d05bb9a2a6
(and that is for now being worked around by a binutils patch). The rtld code tested &_DYNAMIC against 0 to see whether rtld itself was built as PIC or not. While the sparc64 MD code did not rely on the preset value of the GOT slot for _DYNAMIC any more due to previous binutils changes, it still used to not be 0, so that this check did work. The new binutils do however initialize this slot with 0. As a consequence, rtld would not properly initialize itself and crash. Fix that by introducing a new macro, RTLD_IS_DYNAMIC, to take the role of this test. For sparc64, it is implemented using the rtld_dynamic() code that was already there. If an architecture does not provide its own implementation, we default to the old check. While being there, mark _DYNAMIC as a weak symbol in the sparc64 rtld_start.S. This is needed in the LDSCRIPT case, which is however not currently supported for want of an actual ldscript. Sanity checked with md5 on alpha, amd64, i386 and ia64.
171 lines
5.5 KiB
ArmAsm
171 lines
5.5 KiB
ArmAsm
/* $NetBSD: rtld_start.S,v 1.5 2001/08/14 22:17:48 eeh Exp $ */
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/*-
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* Copyright (c) 2001 Jake Burkholder.
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* Copyright (c) 2000 Eduardo Horvath.
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* Copyright (c) 1999 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 Paul Kranenburg.
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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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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the NetBSD
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* Foundation, Inc. and its contributors.
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* 4. Neither the name of The NetBSD Foundation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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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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* $FreeBSD$
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*/
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#include <machine/asm.h>
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/*
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* ELF:
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* On startup the stack should contain 16 extended word register save
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* area, followed by the arg count, etc.
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*/
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ENTRY(.rtld_start)
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clr %fp
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mov %o0, %l0
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mov %o3, %l1
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sub %sp, 16, %sp
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add %sp, SPOFF + CCFSZ + 0x0, %o1
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call _rtld
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add %sp, SPOFF + CCFSZ + 0x8, %o2
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ldx [%sp + SPOFF + CCFSZ + 0x0], %o1
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ldx [%sp + SPOFF + CCFSZ + 0x8], %o2
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add %sp, 16, %sp
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mov %l1, %o3
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jmp %o0
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mov %l0, %o0
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END(.rtld_start)
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/*
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* Find the address of _DYNAMIC by disassembling a call instruction to it.
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* Binutils may not fill in the GOT as expected on other architectures.
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*/
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.weak _DYNAMIC
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ENTRY(rtld_dynamic_addr)
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save %sp, -CCFSZ, %sp
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call 1f
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nop
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call _DYNAMIC + 8
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1: lduw [%o7 + 8], %o0
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sll %o0, 2, %o0
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sra %o0, 0, %o0
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ret
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restore %o0, %o7, %o0
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END(rtld_dynamic_addr)
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/*
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* We have two separate entry points to the runtime linker.
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* I'm implementing this following the SPARC v9 ABI spec.
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*
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* _rtld_bind_start_0(x, y) is called from .PLT0, and is used for
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* PLT entries above 32768.
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*
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* _rtld_bind_start_1(x, y) is called from .PLT1, and is used for
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* PLT entries below 32768.
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*
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* The first two entries of PLT2 contain the xword object pointer.
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*
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* These routines are called with two longword arguments,
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* x and y. To calculate the address of the entry,
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* _rtld_bind_start_1(x, y) does:
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*
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* n = x >> 15;
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*
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* and _rtld_bind_start_0(x, y) should do, according to the SCD:
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*
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* i = x - y - 1048596;
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* n = 32768 + (i/5120)*160 + (i%5120)/24;
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*
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* Note that the number of 1048596 from above is incorrect; rather,
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* we need to use HIPLTOFFS as defined below.
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*
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* Neither routine needs to issue a save since it's already been
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* done in the PLT entry.
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*/
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#define NPLTLOSLOTS 32768
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#define PLTSLOTSZ 32
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/*
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* - 16 to compensate for the difference of the positions of the jumps that
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* generate the arguments in .PLT0 and the high plt entry.
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*/
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#define HIPLTOFFS (NPLTLOSLOTS * PLTSLOTSZ - 16)
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ENTRY(_rtld_bind_start_0)
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sethi %hi(HIPLTOFFS), %l1
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or %l1, %lo(HIPLTOFFS), %l1
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sub %o0, %o1, %l0 /* x - y */
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sub %l0, %l1, %l0 /* i = x - y - HIPLTOFFS */
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sethi %hi(5120), %l7
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sdivx %l0, %l7, %l1 /* Calculate i / 5120 */
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mulx %l1, %l7, %l3
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sub %l0, %l3, %l2 /* And i % 5120 */
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mulx %l1, 160, %l5 /* (i / 5120) * 160 */
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sdivx %l2, 24, %l4 /* (i % 5120) / 24 */
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sethi %hi(NPLTLOSLOTS), %l6
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add %l4, %l5, %l4 /* (i / 5120) * 160 + (i % 5120) / 24 */
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add %l4, %l6, %l4 /* + NPLTLOSLOTS */
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sub %l4, 4, %l4 /* XXX: 4 entries are reserved */
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sllx %l4, 1, %l5 /* Each element is an Elf_Rela which */
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add %l5, %l4, %l4 /* is 3 longwords or 24 bytes. */
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sllx %l4, 3, %l4 /* So multiply by 24. */
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ldx [%o1 + (10*4)], %o0 /* Load object pointer from PLT2 */
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call _rtld_bind /* Call _rtld_bind(obj, offset) */
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mov %l4, %o1
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jmp %o0 /* return value == function address */
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restore /* Dump our stack frame */
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END(_rtld_bind_start_0)
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ENTRY(_rtld_bind_start_1)
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srax %o0, 15, %o2 /* %o0 is the index to our PLT slot */
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sub %o2, 4, %o2 /* XXX: 4 entries are reserved */
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sllx %o2, 1, %o3 /* Each element is an Elf_Rela which */
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add %o3, %o2, %o2 /* is 3 longwords or 24 bytes. */
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sllx %o2, 3, %o2 /* So multiply by 24. */
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ldx [%o1 + 8], %o0 /* The object pointer is at [%o1 + 8] */
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call _rtld_bind /* Call _rtld_bind(obj, offset) */
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mov %o2, %o1
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jmp %o0 /* return value == function address */
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restore /* Dump our stack frame */
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END(_rtld_bind_start_1)
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