From 190839e6be768feebfdb92a2f65813503c76f93f Mon Sep 17 00:00:00 2001
From: Steven Rostedt <srostedt@redhat.com>
Date: Mon, 11 May 2009 14:42:53 -0400
Subject: [PATCH] --- yaml --- r: 146163 b: refs/heads/master c:
 be957c447f7233a67904a1b11eb3ab61e702bf4d h: refs/heads/master i:   146161:
 9b3b41dc665e6683fd52b4d87030e8d90cbe20b9   146159:
 481e1bf20f0ff5732b7b34e7d386395a5a40a000 v: v3

---
 [refs]                           |  2 +-
 trunk/kernel/trace/ring_buffer.c | 14 +++++++++-----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index 3c93e49781ec..c7825f1fc8e6 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1cd8d7358948909ab80b254eb14bcebc555ad417
+refs/heads/master: be957c447f7233a67904a1b11eb3ab61e702bf4d
diff --git a/trunk/kernel/trace/ring_buffer.c b/trunk/kernel/trace/ring_buffer.c
index fe40f6c3507c..493cba46abc9 100644
--- a/trunk/kernel/trace/ring_buffer.c
+++ b/trunk/kernel/trace/ring_buffer.c
@@ -367,6 +367,9 @@ static inline int test_time_stamp(u64 delta)
 
 #define BUF_PAGE_SIZE (PAGE_SIZE - BUF_PAGE_HDR_SIZE)
 
+/* Max payload is BUF_PAGE_SIZE - header (8bytes) */
+#define BUF_MAX_DATA_SIZE (BUF_PAGE_SIZE - (sizeof(u32) * 2))
+
 int ring_buffer_print_page_header(struct trace_seq *s)
 {
 	struct buffer_data_page field;
@@ -1396,6 +1399,7 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer,
 	int commit = 0;
 	int nr_loops = 0;
 
+	length = rb_calculate_event_length(length);
  again:
 	/*
 	 * We allow for interrupts to reenter here and do a trace.
@@ -1552,8 +1556,7 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, unsigned long length)
 	if (atomic_read(&cpu_buffer->record_disabled))
 		goto out;
 
-	length = rb_calculate_event_length(length);
-	if (length > BUF_PAGE_SIZE)
+	if (length > BUF_MAX_DATA_SIZE)
 		goto out;
 
 	event = rb_reserve_next_event(cpu_buffer, length);
@@ -1758,7 +1761,6 @@ int ring_buffer_write(struct ring_buffer *buffer,
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct ring_buffer_event *event;
-	unsigned long event_length;
 	void *body;
 	int ret = -EBUSY;
 	int cpu, resched;
@@ -1781,8 +1783,10 @@ int ring_buffer_write(struct ring_buffer *buffer,
 	if (atomic_read(&cpu_buffer->record_disabled))
 		goto out;
 
-	event_length = rb_calculate_event_length(length);
-	event = rb_reserve_next_event(cpu_buffer, event_length);
+	if (length > BUF_MAX_DATA_SIZE)
+		goto out;
+
+	event = rb_reserve_next_event(cpu_buffer, length);
 	if (!event)
 		goto out;