On Tue, Oct 18, 2016 at 7:03 PM, Kyle Huey <me@xxxxxxxxxxxx> wrote: > rr (http://rr-project.org/), a userspace record-and-replay reverse- > execution debugger, would like to trap and emulate the CPUID instruction. > This would allow us to a) mask away certain hardware features that rr does > not support (e.g. RDRAND) and b) enable trace portability across machines > by providing constant results. > > Newer Intel CPUs (Ivy Bridge and later) can fault when CPUID is executed at > CPL > 0. Expose this capability to userspace as a new pair of arch_prctls, > ARCH_GET_CPUID and ARCH_SET_CPUID, with two values, ARCH_CPUID_ENABLE and > ARCH_CPUID_SIGSEGV. > > v6 did not get any feedback, so I included the changes since v5. > > Since v6: > - Rebased to 4.9-rc1 (primarily over the new VDSO arch_prctls and the new pkey > entries in the syscall table) > > Since v5: > > Patch 3: > - do_arch_prctl is again do_arch_prctl_common > > Patch 6: > - Added static qualifiers on get/set_cpuid_mode > - Braced ifs in disable/enable_cpuid > - Renamed arch_post_exec to arch_setup_new_exec > A friendly ping. Has anybody had an opportunity to look at this patch series again? Any feedback, positive or negative, would be greatly appreciated. - Kyle -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
