bitvisor-gdb
gdbserver implementation on Type1 Thin Hypervisor(BitVisor). You can debug Guest OS on BitVisor from your gdb on local machine.
Install
Firstly you need to download BitVisor. Plz read official document
To enable gdb remote debugging function, please edit defconfig as following.
struct config_data config = {
.ip = {
.ipaddr = { 192, 168, 0, 5 },
.netmask = { 255, 255, 255, 0 },
.gateway = { 192, 168, 0, 1 },
},
.driver = {
.pci = "driver=pro1000,net=ip,tty=1",
},
If you wrote config as above, gdb server waits client connection at 192.168.0.5 on Intel PRO/1000 hardware.
Usage
Then you can start system(ex. Linux kernel) debugging like:
$ gdb -q
(gdb) target remote 192.168.0.5:1234
Warning: not running or target is remote
0xffffffff81428f41 in ?? ()
(gdb) hb *0xffffffff81055ab0 #Set breakpiont to do_page_fault()
Hardware assisted breakpoint 1 at 0xffffffff81055ab0
(gdb) c
Continuing.
Breakpoint 1, 0xffffffff81055ab0 in ?? ()
(gdb) x/10i $rip
=> 0xffffffff81055ab0: nop DWORD PTR [rax+rax*1+0x0]
0xffffffff81055ab5: push rbp
0xffffffff81055ab6: mov rax,QWORD PTR gs:0xc440
0xffffffff81055abf: mov rbp,rsp
0xffffffff81055ac2: push r15
0xffffffff81055ac4: push r14
0xffffffff81055ac6: push r13
0xffffffff81055ac8: push r12
0xffffffff81055aca: mov r15,rdi
0xffffffff81055acd: push rbx
(gdb) i r
rax 0x81784987 0x81784987
rbx 0xffffffff81784987 0xffffffff81784987
rcx 0x7f48fde0b9d0 0x7f48fde0b9d0
rdx 0x1 0x1
rsi 0xffff880087cb3e70 0xffff880087cb3e70
rdi 0xffff880087cb3e78 0xffff880087cb3e78
rbp 0x3 0x3
rsp 0xffff880087cb3e88 0xffff880087cb3e88
r8 0xffff880087cb0000 0xffff880087cb0000
r9 0x0 0x0
r10 0x3 0x3
r11 0x32683 0x32683
r12 0xffffffff818176a0 0xffffffff818176a0
r13 0xffff880034ca12c0 0xffff880034ca12c0
r14 0x3 0x3
r15 0xffff880034cca940 0xffff880034cca940
rip 0xffffffff81055ab0 0xffffffff81055ab0
eflags 0x83 [ CF SF ]
cs 0x10 0x10
ss 0x18 0x18
ds 0x0 0x0
es 0x0 0x0
fs 0x0 0x0
gs 0x0 0x0
NOTE: Port must be 1234.
Reference
You can check the information about Thin hypervisor and GDB remote protocol.
- What is thin hypervisor
http://searchservervirtualization.techtarget.com/definition/thin-hypervisor - シン・ハイパーバイザ2017 (前編) (JPN)
https://ntddk.github.io/2017/03/04/thin-hypervisor-2017/ - Howto: GDB Remote Serial Protocol Writing a RSP Server
http://www.embecosm.com/appnotes/ean4/embecosm-howto-rsp-server-ean4-issue-2.html