Patch "x86/cpufeatures: Make CPU bugs sticky" has been added to the 4.4-stable tree

Patch "x86/cpufeatures: Make CPU bugs sticky" has been added to the 4.4-stable tree

[gregkh]

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

    x86/cpufeatures: Make CPU bugs sticky

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-cpufeatures-make-cpu-bugs-sticky.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 6cbd2171e89b13377261d15e64384df60ecb530e Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 4 Dec 2017 15:07:32 +0100
Subject: x86/cpufeatures: Make CPU bugs sticky

From: Thomas Gleixner <tglx@linutronix.de>

commit 6cbd2171e89b13377261d15e64384df60ecb530e upstream.

There is currently no way to force CPU bug bits like CPU feature bits. That
makes it impossible to set a bug bit once at boot and have it stick for all
upcoming CPUs.

Extend the force set/clear arrays to handle bug bits as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.992156574@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/include/asm/cpufeature.h |    2 ++
 arch/x86/include/asm/processor.h  |    4 ++--
 arch/x86/kernel/cpu/common.c      |    6 +++---
 3 files changed, 7 insertions(+), 5 deletions(-)

--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -359,6 +359,8 @@ extern const char * const x86_bug_flags[
 	set_bit(bit, (unsigned long *)cpu_caps_set);	\
 } while (0)
 
+#define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
+
 #define cpu_has_fpu		boot_cpu_has(X86_FEATURE_FPU)
 #define cpu_has_de		boot_cpu_has(X86_FEATURE_DE)
 #define cpu_has_pse		boot_cpu_has(X86_FEATURE_PSE)
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -156,8 +156,8 @@ extern struct cpuinfo_x86	boot_cpu_data;
 extern struct cpuinfo_x86	new_cpu_data;
 
 extern struct tss_struct	doublefault_tss;
-extern __u32			cpu_caps_cleared[NCAPINTS];
-extern __u32			cpu_caps_set[NCAPINTS];
+extern __u32			cpu_caps_cleared[NCAPINTS + NBUGINTS];
+extern __u32			cpu_caps_set[NCAPINTS + NBUGINTS];
 
 #ifdef CONFIG_SMP
 DECLARE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -432,8 +432,8 @@ static const char *table_lookup_model(st
 	return NULL;		/* Not found */
 }
 
-__u32 cpu_caps_cleared[NCAPINTS];
-__u32 cpu_caps_set[NCAPINTS];
+__u32 cpu_caps_cleared[NCAPINTS + NBUGINTS];
+__u32 cpu_caps_set[NCAPINTS + NBUGINTS];
 
 void load_percpu_segment(int cpu)
 {
@@ -668,7 +668,7 @@ static void apply_forced_caps(struct cpu
 {
 	int i;
 
-	for (i = 0; i < NCAPINTS; i++) {
+	for (i = 0; i < NCAPINTS + NBUGINTS; i++) {
 		c->x86_capability[i] &= ~cpu_caps_cleared[i];
 		c->x86_capability[i] |= cpu_caps_set[i];
 	}


Patches currently in stable-queue which might be from tglx@linutronix.de are

queue-4.4/x86-mm-pat-dev-mem-remove-superfluous-error-message.patch
queue-4.4/x86-cpufeatures-add-x86_bug_spectre_v.patch
queue-4.4/x86-microcode-intel-extend-bdw-late-loading-with-a-revision-check.patch
queue-4.4/x86-alternatives-add-missing-n-at-end-of-alternative-inline-asm.patch
queue-4.4/sysfs-cpu-fix-typos-in-vulnerability-documentation.patch
queue-4.4/locking-mutex-allow-next-waiter-lockless-wakeup.patch
queue-4.4/x86-cpufeatures-add-x86_bug_cpu_insecure.patch
queue-4.4/x86-cpufeatures-make-cpu-bugs-sticky.patch
queue-4.4/x86-vsdo-fix-build-on-paravirt_clock-y-kvm_guest-n.patch
queue-4.4/x86-pti-efi-broken-conversion-from-efi-to-kernel-page-table.patch
queue-4.4/x86-documentation-add-pti-description.patch
queue-4.4/x86-acpi-handle-sci-interrupts-above-legacy-space-gracefully.patch
queue-4.4/x86-cpu-implement-cpu-vulnerabilites-sysfs-functions.patch
queue-4.4/futex-replace-barrier-in-unqueue_me-with-read_once.patch
queue-4.4/x86-cpu-factor-out-application-of-forced-cpu-caps.patch
queue-4.4/selftests-x86-add-test_vsyscall.patch
queue-4.4/x86-cpu-merge-bugs.c-and-bugs_64.c.patch
queue-4.4/sysfs-cpu-add-vulnerability-folder.patch
queue-4.4/x86-pti-rename-bug_cpu_insecure-to-bug_cpu_meltdown.patch
queue-4.4/x86-acpi-reduce-code-duplication-in-mp_override_legacy_irq.patch
queue-4.4/x86-alternatives-fix-optimize_nops-checking.patch