Messages in this thread | | | Date | Thu, 7 Jan 2021 16:32:38 +0100 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH 0/2] drivers:tty:pty: Fix a race causing data loss on close |
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On Mon, Nov 23, 2020 at 06:49:00PM -0600, minyard@acm.org wrote: > I finally got some time to spend with this issue, and I think I have a > good fix. Not really a v2, this is a completely different fix. > Basically, calling tty_vhangup() on the slave when closing a pty master > is just a bad idea. > > >From what I can tell, the tty_vhangup() is there in case there was a > console redirect to the pty slave. When you close the master, you need > to release the redirect. I didn't see another reason for tty_vhangup(). > So this has two parts, export the release of the tty redirect release > for the pty code to use, and call it from the pty code. > > With this change, everything seems to work ok and no data is lost on the > slave side if the master closes with outstanding data. I have updated > my test program to check that all written data is read, it's available > at https://sourceforge.net/projects/ser2net/files/tmp/testpty.c/download > > But, this code is quite intricate and I certainly may have missed > something.
Tricky stuff, but I think this makes sense, so let's see how the test-builders and linux-next work with this...
thanks,
greg k-h
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