Re: [Qemu-devel] [PATCH 0/4] curl: locking cleanups and fixes

[Jeff Cody <jcody@redhat.com>]

On Tue, May 09, 2017 at 11:15:06AM +0100, Richard W.M. Jones wrote:
> 
> No I'm afraid this patch series does not fix the bug.
> 
> The stack trace is below.
> 
> Rich.
> 

I'm looking through qemu-defel, and I'm not finding a reference to the bug
mentioned.  Maybe I'm just missing it... can you describe the bug or point
me to the relevant email thread?

Thanks,
Jeff

> Thread 4 (Thread 0x7f8595cf1700 (LWP 11235)):
> #0  0x00007f86348e6700 in do_futex_wait () at /lib64/libpthread.so.0
> #1  0x00007f86348e6813 in __new_sem_wait_slow () at /lib64/libpthread.so.0
> #2  0x00005610e458519f in qemu_sem_timedwait (sem=sem@entry=0x5610e5db7508, ms=ms@entry=10000) at util/qemu-thread-posix.c:255
> #3  0x00005610e458043c in worker_thread (opaque=0x5610e5db74a0)
>     at util/thread-pool.c:92
> #4  0x00007f86348dd36d in start_thread () at /lib64/libpthread.so.0
> #5  0x00007f862e830e0f in clone () at /lib64/libc.so.6
> 
> Thread 3 (Thread 0x7f8621347700 (LWP 10865)):
> #0  0x00007f862e826837 in ioctl () at /lib64/libc.so.6
> #1  0x00005610e4216387 in kvm_vcpu_ioctl (cpu=cpu@entry=0x5610e60f2030, type=type@entry=44672) at /home/rjones/d/qemu/kvm-all.c:2154
> #2  0x00005610e42164be in kvm_cpu_exec (cpu=cpu@entry=0x5610e60f2030)
>     at /home/rjones/d/qemu/kvm-all.c:1992
> #3  0x00005610e4202f94 in qemu_kvm_cpu_thread_fn (arg=0x5610e60f2030)
>     at /home/rjones/d/qemu/cpus.c:1118
> #4  0x00007f86348dd36d in start_thread () at /lib64/libpthread.so.0
> #5  0x00007f862e830e0f in clone () at /lib64/libc.so.6
> 
> Thread 2 (Thread 0x7f8626559700 (LWP 10863)):
> #0  0x00007f862e82b7a9 in syscall () at /lib64/libc.so.6
> #1  0x00005610e4585325 in qemu_futex_wait (val=<optimized out>, f=<optimized out>) at /home/rjones/d/qemu/include/qemu/futex.h:26
> #2  0x00005610e4585325 in qemu_event_wait (ev=ev@entry=0x5610e5019ee4 <rcu_call_ready_event>) at util/qemu-thread-posix.c:399
> #3  0x00005610e459539e in call_rcu_thread (opaque=<optimized out>)
>     at util/rcu.c:249
> #4  0x00007f86348dd36d in start_thread () at /lib64/libpthread.so.0
> #5  0x00007f862e830e0f in clone () at /lib64/libc.so.6
> 
> Thread 1 (Thread 0x7f863757dc80 (LWP 10861)):
> #0  0x00007f862e824dc6 in ppoll () at /lib64/libc.so.6
> #1  0x00005610e4580ea9 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77
> #2  0x00005610e4580ea9 in qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=timeout@entry=-1) at util/qemu-timer.c:322
> #3  0x00005610e4582af4 in aio_poll (ctx=ctx@entry=0x5610e5d92860, blocking=<optimized out>) at util/aio-posix.c:622
> #4  0x00007f8624848299 in curl_init_state (bs=<optimized out>, s=s@entry=0x5610e5defb10) at block/curl.c:490
> #5  0x00007f8624848a51 in curl_readv_bh_cb (p=0x5610e78afb70)
>     at block/curl.c:871
> #6  0x00005610e457fb1e in aio_bh_call (bh=0x5610e6128f10) at util/async.c:90
> #7  0x00005610e457fb1e in aio_bh_poll (ctx=ctx@entry=0x5610e5d92860)
>     at util/async.c:118
> #8  0x00005610e4582cf4 in aio_poll (ctx=ctx@entry=0x5610e5d92860, blocking=<optimized out>) at util/aio-posix.c:682
> #9  0x00007f8624848299 in curl_init_state (bs=<optimized out>, s=s@entry=0x5610e5defb10) at block/curl.c:490
> #10 0x00007f8624848a51 in curl_readv_bh_cb (p=0x5610e6f01380)
>     at block/curl.c:871
> #11 0x00005610e457fb1e in aio_bh_call (bh=0x5610e6e1fff0) at util/async.c:90
> #12 0x00005610e457fb1e in aio_bh_poll (ctx=ctx@entry=0x5610e5d92860)
>     at util/async.c:118
> #13 0x00005610e4582cf4 in aio_poll (ctx=ctx@entry=0x5610e5d92860, blocking=<optimized out>) at util/aio-posix.c:682
> #14 0x00007f8624848299 in curl_init_state (bs=<optimized out>, s=s@entry=0x5610e5defb10) at block/curl.c:490
> #15 0x00007f8624848a51 in curl_readv_bh_cb (p=0x5610e77d6ec0)
>     at block/curl.c:871
> #16 0x00005610e457fb1e in aio_bh_call (bh=0x5610e7229960) at util/async.c:90
> #17 0x00005610e457fb1e in aio_bh_poll (ctx=ctx@entry=0x5610e5d92860)
>     at util/async.c:118
> #18 0x00005610e4582cf4 in aio_poll (ctx=ctx@entry=0x5610e5d92860, blocking=<optimized out>) at util/aio-posix.c:682
> #19 0x00007f8624848299 in curl_init_state (bs=<optimized out>, s=s@entry=0x5610e5defb10) at block/curl.c:490
> #20 0x00007f8624848a51 in curl_readv_bh_cb (p=0x5610e7877220)
>     at block/curl.c:871
> #21 0x00005610e457fb1e in aio_bh_call (bh=0x5610e7054e20) at util/async.c:90
> #22 0x00005610e457fb1e in aio_bh_poll (ctx=ctx@entry=0x5610e5d92860)
>     at util/async.c:118
> #23 0x00005610e4582cf4 in aio_poll (ctx=ctx@entry=0x5610e5d92860, blocking=<optimized out>) at util/aio-posix.c:682
> #24 0x00007f8624848299 in curl_init_state (bs=<optimized out>, s=s@entry=0x5610e5defb10) at block/curl.c:490
> #25 0x00007f8624848a51 in curl_readv_bh_cb (p=0x5610e7903cb0)
>     at block/curl.c:871
> #26 0x00005610e457fb1e in aio_bh_call (bh=0x5610e7903d10) at util/async.c:90
> #27 0x00005610e457fb1e in aio_bh_poll (ctx=ctx@entry=0x5610e5d92860)
>     at util/async.c:118
> #28 0x00005610e4582cf4 in aio_poll (ctx=ctx@entry=0x5610e5d92860, blocking=<optimized out>) at util/aio-posix.c:682
> #29 0x00007f8624848299 in curl_init_state (bs=<optimized out>, s=s@entry=0x5610e5defb10) at block/curl.c:490
> #30 0x00007f8624848a51 in curl_readv_bh_cb (p=0x5610e7146fb0)
>     at block/curl.c:871
> #31 0x00005610e457fb1e in aio_bh_call (bh=0x5610e70593d0) at util/async.c:90
> #32 0x00005610e457fb1e in aio_bh_poll (ctx=ctx@entry=0x5610e5d92860)
>     at util/async.c:118
> #33 0x00005610e45829c0 in aio_dispatch (ctx=0x5610e5d92860)
>     at util/aio-posix.c:429
> #34 0x00005610e457f9fe in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:261
> #35 0x00007f863235d1d7 in g_main_context_dispatch () at /lib64/libglib-2.0.so.0
> #36 0x00005610e4581c17 in glib_pollfds_poll () at util/main-loop.c:213
> #37 0x00005610e4581c17 in os_host_main_loop_wait (timeout=<optimized out>)
>     at util/main-loop.c:261
> #38 0x00005610e4581c17 in main_loop_wait (nonblocking=<optimized out>)
>     at util/main-loop.c:517
> #39 0x00005610e41c3ad1 in main_loop () at vl.c:1899
> #40 0x00005610e41c3ad1 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4719
> 
> 
> -- 
> Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
> Read my programming and virtualization blog: http://rwmj.wordpress.com
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