1 files changed, 17 insertions, 37 deletions

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 2d7aebd71dbd..0f6facb050a1 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -186,43 +186,33 @@ static const struct file_operations stack_max_size_fops = {
 };
 
 static void *
-t_next(struct seq_file *m, void *v, loff_t *pos)
+__next(struct seq_file *m, loff_t *pos)
 {
-        long i;
-
-        (*pos)++;
-
-        if (v == SEQ_START_TOKEN)
-                i = 0;
-        else {
-                i = *(long *)v;
-                i++;
-        }
+        long n = *pos - 1;
 
-        if (i >= max_stack_trace.nr_entries ||
-            stack_dump_trace[i] == ULONG_MAX)
+        if (n >= max_stack_trace.nr_entries || stack_dump_trace[n] == ULONG_MAX)
                 return NULL;
 
-        m->private = (void *)i;
-
+        m->private = (void *)n;
         return &m->private;
 }
 
-static void *t_start(struct seq_file *m, loff_t *pos)
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
 {
-        void *t = SEQ_START_TOKEN;
-        loff_t l = 0;
+        (*pos)++;
+        return __next(m, pos);
+}
 
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
         local_irq_disable();
         __raw_spin_lock(&max_stack_lock);
 
         if (*pos == 0)
                 return SEQ_START_TOKEN;
 
-        for (; t && l < *pos; t = t_next(m, t, &l))
-                ;
-
-        return t;
+        return __next(m, pos);
 }
 
 static void t_stop(struct seq_file *m, void *p)
@@ -234,15 +224,8 @@ static void t_stop(struct seq_file *m, void *p)
 static int trace_lookup_stack(struct seq_file *m, long i)
 {
         unsigned long addr = stack_dump_trace[i];
-#ifdef CONFIG_KALLSYMS
-        char str[KSYM_SYMBOL_LEN];
 
-        sprint_symbol(str, addr);
-
-        return seq_printf(m, "%s\n", str);
-#else
-        return seq_printf(m, "%p\n", (void*)addr);
-#endif
+        return seq_printf(m, "%pF\n", (void *)addr);
 }
 
 static void print_disabled(struct seq_file *m)
@@ -301,17 +284,14 @@ static const struct seq_operations stack_trace_seq_ops = {
 
 static int stack_trace_open(struct inode *inode, struct file *file)
 {
-        int ret;
-
-        ret = seq_open(file, &stack_trace_seq_ops);
-
-        return ret;
+        return seq_open(file, &stack_trace_seq_ops);
 }
 
 static const struct file_operations stack_trace_fops = {
         .open           = stack_trace_open,
         .read           = seq_read,
         .llseek         = seq_lseek,
+        .release        = seq_release,
 };
 
 int
@@ -326,10 +306,10 @@ stack_trace_sysctl(struct ctl_table *table, int write,
         ret = proc_dointvec(table, write, file, buffer, lenp, ppos);
 
         if (ret || !write ||
-            (last_stack_tracer_enabled == stack_tracer_enabled))
+            (last_stack_tracer_enabled == !!stack_tracer_enabled))
                 goto out;
 
-        last_stack_tracer_enabled = stack_tracer_enabled;
+        last_stack_tracer_enabled = !!stack_tracer_enabled;
 
         if (stack_tracer_enabled)
                 register_ftrace_function(&trace_ops);