[pkg-gnupg-maint] Bug#844117: gnupg locks up until straced

[Ian Jackson]

Package: gnupg
Version: 2.1.15-4

I just tried to use caff.  I found that it seemed to hang, every
time.  I tried debugging it with strace.

I discovered that caff had run a gpg-connect-agent process.  It was
calling connect() to connect to /run/user/1000/gnupg/S.dirmngr.  The
corresponding listening socket in question was owned by a dirmngr
process.

I straced the dirnmgr process and got:

root(ian)@zealot:~> strace -fp14006
strace: Process 14006 attached with 3 threads
[pid 17554] futex(0x7f459d683200, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME, 0, NULL, ffffffff) = -1 EAGAIN (Resource temporarily unavailable)
[pid 17554] getsockopt(1, SOL_SOCKET, SO_PEERCRED, {pid=17553, uid=1000, gid=1000}, [12]) = 0
[pid 17554] futex(0x7f459d683200, FUTEX_WAKE_PRIVATE, 1) = 0
...

And then caff unwedged.

This all happened to me twice.  I may be able to repro it.

I suspect thread mishandling by dirmngr.

Ian.

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