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authorSteven Rostedt <srostedt@redhat.com>2009-06-17 14:11:10 -0400
committerSteven Rostedt <rostedt@goodmis.org>2009-06-17 14:16:20 -0400
commit5f78abeebbf0a80975d719e11374535ca15396cb (patch)
tree8c5a5f11caadc1cb662152fb1ef84b5b1fa19bbb /kernel/trace
parent0dcd4d6c3e5b17ccf88d41cb354bb4d57cb18cbf (diff)
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ring-buffer: check for less than two in size allocation
The ring buffer must have at least two pages allocated for the reader page swap to work. The page count check will miss the case of a zero size passed in. Even though a zero size ring buffer would probably fail an allocation, making the min size check for less than two instead of equal to one makes the code a bit more robust. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/ring_buffer.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 162da2305cbc..2e99dba6dc48 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -657,8 +657,8 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
buffer->reader_lock_key = key;
/* need at least two pages */
- if (buffer->pages == 1)
- buffer->pages++;
+ if (buffer->pages < 2)
+ buffer->pages = 2;
/*
* In case of non-hotplug cpu, if the ring-buffer is allocated