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/* $NetBSD: rtld_start.S,v 1.17 2011/09/26 01:52:22 mrg Exp $ */
/*-
* Copyright (C) 1998 Tsubai Masanari
* Portions copyright 2002 Charles M. Hannum <root@ihack.net>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <machine/asm.h>
.globl _rtld_start
.globl _rtld
.text
_rtld_start:
stwu %r1,-48(%r1)
stw %r3,12(%r1) # argc
stw %r4,16(%r1) # argv
stw %r5,20(%r1) # envp
/* stw %r6,24(%r1) # obj (always 0) */
/* stw %r7,28(%r1) # cleanup (always 0) */
stw %r8,32(%r1) # ps_strings
bcl 20,31,1f
1: mflr %r30
mr %r3,%r30 # save for _DYNAMIC
addis %r30,%r30,_GLOBAL_OFFSET_TABLE_-1b@ha
addi %r30,%r30,_GLOBAL_OFFSET_TABLE_-1b@l
addis %r3,%r3,_DYNAMIC-1b@ha # get _DYNAMIC actual address
addi %r3,%r3,_DYNAMIC-1b@l
lwz %r28,0(%r30) # get base-relative &_DYNAMIC
sub %r28,%r3,%r28 # r28 = relocbase
mr %r4,%r28 # r4 = relocbase
bl _rtld_relocate_nonplt_self
lwz %r3,16(%r1)
addi %r3,%r3,-12 # sp = &argv[-3] /* XXX */
mr %r4,%r28 # r4 = relocbase
bl _rtld # _start = _rtld(sp, relocbase)
mtlr %r3
lwz %r3,12(%r1) # argc
lwz %r4,16(%r1) # argv
lwz %r5,20(%r1) # envp
lwz %r6,-8(%r4) # obj = sp[1] (== argv[-2])
lwz %r7,-12(%r4) # cleanup = sp[0] (== argv[-3])
lwz %r8,32(%r1) # ps_strings
addi %r1,%r1,48
blrl # _start(argc, argv, envp, obj, cleanup, ps_strings)
li %r0,1 # _exit()
sc
END(_rtld_start)
.globl _rtld_bind
/*
* secure-plt expects %r11 to be the offset to the rela entry.
* bss-plt expects %r11 to be index of the rela entry.
* So for bss-plt, we multiply the index by 12 to get the offset.
*/
ENTRY_NOPROFILE(_rtld_bind_secureplt_start)
stwu %r1,-160(%r1)
stw %r0,20(%r1)
/*
* Instead of division which is costly we will use multiplicative
* inverse. a / n = ((a * inv(n)) >> 32)
* where inv(n) = (0x100000000 + n - 1) / n
*/
mr %r0,%r11
lis %r11,0x15555556@h # load multiplicative inverse of 12
ori %r11,%r11,0x15555556@l
mulhwu %r11,%r11,%r0 # get high half of multiplication
b 1f
ENTRY_NOPROFILE(_rtld_bind_bssplt_start)
stwu %r1,-160(%r1)
stw %r0,20(%r1)
1:
mflr %r0
stw %r0,16(%r1) # save lr
mfcr %r0
stw %r0,12(%r1) # save cr
stmw %r3,24(%r1) # save r3-r31
mr %r3,%r12 # obj
mr %r4,%r11 # reloff
bl _rtld_bind # _rtld_bind(obj, reloff)
mtctr %r3
lmw %r3,24(%r1) # load r3-r31
lwz %r0,12(%r1) # restore cr
mtcr %r0
lwz %r0,16(%r1) # restore lr
mtlr %r0
lwz %r0,20(%r1)
addi %r1,%r1,160
bctr
END(_rtld_bind_secureplt_start)
.globl _rtld_powerpc_pltcall
.globl _rtld_powerpc_pltresolve
_rtld_powerpc_pltcall:
slwi %r11,%r11,2
addis %r11,%r11,0 # addis 11,11,jmptab@ha
lwz %r11,0(%r11) # lwz 11,jmptab@l(11)
mtctr %r11
bctr
_rtld_powerpc_pltresolve:
lis %r12,0 # lis 12,_rtld_bind_bssplt_start@ha
addi %r12,%r12,0 # addi 12,12,_rtld_bind_bssplt_start@l
mtctr %r12
lis %r12,0 # lis 12,obj@ha
addi %r12,%r12,0 # addi 12,12,obj@l
bctr
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