libsyscall/custom/__gettimeofday.s

   1 /*
   2  * Copyright (c) 1999-2016 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 "SYS.h"
  30
  31 /*
  32  * A third argument, of type uint64_t*, was added to the gettimeofday syscall
  33  * for use cases that also want to know the mach_absolute_time that matches the
  34  * time value returned.
  35  *
  36  * __gettimeofday takes the traditional two arguments.  It will zero out the
  37  * third argument argument before entering the kernel, behaving like the old
  38  * call.
  39  *
  40  * __gettimeofday_with_mach will pass it through and supporting kernels will
  41  * copy-out the mach_absolute_time.  Old kernels will leave the pointed to
  42  * value alone.
  43  */
  44
  45 .private_extern ___gettimeofday_with_mach
  46
  47 #if defined(__i386__)
  48
  49 LABEL(___gettimeofday)
  50     pushl       $0
  51     pushl       12(%esp)
  52     pushl       12(%esp)
  53     calll       ___gettimeofday_with_mach
  54     addl        $12, %esp
  55     ret
  56
  57 LABEL(___gettimeofday_with_mach)
  58     UNIX_SYSCALL_INT_NONAME(gettimeofday,0)
  59     /*
  60      * <rdar://problem/26410029>
  61      * If eax is 0, we're on a new kernel and timeval was written by the kernel.
  62      * Otherwise, eax:edx contains the timeval and we marshal into timeval.
  63      */
  64     cmp     $0, %eax
  65     je      2f
  66     mov     4(%esp),%ecx
  67     mov     %eax,(%ecx)
  68     mov     %edx,4(%ecx)
  69     xor     %eax,%eax
  70 2:
  71     ret
  72
  73 #elif defined(__x86_64__)
  74
  75 __SYSCALL(___gettimeofday_with_mach, gettimeofday, 3)
  76
  77 LABEL(___gettimeofday)
  78     movq   $0x0, %rdx // zero out third argument
  79
  80     UNIX_SYSCALL_NONAME(gettimeofday,0,cerror_nocancel)
  81     /*
  82      * <rdar://problem/26410029>
  83      * If rax is 0, we're on a new kernel and timeval was written by the kernel.
  84      * Otherwise, rax:rdx contains the timeval and we marshal into timeval.
  85      */
  86     cmp     $0, %rax
  87     je      2f
  88     movq    %rax, (%rdi)
  89     movl    %edx, 8(%rdi)
  90     xorl    %eax, %eax
  91 2:
  92     ret
  93
  94 #elif defined(__arm__)
  95
  96 __SYSCALL2(___gettimeofday_with_mach, gettimeofday, 3, cerror_nocancel)
  97
  98 .text
  99 .align  2
 100 .globl ___gettimeofday
 101 ___gettimeofday:
 102     mov    r2, #0x0
 103     SYSCALL_NONAME(gettimeofday, 3, cerror_nocancel)
 104     bx lr
 105
 106 #elif defined(__arm64__)
 107
 108 __SYSCALL2(___gettimeofday_with_mach, gettimeofday, 3, cerror_nocancel)
 109
 110 .text
 111 .align  2
 112 .globl ___gettimeofday
 113 ___gettimeofday:
 114     movz   x2, #0x0
 115     SYSCALL_NONAME(gettimeofday, 3, cerror_nocancel)
 116     ret
 117
 118 #else
 119 #error Unsupported architecture
 120 #endif