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

6 files changed, 236 insertions, 29 deletions

diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 843feb3eb20b..0a291cdfaf77 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -51,6 +51,7 @@ $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
 
 vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \
         $(objtree)/drivers/firmware/efi/libstub/lib.a
+vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
 
 $(obj)/vmlinux: $(vmlinux-objs-y) FORCE
         $(call if_changed,ld)
diff --git a/arch/x86/boot/compressed/aslr.c b/arch/x86/boot/compressed/aslr.c
index bb1376381985..7083c16cccba 100644
--- a/arch/x86/boot/compressed/aslr.c
+++ b/arch/x86/boot/compressed/aslr.c
@@ -14,6 +14,13 @@
 static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"
                 LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION;
 
+struct kaslr_setup_data {
+        __u64 next;
+        __u32 type;
+        __u32 len;
+        __u8 data[1];
+} kaslr_setup_data;
+
 #define I8254_PORT_CONTROL      0x43
 #define I8254_PORT_COUNTER0     0x40
 #define I8254_CMD_READBACK      0xC0
@@ -295,7 +302,29 @@ static unsigned long find_random_addr(unsigned long minimum,
         return slots_fetch_random();
 }
 
-unsigned char *choose_kernel_location(unsigned char *input,
+static void add_kaslr_setup_data(struct boot_params *params, __u8 enabled)
+{
+        struct setup_data *data;
+
+        kaslr_setup_data.type = SETUP_KASLR;
+        kaslr_setup_data.len = 1;
+        kaslr_setup_data.next = 0;
+        kaslr_setup_data.data[0] = enabled;
+
+        data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
+
+        while (data && data->next)
+                data = (struct setup_data *)(unsigned long)data->next;
+
+        if (data)
+                data->next = (unsigned long)&kaslr_setup_data;
+        else
+                params->hdr.setup_data = (unsigned long)&kaslr_setup_data;
+
+}
+
+unsigned char *choose_kernel_location(struct boot_params *params,
+                                      unsigned char *input,
                                       unsigned long input_size,
                                       unsigned char *output,
                                       unsigned long output_size)
@@ -306,14 +335,17 @@ unsigned char *choose_kernel_location(unsigned char *input,
 #ifdef CONFIG_HIBERNATION
         if (!cmdline_find_option_bool("kaslr")) {
                 debug_putstr("KASLR disabled by default...\n");
+                add_kaslr_setup_data(params, 0);
                 goto out;
         }
 #else
         if (cmdline_find_option_bool("nokaslr")) {
                 debug_putstr("KASLR disabled by cmdline...\n");
+                add_kaslr_setup_data(params, 0);
                 goto out;
         }
 #endif
+        add_kaslr_setup_data(params, 1);
 
         /* Record the various known unsafe memory ranges. */
         mem_avoid_init((unsigned long)input, input_size,
diff --git a/arch/x86/boot/compressed/efi_stub_64.S b/arch/x86/boot/compressed/efi_stub_64.S
index 7ff3632806b1..99494dff2113 100644
--- a/arch/x86/boot/compressed/efi_stub_64.S
+++ b/arch/x86/boot/compressed/efi_stub_64.S
@@ -3,28 +3,3 @@
 #include <asm/processor-flags.h>
 
 #include "../../platform/efi/efi_stub_64.S"
-
-#ifdef CONFIG_EFI_MIXED
-        .code64
-        .text
-ENTRY(efi64_thunk)
-        push    %rbp
-        push    %rbx
-
-        subq    $16, %rsp
-        leaq    efi_exit32(%rip), %rax
-        movl    %eax, 8(%rsp)
-        leaq    efi_gdt64(%rip), %rax
-        movl    %eax, 4(%rsp)
-        movl    %eax, 2(%rax)           /* Fixup the gdt base address */
-        leaq    efi32_boot_gdt(%rip), %rax
-        movl    %eax, (%rsp)
-
-        call    __efi64_thunk
-
-        addq    $16, %rsp
-        pop     %rbx
-        pop     %rbp
-        ret
-ENDPROC(efi64_thunk)
-#endif /* CONFIG_EFI_MIXED */
diff --git a/arch/x86/boot/compressed/efi_thunk_64.S b/arch/x86/boot/compressed/efi_thunk_64.S
new file mode 100644
index 000000000000..630384a4c14a
--- /dev/null
+++ b/arch/x86/boot/compressed/efi_thunk_64.S
@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2014, 2015 Intel Corporation; author Matt Fleming
+ *
+ * Early support for invoking 32-bit EFI services from a 64-bit kernel.
+ *
+ * Because this thunking occurs before ExitBootServices() we have to
+ * restore the firmware's 32-bit GDT before we make EFI serivce calls,
+ * since the firmware's 32-bit IDT is still currently installed and it
+ * needs to be able to service interrupts.
+ *
+ * On the plus side, we don't have to worry about mangling 64-bit
+ * addresses into 32-bits because we're executing with an identify
+ * mapped pagetable and haven't transitioned to 64-bit virtual addresses
+ * yet.
+ */
+
+#include <linux/linkage.h>
+#include <asm/msr.h>
+#include <asm/page_types.h>
+#include <asm/processor-flags.h>
+#include <asm/segment.h>
+
+        .code64
+        .text
+ENTRY(efi64_thunk)
+        push    %rbp
+        push    %rbx
+
+        subq    $8, %rsp
+        leaq    efi_exit32(%rip), %rax
+        movl    %eax, 4(%rsp)
+        leaq    efi_gdt64(%rip), %rax
+        movl    %eax, (%rsp)
+        movl    %eax, 2(%rax)           /* Fixup the gdt base address */
+
+        movl    %ds, %eax
+        push    %rax
+        movl    %es, %eax
+        push    %rax
+        movl    %ss, %eax
+        push    %rax
+
+        /*
+         * Convert x86-64 ABI params to i386 ABI
+         */
+        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. This is the firmware GDT
+         * that was installed when the kernel started executing. This
+         * pointer was saved at the EFI stub entry point in head_64.S.
+         */
+        leaq    efi32_boot_gdt(%rip), %rax
+        lgdt    (%rax)
+
+        pushq   $__KERNEL_CS
+        leaq    efi_enter32(%rip), %rax
+        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:
+        addq    $8, %rsp
+        pop     %rbx
+        pop     %rbp
+        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    56(%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    60(%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:
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index a950864a64da..5903089c818f 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -401,7 +401,8 @@ asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap,
          * the entire decompressed kernel plus relocation table, or the
          * entire decompressed kernel plus .bss and .brk sections.
          */
-        output = choose_kernel_location(input_data, input_len, output,
+        output = choose_kernel_location(real_mode, input_data, input_len,
+                                        output,
                                         output_len > run_size ? output_len
                                                               : run_size);
 
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 04477d68403f..ee3576b2666b 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -57,7 +57,8 @@ int cmdline_find_option_bool(const char *option);
 
 #if CONFIG_RANDOMIZE_BASE
 /* aslr.c */
-unsigned char *choose_kernel_location(unsigned char *input,
+unsigned char *choose_kernel_location(struct boot_params *params,
+                                      unsigned char *input,
                                       unsigned long input_size,
                                       unsigned char *output,
                                       unsigned long output_size);
@@ -65,7 +66,8 @@ unsigned char *choose_kernel_location(unsigned char *input,
 bool has_cpuflag(int flag);
 #else
 static inline
-unsigned char *choose_kernel_location(unsigned char *input,
+unsigned char *choose_kernel_location(struct boot_params *params,
+                                      unsigned char *input,
                                       unsigned long input_size,
                                       unsigned char *output,
                                       unsigned long output_size)