[RFC/RFT PATCH 15/19] x64/acpi: Use PIC-compatible references in wakeup_64.S

Ard Biesheuvel
2026-01-08T09:28:41Z

Use ordinary RIP-relative references to make the code compatible with
running the linker in PIE mode.

Note that wakeup_long64() runs in the kernel's ordinary virtual mapping
so there is no need to record the address of .Lresume_point in a global
variable. And fix the comment while at it.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/x86/kernel/acpi/wakeup_64.S | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S
index 04f561f75e99..15233a4e1c95 100644
--- a/arch/x86/kernel/acpi/wakeup_64.S
+++ b/arch/x86/kernel/acpi/wakeup_64.S
@@ -14,7 +14,7 @@

.code64
/*
- * Hooray, we are in Long 64-bit mode (but still running in low memory)
+ * Hooray, we are in Long 64-bit mode
*/
SYM_FUNC_START(wakeup_long64)
ANNOTATE_NOENDBR
@@ -41,7 +41,7 @@ SYM_FUNC_START(wakeup_long64)
movq saved_rsi(%rip), %rsi
movq saved_rbp(%rip), %rbp

- movq saved_rip(%rip), %rax
+ leaq .Lresume_point(%rip), %rax
ANNOTATE_RETPOLINE_SAFE
jmp *%rax
SYM_FUNC_END(wakeup_long64)
@@ -52,7 +52,7 @@ 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)
@@ -71,8 +71,6 @@ SYM_FUNC_START(do_suspend_lowlevel)
pushfq
popq pt_regs_flags(%rax)

- movq $.Lresume_point, saved_rip(%rip)
-
movq %rsp, saved_rsp(%rip)
movq %rbp, saved_rbp(%rip)
movq %rbx, saved_rbx(%rip)
@@ -90,7 +88,7 @@ SYM_FUNC_START(do_suspend_lowlevel)
.Lresume_point:
ANNOTATE_NOENDBR
/* 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
@@ -139,7 +137,6 @@ saved_rsi: .quad 0
saved_rdi: .quad 0
saved_rbx: .quad 0

-saved_rip: .quad 0
saved_rsp: .quad 0

SYM_DATA(saved_magic, .quad 0)
--
2.47.3