distinguish load and store from segmentation fault

gaven · 08-23-2005, 02:00 PM

Hi there,

I'm programming segmentation fault signal handling.
I can catch the memory address and also the instruction which causes the fault. Is there an easy
way to tell whether that instruction is a load or store instruction? Of course, a solution would be to derive that by decoding the instruction. Even for that solution, I'm not clear on how to do it quickly given the big instruction set of IA32...

Gaven

schneidz · 08-24-2005, 03:40 PM

there's only about 60 instructions that i know of for x86.
amways, try running it in dbx/ gdb. it should give you the offset, the machine opcodes, and the respective assembly instruction with parameters.

you can also try compiliing with the -S option to get a <program>.s file containing the assembly.

hope this helps,
schneidz