System call and registers

Berhanie · 12-14-2006, 12:37 AM

I'm writing an assembly program. Is it necessary to save all the general purpose registers on the stack
before making a system call, or is there some guarantee that certain ones not be changed after the
system call returns?

cyber-worx · 12-14-2006, 04:24 AM

There are never guarantee's

If you want data to be there after a call, make sure you deal with it

Cheers
-rob

Berhanie · 12-14-2006, 06:30 PM

Thank you. I was hoping system calls would be more considerate, but the results made me suspicious that a system call was corrupting the registers.