97cf7f3394
Only provide an implementation for ARM at the moment, since it requires specific assembly fragments (the standard syscall stubs cannot be used because the child returns in a different stack).
128 lines
3.5 KiB
ArmAsm
128 lines
3.5 KiB
ArmAsm
/*
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* Copyright (C) 2008-2010 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/linux-syscalls.h>
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.text
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.type __pthread_clone, #function
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.global __pthread_clone
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.align 4
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.fnstart
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__pthread_clone:
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@ insert the args onto the new stack
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str r0, [r1, #-4]
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str r3, [r1, #-8]
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@ do the system call
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@ get flags
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mov r0, r2
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@ new sp is already in r1
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#if __ARM_EABI__
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stmfd sp!, {r4, r7}
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ldr r7, =__NR_clone
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swi #0
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#else
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swi #__NR_clone
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#endif
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movs r0, r0
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#if __ARM_EABI__
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ldmnefd sp!, {r4, r7}
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#endif
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blt __error
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bxne lr
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@ pick the function arg and call address off the stack and jump
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@ to the C __thread_entry function which does some setup and then
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@ calls the thread's start function
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ldr r0, [sp, #-4]
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ldr r1, [sp, #-8]
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mov r2, sp @ __thread_entry needs the TLS pointer
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b __thread_entry
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__error:
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mov r0, #-1
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bx lr
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.fnend
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#
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# This function is defined as:
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#
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# pid_t __bionic_clone( int flags, void *child_stack,
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# pid_t *pid, void *tls, pid_t *ctid,
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# int (*fn)(void *), void* arg );
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#
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# NOTE: This is not the same signature than the GLibc
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# __clone function here !! Placing 'fn' and 'arg'
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# at the end of the parameter list makes the
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# implementation much simpler.
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#
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.type __bionic_clone, #function
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.globl __bionic_clone
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.align 4
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.fnstart
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__bionic_clone:
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mov ip, sp
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.save {r4, r5, r6, r7}
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# save registers to parent stack
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stmfd sp!, {r4, r5, r6, r7}
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# load extra parameters
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ldmfd ip, {r4, r5, r6}
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# store 'fn' and 'arg' to the child stack
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str r5, [r1, #-4]
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str r6, [r1, #-8]
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# system call
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ldr r7, =__NR_clone
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swi #0
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movs r0, r0
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beq 1f
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# in parent, reload saved registers
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# then either exit or error
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#
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ldmfd sp!, {r4, r5, r6, r7}
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bxne lr
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b __set_syscall_errno
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1: # in the child - pick arguments
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ldr r0, [sp, #-4]
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ldr r1, [sp, #-8]
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b __bionic_clone_entry
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.fnend
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