Messages in this thread |  | | Date | Mon, 18 Jul 2022 09:36:26 -0400 | Subject | Re: Build warnings in Xen 5.15.y and 5.10.y with retbleed backports | From | Boris Ostrovsky <> |
| |
On 7/17/22 1:20 AM, Juergen Gross wrote: > > What about filling the complete hypercall page just with "int 3" or "ud2"? > > Any try to do a hypercall before the hypercall page has been initialized > is a bug anyway. What good can come from calling a function which will > return a basically random value instead of doing a privileged operation? >
This is all about objtool, that's why 'ret' was added there originally by f4b4bc10b0b8 ("x86/xen: Support objtool vmlinux.o validation in xen-head.S").
Before that it was all 'nop' which is similar to what you are suggesting ('int3' or 'ud2' would of course be better)
-boris
|  |