From e9660c862b411b50a588f299eb78531fe77c65e1 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <srostedt@redhat.com>
Date: Fri, 21 May 2010 13:32:26 -0400
Subject: [PATCH] --- yaml --- r: 199438 b: refs/heads/master c:
 2711ca237a084286ea1c2dcf82ab2aadab23a00d h: refs/heads/master v: v3

---
 [refs]                           |  2 +-
 trunk/kernel/trace/ring_buffer.c | 11 +++++++++--
 trunk/kernel/trace/trace.c       |  6 ------
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/[refs] b/[refs]
index e47610b4869f..f9934d5602a9 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b3230c8b44da5838cf396942d5c1ab19f8e8f720
+refs/heads/master: 2711ca237a084286ea1c2dcf82ab2aadab23a00d
diff --git a/trunk/kernel/trace/ring_buffer.c b/trunk/kernel/trace/ring_buffer.c
index b0702ff78218..1da7b6ea8b85 100644
--- a/trunk/kernel/trace/ring_buffer.c
+++ b/trunk/kernel/trace/ring_buffer.c
@@ -3902,12 +3902,12 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
 	ret = read;
 
 	cpu_buffer->lost_events = 0;
+
+	commit = local_read(&bpage->commit);
 	/*
 	 * Set a flag in the commit field if we lost events
 	 */
 	if (missed_events) {
-		commit = local_read(&bpage->commit);
-
 		/* If there is room at the end of the page to save the
 		 * missed events, then record it there.
 		 */
@@ -3915,10 +3915,17 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
 			memcpy(&bpage->data[commit], &missed_events,
 			       sizeof(missed_events));
 			local_add(RB_MISSED_STORED, &bpage->commit);
+			commit += sizeof(missed_events);
 		}
 		local_add(RB_MISSED_EVENTS, &bpage->commit);
 	}
 
+	/*
+	 * This page may be off to user land. Zero it out here.
+	 */
+	if (commit < BUF_PAGE_SIZE)
+		memset(&bpage->data[commit], 0, BUF_PAGE_SIZE - commit);
+
  out_unlock:
 	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
 
diff --git a/trunk/kernel/trace/trace.c b/trunk/kernel/trace/trace.c
index ba0ec81158b2..95d0b1a28f93 100644
--- a/trunk/kernel/trace/trace.c
+++ b/trunk/kernel/trace/trace.c
@@ -3661,7 +3661,6 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
 		     size_t count, loff_t *ppos)
 {
 	struct ftrace_buffer_info *info = filp->private_data;
-	unsigned int pos;
 	ssize_t ret;
 	size_t size;
 
@@ -3688,11 +3687,6 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
 	if (ret < 0)
 		return 0;
 
-	pos = ring_buffer_page_len(info->spare);
-
-	if (pos < PAGE_SIZE)
-		memset(info->spare + pos, 0, PAGE_SIZE - pos);
-
 read:
 	size = PAGE_SIZE - info->read;
 	if (size > count)