root/arch/x86/entry/thunk_32.S

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Trampoline to trace irqs off. (otherwise CALLER_ADDR1 might crash)
   4  * Copyright 2008 by Steven Rostedt, Red Hat, Inc
   5  *  (inspired by Andi Kleen's thunk_64.S)
   6  */
   7         #include <linux/linkage.h>
   8         #include <asm/asm.h>
   9         #include <asm/export.h>
  10 
  11         /* put return address in eax (arg1) */
  12         .macro THUNK name, func, put_ret_addr_in_eax=0
  13         .globl \name
  14 \name:
  15         pushl %eax
  16         pushl %ecx
  17         pushl %edx
  18 
  19         .if \put_ret_addr_in_eax
  20         /* Place EIP in the arg1 */
  21         movl 3*4(%esp), %eax
  22         .endif
  23 
  24         call \func
  25         popl %edx
  26         popl %ecx
  27         popl %eax
  28         ret
  29         _ASM_NOKPROBE(\name)
  30         .endm
  31 
  32 #ifdef CONFIG_TRACE_IRQFLAGS
  33         THUNK trace_hardirqs_on_thunk,trace_hardirqs_on_caller,1
  34         THUNK trace_hardirqs_off_thunk,trace_hardirqs_off_caller,1
  35 #endif
  36 
  37 #ifdef CONFIG_PREEMPTION
  38         THUNK ___preempt_schedule, preempt_schedule
  39         THUNK ___preempt_schedule_notrace, preempt_schedule_notrace
  40         EXPORT_SYMBOL(___preempt_schedule)
  41         EXPORT_SYMBOL(___preempt_schedule_notrace)
  42 #endif
  43