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Subject[PATCH v6 08/27] x86/acpi: Adapt assembly for PIE support
Date
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@chromium.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
arch/x86/kernel/acpi/wakeup_64.S | 31 ++++++++++++++++---------------
1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S
index 50b8ed0317a3..472659c0f811 100644
--- a/arch/x86/kernel/acpi/wakeup_64.S
+++ b/arch/x86/kernel/acpi/wakeup_64.S
@@ -14,7 +14,7 @@
* Hooray, we are in Long 64-bit mode (but still running in low memory)
*/
ENTRY(wakeup_long64)
- movq saved_magic, %rax
+ movq saved_magic(%rip), %rax
movq $0x123456789abcdef0, %rdx
cmpq %rdx, %rax
jne bogus_64_magic
@@ -25,14 +25,14 @@ ENTRY(wakeup_long64)
movw %ax, %es
movw %ax, %fs
movw %ax, %gs
- movq saved_rsp, %rsp
+ movq saved_rsp(%rip), %rsp

- movq saved_rbx, %rbx
- movq saved_rdi, %rdi
- movq saved_rsi, %rsi
- movq saved_rbp, %rbp
+ movq saved_rbx(%rip), %rbx
+ movq saved_rdi(%rip), %rdi
+ movq saved_rsi(%rip), %rsi
+ movq saved_rbp(%rip), %rbp

- movq saved_rip, %rax
+ movq saved_rip(%rip), %rax
jmp *%rax
ENDPROC(wakeup_long64)

@@ -45,7 +45,7 @@ ENTRY(do_suspend_lowlevel)
xorl %eax, %eax
call save_processor_state

- 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)
@@ -64,13 +64,14 @@ ENTRY(do_suspend_lowlevel)
pushfq
popq pt_regs_flags(%rax)

- movq $.Lresume_point, saved_rip(%rip)
+ leaq .Lresume_point(%rip), %rax
+ movq %rax, saved_rip(%rip)

- movq %rsp, saved_rsp
- movq %rbp, saved_rbp
- movq %rbx, saved_rbx
- movq %rdi, saved_rdi
- movq %rsi, saved_rsi
+ movq %rsp, saved_rsp(%rip)
+ movq %rbp, saved_rbp(%rip)
+ movq %rbx, saved_rbx(%rip)
+ movq %rdi, saved_rdi(%rip)
+ movq %rsi, saved_rsi(%rip)

addq $8, %rsp
movl $3, %edi
@@ -82,7 +83,7 @@ ENTRY(do_suspend_lowlevel)
.align 4
.Lresume_point:
/* We don't restore %rax, it must be 0 anyway */
- movq $saved_context, %rax
+ leaq saved_context(%rip), %rax
movq saved_context_cr4(%rax), %rbx
movq %rbx, %cr4
movq saved_context_cr3(%rax), %rbx
--
2.20.1.495.gaa96b0ce6b-goog
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