1 files changed, 61 insertions, 40 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 3718d55fb4c3..25edd5cc5935 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -291,7 +291,9 @@ function_stat_next(void *v, int idx)
         pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
 
  again:
-        rec++;
+        if (idx != 0)
+                rec++;
+
         if ((void *)rec >= (void *)&pg->records[pg->index]) {
                 pg = pg->next;
                 if (!pg)
@@ -766,7 +768,7 @@ static struct tracer_stat function_stats __initdata = {
         .stat_show      = function_stat_show
 };
 
-static void ftrace_profile_debugfs(struct dentry *d_tracer)
+static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
 {
         struct ftrace_profile_stat *stat;
         struct dentry *entry;
@@ -784,7 +786,6 @@ static void ftrace_profile_debugfs(struct dentry *d_tracer)
                          * The files created are permanent, if something happens
                          * we still do not free memory.
                          */
-                        kfree(stat);
                         WARN(1,
                              "Could not allocate stat file for cpu %d\n",
                              cpu);
@@ -811,7 +812,7 @@ static void ftrace_profile_debugfs(struct dentry *d_tracer)
 }
 
 #else /* CONFIG_FUNCTION_PROFILER */
-static void ftrace_profile_debugfs(struct dentry *d_tracer)
+static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
 {
 }
 #endif /* CONFIG_FUNCTION_PROFILER */
@@ -1417,10 +1418,20 @@ static void *t_hash_start(struct seq_file *m, loff_t *pos)
 {
         struct ftrace_iterator *iter = m->private;
         void *p = NULL;
+        loff_t l;
+
+        if (!(iter->flags & FTRACE_ITER_HASH))
+                *pos = 0;
 
         iter->flags |= FTRACE_ITER_HASH;
 
-        return t_hash_next(m, p, pos);
+        iter->hidx = 0;
+        for (l = 0; l <= *pos; ) {
+                p = t_hash_next(m, p, &l);
+                if (!p)
+                        break;
+        }
+        return p;
 }
 
 static int t_hash_show(struct seq_file *m, void *v)
@@ -1467,8 +1478,6 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
                         iter->pg = iter->pg->next;
                         iter->idx = 0;
                         goto retry;
-                } else {
-                        iter->idx = -1;
                 }
         } else {
                 rec = &iter->pg->records[iter->idx++];
@@ -1497,6 +1506,7 @@ static void *t_start(struct seq_file *m, loff_t *pos)
 {
         struct ftrace_iterator *iter = m->private;
         void *p = NULL;
+        loff_t l;
 
         mutex_lock(&ftrace_lock);
         /*
@@ -1508,23 +1518,21 @@ static void *t_start(struct seq_file *m, loff_t *pos)
                 if (*pos > 0)
                         return t_hash_start(m, pos);
                 iter->flags |= FTRACE_ITER_PRINTALL;
-                (*pos)++;
                 return iter;
         }
 
         if (iter->flags & FTRACE_ITER_HASH)
                 return t_hash_start(m, pos);
 
-        if (*pos > 0) {
-                if (iter->idx < 0)
-                        return p;
-                (*pos)--;
-                iter->idx--;
+        iter->pg = ftrace_pages_start;
+        iter->idx = 0;
+        for (l = 0; l <= *pos; ) {
+                p = t_next(m, p, &l);
+                if (!p)
+                        break;
         }
 
-        p = t_next(m, p, pos);
-
-        if (!p)
+        if (!p && iter->flags & FTRACE_ITER_FILTER)
                 return t_hash_start(m, pos);
 
         return p;
@@ -1654,7 +1662,7 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
 
         mutex_lock(&ftrace_regex_lock);
         if ((file->f_mode & FMODE_WRITE) &&
-            !(file->f_flags & O_APPEND))
+            (file->f_flags & O_TRUNC))
                 ftrace_filter_reset(enable);
 
         if (file->f_mode & FMODE_READ) {
@@ -2270,7 +2278,11 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
         read++;
         cnt--;
 
-        if (!(iter->flags & ~FTRACE_ITER_CONT)) {
+        /*
+         * If the parser haven't finished with the last write,
+         * continue reading the user input without skipping spaces.
+         */
+        if (!(iter->flags & FTRACE_ITER_CONT)) {
                 /* skip white space */
                 while (cnt && isspace(ch)) {
                         ret = get_user(ch, ubuf++);
@@ -2280,8 +2292,9 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
                         cnt--;
                 }
 
+                /* only spaces were written */
                 if (isspace(ch)) {
-                        file->f_pos += read;
+                        *ppos += read;
                         ret = read;
                         goto out;
                 }
@@ -2311,12 +2324,12 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
                 if (ret)
                         goto out;
                 iter->buffer_idx = 0;
-        } else
+        } else {
                 iter->flags |= FTRACE_ITER_CONT;
+                iter->buffer[iter->buffer_idx++] = ch;
+        }
 
-
-        file->f_pos += read;
-
+        *ppos += read;
         ret = read;
  out:
         mutex_unlock(&ftrace_regex_lock);
@@ -2500,32 +2513,31 @@ int ftrace_graph_count;
 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
 
 static void *
-g_next(struct seq_file *m, void *v, loff_t *pos)
+__g_next(struct seq_file *m, loff_t *pos)
 {
         unsigned long *array = m->private;
-        int index = *pos;
 
-        (*pos)++;
-
-        if (index >= ftrace_graph_count)
+        if (*pos >= ftrace_graph_count)
                 return NULL;
+        return &array[*pos];
+}
 
-        return &array[index];
+static void *
+g_next(struct seq_file *m, void *v, loff_t *pos)
+{
+        (*pos)++;
+        return __g_next(m, pos);
 }
 
 static void *g_start(struct seq_file *m, loff_t *pos)
 {
-        void *p = NULL;
-
         mutex_lock(&graph_lock);
 
         /* Nothing, tell g_show to print all functions are enabled */
         if (!ftrace_graph_count && !*pos)
                 return (void *)1;
 
-        p = g_next(m, p, pos);
-
-        return p;
+        return __g_next(m, pos);
 }
 
 static void g_stop(struct seq_file *m, void *p)
@@ -2570,7 +2582,7 @@ ftrace_graph_open(struct inode *inode, struct file *file)
 
         mutex_lock(&graph_lock);
         if ((file->f_mode & FMODE_WRITE) &&
-            !(file->f_flags & O_APPEND)) {
+            (file->f_flags & O_TRUNC)) {
                 ftrace_graph_count = 0;
                 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
         }
@@ -2589,6 +2601,14 @@ ftrace_graph_open(struct inode *inode, struct file *file)
 }
 
 static int
+ftrace_graph_release(struct inode *inode, struct file *file)
+{
+        if (file->f_mode & FMODE_READ)
+                seq_release(inode, file);
+        return 0;
+}
+
+static int
 ftrace_set_func(unsigned long *array, int *idx, char *buffer)
 {
         struct dyn_ftrace *rec;
@@ -2717,9 +2737,10 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
 }
 
 static const struct file_operations ftrace_graph_fops = {
-        .open = ftrace_graph_open,
-        .read = seq_read,
-        .write = ftrace_graph_write,
+        .open           = ftrace_graph_open,
+        .read           = seq_read,
+        .write          = ftrace_graph_write,
+        .release        = ftrace_graph_release,
 };
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
@@ -3152,10 +3173,10 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
 
         ret  = proc_dointvec(table, write, file, buffer, lenp, ppos);
 
-        if (ret || !write || (last_ftrace_enabled == ftrace_enabled))
+        if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
                 goto out;
 
-        last_ftrace_enabled = ftrace_enabled;
+        last_ftrace_enabled = !!ftrace_enabled;
 
         if (ftrace_enabled) {