[mythtv-commits] Ticket #9700: 0.24 Crash after Recording Finished with memory Corruption (glibc)

[MythTV]

#9700: 0.24 Crash after Recording Finished with memory Corruption (glibc)
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 Reporter:  flybrick@…                |          Owner:  danielk
     Type:  Bug Report - Crash        |         Status:  infoneeded_new
 Priority:  minor                     |      Milestone:  unknown
Component:  MythTV - Recording        |        Version:  0.24-fixes
 Severity:  medium                    |     Resolution:
 Keywords:                            |  Ticket locked:  0
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Comment (by flybrick@…):

 I am currently rebuilding with "--compile-type=profile" so as to generate
 a better backtrace from a core dump.  It tends to take several days to a
 week to crash.

 Unfortunately, I had already pulled the latest fixes/0.24, not the one
 that crashed here.


 In the meantime, I was able to extract a C++ mangled-name backtrace from
 the last crash, and tracing back through the code, it looks like it
 crashed in I am currently rebuilding with "--compile-type=profile" so as
 to generate a better backtrace from a core dump.  It tends to take several
 days to a week to crash.

 Unfortunately, I had already pulled the latest fixes/0.24, not the one
 that crashed here.


 In the meantime, I was able to extract a C++ mangled-name backtrace from
 the last crash.

 It looks like the crash is somehow entered in the method "''void
 DeviceReadBuffer::fill_ringbuffer(void)''" in DeviceReadBuffer.cpp, at one
 of the calls to ''lock.lock()'' (~line 256 or 304).

 From there, it just continues through libQtCore until glibc detects the
 memory corruption.  If it really is a memory corruption issue, it is quite
 possible it didn't occur anywhere in the call chain, but at some other
 unrelated point.

 {{{
 2011-03-28 23:01:00.737 scheduler: Finished recording: Castle "Law &
 Murder": channel 1013
 *** glibc detected *** /usr/bin/mythbackend: malloc(): memory corruption:
 0x09fc5c39 ***
 ======= Backtrace: =========
 /lib/tls/i686/cmov/libc.so.6(+0x6b591)[0x22cd591]
 /lib/tls/i686/cmov/libc.so.6(+0x6e395)[0x22d0395]
 /lib/tls/i686/cmov/libc.so.6(__libc_malloc+0xec)[0x22d202c]
 /usr/lib/libQtCore.so.4(_Z7qMallocj+0x1d)[0x7c5db8d]
 /usr/lib/libQtCore.so.4(_ZN10QByteArrayC1Eic+0x36)[0x7c65b66]
 /usr/lib/libQtCore.so.4(_Z15qt_error_stringi+0x59)[0x7c5a749]
 /usr/lib/libQtCore.so.4(+0x655ff)[0x7c625ff]
 /usr/lib/libQtCore.so.4(+0x65780)[0x7c62780]
 /usr/lib/libQtCore.so.4(_ZN6QMutex4lockEv+0x132)[0x7c5e052]
 /usr/lib/libmythtv-0.24.so.0(_ZN16DeviceReadBuffer15fill_ringbufferEv+0x2c)[0x12a449c]
 /lib/tls/i686/cmov/libc.so.6(clone+0x5e)[0x232fa4e]

 }}}

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Ticket URL: <http://code.mythtv.org/trac/ticket/9700#comment:3>
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