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 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: x86-kaiser-rename-and-simplify-x86_feature_kaiser-handling.patch and it can be found in the queue-4.9 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 20:37:21 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 @@ -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);

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

queue-4.9/x86-paravirt-dont-patch-flush_tlb_single.patch queue-4.9/x86-kaiser-reenable-paravirt.patch queue-4.9/x86-kaiser-rename-and-simplify-x86_feature_kaiser-handling.patch queue-4.9/x86-kaiser-check-boottime-cmdline-params.patch queue-4.9/x86-kaiser-move-feature-detection-up.patch