NetBSD/libexec/ld.elf_so/arch/alpha/alpha_reloc.c

115 lines
3.5 KiB
C

/* $NetBSD: alpha_reloc.c,v 1.2 2001/12/14 00:53:07 thorpej Exp $ */
/*
* Copyright (c) 2001 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Jason R. Thorpe for Wasabi Systems, Inc.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
* 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 <sys/types.h>
#include <sys/stat.h>
#include "rtld.h"
#include "debug.h"
#ifdef RTLD_DEBUG_ALPHA
#define adbg(x) if (dodebug) xprintf x
#else
#define adbg(x) /* nothing */
#endif
/*
* _rtld_setup_alpha_pltgot:
*
* Set up the Alpha pltgot glue.
*/
void
_rtld_setup_alpha_pltgot(const Obj_Entry *obj, bool dodebug)
{
uint32_t word0;
/*
* The PLTGOT on the Alpha looks like this:
*
* PLT HEADER
* .
* . 32 bytes
* .
* PLT ENTRY #0
* .
* . 12 bytes
* .
* PLT ENTRY #1
* .
* . 12 bytes
* .
* etc.
*
* The old-format entries look like (displacements filled in
* by the linker):
*
* ldah $28, 0($31) # 0x279f0000
* lda $28, 0($28) # 0x239c0000
* br $31, plt0 # 0xc3e00000
*
* The new-format entries look like:
*
* br $28, plt0 # 0xc3800000
* # 0x00000000
* # 0x00000000
*
* What we do is fetch the first PLT entry and check to
* see the first word of it matches the first word of the
* old format. If so, we use a binding routine that can
* handle the old format, otherwise we use a binding routine
* that handles the new format.
*
* Note that this is done on a per-object basis, we can mix
* and match shared objects build with both the old and new
* linker.
*/
word0 = *(uint32_t *)(((char *) obj->pltgot) + 32);
if ((word0 & 0xffff0000) == 0x279f0000) {
/* Old PLT entry format. */
adbg(("ALPHA: object %p has old PLT format\n", obj));
obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start_old;
obj->pltgot[3] = (Elf_Addr) obj;
return;
}
/* New PLT entry format. */
adbg(("ALPHA: object %p has new PLT format\n", obj));
obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
obj->pltgot[3] = (Elf_Addr) obj;
}