Re: [Qemu-devel] tpm-tis-test and tpm-crb-test crash on OSX

[Stefan Berger <stefanb@linux.vnet.ibm.com>]

On 03/16/2018 09:41 AM, Marc-André Lureau wrote:
> Hi
>
> On Fri, Mar 16, 2018 at 2:37 PM, Marc-André Lureau
> <marcandre.lureau@gmail.com> wrote:
>> Hi
>>
>> On Fri, Mar 16, 2018 at 2:27 PM, Daniel P. Berrangé <berrange@redhat.com> wrote:
>>> On Fri, Mar 16, 2018 at 01:24:53PM +0000, Peter Maydell wrote:
>>>> On 16 March 2018 at 13:12, Peter Maydell <peter.maydell@linaro.org> wrote:
>>>>> On OSX host, I noticed that tpm-tis-test and tpm-crb-test
>>>>> both crash on OSX, hitting an error_abort case:
>>>>>
>>>>> (lldb) run
>>>>> Process 65115 launched:
>>>>> '/Users/pm215/src/qemu-for-merges/build/all/tests/tpm-tis-test'
>>>>> (x86_64)
>>>>> /i386/tpm-tis/test_check_localities: OK
>>>>> /i386/tpm-tis/test_check_access_reg: OK
>>>>> /i386/tpm-tis/test_check_access_reg_seize: OK
>>>>> /i386/tpm-tis/test_check_access_reg_release: OK
>>>>> /i386/tpm-tis/test_check_transmit: OK
>>>>> Unexpected error in qio_channel_socket_readv() at
>>>>> /Users/pm215/src/qemu-for-merges/io/channel-socket.c:494:
>>>>> Unable to read from socket: Bad file descriptor
>>>>>
>>>>> Here's a backtrace from tpm-tis-test:
>>>> Dan suggested a race condition, which prompted me to get an
>>>> all-threads backtrace:
>>>>
>>>>    thread #1: tid = 0xb50f19, 0x00007fff7eb97502
>>>> libsystem_kernel.dylib`__wait4 + 10, queue = 'com.apple.main-thread'
>>>>      frame #0: 0x00007fff7eb97502 libsystem_kernel.dylib`__wait4 + 10
>>>>      frame #1: 0x000000010001b303 tpm-tis-test`qtest_quit [inlined]
>>>> kill_qemu(s=<unavailable>) + 99 at libqtest.c:107
>>>>      frame #2: 0x000000010001b2df
>>>> tpm-tis-test`qtest_quit(s=0x0000000100404c60) + 63 at libqtest.c:280
>>>>      frame #3: 0x0000000100001bd1 tpm-tis-test`main [inlined] qtest_end
>>>> + 9 at libqtest.h:555
>>>>      frame #4: 0x0000000100001bc8 tpm-tis-test`main(argc=<unavailable>,
>>>> argv=<unavailable>) + 520 at tpm-tis-test.c:477
>>>>      frame #5: 0x00007fff7ea47115 libdyld.dylib`start + 1
>>>>      frame #6: 0x00007fff7ea47115 libdyld.dylib`start + 1
>>>>
>>>>    thread #3: tid = 0xb50f4a, 0x00007fff7eb977d2
>>>> libsystem_kernel.dylib`close + 10
>>>>      frame #0: 0x00007fff7eb977d2 libsystem_kernel.dylib`close + 10
>>>>      frame #1: 0x0000000100007def
>>>> tpm-tis-test`qio_channel_socket_close(ioc=<unavailable>,
>>>> errp=0x000000010006c930) + 63 at channel-socket.c:693
>>>>      frame #2: 0x00000001000039f9
>>>> tpm-tis-test`tpm_emu_ctrl_thread(data=0x00007ffeefbff0e8) + 713 at
>>>> tpm-emu.c:128
>>>>      frame #3: 0x00000001001b2ec0 libglib-2.0.0.dylib`g_thread_create_proxy + 191
>>>>      frame #4: 0x00007fff7ecd26c1 libsystem_pthread.dylib`_pthread_body + 340
>>>>      frame #5: 0x00007fff7ecd256d libsystem_pthread.dylib`_pthread_start + 377
>>>>      frame #6: 0x00007fff7ecd1c5d libsystem_pthread.dylib`thread_start + 13
>>>>
>>>> * thread #2: tid = 0xb50f50, 0x00007fff7eb96e3e
>>>> libsystem_kernel.dylib`__pthread_kill + 10
>>>>    * frame #0: 0x00007fff7eb96e3e libsystem_kernel.dylib`__pthread_kill + 10
>>>>      frame #1: 0x00007fff7ecd5150 libsystem_pthread.dylib`pthread_kill + 333
>>>>      frame #2: 0x00007fff7eaf3312 libsystem_c.dylib`abort + 127
>>>>      frame #3: 0x0000000100043431 tpm-tis-test`error_setv [inlined]
>>>> error_handle_fatal(errp=<unavailable>) + 43 at error.c:38
>>>>      frame #4: 0x0000000100043406
>>>> tpm-tis-test`error_setv(errp=<unavailable>, src=<unavailable>,
>>>> line=<unavailable>, func=<unavailable>,
>>>> err_class=ERROR_CLASS_GENERIC_ERROR, fmt=<unavailable>,
>>>> ap=<unavailable>, suffix=<unavailable>) + 246 at error.c:71
>>>>      frame #5: 0x00000001000435db
>>>> tpm-tis-test`error_setg_errno_internal(errp=0x000000010006c930,
>>>> src="/Users/pm215/src/qemu-for-merges/io/channel-socket.c", line=494,
>>>> func="qio_channel_socket_readv", os_errno=<unavailable>, fmt="Unable
>>>> to read from socket") + 219 at error.c:111
>>>>      frame #6: 0x0000000100007ba5
>>>> tpm-tis-test`qio_channel_socket_readv(ioc=<unavailable>,
>>>> iov=<unavailable>, niov=<unavailable>, fds=0x0000000000000000,
>>>> nfds=0x0000000000000000, errp=0x000000010006c930) + 341 at
>>>> channel-socket.c:493
>>>>      frame #7: 0x0000000100004717 tpm-tis-test`qio_channel_read
>>>> [inlined] qio_channel_readv_full(ioc=0x00000001007006b0,
>>>> iov=<unavailable>, niov=1, fds=<unavailable>, nfds=<unavailable>,
>>>> errp=0x000000010006c930) + 62 at channel.c:65
>>>>      frame #8: 0x00000001000046d9
>>>> tpm-tis-test`qio_channel_read(ioc=0x00000001007006b0,
>>>> buf=<unavailable>, buflen=<unavailable>, errp=<unavailable>) + 41 at
>>>> channel.c:216
>>>>      frame #9: 0x0000000100003dd1
>>>> tpm-tis-test`tpm_emu_tpm_thread(data=0x00007ffeefbff0e8) + 241 at
>>>> tpm-emu.c:41
>>>>      frame #10: 0x00000001001b2ec0
>>>> libglib-2.0.0.dylib`g_thread_create_proxy + 191
>>>>      frame #11: 0x00007fff7ecd26c1 libsystem_pthread.dylib`_pthread_body + 340
>>>>      frame #12: 0x00007fff7ecd256d libsystem_pthread.dylib`_pthread_start + 377
>>>>      frame #13: 0x00007fff7ecd1c5d libsystem_pthread.dylib`thread_start + 13
>>>>
>>>>
>>>> My guess is that the problem here is that the tpm_emu_ctrl_thread (thread 3) is
>>>> forcibly closing the channel, which causes the tpm_emu_thread (thread 2)
>>>> to abort because its read returned an error.
>>> At least the tpm_emu_tpm_thread() there is only something in the test
>>> suite, so the real system emulator code isn't at risk of crashing.
>>>
>>> Feels like the thread simply should *not* use error_abort, and instead
>>> have a more graceful way to exit when the socket closes
>>>
>> The code expects the read() to return 0 on disconnect, not an error.
>> Apparently this works on !osx. Should we adapt qio-channel-socket to
>> return 0 in this case on osx too?
> Oh I see, it calls close() on the same end, that's not correct. I
> wonder if shutdown would be better. Other suggestions?
>
We could send the thread a special message, like 0xff ff ff ff, and that 
terminates it...

     Stefan