arch/x86/lib/thunk_64.S

   1 /*
   2  * Save registers before calling assembly functions. This avoids
   3  * disturbance of register allocation in some inline assembly constructs.
   4  * Copyright 2001,2002 by Andi Kleen, SuSE Labs.
   5  * Added trace_hardirqs callers - Copyright 2007 Steven Rostedt, Red Hat, Inc.
   6  * Subject to the GNU public license, v.2. No warranty of any kind.
   7  */
   8 #include <linux/linkage.h>
   9 #include <asm/dwarf2.h>
  10 #include <asm/calling.h>
  11 #include <asm/asm.h>
  12
  13         /* rdi: arg1 ... normal C conventions. rax is saved/restored. */
  14         .macro THUNK name, func, put_ret_addr_in_rdi=0
  15         .globl \name
  16 \name:
  17         CFI_STARTPROC
  18
  19         /* this one pushes 9 elems, the next one would be %rIP */
  20         SAVE_ARGS
  21
  22         .if \put_ret_addr_in_rdi
  23         movq_cfi_restore 9*8, rdi
  24         .endif
  25
  26         call \func
  27         jmp  restore
  28         CFI_ENDPROC
  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_DEBUG_LOCK_ALLOC
  38         THUNK lockdep_sys_exit_thunk,lockdep_sys_exit
  39 #endif
  40
  41         /* SAVE_ARGS below is used only for the .cfi directives it contains. */
  42         CFI_STARTPROC
  43         SAVE_ARGS
  44 restore:
  45         RESTORE_ARGS
  46         ret
  47         CFI_ENDPROC
  48         _ASM_NOKPROBE(restore)