breakpoints/2467: Segmentation fault after setting watchpoint in kvm amd64 kernel

breakpoints/2467: Segmentation fault after setting watchpoint in kvm amd64 kernel

[joern]

>Number:         2467
>Category:       breakpoints
>Synopsis:       Segmentation fault after setting watchpoint in kvm amd64 kernel
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jun 11 21:18:01 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     joern@logfs.org
>Release:        GNU gdb 6.8-debian
>Organization:
>Environment:
Latest debian unstable for amd64
kvm running an amd64 kernel with 32bit userspace
>Description:
Simply setting a watchpoint on a kernel address and continuing will cause a segfault in gdb.
>How-To-Repeat:
$ gdb vmlinux
GNU gdb 6.8-debian
Copyright (C) 2008 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"...
(no debugging symbols found)
(gdb) target remote localhost:1234
Remote debugging using localhost:1234
0xffffffff80209f19 in default_idle ()
(gdb) watch (*(long*)0xffffffff80582558)
Hardware watchpoint 1: *(long *) 18446744071567844696
(gdb) c
Continuing.
Segmentation fault
joern@Dublin:/usr/src/kernel/foo/logfs$ 
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: