1 files changed, 155 insertions, 73 deletions

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index d128f65778e6..189b09baf4fb 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -78,7 +78,7 @@ EXPORT_SYMBOL_GPL(trace_define_field);
         if (ret)                                                        \
                 return ret;
 
-int trace_define_common_fields(struct ftrace_event_call *call)
+static int trace_define_common_fields(struct ftrace_event_call *call)
 {
         int ret;
         struct trace_entry ent;
@@ -91,11 +91,8 @@ int trace_define_common_fields(struct ftrace_event_call *call)
 
         return ret;
 }
-EXPORT_SYMBOL_GPL(trace_define_common_fields);
 
-#ifdef CONFIG_MODULES
-
-static void trace_destroy_fields(struct ftrace_event_call *call)
+void trace_destroy_fields(struct ftrace_event_call *call)
 {
         struct ftrace_event_field *field, *next;
 
@@ -107,27 +104,49 @@ static void trace_destroy_fields(struct ftrace_event_call *call)
         }
 }
 
-#endif /* CONFIG_MODULES */
+int trace_event_raw_init(struct ftrace_event_call *call)
+{
+        int id;
+
+        id = register_ftrace_event(call->event);
+        if (!id)
+                return -ENODEV;
+        call->id = id;
+        INIT_LIST_HEAD(&call->fields);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(trace_event_raw_init);
 
-static void ftrace_event_enable_disable(struct ftrace_event_call *call,
+static int ftrace_event_enable_disable(struct ftrace_event_call *call,
                                         int enable)
 {
+        int ret = 0;
+
         switch (enable) {
         case 0:
                 if (call->enabled) {
                         call->enabled = 0;
                         tracing_stop_cmdline_record();
-                        call->unregfunc(call->data);
+                        call->unregfunc(call);
                 }
                 break;
         case 1:
                 if (!call->enabled) {
-                        call->enabled = 1;
                         tracing_start_cmdline_record();
-                        call->regfunc(call->data);
+                        ret = call->regfunc(call);
+                        if (ret) {
+                                tracing_stop_cmdline_record();
+                                pr_info("event trace: Could not enable event "
+                                        "%s\n", call->name);
+                                break;
+                        }
+                        call->enabled = 1;
                 }
                 break;
         }
+
+        return ret;
 }
 
 static void ftrace_clear_events(void)
@@ -406,7 +425,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
         case 0:
         case 1:
                 mutex_lock(&event_mutex);
-                ftrace_event_enable_disable(call, val);
+                ret = ftrace_event_enable_disable(call, val);
                 mutex_unlock(&event_mutex);
                 break;
 
@@ -416,7 +435,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 
         *ppos += cnt;
 
-        return cnt;
+        return ret ? ret : cnt;
 }
 
 static ssize_t
@@ -507,7 +526,7 @@ extern char *__bad_type_size(void);
 #define FIELD(type, name)                                               \
         sizeof(type) != sizeof(field.name) ? __bad_type_size() :        \
         #type, "common_" #name, offsetof(typeof(field), name),          \
-                sizeof(field.name)
+                sizeof(field.name), is_signed_type(type)
 
 static int trace_write_header(struct trace_seq *s)
 {
@@ -515,17 +534,17 @@ static int trace_write_header(struct trace_seq *s)
 
         /* struct trace_entry */
         return trace_seq_printf(s,
-                                "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
-                                "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
-                                "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
-                                "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
-                                "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
-                                "\n",
-                                FIELD(unsigned short, type),
-                                FIELD(unsigned char, flags),
-                                FIELD(unsigned char, preempt_count),
-                                FIELD(int, pid),
-                                FIELD(int, lock_depth));
+                        "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
+                        "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
+                        "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
+                        "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
+                        "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
+                        "\n",
+                        FIELD(unsigned short, type),
+                        FIELD(unsigned char, flags),
+                        FIELD(unsigned char, preempt_count),
+                        FIELD(int, pid),
+                        FIELD(int, lock_depth));
 }
 
 static ssize_t
@@ -878,9 +897,9 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
                            "'%s/filter' entry\n", name);
         }
 
-        entry = trace_create_file("enable", 0644, system->entry,
-                                  (void *)system->name,
-                                  &ftrace_system_enable_fops);
+        trace_create_file("enable", 0644, system->entry,
+                          (void *)system->name,
+                          &ftrace_system_enable_fops);
 
         return system->entry;
 }
@@ -892,7 +911,6 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
                  const struct file_operations *filter,
                  const struct file_operations *format)
 {
-        struct dentry *entry;
         int ret;
 
         /*
@@ -910,55 +928,76 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
         }
 
         if (call->regfunc)
-                entry = trace_create_file("enable", 0644, call->dir, call,
-                                          enable);
+                trace_create_file("enable", 0644, call->dir, call,
+                                  enable);
 
         if (call->id && call->profile_enable)
-                entry = trace_create_file("id", 0444, call->dir, call,
-                                          id);
+                trace_create_file("id", 0444, call->dir, call,
+                                  id);
 
         if (call->define_fields) {
-                ret = call->define_fields(call);
+                ret = trace_define_common_fields(call);
+                if (!ret)
+                        ret = call->define_fields(call);
                 if (ret < 0) {
                         pr_warning("Could not initialize trace point"
                                    " events/%s\n", call->name);
                         return ret;
                 }
-                entry = trace_create_file("filter", 0644, call->dir, call,
-                                          filter);
+                trace_create_file("filter", 0644, call->dir, call,
+                                  filter);
         }
 
         /* A trace may not want to export its format */
         if (!call->show_format)
                 return 0;
 
-        entry = trace_create_file("format", 0444, call->dir, call,
-                                  format);
+        trace_create_file("format", 0444, call->dir, call,
+                          format);
 
         return 0;
 }
 
-#define for_each_event(event, start, end)                       \
-        for (event = start;                                     \
-             (unsigned long)event < (unsigned long)end;         \
-             event++)
+static int __trace_add_event_call(struct ftrace_event_call *call)
+{
+        struct dentry *d_events;
+        int ret;
 
-#ifdef CONFIG_MODULES
+        if (!call->name)
+                return -EINVAL;
 
-static LIST_HEAD(ftrace_module_file_list);
+        if (call->raw_init) {
+                ret = call->raw_init(call);
+                if (ret < 0) {
+                        if (ret != -ENOSYS)
+                                pr_warning("Could not initialize trace "
+                                "events/%s\n", call->name);
+                        return ret;
+                }
+        }
 
-/*
- * Modules must own their file_operations to keep up with
- * reference counting.
- */
-struct ftrace_module_file_ops {
-        struct list_head                list;
-        struct module                   *mod;
-        struct file_operations          id;
-        struct file_operations          enable;
-        struct file_operations          format;
-        struct file_operations          filter;
-};
+        d_events = event_trace_events_dir();
+        if (!d_events)
+                return -ENOENT;
+
+        ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
+                                &ftrace_enable_fops, &ftrace_event_filter_fops,
+                                &ftrace_event_format_fops);
+        if (!ret)
+                list_add(&call->list, &ftrace_events);
+
+        return ret;
+}
+
+/* Add an additional event_call dynamically */
+int trace_add_event_call(struct ftrace_event_call *call)
+{
+        int ret;
+        mutex_lock(&event_mutex);
+        ret = __trace_add_event_call(call);
+        mutex_unlock(&event_mutex);
+        return ret;
+}
 
 static void remove_subsystem_dir(const char *name)
 {
@@ -986,6 +1025,53 @@ static void remove_subsystem_dir(const char *name)
         }
 }
 
+/*
+ * Must be called under locking both of event_mutex and trace_event_mutex.
+ */
+static void __trace_remove_event_call(struct ftrace_event_call *call)
+{
+        ftrace_event_enable_disable(call, 0);
+        if (call->event)
+                __unregister_ftrace_event(call->event);
+        debugfs_remove_recursive(call->dir);
+        list_del(&call->list);
+        trace_destroy_fields(call);
+        destroy_preds(call);
+        remove_subsystem_dir(call->system);
+}
+
+/* Remove an event_call */
+void trace_remove_event_call(struct ftrace_event_call *call)
+{
+        mutex_lock(&event_mutex);
+        down_write(&trace_event_mutex);
+        __trace_remove_event_call(call);
+        up_write(&trace_event_mutex);
+        mutex_unlock(&event_mutex);
+}
+
+#define for_each_event(event, start, end)                       \
+        for (event = start;                                     \
+             (unsigned long)event < (unsigned long)end;         \
+             event++)
+
+#ifdef CONFIG_MODULES
+
+static LIST_HEAD(ftrace_module_file_list);
+
+/*
+ * Modules must own their file_operations to keep up with
+ * reference counting.
+ */
+struct ftrace_module_file_ops {
+        struct list_head                list;
+        struct module                   *mod;
+        struct file_operations          id;
+        struct file_operations          enable;
+        struct file_operations          format;
+        struct file_operations          filter;
+};
+
 static struct ftrace_module_file_ops *
 trace_create_file_ops(struct module *mod)
 {
@@ -1043,7 +1129,7 @@ static void trace_module_add_events(struct module *mod)
                 if (!call->name)
                         continue;
                 if (call->raw_init) {
-                        ret = call->raw_init();
+                        ret = call->raw_init(call);
                         if (ret < 0) {
                                 if (ret != -ENOSYS)
                                         pr_warning("Could not initialize trace "
@@ -1061,10 +1147,11 @@ static void trace_module_add_events(struct module *mod)
                                 return;
                 }
                 call->mod = mod;
-                list_add(&call->list, &ftrace_events);
-                event_create_dir(call, d_events,
-                                 &file_ops->id, &file_ops->enable,
-                                 &file_ops->filter, &file_ops->format);
+                ret = event_create_dir(call, d_events,
+                                       &file_ops->id, &file_ops->enable,
+                                       &file_ops->filter, &file_ops->format);
+                if (!ret)
+                        list_add(&call->list, &ftrace_events);
         }
 }
 
@@ -1078,14 +1165,7 @@ static void trace_module_remove_events(struct module *mod)
         list_for_each_entry_safe(call, p, &ftrace_events, list) {
                 if (call->mod == mod) {
                         found = true;
-                        ftrace_event_enable_disable(call, 0);
-                        if (call->event)
-                                __unregister_ftrace_event(call->event);
-                        debugfs_remove_recursive(call->dir);
-                        list_del(&call->list);
-                        trace_destroy_fields(call);
-                        destroy_preds(call);
-                        remove_subsystem_dir(call->system);
+                        __trace_remove_event_call(call);
                 }
         }
 
@@ -1203,7 +1283,7 @@ static __init int event_trace_init(void)
                 if (!call->name)
                         continue;
                 if (call->raw_init) {
-                        ret = call->raw_init();
+                        ret = call->raw_init(call);
                         if (ret < 0) {
                                 if (ret != -ENOSYS)
                                         pr_warning("Could not initialize trace "
@@ -1211,10 +1291,12 @@ static __init int event_trace_init(void)
                                 continue;
                         }
                 }
-                list_add(&call->list, &ftrace_events);
-                event_create_dir(call, d_events, &ftrace_event_id_fops,
-                                 &ftrace_enable_fops, &ftrace_event_filter_fops,
-                                 &ftrace_event_format_fops);
+                ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
+                                       &ftrace_enable_fops,
+                                       &ftrace_event_filter_fops,
+                                       &ftrace_event_format_fops);
+                if (!ret)
+                        list_add(&call->list, &ftrace_events);
         }
 
         while (true) {