| 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 |
| @@ -135,6 +135,8 @@ 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) |
| + |
| #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_X86_FAST_FEATURE_TESTS) |
| /* |
| * Static testing of CPU features. Used the same as boot_cpu_has(). |
| --- 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 |
| @@ -480,8 +480,8 @@ 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) |
| { |
| @@ -710,7 +710,7 @@ 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]; |
| } |