That chicken bit was added by
4f88651125e2 ("[PATCH] i386: allow disabling X86_FEATURE_SEP at boot")
but measuring int80 vsyscall performance on 32-bit doesn't matter
anymore.
If still needed, one can boot with
clearcpuid=sep
to disable that feature for testing.
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220127115626.14179-3-bp@alien8.de
nosbagart [IA-64]
- nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
-
nosgx [X86-64,SGX] Disables Intel SGX kernel support.
nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
}
__setup("cachesize=", cachesize_setup);
-static int __init x86_sep_setup(char *s)
-{
- setup_clear_cpu_cap(X86_FEATURE_SEP);
- return 1;
-}
-__setup("nosep", x86_sep_setup);
-
/* Standard macro to see if a specific flag is changeable */
static inline int flag_is_changeable_p(u32 flag)
{