4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Borislav Petkov <bp@xxxxxxx>
Concentrate it in arch/x86/mm/kaiser.c and use the upstream string "nopti".
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);