Re: [PATCH v28 04/32] x86/cpufeatures: Introduce CPU setup and option parsing for CET

Borislav Petkov
2021-08-09T16:05:56Z

On Thu, Jul 22, 2021 at 01:51:51PM -0700, Yu-cheng Yu wrote:
> /*
> * Some CPU features depend on higher CPUID levels, which may not always
> * be available due to CPUID level capping or broken virtualization
> @@ -1249,6 +1257,11 @@ static void __init cpu_parse_early_param(void)
> if (cmdline_find_option_bool(boot_command_line, "noxsaves"))
> setup_clear_cpu_cap(X86_FEATURE_XSAVES);
>
> + if (cmdline_find_option_bool(boot_command_line, "no_user_shstk"))
> + setup_clear_cpu_cap(X86_FEATURE_SHSTK);
> + if (cmdline_find_option_bool(boot_command_line, "no_user_ibt"))
> + setup_clear_cpu_cap(X86_FEATURE_IBT);

Patch 1 says:

"Disabling shadow stack also disables IBT."

I don't see that here.

--
Regards/Gruss,
Boris.