From: Oleg Nesterov <o...@redhat.com> event_id_read() has no reason to kmalloc "struct trace_seq" (more than PAGE_SIZE!), it can use a small buffer instead.
Note: "if (*ppos) return 0" looks strange and even wrong, simple_read_from_buffer() handles ppos != 0 case corrrectly. And it seems that almost every user of trace_seq in this file should be converted too. Unless you use seq_open(), trace_seq buys nothing compared to the raw buffer, but it needs a bit more memory and code. Link: http://lkml.kernel.org/r/20130718184712.ga4...@redhat.com Signed-off-by: Oleg Nesterov <o...@redhat.com> Signed-off-by: Steven Rostedt <rost...@goodmis.org> --- kernel/trace/trace_events.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 76defd9..898f868 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -947,23 +947,14 @@ 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; - struct trace_seq *s; - int r; + char buf[32]; + int len; if (*ppos) return 0; - s = kmalloc(sizeof(*s), GFP_KERNEL); - if (!s) - return -ENOMEM; - - trace_seq_init(s); - trace_seq_printf(s, "%d\n", call->event.type); - - r = simple_read_from_buffer(ubuf, cnt, ppos, - s->buffer, s->len); - kfree(s); - return r; + len = sprintf(buf, "%d\n", call->event.type); + return simple_read_from_buffer(ubuf, cnt, ppos, buf, len); } static ssize_t -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
