[Qemu-devel] [Bug 1087590] Re: gdbstub step instruction locks up on OS X

[Peter Maydell]

With current git master, does the bug still occur if you add '--with-
coroutine=sigaltstack' to your configure line?

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1087590

Title:
  gdbstub step instruction locks up on OS X

Status in QEMU:
  New

Bug description:
  OS X 10.8.2
  (Darwin Niels-MacBook-Air.local 12.2.0 Darwin Kernel Version 12.2.0: Sat Aug 
25 00:48:52 PDT 2012; root:xnu-2050.18.24~1/RELEASE_X86_64 x86_64)

  -Only seems to occur with a drive attached

  -To reproduce (from current git master):

  ./configure --cc=clang --enable-debug --disable-user 
--target-list=i386-softmmu
  i386-softmmu/qemu-system-i386 -drive file=~/tmp.qcow2,index=0,media=disk -s -S

  #wait several seconds

  gdb
      target remote localhost:1234
      si

  #qemu locks up, requires kill -9

  -Bisected it to:
  commit 47e6b251a5e9a47c406f2f2c0b01bb88854c98ec
  Author: Paolo Bonzini <address@hidden>
  Date:   Thu May 24 18:03:13 2012 +0200

      block: switch posix-aio-compat to threadpool

      This is not meant for portability, but to remove code duplication.

      Signed-off-by: Paolo Bonzini <address@hidden>

  (cherry picking 1f001dc7bc9e435bf231a5b0edcad1c7c2bd6214,
  c166cb72f1676855816340666c3b618beef4b976 and
  1d8ddda045b4b72dc95a325debb6df0fc19ec821 as needed to keep it
  building, which was kinda dodgy).

  -Trackback while locked up:
  Thread 9 (process 49143):
  #0  0x00007fff93dcd0fa in __psynch_cvwait ()
  #1  0x00007fff931c0f89 in _pthread_cond_wait ()
  #2  0x0000000100202363 in qemu_sem_timedwait (sem=0x1009a6678, ms=10000) at 
qemu-thread-posix.c:214
  #3  0x000000010023017e in worker_thread (unused=0x0) at thread-pool.c:88
  #4  0x00007fff931bc742 in _pthread_start ()
  #5  0x00007fff931a9181 in thread_start ()

  Thread 8 (process 49143):
  #0  0x00007fff93dcd0fa in __psynch_cvwait ()
  #1  0x00007fff931c0f89 in _pthread_cond_wait ()
  #2  0x0000000100ffab83 in g_cond_wait ()
  #3  0x0000000100074aa5 in coroutine_wait_runnable_locked (co=0x1032361d0) at 
coroutine-gthread.c:133
  #4  0x00000001000749fe in qemu_coroutine_switch (from_=0x1032361d0, 
to_=0x103024200, action=COROUTINE_YIELD) at coroutine-gthread.c:191
  #5  0x00000001001f8fbc in coroutine_swap (from=0x1032361d0, to=0x103024200) 
at qemu-coroutine.c:31
  #6  0x00000001001f90b5 in qemu_coroutine_yield () at qemu-coroutine.c:74
  #7  0x0000000100024238 in bdrv_co_flush (bs=0x104007c00) at block.c:4023
  #8  0x00000001000244ae in bdrv_flush_co_entry (opaque=0x103480d80) at 
block.c:3987
  #9  0x000000010001d142 in bdrv_flush (bs=0x104007c00) at block.c:4086
  #10 0x000000010003554a in qcow2_cache_flush (bs=0x10281e600, c=0x10183cd60) 
at block/qcow2-cache.c:151
  #11 0x0000000100041f69 in qcow2_co_flush_to_os (bs=0x10281e600) at 
block/qcow2.c:1559
  #12 0x000000010002415a in bdrv_co_flush (bs=0x10281e600) at block.c:4000
  #13 0x00000001000244ae in bdrv_flush_co_entry (opaque=0x7fff5fbfe320) at 
block.c:3987
  #14 0x00000001000748a2 in coroutine_thread (opaque=0x1032361d0) at 
coroutine-gthread.c:150
  #15 0x0000000100fdf8fa in g_thread_proxy ()
  #16 0x00007fff931bc742 in _pthread_start ()
  #17 0x00007fff931a9181 in thread_start ()

  Thread 7 (process 49143):
  #0  0x00007fff93dcd122 in __psynch_mutexwait ()
  #1  0x00007fff931c1d9d in pthread_mutex_lock ()
  #2  0x00007fff931c1017 in _pthread_cond_wait ()
  #3  0x000000010020205b in qemu_cond_wait (cond=0x10322db90, 
mutex=0x1009b6640) at qemu-thread-posix.c:116
  #4  0x000000010027770a in qemu_tcg_wait_io_event () at cpus.c:708
  #5  0x000000010027747b in qemu_tcg_cpu_thread_fn (arg=0x10381d200) at 
cpus.c:845
  #6  0x00007fff931bc742 in _pthread_start ()
  #7  0x00007fff931a9181 in thread_start ()

  Thread 6 (process 49143):
  #0  0x00007fff93dcd57a in __sigwait ()
  #1  0x00007fff93246e4d in sigwait ()
  #2  0x000000010006eca9 in sigwait_compat (opaque=0x101c253a0) at compatfd.c:40
  #3  0x00007fff931bc742 in _pthread_start ()
  #4  0x00007fff931a9181 in thread_start ()

  Thread 3 (process 49143):
  #0  0x00007fff93dcdd16 in kevent ()
  #1  0x00007fff8bb78dea in _dispatch_mgr_invoke ()
  #2  0x00007fff8bb789ee in _dispatch_mgr_thread ()

  Thread 1 (process 49143):
  #0  0x00007fff93dcd322 in select$DARWIN_EXTSN ()
  #1  0x0000000100004a50 in aio_poll (ctx=0x101c253f0, blocking=true) at 
aio-posix.c:230
  #2  0x00000001001bb857 in qemu_aio_wait () at main-loop.c:449
  #3  0x000000010001d181 in bdrv_flush (bs=0x10281e600) at block.c:4091
  #4  0x0000000100020fc8 in bdrv_flush_all () at block.c:2685
  #5  0x0000000100276642 in do_vm_stop (state=RUN_STATE_DEBUG) at cpus.c:446
  #6  0x00000001002765c5 in vm_stop (state=RUN_STATE_DEBUG) at cpus.c:1078
  #7  0x000000010026e850 in main_loop_should_exit () at vl.c:1718
  #8  0x000000010026e77c in main_loop () at vl.c:1774
  #9  0x0000000100268eed in qemu_main (argc=9, argv=0x7fff5fbffa40, 
envp=0x7fff5fbffa90) at vl.c:3999
  #10 0x0000000100234509 in -[QemuCocoaAppController 
startEmulationWithArgc:argv:] (self=0x101804a90, _cmd=0x1003c7f05, argc=9, 
argv=0x7fff5fbffa40) at ui/cocoa.m:798
  #11 0x0000000100234421 in -[QemuCocoaAppController 
applicationDidFinishLaunching:] (self=0x101804a90, _cmd=0x7fff93597f79, 
note=0x101c218f0) at ui/cocoa.m:776
  #12 0x00007fff952f647a in _CFXNotificationPost ()
  #13 0x00007fff959f0846 in -[NSNotificationCenter 
postNotificationName:object:userInfo:] ()
  #14 0x00007fff8cc6560d in -[NSApplication _postDidFinishNotification] ()
  #15 0x00007fff8cc65346 in -[NSApplication _sendFinishLaunchingNotification] ()
  #16 0x00007fff8cc62532 in -[NSApplication(NSAppleEventHandling) 
_handleAEOpenEvent:] ()
  #17 0x00007fff8cc6212c in -[NSApplication(NSAppleEventHandling) 
_handleCoreEvent:withReplyEvent:] ()
  #18 0x00007fff95a0a12b in -[NSAppleEventManager 
dispatchRawAppleEvent:withRawReply:handlerRefCon:] ()
  #19 0x00007fff95a09f8d in _NSAppleEventManagerGenericHandler ()
  #20 0x00007fff8bc2cb48 in aeDispatchAppleEvent ()
  #21 0x00007fff8bc2c9a9 in dispatchEventAndSendReply ()
  #22 0x00007fff8bc2c869 in aeProcessAppleEvent ()
  #23 0x00007fff9609d8e9 in AEProcessAppleEvent ()
  #24 0x00007fff8cc5e916 in _DPSNextEvent ()
  #25 0x00007fff8cc5ded2 in -[NSApplication 
nextEventMatchingMask:untilDate:inMode:dequeue:] ()
  #26 0x00007fff8cc55283 in -[NSApplication run] ()
  #27 0x00000001002353f6 in main (argc=9, argv=0x7fff5fbffa40) at ui/cocoa.m:946

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1087590/+subscriptions