mirror of
https://sourceware.org/git/glibc.git
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179 lines
4.2 KiB
ArmAsm
179 lines
4.2 KiB
ArmAsm
/* Copyright (C) 2002-2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <unwindbuf.h>
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#include <sysdep.h>
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#include <kernel-features.h>
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#include <lowlevellock.h>
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.comm __fork_generation, 4, 4
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.text
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.globl __pthread_once
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.type __pthread_once,@function
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.align 16
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cfi_startproc
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__pthread_once:
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movl 4(%esp), %ecx
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testl $2, (%ecx)
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jz 1f
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xorl %eax, %eax
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ret
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1: pushl %ebx
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cfi_adjust_cfa_offset (4)
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cfi_rel_offset (3, 0)
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pushl %esi
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cfi_adjust_cfa_offset (4)
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cfi_rel_offset (6, 0)
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movl %ecx, %ebx
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xorl %esi, %esi
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/* Not yet initialized or initialization in progress.
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Get the fork generation counter now. */
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6: movl (%ebx), %eax
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#ifdef PIC
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LOAD_PIC_REG(cx)
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#endif
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5: movl %eax, %edx
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testl $2, %eax
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jnz 4f
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andl $3, %edx
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#ifdef PIC
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orl __fork_generation@GOTOFF(%ecx), %edx
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#else
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orl __fork_generation, %edx
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#endif
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orl $1, %edx
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LOCK
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cmpxchgl %edx, (%ebx)
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jnz 5b
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/* Check whether another thread already runs the initializer. */
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testl $1, %eax
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jz 3f /* No -> do it. */
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/* Check whether the initializer execution was interrupted
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by a fork. */
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xorl %edx, %eax
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testl $0xfffffffc, %eax
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jnz 3f /* Different for generation -> run initializer. */
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/* Somebody else got here first. Wait. */
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#ifdef __ASSUME_PRIVATE_FUTEX
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movl $FUTEX_WAIT|FUTEX_PRIVATE_FLAG, %ecx
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#else
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# if FUTEX_WAIT == 0
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movl %gs:PRIVATE_FUTEX, %ecx
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# else
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movl $FUTEX_WAIT, %ecx
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orl %gs:PRIVATE_FUTEX, %ecx
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# endif
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#endif
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movl $SYS_futex, %eax
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ENTER_KERNEL
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jmp 6b
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3: /* Call the initializer function after setting up the
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cancellation handler. Note that it is not possible here
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to use the unwind-based cleanup handling. This would require
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that the user-provided function and all the code it calls
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is compiled with exceptions. Unfortunately this cannot be
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guaranteed. */
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subl $UNWINDBUFSIZE+8, %esp
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cfi_adjust_cfa_offset (UNWINDBUFSIZE+8)
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movl %ecx, %ebx /* PIC register value. */
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leal 8+UWJMPBUF(%esp), %eax
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movl $0, 4(%esp)
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movl %eax, (%esp)
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call __sigsetjmp@PLT
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testl %eax, %eax
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jne 7f
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leal 8(%esp), %eax
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call HIDDEN_JUMPTARGET(__pthread_register_cancel)
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/* Call the user-provided initialization function. */
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call *24+UNWINDBUFSIZE(%esp)
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/* Pop the cleanup handler. */
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leal 8(%esp), %eax
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call HIDDEN_JUMPTARGET(__pthread_unregister_cancel)
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addl $UNWINDBUFSIZE+8, %esp
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cfi_adjust_cfa_offset (-UNWINDBUFSIZE-8)
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/* Sucessful run of the initializer. Signal that we are done. */
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movl 12(%esp), %ebx
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LOCK
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addl $1, (%ebx)
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/* Wake up all other threads. */
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movl $0x7fffffff, %edx
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#ifdef __ASSUME_PRIVATE_FUTEX
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movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %ecx
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#else
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movl $FUTEX_WAKE, %ecx
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orl %gs:PRIVATE_FUTEX, %ecx
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#endif
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movl $SYS_futex, %eax
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ENTER_KERNEL
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4: popl %esi
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cfi_adjust_cfa_offset (-4)
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cfi_restore (6)
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popl %ebx
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cfi_adjust_cfa_offset (-4)
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cfi_restore (3)
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xorl %eax, %eax
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ret
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7: /* __sigsetjmp returned for the second time. */
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movl 20+UNWINDBUFSIZE(%esp), %ebx
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cfi_adjust_cfa_offset (UNWINDBUFSIZE+16)
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cfi_offset (3, -8)
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cfi_offset (6, -12)
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movl $0, (%ebx)
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movl $0x7fffffff, %edx
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#ifdef __ASSUME_PRIVATE_FUTEX
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movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %ecx
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#else
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movl $FUTEX_WAKE, %ecx
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orl %gs:PRIVATE_FUTEX, %ecx
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#endif
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movl $SYS_futex, %eax
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ENTER_KERNEL
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leal 8(%esp), %eax
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call HIDDEN_JUMPTARGET (__pthread_unwind_next)
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/* NOTREACHED */
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hlt
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cfi_endproc
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.size __pthread_once,.-__pthread_once
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hidden_def (__pthread_once)
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strong_alias (__pthread_once, pthread_once)
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