[PATCH v8 09/11] x86/power/64: Adapt assembly for PIE support

From: Thomas Garnier
Date: Mon Jul 08 2019 - 13:49:52 EST


Change the assembly code to use only relative references of symbols for the
kernel to be PIE compatible.

Position Independent Executable (PIE) support will allow to extend the
KASLR randomization range below 0xffffffff80000000.

Signed-off-by: Thomas Garnier <thgarnie@xxxxxxxxxxxx>
Acked-by: Pavel Machek <pavel@xxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
arch/x86/power/hibernate_asm_64.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/power/hibernate_asm_64.S b/arch/x86/power/hibernate_asm_64.S
index a4d5eb0a7ece..796cd19d575b 100644
--- a/arch/x86/power/hibernate_asm_64.S
+++ b/arch/x86/power/hibernate_asm_64.S
@@ -23,7 +23,7 @@
#include <asm/frame.h>

ENTRY(swsusp_arch_suspend)
- movq $saved_context, %rax
+ leaq saved_context(%rip), %rax
movq %rsp, pt_regs_sp(%rax)
movq %rbp, pt_regs_bp(%rax)
movq %rsi, pt_regs_si(%rax)
@@ -114,7 +114,7 @@ ENTRY(restore_registers)
movq %rax, %cr4; # turn PGE back on

/* We don't restore %rax, it must be 0 anyway */
- movq $saved_context, %rax
+ leaq saved_context(%rip), %rax
movq pt_regs_sp(%rax), %rsp
movq pt_regs_bp(%rax), %rbp
movq pt_regs_si(%rax), %rsi
--
2.22.0.410.gd8fdbe21b5-goog