Remote debugging and dumping using gdbserver
This tutorial is for
advanced users only!
As Google fixed gcore for Windows,
we can finally dump core remotely using gdbserver. I tested GDB on macOS 2
years ago and was working, should still work today and for Linux too. I don't
have device running macOS and Linux at the moment
Important:
A good internet connection is
required for better debugging experience. 5GHz Wi-Fi and Ethernet is highly
recommended.
Root is required.
Samsung devices with KNOX and/or
other phones with security may prevent GDB from working. Use custom rom or
custom kernel that doesn't have such security system. Or just buy old devices
or buy crappy chinese devices that doesn't have any super security. That's the
reason I use Denver tablets all time XD.
Some emulators does not
support core file generation but Bluestacks support it.
Downloads:
Download the correct file for your device
CPU architecture. You can check your CPU architecture using CPU-Z app
GDB server:
GDB client:
Instructions:
Installation:
On PC, extract the folder into your
desired folder.
On Android device, add the gdbserver file to /system/bin and give gdbserver file permission 755. If you
are using X-plore, make sure you enable superuser + writeable in confuguration.
Attach the process and start the server:
Open up the Terminal, grand
superuser/root access
su
Show all process list
dumpsys meminfo
Or search text
dumpsys meminfo
| grep (string of package name, com.*, whatever…)
Find a pid number of process you want to attach
Running gdbserver and attaching to a running process:
Run gdbserver on the target system with TCP connection
and attach to the pid number of process. Just give port 1234
gdbserver :<port>
--attach <pid>
gdbserver will listen on port and waiting for you to
connect.
Attached: pid = <pid>
Listening on port <port>
Connecting to
gdbserver:
Execute the gdb file located in /bin/ (gdb.exe Windows)
Target your device's IP:Port. You can find your
device's IP on Wifi settings (Kitkat and below) or Status (Lollipop and above)
target remote <ip>:<port>
That's all, now you can use GDB for debugging and
dumping remotely.
I'll look into GDB game hacking later. For now, you
can read iOS GDB hacking tutorials
To dump use
gcore <path to your hard drive>
Please note that dumping core to your PC may take 2-5
minutes depending on performance and network speed
Targeting emulator:
Forward TCP
adb forward tcp:<port> tcp:<port>
Then in GDB, you can target your emulator.
target remote :<port>
Some emulators required you to enable USB debugging
and connect adb manually. For example Nox Player, do this to connect to
localhost.
nox_adb.exe connect 127.0.0.1:62001
Then forward TCP
nox_adb.exe forward tcp:1234 tcp:1234
