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tracing: Reset iterator in t_start() 

The iterator is m->private, but it's not reset to trace_types in
t_start(). If the output is larger than PAGE_SIZE and t_start()
is called the 2nd time, things will go wrong.

Reviewed-by: Liming Wang <liming.wang@windriver.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A418728.5020506@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Li Zefan 2009-06-24 09:53:44 +08:00 committed by Ingo Molnar
parent 2961bf345f
commit f129e965be
1 changed files with 4 additions and 14 deletions
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18
kernel/trace/trace.c
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@ -2053,25 +2053,23 @@ static int tracing_open(struct inode *inode, struct file *file)
static void * static void *
t_next(struct seq_file *m, void *v, loff_t *pos) t_next(struct seq_file *m, void *v, loff_t *pos)
{ {
struct tracer *t = m->private; struct tracer *t = v;
(*pos)++; (*pos)++;
if (t) if (t)
t = t->next; t = t->next;
m->private = t;
return t; return t;
} }
static void *t_start(struct seq_file *m, loff_t *pos) static void *t_start(struct seq_file *m, loff_t *pos)
{ {
struct tracer *t = m->private; struct tracer *t;
loff_t l = 0; loff_t l = 0;
mutex_lock(&trace_types_lock); mutex_lock(&trace_types_lock);
for (; t && l < *pos; t = t_next(m, t, &l)) for (t = trace_types; t && l < *pos; t = t_next(m, t, &l))
; ;
return t; return t;
@ -2107,18 +2105,10 @@ static struct seq_operations show_traces_seq_ops = {
static int show_traces_open(struct inode *inode, struct file *file) static int show_traces_open(struct inode *inode, struct file *file)
{ {
int ret;
if (tracing_disabled) if (tracing_disabled)
return -ENODEV; return -ENODEV;
ret = seq_open(file, &show_traces_seq_ops); return seq_open(file, &show_traces_seq_ops);
if (!ret) {
struct seq_file *m = file->private_data;
m->private = trace_types;
}
return ret;
} }
static ssize_t static ssize_t