 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler)
                const struct lttng_kernel_event_desc *desc =
                        &__event_desc___syscall_entry_unknown;
                struct lttng_kernel_event_recorder *event_recorder;
+               struct lttng_event_enabler *event_enabler;
 
                memset(&ev, 0, sizeof(ev));
                strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
@@ -744,8 +751,12 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler)
                ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
                ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
                ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
-               event_recorder = _lttng_kernel_event_recorder_create(chan, &ev, desc,
-                                           ev.instrumentation);
+               event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
+               if (!event_enabler) {
+                       return -ENOMEM;
+               }
+               event_recorder = _lttng_kernel_event_recorder_create(event_enabler, desc);
+               lttng_event_enabler_destroy(event_enabler);
                WARN_ON_ONCE(!event_recorder);
                if (IS_ERR(event_recorder)) {
                        return PTR_ERR(event_recorder);
@@ -757,6 +768,7 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler)
                const struct lttng_kernel_event_desc *desc =
                        &__event_desc___compat_syscall_entry_unknown;
                struct lttng_kernel_event_recorder *event_recorder;
+               struct lttng_event_enabler *event_enabler;
 
                memset(&ev, 0, sizeof(ev));
                strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
@@ -764,9 +776,13 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler)
                ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
                ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
                ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
-               event_recorder = _lttng_kernel_event_recorder_create(chan, &ev, desc,
-                                           ev.instrumentation);
+               event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
+               if (!event_enabler) {
+                       return -ENOMEM;
+               }
+               event_recorder = _lttng_kernel_event_recorder_create(event_enabler, desc);
                WARN_ON_ONCE(!event_recorder);
+               lttng_event_enabler_destroy(event_enabler);
                if (IS_ERR(event_recorder)) {
                        return PTR_ERR(event_recorder);
                }
@@ -777,6 +793,7 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler)
                const struct lttng_kernel_event_desc *desc =
                        &__event_desc___compat_syscall_exit_unknown;
                struct lttng_kernel_event_recorder *event_recorder;
+               struct lttng_event_enabler *event_enabler;
 
                memset(&ev, 0, sizeof(ev));
                strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
@@ -784,9 +801,13 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler)
                ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
                ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
                ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
-               event_recorder = _lttng_kernel_event_recorder_create(chan, &ev, desc,
-                                           ev.instrumentation);
+               event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
+               if (!event_enabler) {
+                       return -ENOMEM;
+               }
+               event_recorder = _lttng_kernel_event_recorder_create(event_enabler, desc);
                WARN_ON_ONCE(!event_recorder);
+               lttng_event_enabler_destroy(event_enabler);
                if (IS_ERR(event_recorder)) {
                        return PTR_ERR(event_recorder);
                }
@@ -797,6 +818,7 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler)
                const struct lttng_kernel_event_desc *desc =
                        &__event_desc___syscall_exit_unknown;
                struct lttng_kernel_event_recorder *event_recorder;
+               struct lttng_event_enabler *event_enabler;
 
                memset(&ev, 0, sizeof(ev));
                strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
@@ -804,9 +826,13 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler)
                ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
                ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
                ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
-               event_recorder = _lttng_kernel_event_recorder_create(chan, &ev, desc,
-                                           ev.instrumentation);
+               event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
+               if (!event_enabler) {
+                       return -ENOMEM;
+               }
+               event_recorder = _lttng_kernel_event_recorder_create(event_enabler, desc);
                WARN_ON_ONCE(!event_recorder);
+               lttng_event_enabler_destroy(event_enabler);
                if (IS_ERR(event_recorder)) {
                        return PTR_ERR(event_recorder);
                }
@@ -814,21 +840,21 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler)
        }
 
        ret = lttng_create_syscall_event_if_missing(sc_table.table, sc_table.len,
-                       chan->priv->parent.sc_table, event_enabler, SC_TYPE_ENTRY);
+                       chan->priv->parent.sc_table, syscall_event_enabler, SC_TYPE_ENTRY);
        if (ret)
                return ret;
        ret = lttng_create_syscall_event_if_missing(sc_exit_table.table, sc_exit_table.len,
-                       chan->priv->parent.sc_exit_table, event_enabler, SC_TYPE_EXIT);
+                       chan->priv->parent.sc_exit_table, syscall_event_enabler, SC_TYPE_EXIT);
        if (ret)
                return ret;
 
 #ifdef CONFIG_COMPAT
        ret = lttng_create_syscall_event_if_missing(compat_sc_table.table, compat_sc_table.len,
-                       chan->priv->parent.compat_sc_table, event_enabler, SC_TYPE_COMPAT_ENTRY);
+                       chan->priv->parent.compat_sc_table, syscall_event_enabler, SC_TYPE_COMPAT_ENTRY);
        if (ret)
                return ret;
        ret = lttng_create_syscall_event_if_missing(compat_sc_exit_table.table, compat_sc_exit_table.len,
-                       chan->priv->parent.compat_sc_exit_table, event_enabler, SC_TYPE_COMPAT_EXIT);
+                       chan->priv->parent.compat_sc_exit_table, syscall_event_enabler, SC_TYPE_COMPAT_EXIT);
        if (ret)
                return ret;
 #endif