Skip to content


Subversion checkout URL

You can clone with
Download ZIP
tree: f3bfef6e56
Fetching contributors…

Cannot retrieve contributors at this time

14 lines (9 sloc) 0.59 kB

Notes for x86-64


syscall and sysret can be assumed to always work for x86-64 code on an x86-64 kernel.

IA32 code running in compatibility mode on a x86-64 kernel is a complete mess and should be avoided:

<XgF> duckinator: No. syscall/sysret always work 64->64
<XgF> Otherwise, its a complete mess
<XgF> On AMD: sysenter/exit are prohibited. #UD raised
<XgF> On Intel: syscall/sysret to/from compatibility mode are prohibitied. #UD raised. You must use sysenter/sysexit from this
<XgF> VIA/Centaur: Who the fuck knows? The CPUID bits are worthless!
Jump to Line
Something went wrong with that request. Please try again.