[PATCH 4.1 51/65] x86/kaiser: Rename and simplify X86_FEATURE_KAISER handling

From: Pavel Tatashin
Date: Mon Mar 05 2018 - 19:29:57 EST


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>
(cherry picked from commit dea9aa9ffae11c91285335cc3215b4f0e48e8139)
Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
---
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(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 2d75f55419e0..c1f3dbed0021 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2439,7 +2439,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.

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

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 4404a78bdc0a..e80e6e5ede48 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -188,20 +188,6 @@ 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)
@@ -776,10 +762,6 @@ 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)
diff --git a/arch/x86/mm/kaiser.c b/arch/x86/mm/kaiser.c
index bfd48347eaac..a724496a5852 100644
--- 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(void)
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);
--
2.16.2