[Pkg-uml-pkgs] Bug#495611: user-mode-linux: page_mapcount(page) went negative!

Graham Cobb g+debian at cobb.uk.net
Mon Aug 18 23:05:09 UTC 2008


Package: user-mode-linux
Version: 2.6.24-1um-1
Severity: normal

I use Debian lenny guest environment in UML to automatically build software 
for the Nokia Maemo environment.

The overnight all work fine using UML 2.6.24-1um-1.  However, UML 
2.6.25-1um-2 and UML 2.6.26-1um-2 both crash, early in each build, with
the kernel panic shown below.  I can easily reproduce this with my automated 
build system although I have not yet found another stress test (even doing a 
kernel build in the guest environment) which reproduces it.

The crash details are:

Eeek! page_mapcount(page) went negative! (-1)
  page pfn = 2cc
  page->flags = 400
  page->count = 1
  page->mapping = 00000000
  vma->vm_ops = 0x83accc8
  vma->vm_ops->fault = special_mapping_fault+0x0/0x60
BUG: failure at mm/rmap.c:669/page_remove_rmap()!
Kernel panic - not syncing: BUG!

EIP: 0073:[<080a407a>] CPU: 0 Not tainted ESP: 007b:bf9ec8fc EFLAGS: 00000246
    Not tainted
EAX: ffffffda EBX: 00008000 ECX: 001b6000 EDX: 00000005
ESI: 00000812 EDI: 00000004 EBP: 00000000 DS: 007b ES: 007b
277ebd38:  [<0809ec74>] notifier_call_chain+0x34/0x70
277ebd5c:  [<08311f2a>] panic+0x71/0xff
277ebd78:  [<080cb4e1>] page_remove_rmap+0x151/0x160
277ebd90:  [<080c3f99>] unmap_vmas+0x2c9/0x600
277ebda4:  [<08060fd3>] flush_tlb_page+0x113/0x1f0
277ebdf8:  [<080c7895>] unmap_region+0xa5/0x150
277ebe2c:  [<080c8a98>] do_munmap+0x1d8/0x290
277ebe58:  [<080c9544>] mmap_region+0xd4/0x590
277ebe90:  [<080c7230>] arch_get_unmapped_area+0x0/0x160
277ebeb8:  [<080b4870>] generic_file_mmap+0x0/0x60
277ebec4:  [<080c9c1a>] do_mmap_pgoff+0x21a/0x300
277ebf00:  [<08060846>] sys_mmap2+0x76/0xe0
277ebf30:  [<080627aa>] handle_syscall+0x8a/0xc0
277ebf4c:  [<080607d0>] sys_mmap2+0x0/0xe0
277ebf78:  [<080789ca>] userspace+0x48a/0x510
277ebf90:  [<08075675>] os_set_thread_area+0x25/0x50
277ebfec:  [<0805f72d>] fork_handler+0x5d/0x70


-- System Information:
Debian Release: lenny/sid
  APT prefers testing
  APT policy: (900, 'testing')
Architecture: i386 (i686)

Kernel: Linux 2.6.25-2-686 (SMP w/1 CPU core)
Locale: LANG=en_IE at euro, LC_CTYPE=en_IE at euro (charmap=ISO-8859-15) (ignored: LC_ALL set to en_IE at euro)
Shell: /bin/sh linked to /bin/bash

Versions of packages user-mode-linux depends on:
ii  uml-utilities               20070815-1.1 User-mode Linux (utility programs)

user-mode-linux recommends no packages.

Versions of packages user-mode-linux suggests:
ii  konsole [x-terminal- 4:3.5.9.dfsg.1-2+b1 X terminal emulator for KDE
pn  linux-patch-skas     <none>              (no description available)
pn  rootstrap            <none>              (no description available)
ii  rxvt [x-terminal-emu 1:2.6.4-14          VT102 terminal emulator for the X 
pn  slirp                <none>              (no description available)
pn  user-mode-linux-doc  <none>              (no description available)
ii  xterm [x-terminal-em 235-1               X terminal emulator

-- no debconf information





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