Merge tag 'v3.16-rc1' into x86/cpufeature

[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 e7c4b979d504e0be9eb041b0b32f80ef7b3185fb..188a8c5cc09425180ea38d251b2d1a2556223ee7 100644 (file)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -8,6 +8,7 @@
 #include <linux/delay.h>
 #include <linux/sched.h>
 #include <linux/init.h>
+#include <linux/kprobes.h>
 #include <linux/kgdb.h>
 #include <linux/smp.h>
 #include <linux/io.h>
@@ -20,6 +21,7 @@
 #include <asm/processor.h>
 #include <asm/debugreg.h>
 #include <asm/sections.h>
+#include <asm/vsyscall.h>
 #include <linux/topology.h>
 #include <linux/cpumask.h>
 #include <asm/pgtable.h>
@@ -962,6 +964,38 @@ static void vgetcpu_set_mode(void)
        else
                vgetcpu_mode = VGETCPU_LSL;
 }
+
+/* May not be __init: called during resume */
+static void syscall32_cpu_init(void)
+{
+       /* Load these always in case some future AMD CPU supports
+          SYSENTER from compat mode too. */
+       wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
+       wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
+       wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
+
+       wrmsrl(MSR_CSTAR, ia32_cstar_target);
+}
+#endif
+
+#ifdef CONFIG_X86_32
+void enable_sep_cpu(void)
+{
+       int cpu = get_cpu();
+       struct tss_struct *tss = &per_cpu(init_tss, cpu);
+
+       if (!boot_cpu_has(X86_FEATURE_SEP)) {
+               put_cpu();
+               return;
+       }
+
+       tss->x86_tss.ss1 = __KERNEL_CS;
+       tss->x86_tss.sp1 = sizeof(struct tss_struct) + (unsigned long) tss;
+       wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
+       wrmsr(MSR_IA32_SYSENTER_ESP, tss->x86_tss.sp1, 0);
+       wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) ia32_sysenter_target, 0);
+       put_cpu();
+}
 #endif
 
 void __init identify_boot_cpu(void)
@@ -1169,6 +1203,7 @@ int is_debug_stack(unsigned long addr)
                (addr <= __get_cpu_var(debug_stack_addr) &&
                 addr > (__get_cpu_var(debug_stack_addr) - DEBUG_STKSZ));
 }
+NOKPROBE_SYMBOL(is_debug_stack);
 
 DEFINE_PER_CPU(u32, debug_idt_ctr);
 
@@ -1177,6 +1212,7 @@ void debug_stack_set_zero(void)
        this_cpu_inc(debug_idt_ctr);
        load_current_idt();
 }
+NOKPROBE_SYMBOL(debug_stack_set_zero);
 
 void debug_stack_reset(void)
 {
@@ -1185,6 +1221,7 @@ void debug_stack_reset(void)
        if (this_cpu_dec_return(debug_idt_ctr) == 0)
                load_current_idt();
 }
+NOKPROBE_SYMBOL(debug_stack_reset);
 
 #else  /* CONFIG_X86_64 */