patches/kernel/0162-x86-cpufeatures-Make-CPU-bugs-sticky.patch

   1 From f9bdf4dc3a7719aa39df4abe58efe3db3fb8b037 Mon Sep 17 00:00:00 2001
   2 From: Thomas Gleixner <tglx@linutronix.de>
   3 Date: Mon, 4 Dec 2017 15:07:32 +0100
   4 Subject: [PATCH 162/233] x86/cpufeatures: Make CPU bugs sticky
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 CVE-2017-5754
  10
  11 There is currently no way to force CPU bug bits like CPU feature bits. That
  12 makes it impossible to set a bug bit once at boot and have it stick for all
  13 upcoming CPUs.
  14
  15 Extend the force set/clear arrays to handle bug bits as well.
  16
  17 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  18 Reviewed-by: Borislav Petkov <bp@suse.de>
  19 Cc: Andy Lutomirski <luto@kernel.org>
  20 Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
  21 Cc: Borislav Petkov <bp@alien8.de>
  22 Cc: Borislav Petkov <bpetkov@suse.de>
  23 Cc: Brian Gerst <brgerst@gmail.com>
  24 Cc: Dave Hansen <dave.hansen@intel.com>
  25 Cc: Dave Hansen <dave.hansen@linux.intel.com>
  26 Cc: David Laight <David.Laight@aculab.com>
  27 Cc: Denys Vlasenko <dvlasenk@redhat.com>
  28 Cc: Eduardo Valentin <eduval@amazon.com>
  29 Cc: Greg KH <gregkh@linuxfoundation.org>
  30 Cc: H. Peter Anvin <hpa@zytor.com>
  31 Cc: Josh Poimboeuf <jpoimboe@redhat.com>
  32 Cc: Juergen Gross <jgross@suse.com>
  33 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  34 Cc: Peter Zijlstra <peterz@infradead.org>
  35 Cc: Rik van Riel <riel@redhat.com>
  36 Cc: Will Deacon <will.deacon@arm.com>
  37 Cc: aliguori@amazon.com
  38 Cc: daniel.gruss@iaik.tugraz.at
  39 Cc: hughd@google.com
  40 Cc: keescook@google.com
  41 Link: https://lkml.kernel.org/r/20171204150606.992156574@linutronix.de
  42 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  43 (cherry picked from commit 6cbd2171e89b13377261d15e64384df60ecb530e)
  44 Signed-off-by: Andy Whitcroft <apw@canonical.com>
  45 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  46 (cherry picked from commit aab40a666a40cd015ca4a53231bed544fc679dcb)
  47 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  48 ---
  49  arch/x86/include/asm/cpufeature.h | 2 ++
  50  arch/x86/include/asm/processor.h  | 4 ++--
  51  arch/x86/kernel/cpu/common.c      | 6 +++---
  52  3 files changed, 7 insertions(+), 5 deletions(-)
  53
  54 diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
  55 index 225fd8374fae..8b9915561ed1 100644
  56 --- a/arch/x86/include/asm/cpufeature.h
  57 +++ b/arch/x86/include/asm/cpufeature.h
  58 @@ -134,6 +134,8 @@ extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
  59         set_bit(bit, (unsigned long *)cpu_caps_set);    \
  60  } while (0)
  61
  62 +#define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
  63 +
  64  #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_X86_FAST_FEATURE_TESTS)
  65  /*
  66   * Static testing of CPU features.  Used the same as boot_cpu_has().
  67 diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
  68 index bccec7ed1676..59a317f8e0ec 100644
  69 --- a/arch/x86/include/asm/processor.h
  70 +++ b/arch/x86/include/asm/processor.h
  71 @@ -162,8 +162,8 @@ extern struct cpuinfo_x86   new_cpu_data;
  72  #include <linux/thread_info.h>
  73
  74  extern struct x86_hw_tss       doublefault_tss;
  75 -extern __u32                   cpu_caps_cleared[NCAPINTS];
  76 -extern __u32                   cpu_caps_set[NCAPINTS];
  77 +extern __u32                   cpu_caps_cleared[NCAPINTS + NBUGINTS];
  78 +extern __u32                   cpu_caps_set[NCAPINTS + NBUGINTS];
  79
  80  #ifdef CONFIG_SMP
  81  DECLARE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
  82 diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
  83 index 7992e5a8076c..fcdba90e0890 100644
  84 --- a/arch/x86/kernel/cpu/common.c
  85 +++ b/arch/x86/kernel/cpu/common.c
  86 @@ -452,8 +452,8 @@ static const char *table_lookup_model(struct cpuinfo_x86 *c)
  87         return NULL;            /* Not found */
  88  }
  89
  90 -__u32 cpu_caps_cleared[NCAPINTS];
  91 -__u32 cpu_caps_set[NCAPINTS];
  92 +__u32 cpu_caps_cleared[NCAPINTS + NBUGINTS];
  93 +__u32 cpu_caps_set[NCAPINTS + NBUGINTS];
  94
  95  void load_percpu_segment(int cpu)
  96  {
  97 @@ -812,7 +812,7 @@ static void apply_forced_caps(struct cpuinfo_x86 *c)
  98  {
  99         int i;
 100
 101 -       for (i = 0; i < NCAPINTS; i++) {
 102 +       for (i = 0; i < NCAPINTS + NBUGINTS; i++) {
 103                 c->x86_capability[i] &= ~cpu_caps_cleared[i];
 104                 c->x86_capability[i] |= cpu_caps_set[i];
 105         }
 106 --
 107 2.14.2
 108