Re: [PATCH] prctl,x86 Add PR_[GET|SET]_CPUID for controlling the CPUID instruction.

On Mon, Sep 12, 2016 at 7:15 AM, Kyle Huey [off-list ref] wrote:

On Mon, Sep 12, 2016 at 2:07 AM, Borislav Petkov [off-list ref] wrote:

quoted

On Sun, Sep 11, 2016 at 05:29:23PM -0700, Kyle Huey wrote:

quoted

@@ -2162,6 +2168,12 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
      case PR_SET_TSC:
              error = SET_TSC_CTL(arg2);
              break;
+     case PR_GET_CPUID:
+             error = GET_CPUID_CTL(arg2);
+             break;
+     case PR_SET_CPUID:
+             error = SET_CPUID_CTL(arg2);
+             break;
      case PR_TASK_PERF_EVENTS_DISABLE:
              error = perf_event_task_disable();
              break;

This whole fun should be in arch_prctl() as it is arch-specific.

Yeah, I was debating about that, and did it this way because of
PR_SET_TSC.  Will fix.

arch_prctl is not yet exposed on 32 bit x86, so we'll have to add that
as well to do this.

- Kyle