[tip: x86/cpu] x86/cpu: Remove "nosep"

tip-bot2 for Borislav Petkov
2022-04-04T21:23:21Z

The following commit has been merged into the x86/cpu branch of tip:

Commit-ID: c949110ef4e31cb5d3387bd8273fd5de66b5227b
Gitweb: https://git.kernel.org/tip/c949110ef4e31cb5d3387bd8273fd5de66b5227b
Author: Borislav Petkov <bp@suse.de>
AuthorDate: Thu, 27 Jan 2022 12:56:22 +01:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Mon, 04 Apr 2022 10:16:55 +02:00

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
---
Documentation/admin-guide/kernel-parameters.txt | 2 --
arch/x86/kernel/cpu/common.c | 7 -------
2 files changed, 9 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 0ea1786..a9f3d31 100644
--- 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 69c7ea8..c71d107 100644
--- 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)
{