Merge tag 'trace-fixes-3.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Oleg Nesterov has been working hard in closing all the holes that can
  lead to race conditions between deleting an event and accessing an
  event debugfs file.  This included a fix to the debugfs system (acked
  by Greg Kroah-Hartman).  We think that all the holes have been patched
  and hopefully we don't find more.  I haven't marked all of them for
  stable because I need to examine them more to figure out how far back
  some of the changes need to go.

  Along the way, some other fixes have been made.  Alexander Z Lam fixed
  some logic where the wrong buffer was being modifed.

  Andrew Vagin found a possible corruption for machines that actually
  allocate cpumask, as a reference to one was being zeroed out by
  mistake.

  Dhaval Giani found a bad prototype when tracing is not configured.

  And I not only had some changes to help Oleg, but also finally fixed a
  long standing bug that Dave Jones and others have been hitting, where
  a module unload and reload can cause the function tracing accounting
  to get screwed up"

* tag 'trace-fixes-3.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix reset of time stamps during trace_clock changes
  tracing: Make TRACE_ITER_STOP_ON_FREE stop the correct buffer
  tracing: Fix trace_dump_stack() proto when CONFIG_TRACING is not set
  tracing: Fix fields of struct trace_iterator that are zeroed by mistake
  tracing/uprobes: Fail to unregister if probe event files are in use
  tracing/kprobes: Fail to unregister if probe event files are in use
  tracing: Add comment to describe special break case in probe_remove_event_call()
  tracing: trace_remove_event_call() should fail if call/file is in use
  debugfs: debugfs_remove_recursive() must not rely on list_empty(d_subdirs)
  ftrace: Check module functions being traced on reload
  ftrace: Consolidate some duplicate code for updating ftrace ops
  tracing: Change remove_event_file_dir() to clear "d_subdirs"->i_private
  tracing: Introduce remove_event_file_dir()
  tracing: Change f_start() to take event_mutex and verify i_private != NULL
  tracing: Change event_filter_read/write to verify i_private != NULL
  tracing: Change event_enable/disable_read() to verify i_private != NULL
  tracing: Turn event/id->i_private into call->event.type

6 files changed, 272 insertions, 131 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8ce9eefc5bb4..a6d098c6df3f 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2169,12 +2169,57 @@ static cycle_t		ftrace_update_time;
 static unsigned long    ftrace_update_cnt;
 unsigned long           ftrace_update_tot_cnt;
 
-static int ops_traces_mod(struct ftrace_ops *ops)
+static inline int ops_traces_mod(struct ftrace_ops *ops)
 {
-        struct ftrace_hash *hash;
+        /*
+         * Filter_hash being empty will default to trace module.
+         * But notrace hash requires a test of individual module functions.
+         */
+        return ftrace_hash_empty(ops->filter_hash) &&
+                ftrace_hash_empty(ops->notrace_hash);
+}
+
+/*
+ * Check if the current ops references the record.
+ *
+ * If the ops traces all functions, then it was already accounted for.
+ * If the ops does not trace the current record function, skip it.
+ * If the ops ignores the function via notrace filter, skip it.
+ */
+static inline bool
+ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+        /* If ops isn't enabled, ignore it */
+        if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+                return 0;
+
+        /* If ops traces all mods, we already accounted for it */
+        if (ops_traces_mod(ops))
+                return 0;
+
+        /* The function must be in the filter */
+        if (!ftrace_hash_empty(ops->filter_hash) &&
+            !ftrace_lookup_ip(ops->filter_hash, rec->ip))
+                return 0;
+
+        /* If in notrace hash, we ignore it too */
+        if (ftrace_lookup_ip(ops->notrace_hash, rec->ip))
+                return 0;
+
+        return 1;
+}
+
+static int referenced_filters(struct dyn_ftrace *rec)
+{
+        struct ftrace_ops *ops;
+        int cnt = 0;
 
-        hash = ops->filter_hash;
-        return ftrace_hash_empty(hash);
+        for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
+                if (ops_references_rec(ops, rec))
+                    cnt++;
+        }
+
+        return cnt;
 }
 
 static int ftrace_update_code(struct module *mod)
@@ -2183,6 +2228,7 @@ static int ftrace_update_code(struct module *mod)
         struct dyn_ftrace *p;
         cycle_t start, stop;
         unsigned long ref = 0;
+        bool test = false;
         int i;
 
         /*
@@ -2196,9 +2242,12 @@ static int ftrace_update_code(struct module *mod)
 
                 for (ops = ftrace_ops_list;
                      ops != &ftrace_list_end; ops = ops->next) {
-                        if (ops->flags & FTRACE_OPS_FL_ENABLED &&
-                            ops_traces_mod(ops))
-                                ref++;
+                        if (ops->flags & FTRACE_OPS_FL_ENABLED) {
+                                if (ops_traces_mod(ops))
+                                        ref++;
+                                else
+                                        test = true;
+                        }
                 }
         }
 
@@ -2208,12 +2257,16 @@ static int ftrace_update_code(struct module *mod)
         for (pg = ftrace_new_pgs; pg; pg = pg->next) {
 
                 for (i = 0; i < pg->index; i++) {
+                        int cnt = ref;
+
                         /* If something went wrong, bail without enabling anything */
                         if (unlikely(ftrace_disabled))
                                 return -1;
 
                         p = &pg->records[i];
-                        p->flags = ref;
+                        if (test)
+                                cnt += referenced_filters(p);
+                        p->flags = cnt;
 
                         /*
                          * Do the initial record conversion from mcount jump
@@ -2233,7 +2286,7 @@ static int ftrace_update_code(struct module *mod)
                          * conversion puts the module to the correct state, thus
                          * passing the ftrace_make_call check.
                          */
-                        if (ftrace_start_up && ref) {
+                        if (ftrace_start_up && cnt) {
                                 int failed = __ftrace_replace_code(p, 1);
                                 if (failed)
                                         ftrace_bug(failed, p->ip);
@@ -3384,6 +3437,12 @@ ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
         return add_hash_entry(hash, ip);
 }
 
+static void ftrace_ops_update_code(struct ftrace_ops *ops)
+{
+        if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled)
+                ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+}
+
 static int
 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
                 unsigned long ip, int remove, int reset, int enable)
@@ -3426,9 +3485,8 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
 
         mutex_lock(&ftrace_lock);
         ret = ftrace_hash_move(ops, enable, orig_hash, hash);
-        if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
-            && ftrace_enabled)
-                ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+        if (!ret)
+                ftrace_ops_update_code(ops);
 
         mutex_unlock(&ftrace_lock);
 
@@ -3655,9 +3713,8 @@ int ftrace_regex_release(struct inode *inode, struct file *file)
                 mutex_lock(&ftrace_lock);
                 ret = ftrace_hash_move(iter->ops, filter_hash,
                                        orig_hash, iter->hash);
-                if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
-                    && ftrace_enabled)
-                        ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+                if (!ret)
+                        ftrace_ops_update_code(iter->ops);
 
                 mutex_unlock(&ftrace_lock);
         }
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 882ec1dd1515..496f94d57698 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -243,20 +243,25 @@ int filter_current_check_discard(struct ring_buffer *buffer,
 }
 EXPORT_SYMBOL_GPL(filter_current_check_discard);
 
-cycle_t ftrace_now(int cpu)
+cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu)
 {
         u64 ts;
 
         /* Early boot up does not have a buffer yet */
-        if (!global_trace.trace_buffer.buffer)
+        if (!buf->buffer)
                 return trace_clock_local();
 
-        ts = ring_buffer_time_stamp(global_trace.trace_buffer.buffer, cpu);
-        ring_buffer_normalize_time_stamp(global_trace.trace_buffer.buffer, cpu, &ts);
+        ts = ring_buffer_time_stamp(buf->buffer, cpu);
+        ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts);
 
         return ts;
 }
 
+cycle_t ftrace_now(int cpu)
+{
+        return buffer_ftrace_now(&global_trace.trace_buffer, cpu);
+}
+
 /**
  * tracing_is_enabled - Show if global_trace has been disabled
  *
@@ -1211,7 +1216,7 @@ void tracing_reset_online_cpus(struct trace_buffer *buf)
         /* Make sure all commits have finished */
         synchronize_sched();
 
-        buf->time_start = ftrace_now(buf->cpu);
+        buf->time_start = buffer_ftrace_now(buf, buf->cpu);
 
         for_each_online_cpu(cpu)
                 ring_buffer_reset_cpu(buffer, cpu);
@@ -1219,11 +1224,6 @@ void tracing_reset_online_cpus(struct trace_buffer *buf)
         ring_buffer_record_enable(buffer);
 }
 
-void tracing_reset_current(int cpu)
-{
-        tracing_reset(&global_trace.trace_buffer, cpu);
-}
-
 /* Must have trace_types_lock held */
 void tracing_reset_all_online_cpus(void)
 {
@@ -4151,6 +4151,7 @@ waitagain:
         memset(&iter->seq, 0,
                sizeof(struct trace_iterator) -
                offsetof(struct trace_iterator, seq));
+        cpumask_clear(iter->started);
         iter->pos = -1;
 
         trace_event_read_lock();
@@ -4468,7 +4469,7 @@ tracing_free_buffer_release(struct inode *inode, struct file *filp)
 
         /* disable tracing ? */
         if (trace_flags & TRACE_ITER_STOP_ON_FREE)
-                tracing_off();
+                tracer_tracing_off(tr);
         /* resize the ring buffer to 0 */
         tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS);
 
@@ -4633,12 +4634,12 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
          * New clock may not be consistent with the previous clock.
          * Reset the buffer so that it doesn't have incomparable timestamps.
          */
-        tracing_reset_online_cpus(&global_trace.trace_buffer);
+        tracing_reset_online_cpus(&tr->trace_buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
         if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer)
                 ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func);
-        tracing_reset_online_cpus(&global_trace.max_buffer);
+        tracing_reset_online_cpus(&tr->max_buffer);
 #endif
 
         mutex_unlock(&trace_types_lock);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 898f868833f2..29a7ebcfb426 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -409,33 +409,42 @@ static void put_system(struct ftrace_subsystem_dir *dir)
         mutex_unlock(&event_mutex);
 }
 
-/*
- * Open and update trace_array ref count.
- * Must have the current trace_array passed to it.
- */
-static int tracing_open_generic_file(struct inode *inode, struct file *filp)
+static void remove_subsystem(struct ftrace_subsystem_dir *dir)
 {
-        struct ftrace_event_file *file = inode->i_private;
-        struct trace_array *tr = file->tr;
-        int ret;
+        if (!dir)
+                return;
 
-        if (trace_array_get(tr) < 0)
-                return -ENODEV;
+        if (!--dir->nr_events) {
+                debugfs_remove_recursive(dir->entry);
+                list_del(&dir->list);
+                __put_system_dir(dir);
+        }
+}
 
-        ret = tracing_open_generic(inode, filp);
-        if (ret < 0)
-                trace_array_put(tr);
-        return ret;
+static void *event_file_data(struct file *filp)
+{
+        return ACCESS_ONCE(file_inode(filp)->i_private);
 }
 
-static int tracing_release_generic_file(struct inode *inode, struct file *filp)
+static void remove_event_file_dir(struct ftrace_event_file *file)
 {
-        struct ftrace_event_file *file = inode->i_private;
-        struct trace_array *tr = file->tr;
+        struct dentry *dir = file->dir;
+        struct dentry *child;
 
-        trace_array_put(tr);
+        if (dir) {
+                spin_lock(&dir->d_lock);        /* probably unneeded */
+                list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
+                        if (child->d_inode)     /* probably unneeded */
+                                child->d_inode->i_private = NULL;
+                }
+                spin_unlock(&dir->d_lock);
 
-        return 0;
+                debugfs_remove_recursive(dir);
+        }
+
+        list_del(&file->list);
+        remove_subsystem(file->system);
+        kmem_cache_free(file_cachep, file);
 }
 
 /*
@@ -679,15 +688,25 @@ static ssize_t
 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
                   loff_t *ppos)
 {
-        struct ftrace_event_file *file = filp->private_data;
+        struct ftrace_event_file *file;
+        unsigned long flags;
         char buf[4] = "0";
 
-        if (file->flags & FTRACE_EVENT_FL_ENABLED &&
-            !(file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
+        mutex_lock(&event_mutex);
+        file = event_file_data(filp);
+        if (likely(file))
+                flags = file->flags;
+        mutex_unlock(&event_mutex);
+
+        if (!file)
+                return -ENODEV;
+
+        if (flags & FTRACE_EVENT_FL_ENABLED &&
+            !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
                 strcpy(buf, "1");
 
-        if (file->flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
-            file->flags & FTRACE_EVENT_FL_SOFT_MODE)
+        if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
+            flags & FTRACE_EVENT_FL_SOFT_MODE)
                 strcat(buf, "*");
 
         strcat(buf, "\n");
@@ -699,13 +718,10 @@ static ssize_t
 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
                    loff_t *ppos)
 {
-        struct ftrace_event_file *file = filp->private_data;
+        struct ftrace_event_file *file;
         unsigned long val;
         int ret;
 
-        if (!file)
-                return -EINVAL;
-
         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
         if (ret)
                 return ret;
@@ -717,8 +733,11 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
         switch (val) {
         case 0:
         case 1:
+                ret = -ENODEV;
                 mutex_lock(&event_mutex);
-                ret = ftrace_event_enable_disable(file, val);
+                file = event_file_data(filp);
+                if (likely(file))
+                        ret = ftrace_event_enable_disable(file, val);
                 mutex_unlock(&event_mutex);
                 break;
 
@@ -825,7 +844,7 @@ enum {
 
 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
 {
-        struct ftrace_event_call *call = m->private;
+        struct ftrace_event_call *call = event_file_data(m->private);
         struct list_head *common_head = &ftrace_common_fields;
         struct list_head *head = trace_get_fields(call);
         struct list_head *node = v;
@@ -857,7 +876,7 @@ static void *f_next(struct seq_file *m, void *v, loff_t *pos)
 
 static int f_show(struct seq_file *m, void *v)
 {
-        struct ftrace_event_call *call = m->private;
+        struct ftrace_event_call *call = event_file_data(m->private);
         struct ftrace_event_field *field;
         const char *array_descriptor;
 
@@ -910,6 +929,11 @@ static void *f_start(struct seq_file *m, loff_t *pos)
         void *p = (void *)FORMAT_HEADER;
         loff_t l = 0;
 
+        /* ->stop() is called even if ->start() fails */
+        mutex_lock(&event_mutex);
+        if (!event_file_data(m->private))
+                return ERR_PTR(-ENODEV);
+
         while (l < *pos && p)
                 p = f_next(m, p, &l);
 
@@ -918,6 +942,7 @@ static void *f_start(struct seq_file *m, loff_t *pos)
 
 static void f_stop(struct seq_file *m, void *p)
 {
+        mutex_unlock(&event_mutex);
 }
 
 static const struct seq_operations trace_format_seq_ops = {
@@ -929,7 +954,6 @@ static const struct seq_operations trace_format_seq_ops = {
 
 static int trace_format_open(struct inode *inode, struct file *file)
 {
-        struct ftrace_event_call *call = inode->i_private;
         struct seq_file *m;
         int ret;
 
@@ -938,7 +962,7 @@ static int trace_format_open(struct inode *inode, struct file *file)
                 return ret;
 
         m = file->private_data;
-        m->private = call;
+        m->private = file;
 
         return 0;
 }
@@ -946,14 +970,18 @@ static int trace_format_open(struct inode *inode, struct file *file)
 static ssize_t
 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 {
-        struct ftrace_event_call *call = filp->private_data;
+        int id = (long)event_file_data(filp);
         char buf[32];
         int len;
 
         if (*ppos)
                 return 0;
 
-        len = sprintf(buf, "%d\n", call->event.type);
+        if (unlikely(!id))
+                return -ENODEV;
+
+        len = sprintf(buf, "%d\n", id);
+
         return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
 }
 
@@ -961,21 +989,28 @@ 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 ftrace_event_call *call;
         struct trace_seq *s;
-        int r;
+        int r = -ENODEV;
 
         if (*ppos)
                 return 0;
 
         s = kmalloc(sizeof(*s), GFP_KERNEL);
+
         if (!s)
                 return -ENOMEM;
 
         trace_seq_init(s);
 
-        print_event_filter(call, s);
-        r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
+        mutex_lock(&event_mutex);
+        call = event_file_data(filp);
+        if (call)
+                print_event_filter(call, s);
+        mutex_unlock(&event_mutex);
+
+        if (call)
+                r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 
         kfree(s);
 
@@ -986,9 +1021,9 @@ 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;
+        struct ftrace_event_call *call;
         char *buf;
-        int err;
+        int err = -ENODEV;
 
         if (cnt >= PAGE_SIZE)
                 return -EINVAL;
@@ -1003,7 +1038,12 @@ event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
         }
         buf[cnt] = '\0';
 
-        err = apply_event_filter(call, buf);
+        mutex_lock(&event_mutex);
+        call = event_file_data(filp);
+        if (call)
+                err = apply_event_filter(call, buf);
+        mutex_unlock(&event_mutex);
+
         free_page((unsigned long) buf);
         if (err < 0)
                 return err;
@@ -1225,10 +1265,9 @@ static const struct file_operations ftrace_set_event_fops = {
 };
 
 static const struct file_operations ftrace_enable_fops = {
-        .open = tracing_open_generic_file,
+        .open = tracing_open_generic,
         .read = event_enable_read,
         .write = event_enable_write,
-        .release = tracing_release_generic_file,
         .llseek = default_llseek,
 };
 
@@ -1240,7 +1279,6 @@ static const struct file_operations ftrace_event_format_fops = {
 };
 
 static const struct file_operations ftrace_event_id_fops = {
-        .open = tracing_open_generic,
         .read = event_id_read,
         .llseek = default_llseek,
 };
@@ -1488,8 +1526,8 @@ event_create_dir(struct dentry *parent,
 
 #ifdef CONFIG_PERF_EVENTS
         if (call->event.type && call->class->reg)
-                trace_create_file("id", 0444, file->dir, call,
-                                  id);
+                trace_create_file("id", 0444, file->dir,
+                                  (void *)(long)call->event.type, id);
 #endif
 
         /*
@@ -1514,33 +1552,16 @@ event_create_dir(struct dentry *parent,
         return 0;
 }
 
-static void remove_subsystem(struct ftrace_subsystem_dir *dir)
-{
-        if (!dir)
-                return;
-
-        if (!--dir->nr_events) {
-                debugfs_remove_recursive(dir->entry);
-                list_del(&dir->list);
-                __put_system_dir(dir);
-        }
-}
-
 static void remove_event_from_tracers(struct ftrace_event_call *call)
 {
         struct ftrace_event_file *file;
         struct trace_array *tr;
 
         do_for_each_event_file_safe(tr, file) {
-
                 if (file->event_call != call)
                         continue;
 
-                list_del(&file->list);
-                debugfs_remove_recursive(file->dir);
-                remove_subsystem(file->system);
-                kmem_cache_free(file_cachep, file);
-
+                remove_event_file_dir(file);
                 /*
                  * The do_for_each_event_file_safe() is
                  * a double loop. After finding the call for this
@@ -1692,16 +1713,53 @@ static void __trace_remove_event_call(struct ftrace_event_call *call)
         destroy_preds(call);
 }
 
+static int probe_remove_event_call(struct ftrace_event_call *call)
+{
+        struct trace_array *tr;
+        struct ftrace_event_file *file;
+
+#ifdef CONFIG_PERF_EVENTS
+        if (call->perf_refcount)
+                return -EBUSY;
+#endif
+        do_for_each_event_file(tr, file) {
+                if (file->event_call != call)
+                        continue;
+                /*
+                 * We can't rely on ftrace_event_enable_disable(enable => 0)
+                 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
+                 * TRACE_REG_UNREGISTER.
+                 */
+                if (file->flags & FTRACE_EVENT_FL_ENABLED)
+                        return -EBUSY;
+                /*
+                 * The do_for_each_event_file_safe() is
+                 * a double loop. After finding the call for this
+                 * trace_array, we use break to jump to the next
+                 * trace_array.
+                 */
+                break;
+        } while_for_each_event_file();
+
+        __trace_remove_event_call(call);
+
+        return 0;
+}
+
 /* Remove an event_call */
-void trace_remove_event_call(struct ftrace_event_call *call)
+int trace_remove_event_call(struct ftrace_event_call *call)
 {
+        int ret;
+
         mutex_lock(&trace_types_lock);
         mutex_lock(&event_mutex);
         down_write(&trace_event_sem);
-        __trace_remove_event_call(call);
+        ret = probe_remove_event_call(call);
         up_write(&trace_event_sem);
         mutex_unlock(&event_mutex);
         mutex_unlock(&trace_types_lock);
+
+        return ret;
 }
 
 #define for_each_event(event, start, end)                       \
@@ -2270,12 +2328,8 @@ __trace_remove_event_dirs(struct trace_array *tr)
 {
         struct ftrace_event_file *file, *next;
 
-        list_for_each_entry_safe(file, next, &tr->events, list) {
-                list_del(&file->list);
-                debugfs_remove_recursive(file->dir);
-                remove_subsystem(file->system);
-                kmem_cache_free(file_cachep, file);
-        }
+        list_for_each_entry_safe(file, next, &tr->events, list)
+                remove_event_file_dir(file);
 }
 
 static void
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 0c7b75a8acc8..97daa8cf958d 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -637,17 +637,15 @@ static void append_filter_err(struct filter_parse_state *ps,
         free_page((unsigned long) buf);
 }
 
+/* caller must hold event_mutex */
 void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s)
 {
-        struct event_filter *filter;
+        struct event_filter *filter = call->filter;
 
-        mutex_lock(&event_mutex);
-        filter = call->filter;
         if (filter && filter->filter_string)
                 trace_seq_printf(s, "%s\n", filter->filter_string);
         else
                 trace_seq_puts(s, "none\n");
-        mutex_unlock(&event_mutex);
 }
 
 void print_subsystem_event_filter(struct event_subsystem *system,
@@ -1841,23 +1839,22 @@ static int create_system_filter(struct event_subsystem *system,
         return err;
 }
 
+/* caller must hold event_mutex */
 int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
 {
         struct event_filter *filter;
-        int err = 0;
-
-        mutex_lock(&event_mutex);
+        int err;
 
         if (!strcmp(strstrip(filter_string), "0")) {
                 filter_disable(call);
                 filter = call->filter;
                 if (!filter)
-                        goto out_unlock;
+                        return 0;
                 RCU_INIT_POINTER(call->filter, NULL);
                 /* Make sure the filter is not being used */
                 synchronize_sched();
                 __free_filter(filter);
-                goto out_unlock;
+                return 0;
         }
 
         err = create_filter(call, filter_string, true, &filter);
@@ -1884,8 +1881,6 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
                         __free_filter(tmp);
                 }
         }
-out_unlock:
-        mutex_unlock(&event_mutex);
 
         return err;
 }
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 3811487e7a7a..243f6834d026 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -95,7 +95,7 @@ static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp)
 }
 
 static int register_probe_event(struct trace_probe *tp);
-static void unregister_probe_event(struct trace_probe *tp);
+static int unregister_probe_event(struct trace_probe *tp);
 
 static DEFINE_MUTEX(probe_lock);
 static LIST_HEAD(probe_list);
@@ -351,9 +351,12 @@ static int unregister_trace_probe(struct trace_probe *tp)
         if (trace_probe_is_enabled(tp))
                 return -EBUSY;
 
+        /* Will fail if probe is being used by ftrace or perf */
+        if (unregister_probe_event(tp))
+                return -EBUSY;
+
         __unregister_trace_probe(tp);
         list_del(&tp->list);
-        unregister_probe_event(tp);
 
         return 0;
 }
@@ -632,7 +635,9 @@ static int release_all_trace_probes(void)
         /* TODO: Use batch unregistration */
         while (!list_empty(&probe_list)) {
                 tp = list_entry(probe_list.next, struct trace_probe, list);
-                unregister_trace_probe(tp);
+                ret = unregister_trace_probe(tp);
+                if (ret)
+                        goto end;
                 free_trace_probe(tp);
         }
 
@@ -1247,11 +1252,15 @@ static int register_probe_event(struct trace_probe *tp)
         return ret;
 }
 
-static void unregister_probe_event(struct trace_probe *tp)
+static int unregister_probe_event(struct trace_probe *tp)
 {
+        int ret;
+
         /* tp->event is unregistered in trace_remove_event_call() */
-        trace_remove_event_call(&tp->call);
-        kfree(tp->call.print_fmt);
+        ret = trace_remove_event_call(&tp->call);
+        if (!ret)
+                kfree(tp->call.print_fmt);
+        return ret;
 }
 
 /* Make a debugfs interface for controlling probe points */
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index a23d2d71188e..272261b5f94f 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -70,7 +70,7 @@ struct trace_uprobe {
         (sizeof(struct probe_arg) * (n)))
 
 static int register_uprobe_event(struct trace_uprobe *tu);
-static void unregister_uprobe_event(struct trace_uprobe *tu);
+static int unregister_uprobe_event(struct trace_uprobe *tu);
 
 static DEFINE_MUTEX(uprobe_lock);
 static LIST_HEAD(uprobe_list);
@@ -164,11 +164,17 @@ static struct trace_uprobe *find_probe_event(const char *event, const char *grou
 }
 
 /* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
-static void unregister_trace_uprobe(struct trace_uprobe *tu)
+static int unregister_trace_uprobe(struct trace_uprobe *tu)
 {
+        int ret;
+
+        ret = unregister_uprobe_event(tu);
+        if (ret)
+                return ret;
+
         list_del(&tu->list);
-        unregister_uprobe_event(tu);
         free_trace_uprobe(tu);
+        return 0;
 }
 
 /* Register a trace_uprobe and probe_event */
@@ -181,9 +187,12 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
 
         /* register as an event */
         old_tp = find_probe_event(tu->call.name, tu->call.class->system);
-        if (old_tp)
+        if (old_tp) {
                 /* delete old event */
-                unregister_trace_uprobe(old_tp);
+                ret = unregister_trace_uprobe(old_tp);
+                if (ret)
+                        goto end;
+        }
 
         ret = register_uprobe_event(tu);
         if (ret) {
@@ -256,6 +265,8 @@ static int create_trace_uprobe(int argc, char **argv)
                 group = UPROBE_EVENT_SYSTEM;
 
         if (is_delete) {
+                int ret;
+
                 if (!event) {
                         pr_info("Delete command needs an event name.\n");
                         return -EINVAL;
@@ -269,9 +280,9 @@ static int create_trace_uprobe(int argc, char **argv)
                         return -ENOENT;
                 }
                 /* delete an event */
-                unregister_trace_uprobe(tu);
+                ret = unregister_trace_uprobe(tu);
                 mutex_unlock(&uprobe_lock);
-                return 0;
+                return ret;
         }
 
         if (argc < 2) {
@@ -408,16 +419,20 @@ fail_address_parse:
         return ret;
 }
 
-static void cleanup_all_probes(void)
+static int cleanup_all_probes(void)
 {
         struct trace_uprobe *tu;
+        int ret = 0;
 
         mutex_lock(&uprobe_lock);
         while (!list_empty(&uprobe_list)) {
                 tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
-                unregister_trace_uprobe(tu);
+                ret = unregister_trace_uprobe(tu);
+                if (ret)
+                        break;
         }
         mutex_unlock(&uprobe_lock);
+        return ret;
 }
 
 /* Probes listing interfaces */
@@ -462,8 +477,13 @@ static const struct seq_operations probes_seq_op = {
 
 static int probes_open(struct inode *inode, struct file *file)
 {
-        if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC))
-                cleanup_all_probes();
+        int ret;
+
+        if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
+                ret = cleanup_all_probes();
+                if (ret)
+                        return ret;
+        }
 
         return seq_open(file, &probes_seq_op);
 }
@@ -968,12 +988,17 @@ static int register_uprobe_event(struct trace_uprobe *tu)
         return ret;
 }
 
-static void unregister_uprobe_event(struct trace_uprobe *tu)
+static int unregister_uprobe_event(struct trace_uprobe *tu)
 {
+        int ret;
+
         /* tu->event is unregistered in trace_remove_event_call() */
-        trace_remove_event_call(&tu->call);
+        ret = trace_remove_event_call(&tu->call);
+        if (ret)
+                return ret;
         kfree(tu->call.print_fmt);
         tu->call.print_fmt = NULL;
+        return 0;
 }
 
 /* Make a trace interface for controling probe points */