drm/vmwgfx: return -EFAULT for copy_to_user errors
[safe/jmp/linux-2.6] / kernel / trace / trace_events.c
index 155b5d5..53cffc0 100644 (file)
@@ -15,6 +15,7 @@
 #include <linux/uaccess.h>
 #include <linux/module.h>
 #include <linux/ctype.h>
+#include <linux/slab.h>
 #include <linux/delay.h>
 
 #include <asm/setup.h>
@@ -28,11 +29,23 @@ DEFINE_MUTEX(event_mutex);
 
 LIST_HEAD(ftrace_events);
 
+struct list_head *
+trace_get_fields(struct ftrace_event_call *event_call)
+{
+       if (!event_call->class->get_fields)
+               return &event_call->class->fields;
+       return event_call->class->get_fields(event_call);
+}
+
 int trace_define_field(struct ftrace_event_call *call, const char *type,
                       const char *name, int offset, int size, int is_signed,
                       int filter_type)
 {
        struct ftrace_event_field *field;
+       struct list_head *head;
+
+       if (WARN_ON(!call->class))
+               return 0;
 
        field = kzalloc(sizeof(*field), GFP_KERNEL);
        if (!field)
@@ -55,15 +68,14 @@ int trace_define_field(struct ftrace_event_call *call, const char *type,
        field->size = size;
        field->is_signed = is_signed;
 
-       list_add(&field->link, &call->fields);
+       head = trace_get_fields(call);
+       list_add(&field->link, head);
 
        return 0;
 
 err:
-       if (field) {
+       if (field)
                kfree(field->name);
-               kfree(field->type);
-       }
        kfree(field);
 
        return -ENOMEM;
@@ -78,7 +90,7 @@ 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;
@@ -91,13 +103,14 @@ int trace_define_common_fields(struct ftrace_event_call *call)
 
        return ret;
 }
-EXPORT_SYMBOL_GPL(trace_define_common_fields);
 
 void trace_destroy_fields(struct ftrace_event_call *call)
 {
        struct ftrace_event_field *field, *next;
+       struct list_head *head;
 
-       list_for_each_entry_safe(field, next, &call->fields, link) {
+       head = trace_get_fields(call);
+       list_for_each_entry_safe(field, next, head, link) {
                list_del(&field->link);
                kfree(field->type);
                kfree(field->name);
@@ -105,25 +118,57 @@ void trace_destroy_fields(struct ftrace_event_call *call)
        }
 }
 
-static void ftrace_event_enable_disable(struct ftrace_event_call *call,
+int trace_event_raw_init(struct ftrace_event_call *call)
+{
+       int id;
+
+       id = register_ftrace_event(&call->event);
+       if (!id)
+               return -ENODEV;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(trace_event_raw_init);
+
+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;
+               if (call->flags & TRACE_EVENT_FL_ENABLED) {
+                       call->flags &= ~TRACE_EVENT_FL_ENABLED;
                        tracing_stop_cmdline_record();
-                       call->unregfunc(call);
+                       if (call->class->reg)
+                               call->class->reg(call, TRACE_REG_UNREGISTER);
+                       else
+                               tracepoint_probe_unregister(call->name,
+                                                           call->class->probe,
+                                                           call);
                }
                break;
        case 1:
-               if (!call->enabled) {
-                       call->enabled = 1;
+               if (!(call->flags & TRACE_EVENT_FL_ENABLED)) {
                        tracing_start_cmdline_record();
-                       call->regfunc(call);
+                       if (call->class->reg)
+                               ret = call->class->reg(call, TRACE_REG_REGISTER);
+                       else
+                               ret = tracepoint_probe_register(call->name,
+                                                               call->class->probe,
+                                                               call);
+                       if (ret) {
+                               tracing_stop_cmdline_record();
+                               pr_info("event trace: Could not enable event "
+                                       "%s\n", call->name);
+                               break;
+                       }
+                       call->flags |= TRACE_EVENT_FL_ENABLED;
                }
                break;
        }
+
+       return ret;
 }
 
 static void ftrace_clear_events(void)
@@ -149,15 +194,16 @@ static int __ftrace_set_clr_event(const char *match, const char *sub,
        mutex_lock(&event_mutex);
        list_for_each_entry(call, &ftrace_events, list) {
 
-               if (!call->name || !call->regfunc)
+               if (!call->name || !call->class ||
+                   (!call->class->probe && !call->class->reg))
                        continue;
 
                if (match &&
                    strcmp(match, call->name) != 0 &&
-                   strcmp(match, call->system) != 0)
+                   strcmp(match, call->class->system) != 0)
                        continue;
 
-               if (sub && strcmp(sub, call->system) != 0)
+               if (sub && strcmp(sub, call->class->system) != 0)
                        continue;
 
                if (event && strcmp(event, call->name) != 0)
@@ -228,10 +274,9 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
                   size_t cnt, loff_t *ppos)
 {
        struct trace_parser parser;
-       size_t read = 0;
-       ssize_t ret;
+       ssize_t read, ret;
 
-       if (!cnt || cnt < 0)
+       if (!cnt)
                return 0;
 
        ret = tracing_update_buffers();
@@ -243,7 +288,7 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
 
        read = trace_get_user(&parser, ubuf, cnt, ppos);
 
-       if (trace_parser_loaded((&parser))) {
+       if (read >= 0 && trace_parser_loaded((&parser))) {
                int set = 1;
 
                if (*parser.buffer == '!')
@@ -276,7 +321,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
                 * The ftrace subsystem is for showing formats only.
                 * They can not be enabled or disabled via the event files.
                 */
-               if (call->regfunc)
+               if (call->class && (call->class->probe || call->class->reg))
                        return call;
        }
 
@@ -307,7 +352,7 @@ s_next(struct seq_file *m, void *v, loff_t *pos)
        (*pos)++;
 
        list_for_each_entry_continue(call, &ftrace_events, list) {
-               if (call->enabled)
+               if (call->flags & TRACE_EVENT_FL_ENABLED)
                        return call;
        }
 
@@ -334,8 +379,8 @@ static int t_show(struct seq_file *m, void *v)
 {
        struct ftrace_event_call *call = v;
 
-       if (strcmp(call->system, TRACE_SYSTEM) != 0)
-               seq_printf(m, "%s:", call->system);
+       if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
+               seq_printf(m, "%s:", call->class->system);
        seq_printf(m, "%s\n", call->name);
 
        return 0;
@@ -366,7 +411,7 @@ event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
        struct ftrace_event_call *call = filp->private_data;
        char *buf;
 
-       if (call->enabled)
+       if (call->flags & TRACE_EVENT_FL_ENABLED)
                buf = "1\n";
        else
                buf = "0\n";
@@ -403,7 +448,7 @@ 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;
 
@@ -413,7 +458,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 
        *ppos += cnt;
 
-       return cnt;
+       return ret ? ret : cnt;
 }
 
 static ssize_t
@@ -429,10 +474,11 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 
        mutex_lock(&event_mutex);
        list_for_each_entry(call, &ftrace_events, list) {
-               if (!call->name || !call->regfunc)
+               if (!call->name || !call->class ||
+                   (!call->class->probe && !call->class->reg))
                        continue;
 
-               if (system && strcmp(call->system, system) != 0)
+               if (system && strcmp(call->class->system, system) != 0)
                        continue;
 
                /*
@@ -440,7 +486,7 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
                 * or if all events or cleared, or if we have
                 * a mixture.
                 */
-               set |= (1 << !!call->enabled);
+               set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
 
                /*
                 * If we have a mixture, no need to look further.
@@ -498,41 +544,17 @@ out:
        return ret;
 }
 
-extern char *__bad_type_size(void);
-
-#undef FIELD
-#define FIELD(type, name)                                              \
-       sizeof(type) != sizeof(field.name) ? __bad_type_size() :        \
-       #type, "common_" #name, offsetof(typeof(field), name),          \
-               sizeof(field.name)
-
-static int trace_write_header(struct trace_seq *s)
-{
-       struct trace_entry field;
-
-       /* 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));
-}
-
 static ssize_t
 event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
                  loff_t *ppos)
 {
        struct ftrace_event_call *call = filp->private_data;
+       struct ftrace_event_field *field;
+       struct list_head *head;
        struct trace_seq *s;
+       int common_field_count = 5;
        char *buf;
-       int r;
+       int r = 0;
 
        if (*ppos)
                return 0;
@@ -543,14 +565,49 @@ event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
 
        trace_seq_init(s);
 
-       /* If any of the first writes fail, so will the show_format. */
-
        trace_seq_printf(s, "name: %s\n", call->name);
-       trace_seq_printf(s, "ID: %d\n", call->id);
+       trace_seq_printf(s, "ID: %d\n", call->event.type);
        trace_seq_printf(s, "format:\n");
-       trace_write_header(s);
 
-       r = call->show_format(call, s);
+       head = trace_get_fields(call);
+       list_for_each_entry_reverse(field, head, link) {
+               /*
+                * Smartly shows the array type(except dynamic array).
+                * Normal:
+                *      field:TYPE VAR
+                * If TYPE := TYPE[LEN], it is shown:
+                *      field:TYPE VAR[LEN]
+                */
+               const char *array_descriptor = strchr(field->type, '[');
+
+               if (!strncmp(field->type, "__data_loc", 10))
+                       array_descriptor = NULL;
+
+               if (!array_descriptor) {
+                       r = trace_seq_printf(s, "\tfield:%s %s;\toffset:%u;"
+                                       "\tsize:%u;\tsigned:%d;\n",
+                                       field->type, field->name, field->offset,
+                                       field->size, !!field->is_signed);
+               } else {
+                       r = trace_seq_printf(s, "\tfield:%.*s %s%s;\toffset:%u;"
+                                       "\tsize:%u;\tsigned:%d;\n",
+                                       (int)(array_descriptor - field->type),
+                                       field->type, field->name,
+                                       array_descriptor, field->offset,
+                                       field->size, !!field->is_signed);
+               }
+
+               if (--common_field_count == 0)
+                       r = trace_seq_printf(s, "\n");
+
+               if (!r)
+                       break;
+       }
+
+       if (r)
+               r = trace_seq_printf(s, "\nprint fmt: %s\n",
+                               call->print_fmt);
+
        if (!r) {
                /*
                 * ug!  The format output is bigger than a PAGE!!
@@ -583,7 +640,7 @@ event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
                return -ENOMEM;
 
        trace_seq_init(s);
-       trace_seq_printf(s, "%d\n", call->id);
+       trace_seq_printf(s, "%d\n", call->event.type);
 
        r = simple_read_from_buffer(ubuf, cnt, ppos,
                                    s->buffer, s->len);
@@ -875,9 +932,9 @@ 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;
 }
@@ -889,15 +946,15 @@ 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;
+       struct list_head *head;
        int ret;
 
        /*
         * If the trace point header did not define TRACE_SYSTEM
         * then the system would be called "TRACE_SYSTEM".
         */
-       if (strcmp(call->system, TRACE_SYSTEM) != 0)
-               d_events = event_subsystem_dir(call->system, d_events);
+       if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
+               d_events = event_subsystem_dir(call->class->system, d_events);
 
        call->dir = debugfs_create_dir(call->name, d_events);
        if (!call->dir) {
@@ -906,31 +963,38 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
                return -1;
        }
 
-       if (call->regfunc)
-               entry = trace_create_file("enable", 0644, call->dir, call,
-                                         enable);
+       if (call->class->probe || call->class->reg)
+               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);
+#ifdef CONFIG_PERF_EVENTS
+       if (call->event.type && (call->class->perf_probe || call->class->reg))
+               trace_create_file("id", 0444, call->dir, call,
+                                 id);
+#endif
 
-       if (call->define_fields) {
-               ret = call->define_fields(call);
-               if (ret < 0) {
-                       pr_warning("Could not initialize trace point"
-                                  " events/%s\n", call->name);
-                       return ret;
+       if (call->class->define_fields) {
+               /*
+                * Other events may have the same class. Only update
+                * the fields if they are not already defined.
+                */
+               head = trace_get_fields(call);
+               if (list_empty(head)) {
+                       ret = trace_define_common_fields(call);
+                       if (!ret)
+                               ret = call->class->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;
 }
@@ -943,8 +1007,8 @@ static int __trace_add_event_call(struct ftrace_event_call *call)
        if (!call->name)
                return -EINVAL;
 
-       if (call->raw_init) {
-               ret = call->raw_init(call);
+       if (call->class->raw_init) {
+               ret = call->class->raw_init(call);
                if (ret < 0) {
                        if (ret != -ENOSYS)
                                pr_warning("Could not initialize trace "
@@ -1008,13 +1072,13 @@ static void remove_subsystem_dir(const char *name)
 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);
+       if (call->event.funcs)
+               __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_subsystem_dir(call->class->system);
 }
 
 /* Remove an event_call */
@@ -1105,8 +1169,8 @@ static void trace_module_add_events(struct module *mod)
                /* The linker may leave blanks */
                if (!call->name)
                        continue;
-               if (call->raw_init) {
-                       ret = call->raw_init(call);
+               if (call->class->raw_init) {
+                       ret = call->class->raw_init(call);
                        if (ret < 0) {
                                if (ret != -ENOSYS)
                                        pr_warning("Could not initialize trace "
@@ -1259,8 +1323,8 @@ static __init int event_trace_init(void)
                /* The linker may leave blanks */
                if (!call->name)
                        continue;
-               if (call->raw_init) {
-                       ret = call->raw_init(call);
+               if (call->class->raw_init) {
+                       ret = call->class->raw_init(call);
                        if (ret < 0) {
                                if (ret != -ENOSYS)
                                        pr_warning("Could not initialize trace "
@@ -1361,8 +1425,8 @@ static __init void event_trace_self_tests(void)
 
        list_for_each_entry(call, &ftrace_events, list) {
 
-               /* Only test those that have a regfunc */
-               if (!call->regfunc)
+               /* Only test those that have a probe */
+               if (!call->class || !call->class->probe)
                        continue;
 
 /*
@@ -1372,8 +1436,8 @@ static __init void event_trace_self_tests(void)
  * syscalls as we test.
  */
 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
-               if (call->system &&
-                   strcmp(call->system, "syscalls") == 0)
+               if (call->class->system &&
+                   strcmp(call->class->system, "syscalls") == 0)
                        continue;
 #endif
 
@@ -1383,7 +1447,7 @@ static __init void event_trace_self_tests(void)
                 * If an event is already enabled, someone is using
                 * it and the self test should not be on.
                 */
-               if (call->enabled) {
+               if (call->flags & TRACE_EVENT_FL_ENABLED) {
                        pr_warning("Enabled event during self test!\n");
                        WARN_ON_ONCE(1);
                        continue;