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authorLai Jiangshan <laijs@cn.fujitsu.com>2009-04-02 15:16:56 +0800
committerIngo Molnar <mingo@elte.hu>2009-04-10 12:44:42 +0200
commitd1e7e02f30be672c6f6ee40908be83877a0d49d1 (patch)
tree24f958961d8de3ef0c1d16a407041d096fc1f098 /kernel
parent62b8e680e61d3f48f2a12ee248ca03ea8f376926 (diff)
downloadlinux-d1e7e02f30be672c6f6ee40908be83877a0d49d1.tar.gz
tracing: disable seeking for trace_pipe_raw
Impact: disable pread()

We set tracing_buffers_fops.llseek to no_llseek,
but we can still perform pread() to read this file.

That is not expected.

This fix uses nonseekable_open() to disable it.

tracing_buffers_fops.llseek is still set to no_llseek,
it mark this file is a "non-seekable device" and is used by
sys_splice(). See also do_splice() or manual of splice(2):

ERRORS
       EINVAL Target file system doesn't support  splicing;
              neither  of the descriptors refers to a pipe;
              or offset given for non-seekable device.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
LKML-Reference: <49D46668.8030806@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/trace.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9d28476a9851..24b0168f1a29 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3285,7 +3285,7 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp)
 
 	filp->private_data = info;
 
-	return 0;
+	return nonseekable_open(inode, filp);
 
  out:
 	kfree(info);