[PATCH v6 04/27] x86: relocate_kernel - Adapt assembly for PIE support

From: Thomas Garnier
Date: Thu Jan 31 2019 - 14:28:25 EST


Change the assembly code to use only absolute 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>
---
arch/x86/kernel/relocate_kernel_64.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
index 11eda21eb697..3320368b6ec9 100644
--- a/arch/x86/kernel/relocate_kernel_64.S
+++ b/arch/x86/kernel/relocate_kernel_64.S
@@ -208,7 +208,7 @@ identity_mapped:
movq %rax, %cr3
lea PAGE_SIZE(%r8), %rsp
call swap_pages
- movq $virtual_mapped, %rax
+ movabsq $virtual_mapped, %rax
pushq %rax
ret

--
2.20.1.495.gaa96b0ce6b-goog