Comments on: Debugging – Modifying Code At Runtime

By: tc

tc — Sat, 25 Sep 2010 20:09:08 +0000

@maverick – I have never run into such a situation when I debug however the same should hold true for a debugger when inserting software breakpoints where the debugger too needs to change instructions in memory to insert the “int 3″ instruction.

By: maverick

maverick — Wed, 01 Sep 2010 20:06:17 +0000

how could we change the assembly instructon in the text segment which is read+execute ? Shouldn’t OS generate an exception ?

By: tc

tc — Tue, 27 Jul 2010 03:08:27 +0000

@Chris,
Thanks for the comments. Edit and Continue is a great feature in Visual Studio however if you are missing the build environment or do not have the sources (in case of a third party library) or are using a different debugger (or a different platform), then it is handy to know how to tweak logic by changing opcodes in memory in any debugger.

By: Chris

Chris — Sat, 24 Jul 2010 13:12:53 +0000

MSVC has edit-and-continue which is much easier and less error prone than manual opcodes editing.