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

Pull misc x86 fixes from Ingo Molnar:
 "This contains:

   - EFI fixes
   - a boot printout fix
   - ASLR/kASLR fixes
   - intel microcode driver fixes
   - other misc fixes

  Most of the linecount comes from an EFI revert"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/ASLR: Avoid PAGE_SIZE redefinition for UML subarch
  x86/microcode/intel: Handle truncated microcode images more robustly
  x86/microcode/intel: Guard against stack overflow in the loader
  x86, mm/ASLR: Fix stack randomization on 64-bit systems
  x86/mm/init: Fix incorrect page size in init_memory_mapping() printks
  x86/mm/ASLR: Propagate base load address calculation
  Documentation/x86: Fix path in zero-page.txt
  x86/apic: Fix the devicetree build in certain configs
  Revert "efi/libstub: Call get_memory_map() to obtain map and desc sizes"
  x86/efi: Avoid triple faults during EFI mixed mode calls

2 files changed, 104 insertions, 178 deletions

diff --git a/arch/x86/platform/efi/efi_stub_64.S b/arch/x86/platform/efi/efi_stub_64.S
index 5fcda7272550..86d0f9e08dd9 100644
--- a/arch/x86/platform/efi/efi_stub_64.S
+++ b/arch/x86/platform/efi/efi_stub_64.S
@@ -91,167 +91,6 @@ ENTRY(efi_call)
         ret
 ENDPROC(efi_call)
 
-#ifdef CONFIG_EFI_MIXED
-
-/*
- * We run this function from the 1:1 mapping.
- *
- * This function must be invoked with a 1:1 mapped stack.
- */
-ENTRY(__efi64_thunk)
-        movl    %ds, %eax
-        push    %rax
-        movl    %es, %eax
-        push    %rax
-        movl    %ss, %eax
-        push    %rax
-
-        subq    $32, %rsp
-        movl    %esi, 0x0(%rsp)
-        movl    %edx, 0x4(%rsp)
-        movl    %ecx, 0x8(%rsp)
-        movq    %r8, %rsi
-        movl    %esi, 0xc(%rsp)
-        movq    %r9, %rsi
-        movl    %esi,  0x10(%rsp)
-
-        sgdt    save_gdt(%rip)
-
-        leaq    1f(%rip), %rbx
-        movq    %rbx, func_rt_ptr(%rip)
-
-        /* Switch to gdt with 32-bit segments */
-        movl    64(%rsp), %eax
-        lgdt    (%rax)
-
-        leaq    efi_enter32(%rip), %rax
-        pushq   $__KERNEL_CS
-        pushq   %rax
-        lretq
-
-1:      addq    $32, %rsp
-
-        lgdt    save_gdt(%rip)
-
-        pop     %rbx
-        movl    %ebx, %ss
-        pop     %rbx
-        movl    %ebx, %es
-        pop     %rbx
-        movl    %ebx, %ds
-
-        /*
-         * Convert 32-bit status code into 64-bit.
-         */
-        test    %rax, %rax
-        jz      1f
-        movl    %eax, %ecx
-        andl    $0x0fffffff, %ecx
-        andl    $0xf0000000, %eax
-        shl     $32, %rax
-        or      %rcx, %rax
-1:
-        ret
-ENDPROC(__efi64_thunk)
-
-ENTRY(efi_exit32)
-        movq    func_rt_ptr(%rip), %rax
-        push    %rax
-        mov     %rdi, %rax
-        ret
-ENDPROC(efi_exit32)
-
-        .code32
-/*
- * EFI service pointer must be in %edi.
- *
- * The stack should represent the 32-bit calling convention.
- */
-ENTRY(efi_enter32)
-        movl    $__KERNEL_DS, %eax
-        movl    %eax, %ds
-        movl    %eax, %es
-        movl    %eax, %ss
-
-        /* Reload pgtables */
-        movl    %cr3, %eax
-        movl    %eax, %cr3
-
-        /* Disable paging */
-        movl    %cr0, %eax
-        btrl    $X86_CR0_PG_BIT, %eax
-        movl    %eax, %cr0
-
-        /* Disable long mode via EFER */
-        movl    $MSR_EFER, %ecx
-        rdmsr
-        btrl    $_EFER_LME, %eax
-        wrmsr
-
-        call    *%edi
-
-        /* We must preserve return value */
-        movl    %eax, %edi
-
-        /*
-         * Some firmware will return with interrupts enabled. Be sure to
-         * disable them before we switch GDTs.
-         */
-        cli
-
-        movl    68(%esp), %eax
-        movl    %eax, 2(%eax)
-        lgdtl   (%eax)
-
-        movl    %cr4, %eax
-        btsl    $(X86_CR4_PAE_BIT), %eax
-        movl    %eax, %cr4
-
-        movl    %cr3, %eax
-        movl    %eax, %cr3
-
-        movl    $MSR_EFER, %ecx
-        rdmsr
-        btsl    $_EFER_LME, %eax
-        wrmsr
-
-        xorl    %eax, %eax
-        lldt    %ax
-
-        movl    72(%esp), %eax
-        pushl   $__KERNEL_CS
-        pushl   %eax
-
-        /* Enable paging */
-        movl    %cr0, %eax
-        btsl    $X86_CR0_PG_BIT, %eax
-        movl    %eax, %cr0
-        lret
-ENDPROC(efi_enter32)
-
-        .data
-        .balign 8
-        .global efi32_boot_gdt
-efi32_boot_gdt: .word   0
-                .quad   0
-
-save_gdt:       .word   0
-                .quad   0
-func_rt_ptr:    .quad   0
-
-        .global efi_gdt64
-efi_gdt64:
-        .word   efi_gdt64_end - efi_gdt64
-        .long   0                       /* Filled out by user */
-        .word   0
-        .quad   0x0000000000000000      /* NULL descriptor */
-        .quad   0x00af9a000000ffff      /* __KERNEL_CS */
-        .quad   0x00cf92000000ffff      /* __KERNEL_DS */
-        .quad   0x0080890000000000      /* TS descriptor */
-        .quad   0x0000000000000000      /* TS continued */
-efi_gdt64_end:
-#endif /* CONFIG_EFI_MIXED */
-
         .data
 ENTRY(efi_scratch)
         .fill 3,8,0
diff --git a/arch/x86/platform/efi/efi_thunk_64.S b/arch/x86/platform/efi/efi_thunk_64.S
index 8806fa73e6e6..ff85d28c50f2 100644
--- a/arch/x86/platform/efi/efi_thunk_64.S
+++ b/arch/x86/platform/efi/efi_thunk_64.S
@@ -1,9 +1,26 @@
 /*
  * Copyright (C) 2014 Intel Corporation; author Matt Fleming
+ *
+ * Support for invoking 32-bit EFI runtime services from a 64-bit
+ * kernel.
+ *
+ * The below thunking functions are only used after ExitBootServices()
+ * has been called. This simplifies things considerably as compared with
+ * the early EFI thunking because we can leave all the kernel state
+ * intact (GDT, IDT, etc) and simply invoke the the 32-bit EFI runtime
+ * services from __KERNEL32_CS. This means we can continue to service
+ * interrupts across an EFI mixed mode call.
+ *
+ * We do however, need to handle the fact that we're running in a full