2 files changed, 81 insertions, 29 deletions

diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index cbed1407a5cd..d6b8aa4c986c 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -30,6 +30,33 @@
 #include <asm/boot.h>
 #include <asm/asm-offsets.h>
 
+/*
+ * Adjust our own GOT
+ *
+ * The relocation base must be in %ebx
+ *
+ * It is safe to call this macro more than once, because in some of the
+ * code paths multiple invocations are inevitable, e.g. via the efi*
+ * entry points.
+ *
+ * Relocation is only performed the first time.
+ */
+.macro FIXUP_GOT
+	cmpb	$1, got_fixed(%ebx)
+	je	2f
+
+	leal	_got(%ebx), %edx
+	leal	_egot(%ebx), %ecx
+1:
+	cmpl	%ecx, %edx
+	jae	2f
+	addl	%ebx, (%edx)
+	addl	$4, %edx
+	jmp	1b
+2:
+	movb	$1, got_fixed(%ebx)
+.endm
+
 	__HEAD
 ENTRY(startup_32)
 #ifdef CONFIG_EFI_STUB
@@ -56,6 +83,9 @@ ENTRY(efi_pe_entry)
 	add	%esi, 88(%eax)
 	pushl	%eax
 
+	movl	%esi, %ebx
+	FIXUP_GOT
+
 	call	make_boot_params
 	cmpl	$0, %eax
 	je	fail
@@ -81,6 +111,10 @@ ENTRY(efi32_stub_entry)
 	leal	efi32_config(%esi), %eax
 	add	%esi, 88(%eax)
 	pushl	%eax
+
+	movl	%esi, %ebx
+	FIXUP_GOT
+
 2:
 	call	efi_main
 	cmpl	$0, %eax
@@ -190,19 +224,7 @@ relocated:
 	shrl	$2, %ecx
 	rep	stosl
 
-/*
- * Adjust our own GOT
- */
-	leal	_got(%ebx), %edx
-	leal	_egot(%ebx), %ecx
-1:
-	cmpl	%ecx, %edx
-	jae	2f
-	addl	%ebx, (%edx)
-	addl	$4, %edx
-	jmp	1b
-2:
-
+	FIXUP_GOT
 /*
  * Do the decompression, and jump to the new kernel..
  */
@@ -225,8 +247,12 @@ relocated:
 	xorl	%ebx, %ebx
 	jmp	*%eax
 
-#ifdef CONFIG_EFI_STUB
 	.data
+/* Have we relocated the GOT? */
+got_fixed:
+	.byte 0
+
+#ifdef CONFIG_EFI_STUB
 efi32_config:
 	.fill 11,8,0
 	.long efi_call_phys
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 2884e0c3e8a5..50f69c7eaaf4 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -32,6 +32,33 @@
 #include <asm/processor-flags.h>
 #include <asm/asm-offsets.h>
 
+/*
+ * Adjust our own GOT
+ *
+ * The relocation base must be in %rbx
+ *
+ * It is safe to call this macro more than once, because in some of the
+ * code paths multiple invocations are inevitable, e.g. via the efi*
+ * entry points.
+ *
+ * Relocation is only performed the first time.
+ */
+.macro FIXUP_GOT
+	cmpb	$1, got_fixed(%rip)
+	je	2f
+
+	leaq	_got(%rip), %rdx
+	leaq	_egot(%rip), %rcx
+1:
+	cmpq	%rcx, %rdx
+	jae	2f
+	addq	%rbx, (%rdx)
+	addq	$8, %rdx
+	jmp	1b
+2:
+	movb	$1, got_fixed(%rip)
+.endm
+
 	__HEAD
 	.code32
 ENTRY(startup_32)
@@ -252,10 +279,13 @@ ENTRY(efi_pe_entry)
 	subq	$1b, %rbp
 
 	/*
-	 * Relocate efi_config->call().
+	 * Relocate efi_config->call() and the GOT entries.
 	 */
 	addq	%rbp, efi64_config+88(%rip)
 
+	movq	%rbp, %rbx
+	FIXUP_GOT
+
 	movq	%rax, %rdi
 	call	make_boot_params
 	cmpq	$0,%rax
@@ -271,10 +301,13 @@ handover_entry:
 	subq	$1b, %rbp
 
 	/*
-	 * Relocate efi_config->call().
+	 * Relocate efi_config->call() and the GOT entries.
 	 */
 	movq	efi_config(%rip), %rax
 	addq	%rbp, 88(%rax)
+
+	movq	%rbp, %rbx
+	FIXUP_GOT
 2:
 	movq	efi_config(%rip), %rdi
 	call	efi_main
@@ -385,19 +418,8 @@ relocated:
 	shrq	$3, %rcx
 	rep	stosq
 
-/*
- * Adjust our own GOT
- */
-	leaq	_got(%rip), %rdx
-	leaq	_egot(%rip), %rcx
-1:
-	cmpq	%rcx, %rdx
-	jae	2f
-	addq	%rbx, (%rdx)
-	addq	$8, %rdx
-	jmp	1b
-2:
-	
+	FIXUP_GOT
+
 /*
  * Do the decompression, and jump to the new kernel..
  */
@@ -437,6 +459,10 @@ gdt:
 	.quad   0x0000000000000000	/* TS continued */
 gdt_end:
 
+/* Have we relocated the GOT? */
+got_fixed:
+	.byte	0
+
 #ifdef CONFIG_EFI_STUB
 efi_config:
 	.quad	0