/* $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 * 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 .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