Re: [PATCH RESEND v2 1/3] x86/cpu: Create helper to parse clearcpuid param
From: Borislav Petkov
Date: Mon Feb 17 2025 - 06:02:04 EST
On Wed, Jan 29, 2025 at 03:35:39PM +0000, Brendan Jackman wrote:
> +/*
> + * We parse cpu parameters early because fpu__init_system() is executed
While at it:
s/We parse cpu parameters/Parse CPU parameters/
> + * before parse_early_param().
> + */
> +static void __init cpu_parse_early_param(void)
> +{
> + char arg[128];
> + int arglen;
> +
> +#ifdef CONFIG_X86_32
> + if (cmdline_find_option_bool(boot_command_line, "no387"))
> +#ifdef CONFIG_MATH_EMULATION
> + setup_clear_cpu_cap(X86_FEATURE_FPU);
> +#else
> + pr_err("Option 'no387' required CONFIG_MATH_EMULATION enabled.\n");
> +#endif
> +
> + if (cmdline_find_option_bool(boot_command_line, "nofxsr"))
> + setup_clear_cpu_cap(X86_FEATURE_FXSR);
> +#endif
> +
> + if (cmdline_find_option_bool(boot_command_line, "noxsave"))
> + setup_clear_cpu_cap(X86_FEATURE_XSAVE);
> +
> + if (cmdline_find_option_bool(boot_command_line, "noxsaveopt"))
> + setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
> +
> + if (cmdline_find_option_bool(boot_command_line, "noxsaves"))
> + setup_clear_cpu_cap(X86_FEATURE_XSAVES);
> +
> + if (cmdline_find_option_bool(boot_command_line, "nousershstk"))
> + setup_clear_cpu_cap(X86_FEATURE_USER_SHSTK);
> +
> + /* Minimize the gap between FRED is available and available but disabled. */
> + arglen = cmdline_find_option(boot_command_line, "fred", arg, sizeof(arg));
> + if (arglen != 2 || strncmp(arg, "on", 2))
> + setup_clear_cpu_cap(X86_FEATURE_FRED);
> +
> + arglen = cmdline_find_option(boot_command_line, "clearcpuid", arg, sizeof(arg));
> + if (arglen <= 0)
> + return;
Newline here.
> + parse_clearcpuid(arg);
> }
>
> /*
>
> --
> 2.48.1.262.g85cc9f2d1e-goog
>
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette