4.9-stable patches

added patches:
	revert-x86-speculation-enable-cross-hyperthread-spectre-v2.patch

diff --git a/queue-4.9/revert-x86-speculation-enable-cross-hyperthread-spectre-v2.patch b/queue-4.9/revert-x86-speculation-enable-cross-hyperthread-spectre-v2.patch
new file mode 100644 (file)
index 0000000..23e036d
--- /dev/null
+++ b/queue-4.9/revert-x86-speculation-enable-cross-hyperthread-spectre-v2.patch
@@ -0,0 +1,163 @@
+From c33b5cc7076b9140d5d393a2d750475b08d8efad Mon Sep 17 00:00:00 2001
+From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Date: Wed, 21 Nov 2018 19:11:06 +0100
+Subject: Revert "x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation"
+
+From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+This reverts commit 66fe51cb35d91d75a67ec8a38caf03da95e8c191 which is
+commit 53c613fe6349994f023245519265999eed75957f upstream.
+
+It's not ready for the stable trees as there are major slowdowns
+involved with this patch.
+
+Reported-by: Jiri Kosina <jkosina@suse.cz>
+Cc: Thomas Gleixner <tglx@linutronix.de>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: Josh Poimboeuf <jpoimboe@redhat.com>
+Cc: Andrea Arcangeli <aarcange@redhat.com>
+Cc:  "WoodhouseDavid" <dwmw@amazon.co.uk>
+Cc: Andi Kleen <ak@linux.intel.com>
+Cc: Tim Chen <tim.c.chen@linux.intel.com>
+Cc:  "SchauflerCasey" <casey.schaufler@intel.com>
+Cc: Rainer Fiebig <jrf@mailbox.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/x86/kernel/cpu/bugs.c |   57 ++++-----------------------------------------
+ kernel/cpu.c               |   11 --------
+ 2 files changed, 7 insertions(+), 61 deletions(-)
+
+--- a/arch/x86/kernel/cpu/bugs.c
++++ b/arch/x86/kernel/cpu/bugs.c
+@@ -33,10 +33,12 @@ static void __init spectre_v2_select_mit
+ static void __init ssb_select_mitigation(void);
+ static void __init l1tf_select_mitigation(void);
+ 
+-/* The base value of the SPEC_CTRL MSR that always has to be preserved. */
+-u64 x86_spec_ctrl_base;
++/*
++ * Our boot-time value of the SPEC_CTRL MSR. We read it once so that any
++ * writes to SPEC_CTRL contain whatever reserved bits have been set.
++ */
++u64 __ro_after_init x86_spec_ctrl_base;
+ EXPORT_SYMBOL_GPL(x86_spec_ctrl_base);
+-static DEFINE_MUTEX(spec_ctrl_mutex);
+ 
+ /*
+  * The vendor and possibly platform specific bits which can be modified in
+@@ -320,46 +322,6 @@ static enum spectre_v2_mitigation_cmd __
+       return cmd;
+ }
+ 
+-static bool stibp_needed(void)
+-{
+-      if (spectre_v2_enabled == SPECTRE_V2_NONE)
+-              return false;
+-
+-      if (!boot_cpu_has(X86_FEATURE_STIBP))
+-              return false;
+-
+-      return true;
+-}
+-
+-static void update_stibp_msr(void *info)
+-{
+-      wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
+-}
+-
+-void arch_smt_update(void)
+-{
+-      u64 mask;
+-
+-      if (!stibp_needed())
+-              return;
+-
+-      mutex_lock(&spec_ctrl_mutex);
+-      mask = x86_spec_ctrl_base;
+-      if (cpu_smt_control == CPU_SMT_ENABLED)
+-              mask |= SPEC_CTRL_STIBP;
+-      else
+-              mask &= ~SPEC_CTRL_STIBP;
+-
+-      if (mask != x86_spec_ctrl_base) {
+-              pr_info("Spectre v2 cross-process SMT mitigation: %s STIBP\n",
+-                              cpu_smt_control == CPU_SMT_ENABLED ?
+-                              "Enabling" : "Disabling");
+-              x86_spec_ctrl_base = mask;
+-              on_each_cpu(update_stibp_msr, NULL, 1);
+-      }
+-      mutex_unlock(&spec_ctrl_mutex);
+-}
+-
+ static void __init spectre_v2_select_mitigation(void)
+ {
+       enum spectre_v2_mitigation_cmd cmd = spectre_v2_parse_cmdline();
+@@ -459,9 +421,6 @@ specv2_set_mode:
+               setup_force_cpu_cap(X86_FEATURE_USE_IBRS_FW);
+               pr_info("Enabling Restricted Speculation for firmware calls\n");
+       }
+-
+-      /* Enable STIBP if appropriate */
+-      arch_smt_update();
+ }
+ 
+ #undef pr_fmt
+@@ -854,8 +813,6 @@ static ssize_t l1tf_show_state(char *buf
+ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr,
+                              char *buf, unsigned int bug)
+ {
+-      int ret;
+-
+       if (!boot_cpu_has_bug(bug))
+               return sprintf(buf, "Not affected\n");
+ 
+@@ -870,12 +827,10 @@ static ssize_t cpu_show_common(struct de
+               return sprintf(buf, "Mitigation: __user pointer sanitization\n");
+ 
+       case X86_BUG_SPECTRE_V2:
+-              ret = sprintf(buf, "%s%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
++              return sprintf(buf, "%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
+                              boot_cpu_has(X86_FEATURE_USE_IBPB) ? ", IBPB" : "",
+                              boot_cpu_has(X86_FEATURE_USE_IBRS_FW) ? ", IBRS_FW" : "",
+-                             (x86_spec_ctrl_base & SPEC_CTRL_STIBP) ? ", STIBP" : "",
+                              spectre_v2_module_string());
+-              return ret;
+ 
+       case X86_BUG_SPEC_STORE_BYPASS:
+               return sprintf(buf, "%s\n", ssb_strings[ssb_mode]);
+--- a/kernel/cpu.c
++++ b/kernel/cpu.c
+@@ -1970,12 +1970,6 @@ static void cpuhp_online_cpu_device(unsi
+       kobject_uevent(&dev->kobj, KOBJ_ONLINE);
+ }
+ 
+-/*
+- * Architectures that need SMT-specific errata handling during SMT hotplug
+- * should override this.
+- */
+-void __weak arch_smt_update(void) { };
+-
+ static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
+ {
+       int cpu, ret = 0;
+@@ -2002,10 +1996,8 @@ static int cpuhp_smt_disable(enum cpuhp_
+                */
+               cpuhp_offline_cpu_device(cpu);
+       }
+-      if (!ret) {
++      if (!ret)
+               cpu_smt_control = ctrlval;
+-              arch_smt_update();
+-      }
+       cpu_maps_update_done();
+       return ret;
+ }
+@@ -2016,7 +2008,6 @@ static int cpuhp_smt_enable(void)
+ 
+       cpu_maps_update_begin();
+       cpu_smt_control = CPU_SMT_ENABLED;
+-      arch_smt_update();
+       for_each_present_cpu(cpu) {
+               /* Skip online CPUs and CPUs on offline nodes */
+               if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))

diff --git a/queue-4.9/series b/queue-4.9/series
new file mode 100644 (file)
index 0000000..8863262
--- /dev/null
+++ b/queue-4.9/series
@@ -0,0 +1 @@
+revert-x86-speculation-enable-cross-hyperthread-spectre-v2.patch