Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[mirror_ubuntu-artful-kernel.git] / arch / x86 / kernel / cpu / common.c

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 68a80e9b67fc23748b83af4d1099895cc8a6291d..4e8d25d395eeca383248d0ed76cc0fe28d0134d2 100644 (file)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -800,6 +800,31 @@ static void detect_nopl(struct cpuinfo_x86 *c)
        clear_cpu_cap(c, X86_FEATURE_NOPL);
 #else
        set_cpu_cap(c, X86_FEATURE_NOPL);
+#endif
+
+       /*
+        * ESPFIX is a strange bug.  All real CPUs have it.  Paravirt
+        * systems that run Linux at CPL > 0 may or may not have the
+        * issue, but, even if they have the issue, there's absolutely
+        * nothing we can do about it because we can't use the real IRET
+        * instruction.
+        *
+        * NB: For the time being, only 32-bit kernels support
+        * X86_BUG_ESPFIX as such.  64-bit kernels directly choose
+        * whether to apply espfix using paravirt hooks.  If any
+        * non-paravirt system ever shows up that does *not* have the
+        * ESPFIX issue, we can change this.
+        */
+#ifdef CONFIG_X86_32
+#ifdef CONFIG_PARAVIRT
+       do {
+               extern void native_iret(void);
+               if (pv_cpu_ops.iret == native_iret)
+                       set_cpu_bug(c, X86_BUG_ESPFIX);
+       } while (0);
+#else
+       set_cpu_bug(c, X86_BUG_ESPFIX);
+#endif
 #endif
 }
 
@@ -975,6 +1000,8 @@ static void identify_cpu(struct cpuinfo_x86 *c)
 #ifdef CONFIG_NUMA
        numa_add_cpu(smp_processor_id());
 #endif
+       /* The boot/hotplug time assigment got cleared, restore it */
+       c->logical_proc_id = topology_phys_to_logical_pkg(c->phys_proc_id);
 }
 
 /*
@@ -1473,20 +1500,6 @@ void cpu_init(void)
 }
 #endif
 
-#ifdef CONFIG_X86_DEBUG_STATIC_CPU_HAS
-void warn_pre_alternatives(void)
-{
-       WARN(1, "You're using static_cpu_has before alternatives have run!\n");
-}
-EXPORT_SYMBOL_GPL(warn_pre_alternatives);
-#endif
-
-inline bool __static_cpu_has_safe(u16 bit)
-{
-       return boot_cpu_has(bit);
-}
-EXPORT_SYMBOL_GPL(__static_cpu_has_safe);
-
 static void bsp_resume(void)
 {
        if (this_cpu->c_bsp_resume)