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Diffstat (limited to 'arch/x86/boot/compressed/head_64.S')
-rw-r--r--arch/x86/boot/compressed/head_64.S56
1 files changed, 41 insertions, 15 deletions
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