Re: [Qemu-devel] Patch Round-up for stable 1.4.1, freeze next Tuesday

[mdroth <mdroth@linux.vnet.ibm.com>]

On Thu, Apr 04, 2013 at 07:55:02AM +0200, Peter Lieven wrote:
> On 02.04.2013 23:45, Michael Roth wrote:
> >Hi everyone,
> >
> >The following new patches are queued for QEMU stable v1.4.1:
> >
> >https://github.com/mdroth/qemu/commits/stable-1.4-staging
> >
> >The release is planned for 04-15-2013:
> >
> >http://wiki.qemu.org/Planning/1.4
> >
> >Please CC qemu-stable@nongnu.org on any patches you think should be
> >included in the release. The cut-off date is 04-09-2013 for new patches.
> >
> >Testing/feedback is greatly appreciated.
> Please include
> 
> 5c91668 Revert "block: complete all IOs before .bdrv_truncate"
> 92b7a08 block: complete all IOs before resizing a device
> 142c6b1 vl.c: call bdrv_init_with_whitelist() before cmdline parsing

This one ^ causes a segfault on top of 1.4.0:

mdroth@loki:~/w/qemu-build-stable$ gdb --args x86_64-softmmu/qemu-system-x86_64 
GNU gdb (Ubuntu/Linaro 7.4-2012.04-0ubuntu2.1) 7.4-2012.04
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://bugs.launchpad.net/gdb-linaro/>...
Reading symbols from /home/mdroth/dev/kvm/qemu-build-stable/x86_64-softmmu/qemu-system-x86_64...done.
(gdb) run
Starting program: /home/mdroth/dev/kvm/qemu-build-stable/x86_64-softmmu/qemu-system-x86_64 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
aio_set_fd_handler (ctx=0x0, fd=8, io_read=0x55555570a2d0 <event_notifier_ready>, io_write=0, 
    io_flush=0x55555570a1d0 <thread_pool_active>, opaque=0x55555600b9e0)
    at /home/mdroth/w/qemu-stable.git/aio-posix.c:269
269 }
(gdb) bt
#0  aio_set_fd_handler (ctx=0x0, fd=8, io_read=0x55555570a2d0 <event_notifier_ready>, io_write=0, 
    io_flush=0x55555570a1d0 <thread_pool_active>, opaque=0x55555600b9e0)
    at /home/mdroth/w/qemu-stable.git/aio-posix.c:269
#1  0x000055555570a27d in thread_pool_init () at /home/mdroth/w/qemu-stable.git/thread-pool.c:282
#2  0x000055555583529a in module_call_init (type=<optimized out>)
    at /home/mdroth/w/qemu-stable.git/util/module.c:79
#3  0x00005555555c6ad1 in main (argc=1, argv=0x7fffffffe3c8, envp=<optimized out>)
    at /home/mdroth/w/qemu-stable.git/vl.c:2890
(gdb)


>From what I can tell initialization to before qemu_init_main_loop() causes
thread-pools block_init() function to get called before qemu_aio_context is
set. This isn't an issue upstream due to the following patch:

f7311ccc630d925e7351e9440b7ad8bc6f0a51de

Which I think is out of scope for stable. Not sure what the right approach is
here.

> 
> Peter
>