hardware watchpoint does not stop with the value modified

Dear GDB Developers and Users,

I'd like you to help me solve one problem, hardware watchpoint does not
stop at particular memory address.

I have debugged QEMU, the VM emulator, with gdb, and set a watchpoint to a
certain memory address. However, gdb does not stop while the value at the
address is changed. Why? I want to know why this happened.

Would you tell me that?


The following is the gdb history.

Best regards,
Yuya Kobayashi

$ gdb --args ./qemu-system-x86_64 -m 512 -hda linux-0.2.mg

...

(gdb) x 0x7fffbbe8e000
0x7fffbbe8e000: 0x00000000
(gdb) watch *(int *)0x7fffbbe8e000 Hardware watchpoint 1: *(int
*)0x7fffbbe8e000
(gdb) c Continuing.
[Thread 0x7fffc2dad700 (LWP 3162) exited]
[New Thread 0x7fffc2dad700 (LWP 3169)]
[Thread 0x7fffc2dad700 (LWP 3169) exited]
[New Thread 0x7fffc2dad700 (LWP 3173)] qemu:
/home/nutsman/git_repo/M-QEMU/qemu-2.3.1/exec.c:3007: ldl_phys_internal:
Assertion `val1 == val' failed.
Program received signal SIGABRT, Aborted.
[Switching to Thread 0x7fffc23ca700 (LWP 3163)] 0x00007ffff61f4cc9 in
__GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
56 ../nptl/sysdeps/unix/sysv/linux/raise.c: no such a file or directory
(gdb) x 0x7fffbbe8e000
0x7fffbbe8e000: 0x6c7cebfa