sysdeps/unix/sysv/linux/i386/i486/lowlevelrobustlock.S

   1 /* Copyright (C) 2002-2014 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 <pthread-errnos.h>
  21 #include <lowlevellock.h>
  22 #include <lowlevelrobustlock.h>
  23 #include <kernel-features.h>
  24
  25         .text
  26
  27 #define FUTEX_WAITERS           0x80000000
  28 #define FUTEX_OWNER_DIED        0x40000000
  29
  30 #ifdef __ASSUME_PRIVATE_FUTEX
  31 # define LOAD_FUTEX_WAIT(reg) \
  32         xorl    $(FUTEX_WAIT | FUTEX_PRIVATE_FLAG), reg
  33 #else
  34 # if FUTEX_WAIT == 0
  35 #  define LOAD_FUTEX_WAIT(reg) \
  36         xorl    $FUTEX_PRIVATE_FLAG, reg ; \
  37         andl    %gs:PRIVATE_FUTEX, reg
  38 # else
  39 #  define LOAD_FUTEX_WAIT(reg) \
  40         xorl    $FUTEX_PRIVATE_FLAG, reg ; \
  41         andl    %gs:PRIVATE_FUTEX, reg ; \
  42         orl     $FUTEX_WAIT, reg
  43 # endif
  44 #endif
  45
  46         .globl  __lll_robust_lock_wait
  47         .type   __lll_robust_lock_wait,@function
  48         .hidden __lll_robust_lock_wait
  49         .align  16
  50 __lll_robust_lock_wait:
  51         cfi_startproc
  52         pushl   %edx
  53         cfi_adjust_cfa_offset(4)
  54         pushl   %ebx
  55         cfi_adjust_cfa_offset(4)
  56         pushl   %esi
  57         cfi_adjust_cfa_offset(4)
  58         cfi_offset(%edx, -8)
  59         cfi_offset(%ebx, -12)
  60         cfi_offset(%esi, -16)
  61
  62         movl    %edx, %ebx
  63         xorl    %esi, %esi      /* No timeout.  */
  64         LOAD_FUTEX_WAIT (%ecx)
  65
  66 4:      movl    %eax, %edx
  67         orl     $FUTEX_WAITERS, %edx
  68
  69         testl   $FUTEX_OWNER_DIED, %eax
  70         jnz     3f
  71
  72         cmpl    %edx, %eax      /* NB:   %edx == 2 */
  73         je      1f
  74
  75         LOCK
  76         cmpxchgl %edx, (%ebx)
  77         jnz     2f
  78
  79 1:      movl    $SYS_futex, %eax
  80         ENTER_KERNEL
  81
  82         movl    (%ebx), %eax
  83
  84 2:      test    %eax, %eax
  85         jne     4b
  86
  87         movl    %gs:TID, %edx
  88         orl     $FUTEX_WAITERS, %edx
  89         LOCK
  90         cmpxchgl %edx, (%ebx)
  91         jnz     4b
  92         /* NB:   %eax == 0 */
  93
  94 3:      popl    %esi
  95         cfi_adjust_cfa_offset(-4)
  96         cfi_restore(%esi)
  97         popl    %ebx
  98         cfi_adjust_cfa_offset(-4)
  99         cfi_restore(%ebx)
 100         popl    %edx
 101         cfi_adjust_cfa_offset(-4)
 102         cfi_restore(%edx)
 103         ret
 104         cfi_endproc
 105         .size   __lll_robust_lock_wait,.-__lll_robust_lock_wait
 106
 107
 108         .globl  __lll_robust_timedlock_wait
 109         .type   __lll_robust_timedlock_wait,@function
 110         .hidden __lll_robust_timedlock_wait
 111         .align  16
 112 __lll_robust_timedlock_wait:
 113         cfi_startproc
 114         /* Check for a valid timeout value.  */
 115         cmpl    $1000000000, 4(%edx)
 116         jae     3f
 117
 118         pushl   %edi
 119         cfi_adjust_cfa_offset(4)
 120         pushl   %esi
 121         cfi_adjust_cfa_offset(4)
 122         pushl   %ebx
 123         cfi_adjust_cfa_offset(4)
 124         pushl   %ebp
 125         cfi_adjust_cfa_offset(4)
 126         cfi_offset(%edi, -8)
 127         cfi_offset(%esi, -12)
 128         cfi_offset(%ebx, -16)
 129         cfi_offset(%ebp, -20)
 130
 131         /* Stack frame for the timespec and timeval structs.  */
 132         subl    $12, %esp
 133         cfi_adjust_cfa_offset(12)
 134
 135         movl    %ecx, %ebp
 136         movl    %edx, %edi
 137
 138 1:      movl    %eax, 8(%esp)
 139
 140         /* Get current time.  */
 141         movl    %esp, %ebx
 142         xorl    %ecx, %ecx
 143         movl    $__NR_gettimeofday, %eax
 144         ENTER_KERNEL
 145
 146         /* Compute relative timeout.  */
 147         movl    4(%esp), %eax
 148         movl    $1000, %edx
 149         mul     %edx            /* Milli seconds to nano seconds.  */
 150         movl    (%edi), %ecx
 151         movl    4(%edi), %edx
 152         subl    (%esp), %ecx
 153         subl    %eax, %edx
 154         jns     4f
 155         addl    $1000000000, %edx
 156         subl    $1, %ecx
 157 4:      testl   %ecx, %ecx
 158         js      8f              /* Time is already up.  */
 159
 160         /* Store relative timeout.  */
 161         movl    %ecx, (%esp)
 162         movl    %edx, 4(%esp)
 163
 164         movl    %ebp, %ebx
 165
 166         movl    8(%esp), %edx
 167         movl    %edx, %eax
 168         orl     $FUTEX_WAITERS, %edx
 169
 170         testl   $FUTEX_OWNER_DIED, %eax
 171         jnz     6f
 172
 173         cmpl    %eax, %edx
 174         je      2f
 175
 176         LOCK
 177         cmpxchgl %edx, (%ebx)
 178         movl    $0, %ecx        /* Must use mov to avoid changing cc.  */
 179         jnz     5f
 180
 181 2:
 182         /* Futex call.  */
 183         movl    %esp, %esi
 184         movl    20(%esp), %ecx
 185         LOAD_FUTEX_WAIT (%ecx)
 186         movl    $SYS_futex, %eax
 187         ENTER_KERNEL
 188         movl    %eax, %ecx
 189
 190         movl    (%ebx), %eax
 191
 192 5:      testl   %eax, %eax
 193         jne     7f
 194
 195         movl    %gs:TID, %edx
 196         orl     $FUTEX_WAITERS, %edx
 197         LOCK
 198         cmpxchgl %edx, (%ebx)
 199         jnz     7f
 200
 201 6:      addl    $12, %esp
 202         cfi_adjust_cfa_offset(-12)
 203         popl    %ebp
 204         cfi_adjust_cfa_offset(-4)
 205         cfi_restore(%ebp)
 206         popl    %ebx
 207         cfi_adjust_cfa_offset(-4)
 208         cfi_restore(%ebx)
 209         popl    %esi
 210         cfi_adjust_cfa_offset(-4)
 211         cfi_restore(%esi)
 212         popl    %edi
 213         cfi_adjust_cfa_offset(-4)
 214         cfi_restore(%edi)
 215         ret
 216
 217 3:      movl    $EINVAL, %eax
 218         ret
 219
 220         cfi_adjust_cfa_offset(28)
 221         cfi_offset(%edi, -8)
 222         cfi_offset(%esi, -12)
 223         cfi_offset(%ebx, -16)
 224         cfi_offset(%ebp, -20)
 225         /* Check whether the time expired.  */
 226 7:      cmpl    $-ETIMEDOUT, %ecx
 227         jne     1b
 228
 229 8:      movl    $ETIMEDOUT, %eax
 230         jmp     6b
 231         cfi_endproc
 232         .size   __lll_robust_timedlock_wait,.-__lll_robust_timedlock_wait