src/setjmp/generic/sigtramp.c

   1 /*
   2  * Copyright (c) 1999, 2007 Apple 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) 1995 NeXT Computer, Inc. All Rights Reserved
  25  */
  26
  27 #define _XOPEN_SOURCE 600
  28
  29 #import <sys/types.h>
  30 #import <signal.h>
  31 #import <unistd.h>
  32 #import <ucontext.h>
  33 #import <mach/thread_status.h>
  34 #include <TargetConditionals.h>
  35
  36 extern int __sigreturn(ucontext_t *, int);
  37
  38 /*
  39  * sigvec registers _sigtramp as the handler for any signal requiring
  40  * user-mode intervention.  All _sigtramp does is find the real handler,
  41  * calls it, then sigreturn's.
  42  *
  43  * Note that the kernel saves/restores all of our register state.
  44  */
  45
  46 /* On i386, i386/sys/_sigtramp.s defines this. There is no in_sigtramp on arm */
  47 #if defined(__DYNAMIC__) && defined(__x86_64__)
  48 __attribute__((visibility("hidden")))
  49 int __in_sigtramp = 0;
  50 #endif
  51
  52 /* These defn should match the kernel one */
  53 #define UC_TRAD                 1
  54 #define UC_FLAVOR               30
  55 #if defined(__ppc__) || defined(__ppc64__)
  56 #define UC_TRAD64               20
  57 #define UC_TRAD64_VEC           25
  58 #define UC_FLAVOR_VEC           35
  59 #define UC_FLAVOR64             40
  60 #define UC_FLAVOR64_VEC         45
  61 #define UC_DUAL                 50
  62 #define UC_DUAL_VEC             55
  63
  64  /* The following are valid mcontext sizes */
  65 #define UC_FLAVOR_SIZE ((PPC_THREAD_STATE_COUNT + PPC_EXCEPTION_STATE_COUNT + PPC_FLOAT_STATE_COUNT) * sizeof(int))
  66
  67 #define UC_FLAVOR_VEC_SIZE ((PPC_THREAD_STATE_COUNT + PPC_EXCEPTION_STATE_COUNT + PPC_FLOAT_STATE_COUNT + PPC_VECTOR_STATE_COUNT) * sizeof(int))
  68
  69 #define UC_FLAVOR64_SIZE ((PPC_THREAD_STATE64_COUNT + PPC_EXCEPTION_STATE64_COUNT + PPC_FLOAT_STATE_COUNT) * sizeof(int))
  70
  71 #define UC_FLAVOR64_VEC_SIZE ((PPC_THREAD_STATE64_COUNT + PPC_EXCEPTION_STATE64_COUNT + PPC_FLOAT_STATE_COUNT + PPC_VECTOR_STATE_COUNT) * sizeof(int))
  72 #endif
  73
  74 #define UC_SET_ALT_STACK        0x40000000
  75 #define UC_RESET_ALT_STACK      0x80000000
  76
  77 /*
  78  * Reset the kernel's idea of the use of an alternate stack; this is used by
  79  * both longjmp() and siglongjmp().  Nothing other than this reset is needed,
  80  * since restoring the registers and other operations that would normally be
  81  * done by sigreturn() are handled in user space, so we do not pass a user
  82  * context (in PPC, a user context is not the same as a jmpbuf mcontext, due
  83  * to having more than one set of registers, etc., for the various 32/64 etc.
  84  * contexts)..
  85  */
  86 void
  87 _sigunaltstack(int set)
  88 {
  89         /* sigreturn(uctx, ctxstyle); */
  90         /* syscall (SYS_SIGRETURN, uctx, ctxstyle); */
  91         __sigreturn (NULL, (set == SS_ONSTACK) ? UC_SET_ALT_STACK : UC_RESET_ALT_STACK);
  92 }
  93
  94 /* On these architectures, _sigtramp is implemented in assembly to
  95    ensure it matches its DWARF unwind information.  */
  96 #if !defined (__i386__) && !defined (__x86_64__)
  97
  98 void
  99 _sigtramp(
 100         union __sigaction_u __sigaction_u,
 101         int                     sigstyle,
 102         int                     sig,
 103         siginfo_t               *sinfo,
 104         ucontext_t              *uctx
 105 ) {
 106         int ctxstyle = UC_FLAVOR;
 107
 108         if (sigstyle == UC_TRAD)
 109                 sa_handler(sig);
 110         else {
 111 #if TARGET_OS_WATCH
 112                 // <rdar://problem/22016014>
 113                 sa_sigaction(sig, sinfo, NULL);
 114 #else
 115                 sa_sigaction(sig, sinfo, uctx);
 116 #endif
 117         }
 118
 119         /* sigreturn(uctx, ctxstyle); */
 120         /* syscall (SYS_SIGRETURN, uctx, ctxstyle); */
 121         __sigreturn (uctx, ctxstyle);
 122 }
 123
 124 #endif /* not ppc nor ppc64 nor i386 nor x86_64 */