HardenedBSD/stand/common/reloc_elf.c
Andrew Turner f6f0b849fb Reuse the amd64 loader relocation code on arm64
There is no need to keep multiple copies of the relocation code. The
amd64 code works on arm64 with a few small changes to relocation types.

Sponsored by:	Innovate UK
Differential Revision:	https://reviews.freebsd.org/D28213
2021-01-20 17:59:38 +00:00

222 lines
6.1 KiB
C

/*-
* Copyright (c) 2003 Jake Burkholder.
* Copyright 1996-1998 John D. Polstra.
* Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
* Copyright (c) 1998 Peter Wemm <peter@freebsd.org>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <machine/elf.h>
#include <stand.h>
#define FREEBSD_ELF
#include <sys/link_elf.h>
#include "bootstrap.h"
#define COPYOUT(s,d,l) archsw.arch_copyout((vm_offset_t)(s), d, l)
/*
* Apply a single intra-module relocation to the data. `relbase' is the
* target relocation base for the section (i.e. it corresponds to where
* r_offset == 0). `dataaddr' is the relocated address corresponding to
* the start of the data, and `len' is the number of bytes.
*/
int
__elfN(reloc)(struct elf_file *ef, symaddr_fn *symaddr, const void *reldata,
int reltype, Elf_Addr relbase, Elf_Addr dataaddr, void *data, size_t len)
{
#if (defined(__aarch64__) || defined(__amd64__) || defined(__i386__)) && \
__ELF_WORD_SIZE == 64
Elf64_Addr *where, val;
Elf_Addr addend, addr;
Elf_Size rtype, symidx;
const Elf_Rel *rel;
const Elf_Rela *rela;
switch (reltype) {
case ELF_RELOC_REL:
rel = (const Elf_Rel *)reldata;
where = (Elf_Addr *)((char *)data + relbase + rel->r_offset -
dataaddr);
addend = 0;
rtype = ELF_R_TYPE(rel->r_info);
symidx = ELF_R_SYM(rel->r_info);
addend = 0;
break;
case ELF_RELOC_RELA:
rela = (const Elf_Rela *)reldata;
where = (Elf_Addr *)((char *)data + relbase + rela->r_offset -
dataaddr);
addend = rela->r_addend;
rtype = ELF_R_TYPE(rela->r_info);
symidx = ELF_R_SYM(rela->r_info);
break;
default:
return (EINVAL);
}
if ((char *)where < (char *)data || (char *)where >= (char *)data + len)
return (0);
if (reltype == ELF_RELOC_REL)
addend = *where;
#if defined(__aarch64__)
#define RELOC_RELATIVE R_AARCH64_RELATIVE
#define RELOC_IRELATIVE R_AARCH64_IRELATIVE
#elif defined(__amd64__) || defined(__i386__)
/* XXX, definitions not available on i386. */
#define R_X86_64_64 1
#define R_X86_64_RELATIVE 8
#define R_X86_64_IRELATIVE 37
#define RELOC_RELATIVE R_X86_64_RELATIVE
#define RELOC_IRELATIVE R_X86_64_IRELATIVE
#endif
switch (rtype) {
case RELOC_RELATIVE:
addr = (Elf_Addr)addend + relbase;
val = addr;
memcpy(where, &val, sizeof(val));
break;
case RELOC_IRELATIVE:
/* leave it to kernel */
break;
#if defined(__amd64__) || defined(__i386__)
case R_X86_64_64: /* S + A */
addr = symaddr(ef, symidx);
if (addr == 0)
return (ESRCH);
val = addr + addend;
*where = val;
break;
#endif
default:
printf("\nunhandled relocation type %u\n", (u_int)rtype);
return (EFTYPE);
}
return (0);
#elif defined(__i386__) && __ELF_WORD_SIZE == 32
Elf_Addr addend, addr, *where, val;
Elf_Size rtype, symidx;
const Elf_Rel *rel;
const Elf_Rela *rela;
switch (reltype) {
case ELF_RELOC_REL:
rel = (const Elf_Rel *)reldata;
where = (Elf_Addr *)((char *)data + relbase + rel->r_offset -
dataaddr);
addend = 0;
rtype = ELF_R_TYPE(rel->r_info);
symidx = ELF_R_SYM(rel->r_info);
addend = 0;
break;
case ELF_RELOC_RELA:
rela = (const Elf_Rela *)reldata;
where = (Elf_Addr *)((char *)data + relbase + rela->r_offset -
dataaddr);
addend = rela->r_addend;
rtype = ELF_R_TYPE(rela->r_info);
symidx = ELF_R_SYM(rela->r_info);
break;
default:
return (EINVAL);
}
if ((char *)where < (char *)data || (char *)where >= (char *)data + len)
return (0);
if (reltype == ELF_RELOC_REL)
addend = *where;
/* XXX, definitions not available on amd64. */
#define R_386_32 1 /* Add symbol value. */
#define R_386_GLOB_DAT 6 /* Set GOT entry to data address. */
#define R_386_RELATIVE 8 /* Add load address of shared object. */
#define R_386_IRELATIVE 42
switch (rtype) {
case R_386_RELATIVE:
addr = addend + relbase;
*where = addr;
break;
case R_386_32: /* S + A */
addr = symaddr(ef, symidx);
if (addr == 0)
return (ESRCH);
val = addr + addend;
*where = val;
break;
case R_386_IRELATIVE:
/* leave it to kernel */
break;
default:
printf("\nunhandled relocation type %u\n", (u_int)rtype);
return (EFTYPE);
}
return (0);
#elif defined(__powerpc__) || defined(__riscv)
Elf_Size w;
const Elf_Rela *rela;
switch (reltype) {
case ELF_RELOC_RELA:
rela = reldata;
if (relbase + rela->r_offset >= dataaddr &&
relbase + rela->r_offset < dataaddr + len) {
switch (ELF_R_TYPE(rela->r_info)) {
#if defined(__powerpc__)
case R_PPC_RELATIVE:
#elif defined(__riscv)
case R_RISCV_RELATIVE:
#endif
w = relbase + rela->r_addend;
bcopy(&w, (u_char *)data + (relbase +
rela->r_offset - dataaddr), sizeof(w));
break;
default:
printf("\nunhandled relocation type %u\n",
(u_int)ELF_R_TYPE(rela->r_info));
return (EFTYPE);
}
}
break;
}
return (0);
#else
return (EOPNOTSUPP);
#endif
}