cd15bacf33
This change fixes a segmentation fault in the libc unwinder when it goes past __libc_init. Unwind instructions for __libc_init direct it to grab the return address from the stack frame. Without this change, the unwinder gets a wild address and looks up further unwind instructions for the routine at that address. If it's unlucky enough to hit an existing function, it will try to unwind it. Bad things happen then. With this change, the return address always points to the _start function, which does not have unwind instructions associated with it. This stop the unwind process. __libc_init never returns, so this does not affect program execution, other than adding 4 bytes on the main thread stack. Change-Id: Id58612172e8825c8729cccd081541a13bff96bd0
86 lines
2.5 KiB
ArmAsm
86 lines
2.5 KiB
ArmAsm
/*
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* Copyright (C) 2008 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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.text
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.align 4
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.type _start,#function
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.globl _start
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# this is the small startup code that is first run when
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# any executable that is dynamically-linked with Bionic
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# runs.
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#
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# it's purpose is to call __libc_init with appropriate
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# arguments, which are:
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#
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# - the address of the raw data block setup by the Linux
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# kernel ELF loader
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#
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# - address of an "onexit" function, not used on any
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# platform supported by Bionic
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#
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# - address of the "main" function of the program.
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#
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# - address of the constructor list
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#
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_start:
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mov r0, sp
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mov r1, #0
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ldr r2, =main
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adr r3, 1f
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ldr r4, =__libc_init
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blx r4
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mov r0, #0
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bx r0
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1: .long __PREINIT_ARRAY__
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.long __INIT_ARRAY__
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.long __FINI_ARRAY__
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.long __CTOR_LIST__
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.section .preinit_array, "aw"
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.globl __PREINIT_ARRAY__
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__PREINIT_ARRAY__:
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.long -1
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.section .init_array, "aw"
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.globl __INIT_ARRAY__
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__INIT_ARRAY__:
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.long -1
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.section .fini_array, "aw"
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.globl __FINI_ARRAY__
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__FINI_ARRAY__:
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.long -1
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.section .ctors, "aw"
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.globl __CTOR_LIST__
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__CTOR_LIST__:
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.long -1
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#include "__dso_handle.S"
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#include "atexit.S"
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