libsyscall/custom/errno.c

   1 /*
   2  * Copyright (c) 2010 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <TargetConditionals.h>
  30 #include <stddef.h>
  31 #include <stdint.h>
  32 #include "tsd.h"
  33
  34 /*
  35  * cerror takes the return value of the syscall, being non-zero, and
  36  * stores it in errno. It needs to return -1 to indicate failure but
  37  * 64-bit platforms need to ensure that possible 128-bit wide return
  38  * values are also properly set.
  39  */
  40 #ifdef __LP64__
  41 typedef unsigned __int128 cerror_return_t;
  42 #else
  43 typedef uint64_t cerror_return_t;
  44 #endif
  45
  46 extern void _pthread_exit_if_canceled(int error);
  47
  48 #undef errno
  49 int errno;
  50
  51 int *
  52 __error(void)
  53 {
  54         void *ptr = _os_tsd_get_direct(__TSD_ERRNO);
  55         if (ptr != NULL) {
  56                 return (int*)ptr;
  57         }
  58         return &errno;
  59 }
  60
  61 __attribute__((noinline))
  62 cerror_return_t
  63 cerror_nocancel(int err)
  64 {
  65         errno = err;
  66         int *tsderrno = (int*)_os_tsd_get_direct(__TSD_ERRNO);
  67         if (tsderrno) {
  68                 *tsderrno = err;
  69         }
  70         return -1;
  71 }
  72
  73 __attribute__((noinline))
  74 cerror_return_t
  75 cerror(int err)
  76 {
  77         _pthread_exit_if_canceled(err);
  78         return cerror_nocancel(err);
  79 }
  80
  81 #if !TARGET_OS_EMBEDDED
  82
  83 // Internal symbol no longer used by anybody in Libsystem but required for
  84 // backwards compatibility with 3rd parties <rdar://problem/14380572>
  85
  86 void
  87 cthread_set_errno_self(int err, int nocancel)
  88 {
  89         asm(".global $ld$hide$os10.9$_cthread_set_errno_self\n\t"
  90                 ".set $ld$hide$os10.9$_cthread_set_errno_self, _cthread_set_errno_self");
  91         if (nocancel) {
  92                 cerror_nocancel(err);
  93         } else {
  94                 cerror(err);
  95         }
  96 }
  97
  98 #endif