4.9-stable review patch. If anyone has any objections, please let me know.
------------------
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 @@ -2763,7 +2763,7 @@ 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 @@ -179,20 +179,6 @@ 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) @@ -813,10 +799,6 @@ void get_cpu_cap(struct cpuinfo_x86 *c) c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a);
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 @@ -274,8 +274,13 @@ 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) { @@ -418,3 +423,16 @@ 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);