[Qemu-devel] [Bug 898474] Re: aptitude in a lucid-based qemu-arm-static chroot segfaults/hangs, but works on real h/w

[Matt Fischer]

One more bit of info:

There is a similar bug posted here, although they retitled it and
chalked it up to an unsupported platform:  http://bugs.debian.org/cgi-
bin/bugreport.cgi?bug=641270


** Bug watch added: Debian Bug tracker #641270
   http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=641270

** Description changed:

  Running aptitude in a lucid-based chroot qemu-arm-static on top of
  amd64/oneiric segfaults/hangs.   I get the segfault output about 30% of
  the time, the rest of the time the problem exhibits as a hang.   The
  same commands work fine on a real armel platform (armv7l) running the
  same package versions as the chroot.
  
  Every command I have tried exhibits this behavior except for:
  
  aptitude help
  aptitude moo
  
  Two simple commands that exhibit this behavior are:
  
  aptitude show totem
  aptitude hold
  aptitude (no args to launch GUI)
- 
  
  Here is an example of the output:
  
  address@hidden:/# aptitude show totem
  Segmentation fault (core dumped)
  address@hidden:/# aptitude show totem
  <hangs here>
  ^C
  address@hidden:/# aptitude show totem
  Segmentation fault (core dumped)
  address@hidden:/# aptitude show totem
  <hangs here>
  ^C
  address@hidden:/# aptitude show totem
  <hangs here>
  ^C
  address@hidden:/# aptitude show totem
  Segmentation fault (core dumped)
  
- 
- Through printf debugging, I have traced the issue to the following area (if 
you're looking at the case of "aptitude show totem" command).  Basically, we 
never make it into many of these cmdline_xxxx calls.  I suspect the stack might 
be corrupt, but cannot verify that:
+ Through printf debugging, I have traced the issue to the following area
+ (if you're looking at the case of "aptitude show totem" command).
+ Basically, we never make it into many of these cmdline_xxxx calls.  I
+ suspect the stack might be corrupt, but cannot verify that:
  
  Code snippet:
  
  aptitude/src/main.cc:
-      else if(!strcasecmp(argv[optind], "show")) {
-          printf("we get here");
-         return cmdline_show(argc-optind, argv+optind, verbose);
+      else if(!strcasecmp(argv[optind], "show")) {
+          printf("we get here");
+         return cmdline_show(argc-optind, argv+optind, verbose);
  }
  
  aptitude/src/cmdline/cmdline_show.cc:
  int cmdline_show(int argc, char *argv[], int verbose)
  {
-       printf("We never get here!");
-   _error->DumpErrors();
+       printf("We never get here!");
+   _error->DumpErrors();
  ...
  
  
-------------------------------------------------------------------------------------------------------------------------------------
  Versions:
  
  chroot guest:
  address@hidden:/# uname -a
  Linux caprica 3.0.0-13-generic #22-Ubuntu SMP Wed Nov 2 13:27:26 UTC 2011 
armv7l GNU/Linux
  address@hidden:/# apt-cache policy aptitude
  aptitude:
-   Installed: 0.4.11.11-1ubuntu10
-   Candidate: 0.4.11.11-1ubuntu10
-   Version table:
-  *** 0.4.11.11-1ubuntu10 0
-         500 http://ports.ubuntu.com/ubuntu-ports/ lucid/main Packages
-         100 /var/lib/dpkg/status
- 
+   Installed: 0.4.11.11-1ubuntu10
+   Candidate: 0.4.11.11-1ubuntu10
+   Version table:
+  *** 0.4.11.11-1ubuntu10 0
+         500 http://ports.ubuntu.com/ubuntu-ports/ lucid/main Packages
+         100 /var/lib/dpkg/status
  
  Host:
- address@hidden:~/Projects/charlotte-armel$ uname -a
- Linux caprica 3.0.0-13-generic #22-Ubuntu SMP Wed Nov 2 13:27:26 UTC 2011 
x86_64 x86_64 x86_64 GNU/Linux
- address@hidden:~/Projects/charlotte-armel$ apt-cache policy qemu
- qemu:
-   Installed: (none)
-   Candidate: 0.14.1+noroms-0ubuntu6
+ address@hidden:~/Projects/charlotte-armel$ apt-cache policy qemu-user-static
+ qemu-user-static:
+   Installed: 0.15.50-2011.10-0ubuntu1~ppa11.10.1
+   Candidate: 0.15.50-2011.10-0ubuntu1~ppa11.10.1
    Version table:
-      0.14.1+noroms-0ubuntu6 0
+  *** 0.15.50-2011.10-0ubuntu1~ppa11.10.1 0
+         500 http://ppa.launchpad.net/linaro-maintainers/tools/ubuntu/ 
oneiric/main amd64 Packages
+         100 /var/lib/dpkg/status
+      0.15.50-2011.08-0ubuntu4 0
          500 http://us.archive.ubuntu.com/ubuntu/ oneiric/universe amd64 
Packages
- 
  
  
-------------------------------------------------------------------------------------------------------------------------------------
  Things I've tried:
- I have been unable to get any useful info via gdb, local or remote.  
+ I have been unable to get any useful info via gdb, local or remote.
  I have been unable to reproduce this using a stripped down copy of main.
  The core file I generated was deemed unusable by gdb.
  I do not have a syslog inside the chroot (it was suggested that I post the 
syslog from the guest).
  There is nothing in the host's syslog to indicate that the OOM killer was 
running.
  
  I am attaching two stack traces for two different commands.  In both of
  those cases the problem exhibited as a hang.
  
  I realize that this bug might lack some details/debugging info that you
  need, so if you need more details or need me to test anything, please
  contact me on IRC or via email.

** Project changed: qemu => qemu-linaro

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https://bugs.launchpad.net/bugs/898474

Title:
  aptitude in a lucid-based qemu-arm-static chroot segfaults/hangs, but
  works on real h/w

Status in Linaro QEMU:
  New

Bug description:
  Running aptitude in a lucid-based chroot qemu-arm-static on top of
  amd64/oneiric segfaults/hangs.   I get the segfault output about 30%
  of the time, the rest of the time the problem exhibits as a hang.
  The same commands work fine on a real armel platform (armv7l) running
  the same package versions as the chroot.

  Every command I have tried exhibits this behavior except for:

  aptitude help
  aptitude moo

  Two simple commands that exhibit this behavior are:

  aptitude show totem
  aptitude hold
  aptitude (no args to launch GUI)

  Here is an example of the output:

  address@hidden:/# aptitude show totem
  Segmentation fault (core dumped)
  address@hidden:/# aptitude show totem
  <hangs here>
  ^C
  address@hidden:/# aptitude show totem
  Segmentation fault (core dumped)
  address@hidden:/# aptitude show totem
  <hangs here>
  ^C
  address@hidden:/# aptitude show totem
  <hangs here>
  ^C
  address@hidden:/# aptitude show totem
  Segmentation fault (core dumped)

  Through printf debugging, I have traced the issue to the following
  area (if you're looking at the case of "aptitude show totem" command).
  Basically, we never make it into many of these cmdline_xxxx calls.  I
  suspect the stack might be corrupt, but cannot verify that:

  Code snippet:

  aptitude/src/main.cc:
       else if(!strcasecmp(argv[optind], "show")) {
           printf("we get here");
          return cmdline_show(argc-optind, argv+optind, verbose);
  }

  aptitude/src/cmdline/cmdline_show.cc:
  int cmdline_show(int argc, char *argv[], int verbose)
  {
        printf("We never get here!");
    _error->DumpErrors();
  ...

  
-------------------------------------------------------------------------------------------------------------------------------------
  Versions:

  chroot guest:
  address@hidden:/# uname -a
  Linux caprica 3.0.0-13-generic #22-Ubuntu SMP Wed Nov 2 13:27:26 UTC 2011 
armv7l GNU/Linux
  address@hidden:/# apt-cache policy aptitude
  aptitude:
    Installed: 0.4.11.11-1ubuntu10
    Candidate: 0.4.11.11-1ubuntu10
    Version table:
   *** 0.4.11.11-1ubuntu10 0
          500 http://ports.ubuntu.com/ubuntu-ports/ lucid/main Packages
          100 /var/lib/dpkg/status

  Host:
  address@hidden:~/Projects/charlotte-armel$ apt-cache policy qemu-user-static
  qemu-user-static:
    Installed: 0.15.50-2011.10-0ubuntu1~ppa11.10.1
    Candidate: 0.15.50-2011.10-0ubuntu1~ppa11.10.1
    Version table:
   *** 0.15.50-2011.10-0ubuntu1~ppa11.10.1 0
          500 http://ppa.launchpad.net/linaro-maintainers/tools/ubuntu/ 
oneiric/main amd64 Packages
          100 /var/lib/dpkg/status
       0.15.50-2011.08-0ubuntu4 0
          500 http://us.archive.ubuntu.com/ubuntu/ oneiric/universe amd64 
Packages

  
-------------------------------------------------------------------------------------------------------------------------------------
  Things I've tried:
  I have been unable to get any useful info via gdb, local or remote.
  I have been unable to reproduce this using a stripped down copy of main.
  The core file I generated was deemed unusable by gdb.
  I do not have a syslog inside the chroot (it was suggested that I post the 
syslog from the guest).
  There is nothing in the host's syslog to indicate that the OOM killer was 
running.

  I am attaching two stack traces for two different commands.  In both
  of those cases the problem exhibited as a hang.

  I realize that this bug might lack some details/debugging info that
  you need, so if you need more details or need me to test anything,
  please contact me on IRC or via email.

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