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Why did the value of the rbx register change unexpectedly in GDB?

Posted by Marvee Amasi
11:56 am
21/11/2024

I am debugging a program on an `x86-64` system `Ubuntu 22.04` `GDB v10.2` `GCC 11.2.0` using `GDB` and encountered an unexpected behavior. I was inspecting the value of the `rbx` register and noticed that the value changed from `28` to `-5604` without stepping through any new instructions. I am trying to understand what caused this change, as I did not execute any additional steps `stepi` or similar commands that would modify the register value.

The sequence of GDB commands I used is in my `gdb.txt` file

The value of `rbx` initially read as `28` in decimal format, but after running the `x/1wd $rbx` command, the value changed to `-5604`. I haven’t taken any further steps `stepi` or `continue`, so I’m unsure what caused the value to change