Messages in this thread | | | From | Rainer Weikusat <> | Subject | Re: [V4.4-rc6 Regression] af_unix: Revert 'lock_interruptible' in stream receive code | Date | Sun, 07 Feb 2016 22:24:22 +0000 |
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Rainer Weikusat <rw@doppelsaurus.mobileactivedefense.com> writes:
[...]
> The start uses that to record an error which might need to be > reported, the return statement uses it to indicate that an error has > occurred. Hence, some kind of in-between translation must occur. The > mutex_lock_interruptible happened to do that but that was never it's > intended purpose.
Additional information: The 'trick' of using recvmsg w/o a receive buffer in order to retrieve control messages in fact wouldn't have worked with the unix_stream_recvmsg prior to introduction of the interruptible lock as that (judging from the git source) would have triggered all the same issues,
- -EOPNOTSUP if a msg was available
- -EAGAIN if the code had to wait
- not receiving the creds if the -EAGAIN hadn't happened because of the continue (that's the other patch)
IOW, that's a feature inadvertendly added by an otherwise useless code change (mea culpa).
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