Patch "x86/kaiser: Rename and simplify X86_FEATURE_KAISER handling" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    x86/kaiser: Rename and simplify X86_FEATURE_KAISER handling

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     x86-kaiser-rename-and-simplify-x86_feature_kaiser-handling.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Wed Jan  3 18:58:12 CET 2018
From: Borislav Petkov <bp@suse.de>
Date: Tue, 2 Jan 2018 14:19:48 +0100
Subject: x86/kaiser: Rename and simplify X86_FEATURE_KAISER handling

From: Borislav Petkov <bp@suse.de>


Concentrate it in arch/x86/mm/kaiser.c and use the upstream string "nopti".

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 Documentation/kernel-parameters.txt |    2 +-
 arch/x86/kernel/cpu/common.c        |   18 ------------------
 arch/x86/mm/kaiser.c                |   20 +++++++++++++++++++-
 3 files changed, 20 insertions(+), 20 deletions(-)

--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2523,7 +2523,7 @@ bytes respectively. Such letter suffixes
 
 	nojitter	[IA-64] Disables jitter checking for ITC timers.
 
-	nokaiser	[X86-64] Disable KAISER isolation of kernel from user.
+	nopti		[X86-64] Disable KAISER isolation of kernel from user.
 
 	no-kvmclock	[X86,KVM] Disable paravirtualized KVM clock driver
 
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -178,20 +178,6 @@ static int __init x86_pcid_setup(char *s
 	return 1;
 }
 __setup("nopcid", x86_pcid_setup);
-
-static int __init x86_nokaiser_setup(char *s)
-{
-	/* nokaiser doesn't accept parameters */
-	if (s)
-		return -EINVAL;
-#ifdef CONFIG_KAISER
-	kaiser_enabled = 0;
-	setup_clear_cpu_cap(X86_FEATURE_KAISER);
-	pr_info("nokaiser: KAISER feature disabled\n");
-#endif
-	return 0;
-}
-early_param("nokaiser", x86_nokaiser_setup);
 #endif
 
 static int __init x86_noinvpcid_setup(char *s)
@@ -761,10 +747,6 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
 		c->x86_power = cpuid_edx(0x80000007);
 
 	init_scattered_cpuid_features(c);
-#ifdef CONFIG_KAISER
-	if (kaiser_enabled)
-		set_cpu_cap(c, X86_FEATURE_KAISER);
-#endif
 }
 
 static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
--- a/arch/x86/mm/kaiser.c
+++ b/arch/x86/mm/kaiser.c
@@ -275,8 +275,13 @@ void __init kaiser_init(void)
 {
 	int cpu;
 
-	if (!kaiser_enabled)
+	if (!kaiser_enabled) {
+		setup_clear_cpu_cap(X86_FEATURE_KAISER);
 		return;
+	}
+
+	setup_force_cpu_cap(X86_FEATURE_KAISER);
+
 	kaiser_init_all_pgds();
 
 	for_each_possible_cpu(cpu) {
@@ -419,3 +424,16 @@ void kaiser_flush_tlb_on_return_to_user(
 			X86_CR3_PCID_USER_FLUSH | KAISER_SHADOW_PGD_OFFSET);
 }
 EXPORT_SYMBOL(kaiser_flush_tlb_on_return_to_user);
+
+static int __init x86_nokaiser_setup(char *s)
+{
+	/* nopti doesn't accept parameters */
+	if (s)
+		return -EINVAL;
+
+	kaiser_enabled = 0;
+	pr_info("Kernel/User page tables isolation: disabled\n");
+
+	return 0;
+}
+early_param("nopti", x86_nokaiser_setup);


Patches currently in stable-queue which might be from bp@suse.de are

queue-4.4/x86-paravirt-dont-patch-flush_tlb_single.patch
queue-4.4/x86-kaiser-reenable-paravirt.patch
queue-4.4/x86-kaiser-rename-and-simplify-x86_feature_kaiser-handling.patch
queue-4.4/x86-kaiser-check-boottime-cmdline-params.patch
queue-4.4/x86-kaiser-move-feature-detection-up.patch