I compiled gdbserver 7.6 for arm with:
cd /gdb-7.6-src/gdb/gdbserver
./configure --target=arm-linux --host=arm-linux
make CC=/path/to/cross-compiler-gcc
Then I compiled gdb 7.6 for arm with:
cd /gdb-7.6-src/
./configure --target=arm-linux --prefix=/opt/gdb-arm/install/
make && make install
I compiled my trivial application with:
/path/to/cross-compiler-gcc hello.c -g -o hello
I copied gdbserver and my cross-compiled application on my board.
From my pc (x86-pc-linux) I run:
gdb hello
(gdb) set target-async on
(gdb) tvariable $c
(gdb) actions
>teval $c=$c+1
>end
(gdb) break main
(gdb) target remote <ipaddr>:<port>
[Thread 1585] #1 stopped.
0x40000800 in ?? ()
Cannot access memory at address 0x0
(gdb) continue &
(gdb) tstart
Target does not support this command.
(gdb) tstatus
Target does not support this command.
The behaviour is 'normal' until the tstart command: I can debug the application as I want, but I am unable to start tracing the app.
The question is: does gdbserver support tracepoints for arm or only for x86/amd_64?
I was searching samething, what I've found in GDB online docs webdocs that there is no support for now to any Archs.
Check for more info:
https://sourceware.org/gdb/onlinedocs/gdb/Tracepoints.html
Quoting:
This functionality is implemented in the remote stub; however, none of the stubs distributed with GDB support tracepoints as of this writing
Related
The following workflow worked for me at one point, and then it suddenly stopped working. I'd like to figure out why and get it to work again.
on the host, build binary for target system with debug information
send the stripped version of the binary to the target system
on the target, run the binary with gdbserver :6006 mybinary args...
on the host, run gdb-multiarch mybinary. This is the unstripped version. It shows that it loaded symbols from the local binary.
At the gdb prompt, run target remote <ip_of_target>:6006
Then, if I say b main, it inserts a breakpoint at an unrelocated address like 0x621730, which is the offset of the main function in the local binary, whereas it should be added on top of the VM address the remote binary is loaded at (0x5555555000 in this case.) Obviously the unrelocated address doesn't work.
So step 6 was working at one point. I don't know what I'm doing now differently to make the relocation no longer work. Help would be appreciated.
Version of gdbserver and that of host gdb are both Ubuntu 8.1.1-0ubuntu1. The remote system is aarch64.
So step 6 was working at one point. I don't know what I'm doing now differently to make the relocation no longer work.
I suspect that you have upgraded your toolchain, and that your upgraded toolchain produces a Position-Independent Executable mybinary by default, where the old toolchain didn't.
Try adding -no-pie to the link line of mybinary.
Obviously the unrelocated address doesn't work.
Actually, this does work for local debugging -- GDB is smart enough to realize that the code got loaded at a different address:
gdb -q a.out
Reading symbols from a.out...
(gdb) b main
Breakpoint 1 at 0x112d: file t.c, line 1. <<< Note: unrelocated address
(gdb) run
Starting program: /tmp/a.out
Breakpoint 1, main () at t.c:1
1 int main() {return 0; }
(gdb) p/x $pc
$1 = 0x55555555512d <<< Note: breakpoint worked.
It's possible that remote debugging doesn't work, although this worked fine for me using GDB-10.0:
strip a.out -o b.out
gdbserver :6006 ./b.out
Process ./b.out created; pid = 239653
Listening on port 6006
... in another window:
gdb -q ./a.out
Reading symbols from ./a.out...
(gdb) target remote :6006
Remote debugging using :6006
Reading /lib64/ld-linux-x86-64.so.2 from remote target...
warning: File transfers from remote targets can be slow. Use "set sysroot" to access files locally instead.
Reading /lib64/ld-linux-x86-64.so.2 from remote target...
Reading symbols from target:/lib64/ld-linux-x86-64.so.2...
Reading symbols from /usr/lib/debug/.build-id/a8/97a1105e21dd270bd418fe58c441700a6d8ec5.debug...
0x00007ffff7fe4940 in _start () from target:/lib64/ld-linux-x86-64.so.2
(gdb) b main
Breakpoint 1 at 0x55555555512d: file t.c, line 1.
I am trying to debug AVX-512 instructions on an emulated CPU using Intel® Software Development Emulator but it doesn't work as desired after setting a breakpoint. I followed this blog post: Debugging Emulated Code on Linux*
In window #1:
~$ g++ -g -O0 -mavx512f main.cpp -o main # compile main.cpp file
~$ sde -debug -- ./main # enable debugging
Application stopped until continued from debugger.
Start GDB, then issue this command at the (gdb) prompt:
target remote :54105
In window #2
# run debugger
~$ gdb ./main
GNU gdb (Ubuntu 9.2-0ubuntu1~20.04) 9.2
Copyright (C) 2020 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".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://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 ./main...
# set target "target remote :portnumber"
(gdb) target remote :54105
Remote debugging using :54105
warning: remote target does not support file transfer, attempting to access files from local filesystem.
Reading symbols from /lib64/ld-linux-x86-64.so.2...
(No debugging symbols found in /lib64/ld-linux-x86-64.so.2)
0x00007fa7bbbcc100 in ?? () from /lib64/ld-linux-x86-64.so.2
# suspend program at main function
(gdb) break main
Breakpoint 1 at 0x2c9c: file /home/borrow/source/repos/se-test/main.cpp, line 165.
# start program execution from the beginning of the program
(gdb) run
The "remote" target does not support "run". Try "help target" or
"continue".
# step to next line of code
(gdb) step
Cannot find bounds of current function
# continue executing until next break point
(gdb) c
Continuing.
warning: Probes-based dynamic linker interface failed.
Reverting to original interface.
[Inferior 1 (Remote target) exited normally]
In window #2: as you can see
gdb run should run a program but it doesn't work. gdb c should also run until the next breakpoint but executes the program and terminates. This command gives me the following warning message:
warning: Probes-based dynamic linker interface failed.
In window #1: The program runs and ends (without stopping).
Program code looks like this:
// main.cpp
#include <immintrin.h>
const int N=64;
int64_t srcA[N] = {0};
int64_t srcB[N] = {0};
int64_t dst[N] = {0};
void foo()
{
__m512i result,B,C;
for ( int i=0; i<N; i+=8 ){
B = _mm512_loadu_si512(&srcA[i]);
C = _mm512_loadu_si512(&srcB[i]);
result = _mm512_add_epi64(B,C);
_mm512_storeu_si512(&dst[i], result);
}
}
int main() {
...
foo();
...
}
I tried running AVX2 code without SDE emulator using gdb and it worked. First I start it on an emulated CPU with SDE, it fails. How can I solve this problem?
It seems to be broken for PIE executables
(confirmed on Arch GNU/Linux with GCC 10.2, GDB 10.1, SDE 8.33.)
Build with g++ -O2 -fno-pie -no-pie -g -march=skylake-avx512 and everything works. (I had to run gdb ./a.out instead of bare GDB; without that it couldn't find the right file even after connecting to the remote.)
$ g++ -O2 -march=skylake-avx512 -no-pie -fno-pie -g avx512.cpp
$ /opt/sde-external-8.33.0-2019-02-07-lin/sde64 -debug -- ./a.out
Application stopped until continued from debugger.
Start GDB, then issue this command at the (gdb) prompt:
target remote :59783
Then in another terminal tab
$ gdb ./a.out
...
(gdb) target remote :59783
warning: remote target does not support file transfer, attempting to access files from local filesystem.
Reading symbols from /lib64/ld-linux-x86-64.so.2...
(No debugging symbols found in /lib64/ld-linux-x86-64.so.2)
0x00007f4f7033b090 in _start () from /lib64/ld-linux-x86-64.so.2
(gdb) b main
Breakpoint 1 at 0x401050: file avx512.cpp, line 29.
(gdb) b foo
Breakpoint 2 at 0x401190: file avx512.cpp, line 14.
(gdb) c
Continuing.
Breakpoint 1, main () at avx512.cpp:23
(gdb) layout asm
(copy-paste of some of the disassembly window)
│B+ 0x401120 <_Z3foov> xor eax,eax
│ 0x401122 <_Z3foov+2> nop WORD PTR [rax+rax*1+0x0]
│ >0x401128 <_Z3foov+8> vmovdqu64 zmm1,ZMMWORD PTR [rax+0x404260]
│ 0x401132 <_Z3foov+18> add rax,0x40
│ 0x401136 <_Z3foov+22> vpaddq zmm0,zmm1,ZMMWORD PTR [rax+0x404420]
│ 0x401140 <_Z3foov+32> vmovdqu64 ZMMWORD PTR [rax+0x404020],zmm0
│ 0x40114a <_Z3foov+42> cmp rax,0x200
│ 0x401150 <_Z3foov+48> jne 0x401128 <_Z3foov+8>
│ 0x401152 <_Z3foov+50> vzeroupper
│ 0x401155 <_Z3foov+53> ret
(gdb) layout src
asm-level and source-level debugging both work fine, stepping into intrinsic "functions" in avx512fintrin.h and so on when using stepi (aka si).
Without specifying the filename separately from connecting to the remote:
$ gdb
(gdb) target remote :46879
Remote debugging using :46879 warning: No executable has been specified and target does not support determining executable automatically. Try using the "file" command.
0x00007f0f85830090 in ?? ()
(gdb)
(IDK if it matters that my .gdbinit includes layout reg, the full-screen terminal TUI mode. Nice when it works but somewhat buggy.)
Or as a super hacky workaround with PIE executables, I was also able to put a delay loop at the top of main, giving you a chance to attach and then control-C before SDE finishes executing your program.
Then I could set breakpoints and start single-stepping. (Presumably a sleep or read system call would work). Source-level debugging still seemed broken, but I was able to debug the asm with layout reg. I used set $rip = ... with a copy-pasted address to get out of the _mm_pause() loop after attaching and hitting control-C.
I'm new to kernel development and I would like to know how to run/debug the linux kernel using QEMU and gdb. I'm actually reading Robert Love's book but unfortunately it doesn't help the reader on how to install proper tools to run or debug the kernel... So what I did was to follow this tutorial http://opensourceforu.efytimes.com/2011/02/kernel-development-debugging-using-eclipse/. I'm using eclipse as an IDE to develop on the kernel but I wanted first to get it work under QEMU/gdb. So what I did so far was:
1) To compile the kernel with:
make defconfig (then setting the CONFIG_DEBUG_INFO=y in the .config)
make -j4
2) Once the compilation is over I run Qemu using:
qemu-system-x86_64 -s -S /dev/zero -kernel /arch/x86/boot/bzImage
which launch the kernel in "stopped" state
3) Thus I have to use gdb, I try the following command:
gdb ./vmlinux
which run it correctly but... Now I don't know what to do... I know that I have to use remote debugging on the port 1234 (default port used by Qemu), using the vmlinux as the symbol table file for debugging.
So my question is: What should I do to run the kernel on Qemu, attach my debugger to it and thus, get them work together to make my life easier with kernel development.
I'd try:
(gdb) target remote localhost:1234
(gdb) continue
Using the '-s' option makes qemu listen on port tcp::1234, which you can connect to as localhost:1234 if you are on the same machine. Qemu's '-S' option makes Qemu stop execution until you give the continue command.
Best thing would probably be to have a look at a decent GDB tutorial to get along with what you are doing. This one looks quite nice.
Step-by-step procedure tested on Ubuntu 16.10 host
To get started from scratch quickly I've made a minimal fully automated QEMU + Buildroot example at: https://github.com/cirosantilli/linux-kernel-module-cheat/blob/c7bbc6029af7f4fab0a23a380d1607df0b2a3701/gdb-step-debugging.md Major steps are covered below.
First get a root filesystem rootfs.cpio.gz. If you need one, consider:
a minimal init-only executable image: https://unix.stackexchange.com/questions/122717/custom-linux-distro-that-runs-just-one-program-nothing-else/238579#238579
a Busybox interactive system: https://unix.stackexchange.com/questions/2692/what-is-the-smallest-possible-linux-implementation/203902#203902
Then on the Linux kernel:
git checkout v4.15
make mrproper
make x86_64_defconfig
cat <<EOF >.config-fragment
CONFIG_DEBUG_INFO=y
CONFIG_DEBUG_KERNEL=y
CONFIG_GDB_SCRIPTS=y
EOF
./scripts/kconfig/merge_config.sh .config .config-fragment
make -j"$(nproc)"
qemu-system-x86_64 -kernel arch/x86/boot/bzImage \
-initrd rootfs.cpio.gz -S -s \
-append nokaslr
On another terminal, from inside the Linux kernel tree, supposing you want to start debugging from start_kernel:
gdb \
-ex "add-auto-load-safe-path $(pwd)" \
-ex "file vmlinux" \
-ex 'set arch i386:x86-64:intel' \
-ex 'target remote localhost:1234' \
-ex 'break start_kernel' \
-ex 'continue' \
-ex 'disconnect' \
-ex 'set arch i386:x86-64' \
-ex 'target remote localhost:1234'
and we are done!!
For kernel modules see: How to debug Linux kernel modules with QEMU?
For Ubuntu 14.04, GDB 7.7.1, hbreak was needed, break software breakpoints were ignored. Not the case anymore in 16.10. See also: https://bugs.launchpad.net/ubuntu/+source/qemu-kvm/+bug/901944
The messy disconnect and what come after it are to work around the error:
Remote 'g' packet reply is too long: 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
Related threads:
https://sourceware.org/bugzilla/show_bug.cgi?id=13984 might be a GDB bug
Remote 'g' packet reply is too long
http://wiki.osdev.org/QEMU_and_GDB_in_long_mode osdev.org is as usual an awesome source for these problems
https://lists.nongnu.org/archive/html/qemu-discuss/2014-10/msg00069.html
nokaslr: https://unix.stackexchange.com/questions/397939/turning-off-kaslr-to-debug-linux-kernel-using-qemu-and-gdb/421287#421287
Known limitations:
the Linux kernel does not support (and does not even compile without patches) with -O0: How to de-optimize the Linux kernel to and compile it with -O0?
GDB 7.11 will blow your memory on some types of tab completion, even after the max-completions fix: Tab completion interrupt for large binaries Likely some corner case which was not covered in that patch. So an ulimit -Sv 500000 is a wise action before debugging. Blew up specifically when I tab completed file<tab> for the filename argument of sys_execve as in: https://stackoverflow.com/a/42290593/895245
See also:
https://github.com/torvalds/linux/blob/v4.9/Documentation/dev-tools/gdb-kernel-debugging.rst official Linux kernel "documentation"
Linux kernel live debugging, how it's done and what tools are used?
When you try to start vmlinux exe using gdb, then first thing on gdb is to issue cmds:
(gdb) target remote localhost:1234
(gdb) break start_kernel
(continue)
This will break the kernel at start_kernel.
BjoernID's answer did not really work for me. After the first continuation, no breakpoint is reached and on interrupt, I would see lines such as:
0x0000000000000000 in ?? ()
(gdb) break rapl_pmu_init
Breakpoint 1 at 0xffffffff816631e7
(gdb) c
Continuing.
^CRemote 'g' packet reply is too long: 08793000000000002988d582000000002019[..]
I guess this has something to do with different CPU modes (real mode in BIOS vs. long mode when Linux has booted). Anyway, the solution is to run QEMU first without waiting (i.e. without -S):
qemu-system-x86_64 -enable-kvm -kernel arch/x86/boot/bzImage -cpu SandyBridge -s
In my case, I needed to break at something during boot, so after some deciseconds, I ran the gdb command. If you have more time (e.g. you need to debug a module that is loaded manually), then the timing doesn't really matter.
gdb allows you to specify commands that should be run when started. This makes automation a bit easier. To connect to QEMU (which should now already be started), break on a function and continue execution, use:
gdb -ex 'target remote localhost:1234' -ex 'break rapl_pmu_init' -ex c ./vmlinux
As for me the best solution for debugging the kernel - is to use gdb from Eclipse environment. You should just set appropriate port for gdb (must be the same with one you specified in qemu launch string) in remote debugging section. Here is the manual:
http://www.sw-at.com/blog/2011/02/11/linux-kernel-development-and-debugging-using-eclipse-cdt/
On Linux systems, vmlinux is a statically linked executable file that contains
the Linux kernel in one of the object file formats supported by Linux, which
includes ELF, COFF and a.out. The vmlinux file might be required for kernel
debugging, symbol table generation or other operations, but must be made
bootable before being used as an operating system kernel by adding a multiboot
header, bootsector and setup routines.
An image of this initial root file system must be stored somewhere accessible
by the Linux bootloader to the boot firmware of the computer. This can be the
root file system itself, a boot image on an optical disc, a small partition on
a local disk (a boot paratition, usually using ext4 or FAT file systems), or a
TFTP server (on systems that can boot from Ethernet).
Compile linux kernel
Build the kernel with this series applied, enabling CONFIG_DEBUG_INFO (but leave CONFIG_DEBUG_INFO_REDUCED off)
https://www.kernel.org/doc/html/latest/admin-guide/README.html
https://wiki.archlinux.org/index.php/Kernel/Traditional_compilation
https://lwn.net/Articles/533552/
Install GDB and Qemu
sudo pacman -S gdb qemu
Create initramfs
#!/bin/bash
# Os : Arch Linux
# Kernel : 5.0.3
INIT_DIR=$(pwd)
BBOX_URL="https://busybox.net/downloads/busybox-1.30.1.tar.bz2"
BBOX_FILENAME=$(basename ${BBOX_URL})
BBOX_DIRNAME=$(basename ${BBOX_FILENAME} ".tar.bz2")
RAM_FILENAME="${INIT_DIR}/initramfs.cpio.gz"
function download_busybox {
wget -c ${BBOX_URL} 2>/dev/null
}
function compile_busybox {
tar xvf ${BBOX_FILENAME} && cd "${INIT_DIR}/${BBOX_DIRNAME}/"
echo "[*] Settings > Build options > Build static binary (no shared libs)"
echo "[!] Please enter to continue"
read tmpvar
make menuconfig && make -j2 && make install
}
function config_busybox {
cd "${INIT_DIR}/${BBOX_DIRNAME}/"
rm -rf initramfs/ && cp -rf _install/ initramfs/
rm -f initramfs/linuxrc
mkdir -p initramfs/{dev,proc,sys}
sudo cp -a /dev/{null,console,tty,tty1,tty2,tty3,tty4} initramfs/dev/
cat > "${INIT_DIR}/${BBOX_DIRNAME}/initramfs/init" << EOF
#!/bin/busybox sh
mount -t proc none /proc
mount -t sysfs none /sys
exec /sbin/init
EOF
chmod a+x initramfs/init
cd "${INIT_DIR}/${BBOX_DIRNAME}/initramfs/"
find . -print0 | cpio --null -ov --format=newc | gzip -9 > "${RAM_FILENAME}"
echo "[*] output: ${RAM_FILENAME}"
}
download_busybox
compile_busybox
config_busybox
Boot Linux Kernel With Qemu
#!/bin/bash
KER_FILENAME="/home/debug/Projects/kernelbuild/linux-5.0.3/arch/x86/boot/bzImage"
RAM_FILENAME="/home/debug/Projects/kerneldebug/initramfs.cpio.gz"
qemu-system-x86_64 -s -kernel "${KER_FILENAME}" -initrd "${RAM_FILENAME}" -nographic -append "console=ttyS0"
$ ./qemuboot_vmlinux.sh
SeaBIOS (version 1.12.0-20181126_142135-anatol)
iPXE (http://ipxe.org) 00:03.0 C980 PCI2.10 PnP PMM+07F92120+07EF2120 C980
Booting from ROM...
Probing EDD (edd=off to disable)... o
[ 0.019814] Spectre V2 : Spectre mitigation: LFENCE not serializing, switching to generic retpoline
can't run '/etc/init.d/rcS': No such file or directory
Please press Enter to activate this console.
/ # uname -a
Linux archlinux 5.0.3 #2 SMP PREEMPT Mon Mar 25 10:27:13 CST 2019 x86_64 GNU/Linux
/ #
Debug Linux Kernel With GDB
~/Projects/kernelbuild/linux-5.0.3 ➭ gdb vmlinux
...
(gdb) target remote localhost:1234
Remote debugging using localhost:1234
0xffffffff89a4b852 in ?? ()
(gdb) break start_kernel
Breakpoint 1 at 0xffffffff826ccc08
(gdb)
Display all 190 possibilities? (y or n)
(gdb) info functions
All defined functions:
Non-debugging symbols:
0xffffffff81000000 _stext
0xffffffff81000000 _text
0xffffffff81000000 startup_64
0xffffffff81000030 secondary_startup_64
0xffffffff810000e0 verify_cpu
0xffffffff810001e0 start_cpu0
0xffffffff810001f0 __startup_64
0xffffffff81000410 pvh_start_xen
0xffffffff81001000 hypercall_page
0xffffffff81001000 xen_hypercall_set_trap_table
0xffffffff81001020 xen_hypercall_mmu_update
0xffffffff81001040 xen_hypercall_set_gdt
0xffffffff81001060 xen_hypercall_stack_switch
0xffffffff81001080 xen_hypercall_set_callbacks
0xffffffff810010a0 xen_hypercall_fpu_taskswitch
0xffffffff810010c0 xen_hypercall_sched_op_compat
0xffffffff810010e0 xen_hypercall_platform_op
Ubuntu 16.04.4 LTS, GNU gdb (Ubuntu 7.11.1-0ubuntu1~16.5) 7.11.1
I am trying to call a function in a compiled C program and get the following:
"(gdb) call getVarName(someParam)
You can't do that without a process to debug."
There are no other codes or messages.
I can run the program from the shell prompt
jef#ubuntu$ ./program.
I can run the program within gdb after designating the file. Permissions are 777 (just to cover all bases).
Based on research, I set the SHELL with "export SHELL=/bin/bash"
and
set kernal.yama.ptrace_scope = 0 in /etc/sysctl.d/10-ptrace.conf
I still get the same behavior.
I still get the same behavior.
Naturally.
The error you are getting means: you can't do this, unless you are debugging a live process.
This will work:
(gdb) break main
(gdb) run
... GDB is now stopped, *and* you have a live process.
... you *can* call getVarName(...) now
(gdb) call getVarName(...)
(gdb) continue # causes the process to run to end and exit
[Inferior 1 (process 195969) exited normally]
(gdb) # Now you no longer have a live process, so you *again* can't
# call functions in it.
I use this (http://cs.baylor.edu/~donahoo/tools/gdb/tutorial.html) guide to learn how GDB works.
After compiling and uploading the code to my embedded linux arm platform I use a remote connection to connect with the gdbserver on my target:
Target:
root#zedboard-zynq7:/Software# gdbserver HOST:1234 broken
Process broken created; pid = 1103
Listening on port 1234
Remote debugging from host 192.168.178.32
Host (Ubuntu 14.04 running in a virtual machine):
Remote debugging using 192.168.178.33:1234
warning: A handler for the OS ABI "GNU/Linux" is not built into this
configuration of GDB. Attempting to continue with the default arm settings.
Cannot access memory at address 0x0
0x43330d40 in ?? ()
(gdb)
I set the breakpoint to line 43 and continue the program until it stops at the breakpoint:
(gdb) b 43
Breakpoint 1 at 0x8b68: file broken.cpp, line 43.
(gdb) continue
Continuing.
Breakpoint 1, main () at broken.cpp:43
43 double seriesValue = ComputeSeriesValue(x, n);
(gdb)
But after a step call on my host I got this error:
Host:
warning: Remote failure reply: E01
Ignoring packet error, continuing...
Target:
ptrace: Input/output error.
input_interrupt, count = 1 c = 36 ('$')
What does it mean and how can I fix it?
Thanks for help.
Host (Ubuntu 14.04 running in a virtual machine):
Remote debugging using 192.168.178.33:1234
warning: A handler for the OS ABI "GNU/Linux" is not built into this
configuration of GDB. Attempting to continue with the default arm settings.`
This says that your (host) GDB has not been built with support for the target you want to debug.
What does it mean and how can I fix it?
You need to either get a different build of (host) GDB, or build one yourself with correct --target setting.
Usually a correct host GDB is included with the cross-gcc that you use to build for your target. So a fix may be as simple as running /path/to/cross-gdb instead of gdb.