nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S

   1 /* Copyright (C) 2002, 2003, 2005, 2007, 2009, 2011 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <sysdep.h>
  20 #include <lowlevellock.h>
  21 #include <shlib-compat.h>
  22 #include <pthread-errnos.h>
  23 #include <structsem.h>
  24
  25
  26         .text
  27
  28         .globl  sem_wait
  29         .type   sem_wait,@function
  30         .align  16
  31 sem_wait:
  32 .LSTARTCODE:
  33         cfi_startproc
  34 #ifdef SHARED
  35         cfi_personality(DW_EH_PE_pcrel | DW_EH_PE_sdata4 | DW_EH_PE_indirect,
  36                         DW.ref.__gcc_personality_v0)
  37         cfi_lsda(DW_EH_PE_pcrel | DW_EH_PE_sdata4, .LexceptSTART)
  38 #else
  39         cfi_personality(DW_EH_PE_udata4, __gcc_personality_v0)
  40         cfi_lsda(DW_EH_PE_udata4, .LexceptSTART)
  41 #endif
  42
  43 #if VALUE == 0
  44         movl    (%rdi), %eax
  45 #else
  46         movl    VALUE(%rdi), %eax
  47 #endif
  48 2:      testl   %eax, %eax
  49         je      1f
  50
  51         leal    -1(%rax), %edx
  52         LOCK
  53 #if VALUE == 0
  54         cmpxchgl %edx, (%rdi)
  55 #else
  56         cmpxchgl %edx, VALUE(%rdi)
  57 #endif
  58         jne     2b
  59
  60         xorl    %eax, %eax
  61         retq
  62
  63         /* This push is only needed to store the sem_t pointer for the
  64            exception handler.  */
  65 1:      pushq   %rdi
  66         cfi_adjust_cfa_offset(8)
  67
  68         LOCK
  69         LP_OP(add) $1, NWAITERS(%rdi)
  70
  71 .LcleanupSTART:
  72 6:      call    __pthread_enable_asynccancel
  73         movl    %eax, %r8d
  74
  75         xorq    %r10, %r10
  76         movl    $SYS_futex, %eax
  77 #if FUTEX_WAIT == 0
  78         movl    PRIVATE(%rdi), %esi
  79 #else
  80         movl    $FUTEX_WAIT, %esi
  81         orl     PRIVATE(%rdi), %esi
  82 #endif
  83         xorl    %edx, %edx
  84         syscall
  85         movq    %rax, %rcx
  86
  87         xchgq   %r8, %rdi
  88         call    __pthread_disable_asynccancel
  89 .LcleanupEND:
  90         movq    %r8, %rdi
  91
  92         testq   %rcx, %rcx
  93         je      3f
  94         cmpq    $-EWOULDBLOCK, %rcx
  95         jne     4f
  96
  97 3:
  98 #if VALUE == 0
  99         movl    (%rdi), %eax
 100 #else
 101         movl    VALUE(%rdi), %eax
 102 #endif
 103 5:      testl   %eax, %eax
 104         je      6b
 105
 106         leal    -1(%rax), %edx
 107         LOCK
 108 #if VALUE == 0
 109         cmpxchgl %edx, (%rdi)
 110 #else
 111         cmpxchgl %edx, VALUE(%rdi)
 112 #endif
 113         jne     5b
 114
 115         xorl    %eax, %eax
 116
 117 9:      LOCK
 118         LP_OP(sub) $1, NWAITERS(%rdi)
 119
 120         leaq    8(%rsp), %rsp
 121         cfi_adjust_cfa_offset(-8)
 122
 123         retq
 124
 125         cfi_adjust_cfa_offset(8)
 126 4:      negq    %rcx
 127         movq    errno@gottpoff(%rip), %rdx
 128         movl    %ecx, %fs:(%rdx)
 129         orl     $-1, %eax
 130
 131         jmp 9b
 132         .size   sem_wait,.-sem_wait
 133
 134
 135         .type   sem_wait_cleanup,@function
 136 sem_wait_cleanup:
 137         movq    (%rsp), %rdi
 138         LOCK
 139         LP_OP(sub) $1, NWAITERS(%rdi)
 140         movq    %rax, %rdi
 141 .LcallUR:
 142         call    _Unwind_Resume@PLT
 143         hlt
 144 .LENDCODE:
 145         cfi_endproc
 146         .size   sem_wait_cleanup,.-sem_wait_cleanup
 147
 148
 149         .section .gcc_except_table,"a",@progbits
 150 .LexceptSTART:
 151         .byte   DW_EH_PE_omit                   # @LPStart format
 152         .byte   DW_EH_PE_omit                   # @TType format
 153         .byte   DW_EH_PE_uleb128                # call-site format
 154         .uleb128 .Lcstend-.Lcstbegin
 155 .Lcstbegin:
 156         .uleb128 .LcleanupSTART-.LSTARTCODE
 157         .uleb128 .LcleanupEND-.LcleanupSTART
 158         .uleb128 sem_wait_cleanup-.LSTARTCODE
 159         .uleb128  0
 160         .uleb128 .LcallUR-.LSTARTCODE
 161         .uleb128 .LENDCODE-.LcallUR
 162         .uleb128 0
 163         .uleb128  0
 164 .Lcstend:
 165
 166
 167 #ifdef SHARED
 168         .hidden DW.ref.__gcc_personality_v0
 169         .weak   DW.ref.__gcc_personality_v0
 170         .section .gnu.linkonce.d.DW.ref.__gcc_personality_v0,"aw",@progbits
 171         .align  LP_SIZE
 172         .type   DW.ref.__gcc_personality_v0, @object
 173         .size   DW.ref.__gcc_personality_v0, LP_SIZE
 174 DW.ref.__gcc_personality_v0:
 175         ASM_ADDR __gcc_personality_v0
 176 #endif