x86/cpu: Remove "nosep"

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

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 0ea17869a0898dca8668a76c6e4e44041fc6d481..a9f3d3158e77b47ff90ddf571704c316639cf11d 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3665,8 +3665,6 @@
 
        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,

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 69c7ea84b00546088354688d1fe9325ddf23e40b..c71d1075db938144372d176d7b42247b2361bb7f 100644 (file)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -298,13 +298,6 @@ static int __init cachesize_setup(char *str)
 }
 __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)
 {