getcontext.s

Glibc 2.3.2源代码(解压后有100多M)

/* Save current context.
   Copyright (C) 2002 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <sysdep.h>
#include "kernel-features.h"

#define __ASSEMBLY__
#include <asm/ptrace.h>
#include <asm/errno.h>
#include "ucontext_i.h"

ENTRY(__getcontext)
#ifdef __ASSUME_NEW_RT_SIGRETURN_SYSCALL
  std  r0,(SIGCONTEXT_GP_REGS+(PT_R0*8))(r3)
  std  r1,(SIGCONTEXT_GP_REGS+(PT_R1*8))(r3)
  mflr  r0
  std  r2,(SIGCONTEXT_GP_REGS+(PT_R2*8))(r3)
  std  r0,FRAME_LR_SAVE(r1)
  std  r0,(SIGCONTEXT_GP_REGS+(PT_LNK*8))(r3)
  std  r0,(SIGCONTEXT_GP_REGS+(PT_NIP*8))(r3)
  stdu  r1,-128(r1)
  std  r4,(SIGCONTEXT_GP_REGS+(PT_R4*8))(r3)
  std  r5,(SIGCONTEXT_GP_REGS+(PT_R5*8))(r3)
  std  r6,(SIGCONTEXT_GP_REGS+(PT_R6*8))(r3)
  std  r7,(SIGCONTEXT_GP_REGS+(PT_R7*8))(r3)
  std  r8,(SIGCONTEXT_GP_REGS+(PT_R8*8))(r3)
  std  r9,(SIGCONTEXT_GP_REGS+(PT_R9*8))(r3)
  std  r10,(SIGCONTEXT_GP_REGS+(PT_R10*8))(r3)
  std  r11,(SIGCONTEXT_GP_REGS+(PT_R11*8))(r3)
  std  r12,(SIGCONTEXT_GP_REGS+(PT_R12*8))(r3)
  std  r13,(SIGCONTEXT_GP_REGS+(PT_R13*8))(r3)
  std  r14,(SIGCONTEXT_GP_REGS+(PT_R14*8))(r3)
  std  r15,(SIGCONTEXT_GP_REGS+(PT_R15*8))(r3)
  std  r16,(SIGCONTEXT_GP_REGS+(PT_R16*8))(r3)
  std  r17,(SIGCONTEXT_GP_REGS+(PT_R17*8))(r3)
  std  r18,(SIGCONTEXT_GP_REGS+(PT_R18*8))(r3)
  std  r19,(SIGCONTEXT_GP_REGS+(PT_R19*8))(r3)
  std  r20,(SIGCONTEXT_GP_REGS+(PT_R20*8))(r3)
  std  r21,(SIGCONTEXT_GP_REGS+(PT_R21*8))(r3)
  std  r22,(SIGCONTEXT_GP_REGS+(PT_R22*8))(r3)
  std  r23,(SIGCONTEXT_GP_REGS+(PT_R23*8))(r3)
  std  r24,(SIGCONTEXT_GP_REGS+(PT_R24*8))(r3)
  std  r25,(SIGCONTEXT_GP_REGS+(PT_R25*8))(r3)
  std  r26,(SIGCONTEXT_GP_REGS+(PT_R26*8))(r3)
  std  r27,(SIGCONTEXT_GP_REGS+(PT_R27*8))(r3)
  std  r28,(SIGCONTEXT_GP_REGS+(PT_R28*8))(r3)
  std  r29,(SIGCONTEXT_GP_REGS+(PT_R29*8))(r3)
  std  r30,(SIGCONTEXT_GP_REGS+(PT_R30*8))(r3)
  std  r31,(SIGCONTEXT_GP_REGS+(PT_R31*8))(r3)
  mfctr  r0
  std  r0,(SIGCONTEXT_GP_REGS+(PT_CTR*8))(r3)
  mfxer  r0
  std  r0,(SIGCONTEXT_GP_REGS+(PT_XER*8))(r3)
  mfcr  r0
  std  r0,(SIGCONTEXT_GP_REGS+(PT_CCR*8))(r3)
  
  /* Set the return value of swapcontext to "success".  R3 is the only 
     register whose value is not preserved in the saved context.  */
  li   r0,0
  std  r0,(SIGCONTEXT_GP_REGS+(PT_R3*8))(r3)
  
  /* Zero fill fields that can't be set in user state or are unused.  */
  std  r0,(SIGCONTEXT_GP_REGS+(PT_MSR*8))(r3)
  std  r0,(SIGCONTEXT_GP_REGS+(34*8))(r3)
  std  r0,(SIGCONTEXT_GP_REGS+(PT_SOFTE*8))(r3)
  std  r0,(SIGCONTEXT_GP_REGS+(40*8))(r3)
  std  r0,(SIGCONTEXT_GP_REGS+(41*8))(r3)
  std  r0,(SIGCONTEXT_GP_REGS+(42*8))(r3)
  std  r0,(SIGCONTEXT_GP_REGS+(PT_RESULT*8))(r3)
  
  /* Set the PT_REGS pointer to the address of sigcontext's gp_regs 
     field.  Struct pt_regs and elf_gregset_t are the same thing.  
     We kept the regs field for backwards compatibility with
     libraries built before we extended sigcontext.  */
  addi r0,r3,SIGCONTEXT_GP_REGS
  std  r0,SIGCONTEXT_PT_REGS(r3)
  
  stfd  fp0,(SIGCONTEXT_FP_REGS+(PT_R0*8))(r3)
  stfd  fp1,(SIGCONTEXT_FP_REGS+(PT_R1*8))(r3)
  stfd  fp2,(SIGCONTEXT_FP_REGS+(PT_R2*8))(r3)
  stfd  fp3,(SIGCONTEXT_FP_REGS+(PT_R3*8))(r3)
  stfd  fp4,(SIGCONTEXT_FP_REGS+(PT_R4*8))(r3)
  stfd  fp5,(SIGCONTEXT_FP_REGS+(PT_R5*8))(r3)
  stfd  fp6,(SIGCONTEXT_FP_REGS+(PT_R6*8))(r3)
  stfd  fp7,(SIGCONTEXT_FP_REGS+(PT_R7*8))(r3)
  stfd  fp8,(SIGCONTEXT_FP_REGS+(PT_R8*8))(r3)
  stfd  fp9,(SIGCONTEXT_FP_REGS+(PT_R9*8))(r3)
  stfd  fp10,(SIGCONTEXT_FP_REGS+(PT_R10*8))(r3)
  stfd  fp11,(SIGCONTEXT_FP_REGS+(PT_R11*8))(r3)
  stfd  fp12,(SIGCONTEXT_FP_REGS+(PT_R12*8))(r3)
  stfd  fp13,(SIGCONTEXT_FP_REGS+(PT_R13*8))(r3)
  stfd  fp14,(SIGCONTEXT_FP_REGS+(PT_R14*8))(r3)
  stfd  fp15,(SIGCONTEXT_FP_REGS+(PT_R15*8))(r3)
  stfd  fp16,(SIGCONTEXT_FP_REGS+(PT_R16*8))(r3)
  stfd  fp17,(SIGCONTEXT_FP_REGS+(PT_R17*8))(r3)
  stfd  fp18,(SIGCONTEXT_FP_REGS+(PT_R18*8))(r3)
  stfd  fp19,(SIGCONTEXT_FP_REGS+(PT_R19*8))(r3)
  stfd  fp20,(SIGCONTEXT_FP_REGS+(PT_R20*8))(r3)
  stfd  fp21,(SIGCONTEXT_FP_REGS+(PT_R21*8))(r3)
  stfd  fp22,(SIGCONTEXT_FP_REGS+(PT_R22*8))(r3)
  stfd  fp23,(SIGCONTEXT_FP_REGS+(PT_R23*8))(r3)
  stfd  fp24,(SIGCONTEXT_FP_REGS+(PT_R24*8))(r3)
  stfd  fp25,(SIGCONTEXT_FP_REGS+(PT_R25*8))(r3)
  stfd  fp26,(SIGCONTEXT_FP_REGS+(PT_R26*8))(r3)
  stfd  fp27,(SIGCONTEXT_FP_REGS+(PT_R27*8))(r3)
  stfd  fp28,(SIGCONTEXT_FP_REGS+(PT_R28*8))(r3)
  stfd  fp29,(SIGCONTEXT_GP_REGS+(PT_R29*8))(r3)
  mffs  fp0
  stfd  fp30,(SIGCONTEXT_FP_REGS+(PT_R30*8))(r3)
  stfd  fp31,(SIGCONTEXT_FP_REGS+(PT_R31*8))(r3)
  stfd  fp0,(SIGCONTEXT_FP_REGS+(32*8))(r3)

  addi  r5,r3,UCONTEXT_SIGMASK
  li  r4,0
  li  r3,SIG_BLOCK
  bl  JUMPTARGET(sigprocmask)
  nop
#else
  /* If the kernel is not at least 2.4.21 then generate a ENOSYS stub.  */
  mflr r0
  std  r0,FRAME_LR_SAVE(r1)
  stdu r1,-128(r1)
  li   r3,ENOSYS
  bl   JUMPTARGET(__syscall_error)
  nop
  li   r3,-1
#endif
  
  ld    r0,128+FRAME_LR_SAVE(r1)  
  addi  r1,r1,128
  mtlr  r0
  blr
PSEUDO_END(__getcontext)

weak_alias(__getcontext, getcontext)