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| author | Steven Rostedt <srostedt@redhat.com> | 2009-12-10 23:20:52 -0500 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2009-12-10 23:20:52 -0500 |
| commit | dd7f59435782a02ceb6d16b9ce823dd3345d75ec (patch) | |
| tree | d85e0a7b2b587b41afd1c764e7c25b3fa2962613 /kernel/trace | |
| parent | 184210154b9aa570099183f6c062ac4eb11190b7 (diff) | |
| download | blackbird-op-linux-dd7f59435782a02ceb6d16b9ce823dd3345d75ec.tar.gz blackbird-op-linux-dd7f59435782a02ceb6d16b9ce823dd3345d75ec.zip | |
ring-buffer: Move resize integrity check under reader lock
While using an application that does splice on the ftrace ring
buffer at start up, I triggered an integrity check failure.
Looking into this, I discovered that resizing the buffer performs
an integrity check after the buffer is resized. This check unfortunately
is preformed after it releases the reader lock. If a reader is
reading the buffer it may cause the integrity check to trigger a
false failure.
This patch simply moves the integrity checker under the protection
of the ring buffer reader lock.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 0d64c51ab4df..eccb4cf1e998 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1208,9 +1208,9 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages) return; rb_reset_cpu(cpu_buffer); - spin_unlock_irq(&cpu_buffer->reader_lock); - rb_check_pages(cpu_buffer); + + spin_unlock_irq(&cpu_buffer->reader_lock); } static void @@ -1233,9 +1233,9 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer, list_add_tail(&bpage->list, cpu_buffer->pages); } rb_reset_cpu(cpu_buffer); - spin_unlock_irq(&cpu_buffer->reader_lock); - rb_check_pages(cpu_buffer); + + spin_unlock_irq(&cpu_buffer->reader_lock); } /** |
