[PATCH RFC 07/43] x86/acpi: Adapt assembly for PIE support

From: Hou Wenlong
Date: Fri Apr 28 2023 - 05:52:40 EST


From: Thomas Garnier <thgarnie@xxxxxxxxxxxx>

From: Thomas Garnier <thgarnie@xxxxxxxxxxxx>

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

Signed-off-by: Thomas Garnier <thgarnie@xxxxxxxxxxxx>
Signed-off-by: Hou Wenlong <houwenlong.hwl@xxxxxxxxxxxx>
Cc: Lai Jiangshan <jiangshan.ljs@xxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
---
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 d5d8a352eafa..fe688bd87d72 100644
--- a/arch/x86/kernel/acpi/wakeup_64.S
+++ b/arch/x86/kernel/acpi/wakeup_64.S
@@ -17,7 +17,7 @@
* Hooray, we are in Long 64-bit mode (but still running in low memory)
*/
SYM_FUNC_START(wakeup_long64)
- movq saved_magic, %rax
+ movq saved_magic(%rip), %rax
movq $0x123456789abcdef0, %rdx
cmpq %rdx, %rax
je 2f
@@ -33,14 +33,14 @@ SYM_FUNC_START(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
ANNOTATE_RETPOLINE_SAFE
jmp *%rax
SYM_FUNC_END(wakeup_long64)
@@ -51,7 +51,7 @@ SYM_FUNC_START(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)
@@ -70,13 +70,14 @@ SYM_FUNC_START(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
@@ -88,7 +89,7 @@ SYM_FUNC_START(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
--
2.31.1