Messages in this thread | | | Date | Thu, 23 Jan 2020 17:23:21 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH RESEND] kernel/relay.c: fix read_pos error when multiple readers |
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On Wed, 22 Jan 2020 19:06:15 +0800 Pengcheng Yang <yangpc@wangsu.com> wrote:
> When reading, read_pos should start with bytes_consumed, > not file->f_pos. Because when there is more than one reader, > the read_pos corresponding to file->f_pos may have been consumed, > which will cause the data that has been consumed to be read > and the bytes_consumed update error.
That sounds fairly serious. Are you able to describe a userspace setup which will trigger this? Do you have any test code which is able to demonstrate the bug?
We really should have a relay testcase in tools/testing, but relay came along before we became diligent about this.
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