Fix: _lttng_kernel_event_create never returns NULL

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

diff --git a/src/lttng-syscalls.c b/src/lttng-syscalls.c
index 5646053959b1583a4f650b55f0b52eaf8e394b2c..2e8324133d53ed069ec325bd29fd958ca6360d28 100644 (file)
--- a/src/lttng-syscalls.c
+++ b/src/lttng-syscalls.c
@@ -132,9 +132,6 @@ struct lttng_syscall_filter {
        DECLARE_BITMAP(sc_compat_exit, NR_compat_syscalls);
 };
 
-static
-int lttng_syscalls_create_matching_event_notifiers(struct lttng_event_enabler_common *event_enabler);
-
 static void syscall_entry_event_unknown(struct hlist_head *unknown_action_list_head,
        struct pt_regs *regs, long id)
 {
@@ -571,9 +568,9 @@ void lttng_syscall_event_enabler_create_event(struct lttng_event_enabler_common
                if (!event_recorder_enabler)
                        return;
                event = _lttng_kernel_event_create(&event_recorder_enabler->parent, desc);
-               WARN_ON_ONCE(!event || IS_ERR(event));
+               WARN_ON_ONCE(IS_ERR(event));
                lttng_event_enabler_destroy(&event_recorder_enabler->parent);
-               if (!event || IS_ERR(event)) {
+               if (IS_ERR(event)) {
                        printk(KERN_INFO "Unable to create event recorder %s\n", desc->event_name);
                        return;
                }
@@ -621,9 +618,9 @@ void lttng_syscall_event_enabler_create_event(struct lttng_event_enabler_common
                                &event_notifier_param, syscall_event_notifier_enabler->group);
                WARN_ON_ONCE(!event_notifier_enabler);
                event = _lttng_kernel_event_create(&event_notifier_enabler->parent, desc);
-               WARN_ON_ONCE(!event || IS_ERR(event));
+               WARN_ON_ONCE(IS_ERR(event));
                lttng_event_enabler_destroy(&event_notifier_enabler->parent);
-               if (!event || IS_ERR(event)) {
+               if (IS_ERR(event)) {
                        printk(KERN_INFO "Unable to create event notifier %s\n", desc->event_name);
                        return;
                }
@@ -638,10 +635,8 @@ void lttng_syscall_event_enabler_create_event(struct lttng_event_enabler_common
 }
 
 static
-void lttng_syscall_event_enabler_create_matching_events(struct lttng_event_enabler_common *syscall_event_enabler_common,
-               const struct trace_syscall_entry *table,
-               size_t table_len,
-               enum sc_type type)
+void lttng_syscall_event_enabler_create_matching_syscall_table_events(struct lttng_event_enabler_common *syscall_event_enabler_common,
+               const struct trace_syscall_entry *table, size_t table_len, enum sc_type type)
 {
        struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(syscall_event_enabler_common);
        const struct lttng_kernel_event_desc *desc;
@@ -650,7 +645,7 @@ void lttng_syscall_event_enabler_create_matching_events(struct lttng_event_enabl
        if (!IS_ENABLED(CONFIG_COMPAT) && (type == SC_TYPE_COMPAT_ENTRY || type == SC_TYPE_COMPAT_EXIT))
                return;
 
-       /* iterate over all syscall and create event_notifier that match */
+       /* iterate over all syscall and create event that match */
        for (i = 0; i < table_len; i++) {
                struct lttng_kernel_event_common_private *event_priv;
                struct hlist_head *head;
@@ -754,28 +749,27 @@ void create_unknown_syscall_event(struct lttng_event_enabler_common *event_enabl
 }
 
 static
-int lttng_syscalls_populate_events(struct lttng_event_enabler_common *syscall_event_enabler)
+void lttng_syscall_event_enabler_create_matching_events(struct lttng_event_enabler_common *event_enabler)
 {
-       struct lttng_event_recorder_enabler *event_recorder_enabler;
-       struct lttng_kernel_channel_buffer *chan;
-       int ret;
-
-       if (syscall_event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_RECORDER)
-               return 0;
-       event_recorder_enabler = container_of(syscall_event_enabler, struct lttng_event_recorder_enabler, parent);
-       chan = event_recorder_enabler->chan;
-
-       lttng_syscall_event_enabler_create_matching_events(&event_recorder_enabler->parent, sc_table.table, sc_table.len, SC_TYPE_ENTRY);
-       lttng_syscall_event_enabler_create_matching_events(&event_recorder_enabler->parent, sc_exit_table.table, sc_exit_table.len, SC_TYPE_EXIT);
-       create_unknown_syscall_event(syscall_event_enabler, SC_TYPE_ENTRY);
-       create_unknown_syscall_event(syscall_event_enabler, SC_TYPE_EXIT);
+       enum lttng_kernel_abi_syscall_entryexit entryexit = event_enabler->event_param.u.syscall.entryexit;
 
-       lttng_syscall_event_enabler_create_matching_events(&event_recorder_enabler->parent, compat_sc_table.table, compat_sc_table.len, SC_TYPE_COMPAT_ENTRY);
-       lttng_syscall_event_enabler_create_matching_events(&event_recorder_enabler->parent, compat_sc_exit_table.table, compat_sc_exit_table.len, SC_TYPE_COMPAT_EXIT);
-       create_unknown_syscall_event(syscall_event_enabler, SC_TYPE_COMPAT_ENTRY);
-       create_unknown_syscall_event(syscall_event_enabler, SC_TYPE_COMPAT_EXIT);
+       if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
+               lttng_syscall_event_enabler_create_matching_syscall_table_events(event_enabler,
+                       sc_table.table, sc_table.len, SC_TYPE_ENTRY);
+               lttng_syscall_event_enabler_create_matching_syscall_table_events(event_enabler,
+                       compat_sc_table.table, compat_sc_table.len, SC_TYPE_COMPAT_ENTRY);
+               create_unknown_syscall_event(event_enabler, SC_TYPE_ENTRY);
+               create_unknown_syscall_event(event_enabler, SC_TYPE_COMPAT_ENTRY);
+       }
 
-       return ret;
+       if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
+               lttng_syscall_event_enabler_create_matching_syscall_table_events(event_enabler,
+                       sc_exit_table.table, sc_exit_table.len, SC_TYPE_EXIT);
+               lttng_syscall_event_enabler_create_matching_syscall_table_events(event_enabler,
+                       compat_sc_exit_table.table, compat_sc_exit_table.len, SC_TYPE_COMPAT_EXIT);
+               create_unknown_syscall_event(event_enabler, SC_TYPE_EXIT);
+               create_unknown_syscall_event(event_enabler, SC_TYPE_COMPAT_EXIT);
+       }
 }
 
 /*
@@ -821,14 +815,6 @@ int lttng_event_enabler_create_syscall_events_if_missing(struct lttng_event_enab
                        return -ENOMEM;
        }
 
-       ret = lttng_syscalls_populate_events(syscall_event_enabler);
-       if (ret)
-               return ret;
-
-       ret = lttng_syscalls_create_matching_event_notifiers(syscall_event_enabler);
-       if (ret)
-               return ret;
-
        if (!syscall_table->sys_enter_registered) {
                ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
                                (void *) syscall_entry_event_probe, syscall_table);
@@ -847,38 +833,8 @@ int lttng_event_enabler_create_syscall_events_if_missing(struct lttng_event_enab
                syscall_table->sys_exit_registered = 1;
        }
 
-       return ret;
-}
-
-static
-int lttng_syscalls_create_matching_event_notifiers(struct lttng_event_enabler_common *event_enabler)
-{
-       int ret;
-       enum lttng_kernel_abi_syscall_entryexit entryexit =
-                       event_enabler->event_param.u.syscall.entryexit;
-       struct lttng_event_notifier_enabler *event_notifier_enabler;
-
-       if (event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_NOTIFIER)
-               return 0;
-       event_notifier_enabler = container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
+       lttng_syscall_event_enabler_create_matching_events(syscall_event_enabler);
 
-       if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
-               lttng_syscall_event_enabler_create_matching_events(&event_notifier_enabler->parent,
-                       sc_table.table, sc_table.len, SC_TYPE_ENTRY);
-               lttng_syscall_event_enabler_create_matching_events(&event_notifier_enabler->parent,
-                       compat_sc_table.table, compat_sc_table.len, SC_TYPE_COMPAT_ENTRY);
-               create_unknown_syscall_event(event_enabler, SC_TYPE_ENTRY);
-               create_unknown_syscall_event(event_enabler, SC_TYPE_COMPAT_ENTRY);
-       }
-
-       if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
-               lttng_syscall_event_enabler_create_matching_events(&event_notifier_enabler->parent,
-                       sc_exit_table.table, sc_exit_table.len, SC_TYPE_EXIT);
-               lttng_syscall_event_enabler_create_matching_events(&event_notifier_enabler->parent,
-                       compat_sc_exit_table.table, compat_sc_exit_table.len, SC_TYPE_COMPAT_EXIT);
-               create_unknown_syscall_event(event_enabler, SC_TYPE_EXIT);
-               create_unknown_syscall_event(event_enabler, SC_TYPE_COMPAT_EXIT);
-       }
        return ret;
 }