ppc/sys/longjmp.s

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Copyright (c) 1998 Apple Computer, Inc. All rights reserved.
  25  *
  26  *      File: sys/ppc/longjmp.s
  27  *
  28  *      Implements siglongjmp(), longjmp(), _longjmp()
  29  *
  30  *      NOTE:   Scatterloading this file will BREAK the functions.
  31  *
  32  *      History:
  33  *      30-Aug-1998     Umesh Vaishampayan      (umeshv@apple.com)
  34  *              Created. Derived from _setjmp.s, setjmp.c and setjmp.s
  35  */
  36
  37 /* We use mode-independent "g" opcodes such as "stg", and/or
  38  * mode-independent macros such as MI_GET_ADDRESS.  These expand
  39  * into word operations when targeting __ppc__, and into doubleword
  40  * operations when targeting __ppc64__.
  41  */
  42 #include <architecture/ppc/mode_independent_asm.h>
  43
  44 #include "_setjmp.h"
  45
  46 /*
  47  *      longjmp routines
  48  */
  49
  50 /*      void siglongjmp(sigjmp_buf env, int val); */
  51
  52 MI_ENTRY_POINT(_siglongjmp)
  53         lg      r0, JMP_SIGFLAG(r3)     ; load sigflag saved by siglongjmp()
  54         cmpgi   cr1,r0,0                        ; this changes cr1 which is volatile
  55         mr      r30, r3             ; preserve args across _sigsetmask
  56         mr      r31, r4
  57         beq--   cr1, L__exit        ; if r0 == 0 do _longjmp()
  58         ; else *** fall through *** to longjmp()
  59
  60 /*      void longjmp(jmp_buf env, int val); */
  61
  62 MI_ENTRY_POINT(_longjmp)
  63         mr      r30, r3             ; preserve args across _sigsetmask
  64         mr      r31, r4
  65
  66     /* NB: this code assumes the signal mask is an int.  Change the "lwz" below
  67      * if not. The JMP_sig field is already 8 bytes in the jmpbuf.
  68      */
  69         lwz     r3, JMP_sig(r3)         ; restore the signal mask
  70         MI_CALL_EXTERNAL(_sigsetmask)   // make a (deprecated!) syscall to set the mask
  71 L__exit:
  72         lwz             r3,JMP_ss_flags(r30)
  73         MI_CALL_EXTERNAL(__sigunaltstack)
  74 L__exit2:
  75         mr      r3, r30
  76         mr      r4, r31
  77         MI_BRANCH_EXTERNAL(__longjmp)
  78
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