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1e6d04c746
Tweak the PLT trampoline to avoid generating textrels in LibC. This allows us to share all the LibC mappings, reducing per-process memory consumption by ~200 KB. :^) Patch originally by @nico.
58 lines
2.2 KiB
ArmAsm
58 lines
2.2 KiB
ArmAsm
/*-
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* Copyright (c) 1998, 2002 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Christos Zoulas and by Charles M. Hannum.
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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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* 1. 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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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* This asm method is copied from NetBSD. We changed the internal method that
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* gets called and the name, but it's still essentially the same as
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* _rtld_bind_start from libexec/ld.elf_so/arch/i386/rtld_start.S
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*/
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.align 4
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.globl _plt_trampoline
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.hidden _plt_trampoline
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.type _plt_trampoline,@function
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_plt_trampoline: # (obj, reloff)
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pushf # save registers
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pushl %eax
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pushl %ecx
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pushl %edx
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pushl 20(%esp) # Copy of reloff
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pushl 20(%esp) # Copy of obj
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call _fixup_plt_entry@PLT # Call the binder
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addl $8,%esp # pop binder args
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movl %eax,20(%esp) # Store function to be called in obj
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popl %edx
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popl %ecx
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popl %eax
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popf
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leal 4(%esp),%esp # Discard reloff, do not change eflags
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ret
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