Root Galaxy Tab 2 7.0 GT-P3110 On Android 4.0.3 ICS

 
Step 1: Download the .zip file of Heimdall [Official Website] and extract using an app like WinRAR or 7-zip.
Step 2: Boot your Samsung Galaxy Tab into Download Mode. To achieve this, power your device down, and then turn it on while holding the Volume Down button.
Step 3: Your device will say Download Mode Do Not Turn Off Target. At this moment, you must connect your phone to your computer with a USB cable.
Step 4: Download the following files:

• gt-p3110.pit
• boot-bjr.img

And then place them in the same place you extracted Heimdall in Step 1.
 Step 5: Open a command prompt and locate the folder from Step 1. Then type in adb reboot download
Step 6: Launch heimdall-frontend, and go to the “Flash” tab. Then, load the attached pit file (gt-p3110.pit).
Step 7: In partition details, select “KERNEL”, and then click “Add”
Step 8: Next, choose “Browse” and select the attached boot-bjr.img. Then, click “Start”.
Step 9: After the tablet reboots, type the following into the command prompt:
adb shell
./su
./gtab2-root.sh
And that’s it, your Galaxy Tab should now be rooted!