1 files changed, 196 insertions, 7 deletions

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 3047b56f6637..64ec4d278ffb 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -19,6 +19,39 @@
 
 static DEFINE_MUTEX(event_mutex);
 
+int trace_define_field(struct ftrace_event_call *call, char *type,
+                       char *name, int offset, int size)
+{
+        struct ftrace_event_field *field;
+
+        field = kzalloc(sizeof(*field), GFP_KERNEL);
+        if (!field)
+                goto err;
+
+        field->name = kstrdup(name, GFP_KERNEL);
+        if (!field->name)
+                goto err;
+
+        field->type = kstrdup(type, GFP_KERNEL);
+        if (!field->type)
+                goto err;
+
+        field->offset = offset;
+        field->size = size;
+        list_add(&field->link, &call->fields);
+
+        return 0;
+
+err:
+        if (field) {
+                kfree(field->name);
+                kfree(field->type);
+        }
+        kfree(field);
+
+        return -ENOMEM;
+}
+
 static void ftrace_clear_events(void)
 {
         struct ftrace_event_call *call = (void *)__start_ftrace_events;
@@ -343,7 +376,8 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 
 #undef FIELD
 #define FIELD(type, name)                                               \
-        #type, #name, offsetof(typeof(field), name), sizeof(field.name)
+        #type, "common_" #name, offsetof(typeof(field), name),          \
+                sizeof(field.name)
 
 static int trace_write_header(struct trace_seq *s)
 {
@@ -430,6 +464,139 @@ event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
         return r;
 }
 
+static ssize_t
+event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
+                  loff_t *ppos)
+{
+        struct ftrace_event_call *call = filp->private_data;
+        struct trace_seq *s;
+        int r;
+
+        if (*ppos)
+                return 0;
+
+        s = kmalloc(sizeof(*s), GFP_KERNEL);
+        if (!s)
+                return -ENOMEM;
+
+        trace_seq_init(s);
+
+        filter_print_preds(call->preds, s);
+        r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
+
+        kfree(s);
+
+        return r;
+}
+
+static ssize_t
+event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
+                   loff_t *ppos)
+{
+        struct ftrace_event_call *call = filp->private_data;
+        char buf[64], *pbuf = buf;
+        struct filter_pred *pred;
+        int err;
+
+        if (cnt >= sizeof(buf))
+                return -EINVAL;
+
+        if (copy_from_user(&buf, ubuf, cnt))
+                return -EFAULT;
+
+        pred = kzalloc(sizeof(*pred), GFP_KERNEL);
+        if (!pred)
+                return -ENOMEM;
+
+        err = filter_parse(&pbuf, pred);
+        if (err < 0) {
+                filter_free_pred(pred);
+                return err;
+        }
+
+        if (pred->clear) {
+                filter_free_preds(call);
+                filter_free_pred(pred);
+                return cnt;
+        }
+
+        if (filter_add_pred(call, pred)) {
+                filter_free_pred(pred);
+                return -EINVAL;
+        }
+
+        *ppos += cnt;
+
+        return cnt;
+}
+
+static ssize_t
+subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
+                      loff_t *ppos)
+{
+        struct event_subsystem *system = filp->private_data;
+        struct trace_seq *s;
+        int r;
+
+        if (*ppos)
+                return 0;
+
+        s = kmalloc(sizeof(*s), GFP_KERNEL);
+        if (!s)
+                return -ENOMEM;
+
+        trace_seq_init(s);
+
+        filter_print_preds(system->preds, s);
+        r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
+
+        kfree(s);
+
+        return r;
+}
+
+static ssize_t
+subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
+                       loff_t *ppos)
+{
+        struct event_subsystem *system = filp->private_data;
+        char buf[64], *pbuf = buf;
+        struct filter_pred *pred;
+        int err;
+
+        if (cnt >= sizeof(buf))
+                return -EINVAL;
+
+        if (copy_from_user(&buf, ubuf, cnt))
+                return -EFAULT;
+
+        pred = kzalloc(sizeof(*pred), GFP_KERNEL);
+        if (!pred)
+                return -ENOMEM;
+
+        err = filter_parse(&pbuf, pred);
+        if (err < 0) {
+                filter_free_pred(pred);
+                return err;
+        }
+
+        if (pred->clear) {
+                filter_free_subsystem_preds(system);
+                filter_free_pred(pred);
+                return cnt;
+        }
+
+        if (filter_add_subsystem_pred(system, pred)) {
+                filter_free_subsystem_preds(system);
+                filter_free_pred(pred);
+                return -EINVAL;
+        }
+
+        *ppos += cnt;
+
+        return cnt;
+}
+
 static const struct seq_operations show_event_seq_ops = {
         .start = t_start,
         .next = t_next,
@@ -475,6 +642,18 @@ static const struct file_operations ftrace_event_id_fops = {
         .read = event_id_read,
 };
 
+static const struct file_operations ftrace_event_filter_fops = {
+        .open = tracing_open_generic,
+        .read = event_filter_read,
+        .write = event_filter_write,
+};
+
+static const struct file_operations ftrace_subsystem_filter_fops = {
+        .open = tracing_open_generic,
+        .read = subsystem_filter_read,
+        .write = subsystem_filter_write,
+};
+
 static struct dentry *event_trace_events_dir(void)
 {
         static struct dentry *d_tracer;
@@ -495,12 +674,6 @@ static struct dentry *event_trace_events_dir(void)
         return d_events;
 }
 
-struct event_subsystem {
-        struct list_head        list;
-        const char              *name;
-        struct dentry           *entry;
-};
-
 static LIST_HEAD(event_subsystems);
 
 static struct dentry *
@@ -533,6 +706,8 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
         system->name = name;
         list_add(&system->list, &event_subsystems);
 
+        system->preds = NULL;
+
         return system->entry;
 }
 
@@ -581,6 +756,20 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
                                         call->name);
         }
 
+        if (call->define_fields) {
+                ret = call->define_fields();
+                if (ret < 0) {
+                        pr_warning("Could not initialize trace point"
+                                   " events/%s\n", call->name);
+                        return ret;
+                }
+                entry = debugfs_create_file("filter", 0644, call->dir, call,
+                                            &ftrace_event_filter_fops);
+                if (!entry)
+                        pr_warning("Could not create debugfs "
+                                   "'%s/filter' entry\n", call->name);
+        }
+
         /* A trace may not want to export its format */
         if (!call->show_format)
                 return 0;