From c8961ec6da22ea010bf4470a8e0fb3fdad0f11c4 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 24 Jun 2009 09:52:58 +0800 Subject: [PATCH] tracing_bprintk: Don't increment @pos in t_start() It's wrong to increment @pos in t_start(), otherwise we'll lose some entries when reading printk_formats, if the output is larger than PAGE_SIZE. Reported-by: Lai Jiangshan Reviewed-by: Liming Wang Signed-off-by: Li Zefan Cc: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <4A4186FA.1020106@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace_printk.c | 26 ++++++-------------------- 1 file changed, 6 insertions(+), 20 deletions(-) diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index 9bece9687b62..7b6278110827 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -155,25 +155,19 @@ int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap) EXPORT_SYMBOL_GPL(__ftrace_vprintk); static void * -t_next(struct seq_file *m, void *v, loff_t *pos) +t_start(struct seq_file *m, loff_t *pos) { - const char **fmt = m->private; - const char **next = fmt; - - (*pos)++; + const char **fmt = __start___trace_bprintk_fmt + *pos; if ((unsigned long)fmt >= (unsigned long)__stop___trace_bprintk_fmt) return NULL; - - next = fmt; - m->private = ++next; - return fmt; } -static void *t_start(struct seq_file *m, loff_t *pos) +static void *t_next(struct seq_file *m, void * v, loff_t *pos) { - return t_next(m, NULL, pos); + (*pos)++; + return t_start(m, pos); } static int t_show(struct seq_file *m, void *v) @@ -224,15 +218,7 @@ static const struct seq_operations show_format_seq_ops = { static int ftrace_formats_open(struct inode *inode, struct file *file) { - int ret; - - ret = seq_open(file, &show_format_seq_ops); - if (!ret) { - struct seq_file *m = file->private_data; - - m->private = __start___trace_bprintk_fmt; - } - return ret; + return seq_open(file, &show_format_seq_ops); } static const struct file_operations ftrace_formats_fops = {