kernel/Revert-x86-efi-Fixup-GOT-in-all-boot-code-paths.patch

From 6b57872f1ef945b97044a7fbbd75dfb526cd6aff Mon Sep 17 00:00:00 2001
From: Josh Boyer <jwboyer@fedoraproject.org>
Date: Mon, 22 Sep 2014 14:45:11 -0400
Subject: [PATCH] Revert "x86/efi: Fixup GOT in all boot code paths"

This reverts commit 9cb0e394234d244fe5a97e743ec9dd7ddff7e64b.
---
 arch/x86/boot/compressed/head_32.S | 54 ++++++++++--------------------------
 arch/x86/boot/compressed/head_64.S | 56 ++++++++++----------------------------
 2 files changed, 29 insertions(+), 81 deletions(-)

diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index d6b8aa4c986c..cbed1407a5cd 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -30,33 +30,6 @@
 #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
@@ -83,9 +56,6 @@ ENTRY(efi_pe_entry)
 	add	%esi, 88(%eax)
 	pushl	%eax
 
-	movl	%esi, %ebx
-	FIXUP_GOT
-
 	call	make_boot_params
 	cmpl	$0, %eax
 	je	fail
@@ -111,10 +81,6 @@ 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
@@ -224,7 +190,19 @@ relocated:
 	shrl	$2, %ecx
 	rep	stosl
 
-	FIXUP_GOT
+/*
+ * 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:
+
 /*
  * Do the decompression, and jump to the new kernel..
  */
@@ -247,12 +225,8 @@ relocated:
 	xorl	%ebx, %ebx
 	jmp	*%eax
 
-	.data
-/* Have we relocated the GOT? */
-got_fixed:
-	.byte 0
-
 #ifdef CONFIG_EFI_STUB
+	.data
 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 50f69c7eaaf4..2884e0c3e8a5 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -32,33 +32,6 @@
 #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)
@@ -279,13 +252,10 @@ ENTRY(efi_pe_entry)
 	subq	$1b, %rbp
 
 	/*
-	 * Relocate efi_config->call() and the GOT entries.
+	 * Relocate efi_config->call().
 	 */
 	addq	%rbp, efi64_config+88(%rip)
 
-	movq	%rbp, %rbx
-	FIXUP_GOT
-
 	movq	%rax, %rdi
 	call	make_boot_params
 	cmpq	$0,%rax
@@ -301,13 +271,10 @@ handover_entry:
 	subq	$1b, %rbp
 
 	/*
-	 * Relocate efi_config->call() and the GOT entries.
+	 * Relocate efi_config->call().
 	 */
 	movq	efi_config(%rip), %rax
 	addq	%rbp, 88(%rax)
-
-	movq	%rbp, %rbx
-	FIXUP_GOT
 2:
 	movq	efi_config(%rip), %rdi
 	call	efi_main
@@ -418,8 +385,19 @@ relocated:
 	shrq	$3, %rcx
 	rep	stosq
 
-	FIXUP_GOT
-
+/*
+ * 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:
+	
 /*
  * Do the decompression, and jump to the new kernel..
  */
@@ -459,10 +437,6 @@ gdt:
 	.quad   0x0000000000000000	/* TS continued */
 gdt_end:
 
-/* Have we relocated the GOT? */
-got_fixed:
-	.byte	0
-
 #ifdef CONFIG_EFI_STUB
 efi_config:
 	.quad	0
-- 
1.9.3