arch/x86/entry/thunk_64.S

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Save registers before calling assembly functions. This avoids
   4  * disturbance of register allocation in some inline assembly constructs.
   5  * Copyright 2001,2002 by Andi Kleen, SuSE Labs.
   6  */
   7 #include <linux/linkage.h>
   8 #include "calling.h"
   9 #include <asm/asm.h>
  10 #include <asm/export.h>
  11
  12         /* rdi: arg1 ... normal C conventions. rax is saved/restored. */
  13         .macro THUNK name, func
  14 SYM_FUNC_START_NOALIGN(\name)
  15         pushq %rbp
  16         movq %rsp, %rbp
  17
  18         pushq %rdi
  19         pushq %rsi
  20         pushq %rdx
  21         pushq %rcx
  22         pushq %rax
  23         pushq %r8
  24         pushq %r9
  25         pushq %r10
  26         pushq %r11
  27
  28         call \func
  29         jmp  __thunk_restore
  30 SYM_FUNC_END(\name)
  31         _ASM_NOKPROBE(\name)
  32         .endm
  33
  34 #ifdef CONFIG_PREEMPTION
  35         THUNK preempt_schedule_thunk, preempt_schedule
  36         THUNK preempt_schedule_notrace_thunk, preempt_schedule_notrace
  37         EXPORT_SYMBOL(preempt_schedule_thunk)
  38         EXPORT_SYMBOL(preempt_schedule_notrace_thunk)
  39 #endif
  40
  41 #ifdef CONFIG_PREEMPTION
  42 SYM_CODE_START_LOCAL_NOALIGN(__thunk_restore)
  43         popq %r11
  44         popq %r10
  45         popq %r9
  46         popq %r8
  47         popq %rax
  48         popq %rcx
  49         popq %rdx
  50         popq %rsi
  51         popq %rdi
  52         popq %rbp
  53         RET
  54         _ASM_NOKPROBE(__thunk_restore)
  55 SYM_CODE_END(__thunk_restore)
  56 #endif