qemu-system-x86_64: stuck on watchpoint hit
Host environment
- Operating system: Ubuntu 2022.04
- OS/kernel version: 5.15.0-86-generic
- Architecture: x86
- QEMU flavor: qemu-system-x86_64
- QEMU version: 8.2.92 (v9.0.0-rc2-7-g786fd793b8
- QEMU command line:
./qemu-system-x86_64 -nographic -object rng-random,filename=/dev/urandom,id=rng0 -device virtio-rng-pci,rng=rng0 -drive file=./tmp/deploy/images/qemux86-64/core-image-minimal-qemux86-64.rootfs.ext4,if=virtio,format=raw -cpu max -smp 1 -m 4G -kernel ./tmp/deploy/images/qemux86-64/bzImage -append 'root=/dev/vda rw mem=4G'
Emulated/Virtualized environment
- Operating system: Yocto current build
- OS/kernel version: Linux qemux86-64 6.5.13-yocto-standard
- Architecture: x86
Description of problem
Steps to reproduce
gcc -O0 -g watch-bug.c -o watch-bug
gdb watch-bug
- gdb commands:
b main
r
watch l1
next [ correct stop on the next line ]
next [ qemu is stuck as watchpoint should be hit ]
Additional information
- NOTE: it works correctly, if 'continue' command is used instead of 'next'
watch-bug.c
int i0;
long l1;
int main(int argc, char* argv[])
{
i0 = argc;
l1 = i0 * 7;
return 0;
}
Log:
Log:
root@qemux86-64:~# gdb watch-bug
GNU gdb (GDB) 13.2
Copyright (C) 2023 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-poky-linux".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from watch-bug...
(gdb) b main
Breakpoint 1 at 0x1134: file watch-bug.c, line 8.
(gdb) r
Starting program: /home/root/watch-bug
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/libthread_db.so.1".
Breakpoint 1, main (argc=1, argv=0x7fffffffecd8) at watch-bug.c:8
8 i0 = argc;
(gdb) watch l1
Hardware watchpoint 2: l1
(gdb) next
9 l1 = i0 * 7;
(gdb) next