Commit d1e7e02f authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Ingo Molnar
Browse files

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: default avatarLai 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: default avatarIngo Molnar <mingo@elte.hu>
parent 62b8e680
......@@ -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);
......
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