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

Pull x86 fixes from Peter Anvin.

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86-64, modify_ldt: Make support for 16-bit segments a runtime option
  x86, mm, hugetlb: Add missing TLB page invalidation for hugetlb_cow()
  x86, rdrand: When nordrand is specified, disable RDSEED as well

5 files changed, 17 insertions, 5 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 43842177b771..30a8ad0dae53 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2218,10 +2218,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
         noreplace-smp   [X86-32,SMP] Don't replace SMP instructions
                         with UP alternatives
 
-        nordrand        [X86] Disable the direct use of the RDRAND
-                        instruction even if it is supported by the
-                        processor.  RDRAND is still available to user
-                        space applications.
+        nordrand        [X86] Disable kernel use of the RDRAND and
+                        RDSEED instructions even if they are supported
+                        by the processor.  RDRAND and RDSEED are still
+                        available to user space applications.
 
         noresume        [SWSUSP] Disables resume and restores original swap
                         space.
diff --git a/arch/x86/include/asm/hugetlb.h b/arch/x86/include/asm/hugetlb.h
index a8091216963b..68c05398bba9 100644
--- a/arch/x86/include/asm/hugetlb.h
+++ b/arch/x86/include/asm/hugetlb.h
@@ -52,6 +52,7 @@ static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
 static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
                                          unsigned long addr, pte_t *ptep)
 {
+        ptep_clear_flush(vma, addr, ptep);
 }
 
 static inline int huge_pte_none(pte_t pte)
diff --git a/arch/x86/kernel/cpu/rdrand.c b/arch/x86/kernel/cpu/rdrand.c
index 384df5105fbc..136ac74dee82 100644
--- a/arch/x86/kernel/cpu/rdrand.c
+++ b/arch/x86/kernel/cpu/rdrand.c
@@ -27,6 +27,7 @@
 static int __init x86_rdrand_setup(char *s)
 {
         setup_clear_cpu_cap(X86_FEATURE_RDRAND);
+        setup_clear_cpu_cap(X86_FEATURE_RDSEED);
         return 1;
 }
 __setup("nordrand", x86_rdrand_setup);
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index af1d14a9ebda..dcbbaa165bde 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -20,6 +20,8 @@
 #include <asm/mmu_context.h>
 #include <asm/syscalls.h>
 
+int sysctl_ldt16 = 0;
+
 #ifdef CONFIG_SMP
 static void flush_ldt(void *current_mm)
 {
@@ -234,7 +236,7 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
          * IRET leaking the high bits of the kernel stack address.
          */
 #ifdef CONFIG_X86_64
-        if (!ldt_info.seg_32bit) {
+        if (!ldt_info.seg_32bit && !sysctl_ldt16) {
                 error = -EINVAL;
                 goto out_unlock;
         }
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 00348980a3a6..e1f220e3ca68 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -39,6 +39,7 @@
 #ifdef CONFIG_X86_64
 #define vdso_enabled                    sysctl_vsyscall32
 #define arch_setup_additional_pages     syscall32_setup_pages
+extern int sysctl_ldt16;
 #endif
 
 /*
@@ -249,6 +250,13 @@ static struct ctl_table abi_table2[] = {
                 .mode           = 0644,
                 .proc_handler   = proc_dointvec
         },
+        {
+                .procname       = "ldt16",
+                .data           = &sysctl_ldt16,
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = proc_dointvec
+        },
         {}
 };