[PATCH v2 3/5] cpukit/libdl: Add support for AArch64
Chris Johns
chrisj at rtems.org
Tue Jul 26 03:46:47 UTC 2022
On 26/7/2022 12:06 am, Ryan Long wrote:
> rtl-mdreloc-aarch64.c and elf_machdep.h came from NetBSD.
>
> Updates #4682
> ---
> cpukit/libdl/rtl-mdreloc-aarch64.c | 599 ++++++++++++++++++
> .../cpu/aarch64/include/machine/elf_machdep.h | 256 ++++++++
> spec/build/cpukit/objdl.yml | 2 +
> spec/build/cpukit/objdlaarch64.yml | 15 +
> spec/build/cpukit/optlibdl.yml | 1 +
> 5 files changed, 873 insertions(+)
> create mode 100644 cpukit/libdl/rtl-mdreloc-aarch64.c
> create mode 100644 cpukit/score/cpu/aarch64/include/machine/elf_machdep.h
> create mode 100644 spec/build/cpukit/objdlaarch64.yml
>
> diff --git a/cpukit/libdl/rtl-mdreloc-aarch64.c b/cpukit/libdl/rtl-mdreloc-aarch64.c
> new file mode 100644
> index 0000000000..41147e285c
> --- /dev/null
> +++ b/cpukit/libdl/rtl-mdreloc-aarch64.c
> @@ -0,0 +1,599 @@
> +/*
> + * Taken from NetBSD and stripped of the relocations not needed on RTEMS.
> + */
> +
> +/* $NetBSD: mdreloc.c,v 1.14 2020/06/16 21:01:30 joerg Exp $ */
> +
> +/*-
> + * Copyright (c) 2014 The NetBSD Foundation, Inc.
> + * All rights reserved.
> + *
> + * This code is derived from software contributed to The NetBSD Foundation
> + * by Matt Thomas of 3am Software Foundry.
> + *
> + * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
> + */
> +
> +/*-
> + * Copyright (c) 2014-2015 The FreeBSD Foundation
> + * All rights reserved.
> + *
> + * Portions of this software were developed by Andrew Turner
> + * under sponsorship from the FreeBSD Foundation.
> + *
> + * 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>
> +#ifndef lint
> +__RCSID("$NetBSD: mdreloc.c,v 1.14 2020/06/16 21:01:30 joerg Exp $");
> +#endif /* not lint */
> +
> +#include <sys/types.h>
> +#include <string.h>
> +#include <errno.h>
> +#include <inttypes.h>
> +#include <sys/stat.h>
> +#include <sys/endian.h>
> +#include <unwind.h>
> +
> +#include <rtems/rtl/rtl.h>
> +#include "rtl-elf.h"
> +#include "rtl-error.h"
> +#include <rtems/rtl/rtl-trace.h>
> +#include "rtl-unwind.h"
> +
> +typedef unsigned _Unwind_Word __attribute__((__mode__(__word__)));
> +typedef _Unwind_Word _uw;
> +
> +struct tls_data {
> + size_t td_tlsindex;
> + Elf_Addr td_tlsoffs;
> +};
> +
> +rtems_rtl_elf_rel_status
> +rtems_rtl_elf_reloc_rela (
> + rtems_rtl_obj* obj,
> + const Elf_Rela* rela,
> + const rtems_rtl_obj_sect* sect,
> + const char* symname,
> + const Elf_Byte syminfo,
> + const Elf_Word symvalue,
> + const bool parsing
> +);
> +
> +#define __BITS(hi,lo) ((~((~(Elf_Addr)0)<<((hi)+1)))&((~(Elf_Addr)0)<<(lo)))
> +#define WIDTHMASK(w) (0xffffffffffffffffUL >> (64 - (w)))
> +
> +static inline bool
> +checkoverflow(Elf_Addr addr, int bitwidth, Elf_Addr targetaddr,
> + const char *bitscale, void *where, Elf64_Addr off)
> +{
> + const Elf_Addr mask = ~__BITS(bitwidth - 1, 0);
> +
> + if (((addr & mask) != 0) && ((addr & mask) != mask)) {
> + printf("kobj_reloc: Relocation 0x%jx too far from %p"
> + " (base+0x%jx) for %dbit%s\n",
> + (uintptr_t)targetaddr, where, off, bitwidth, bitscale);
> + return true;
> + }
> +
> + return false;
> +}
> +
> +static inline bool
> +checkalign(Elf_Addr addr, int alignbyte, void *where, Elf64_Addr off)
> +{
> + if ((addr & (alignbyte - 1)) != 0) {
> + printf("kobj_reloc: Relocation 0x%jx unaligned at %p"
> + " (base+0x%jx). must be aligned %d\n",
> + (uintptr_t)addr, where, off, alignbyte);
> + return true;
> + }
> + return false;
> +}
> +
> +/*
> + * Set to 1 to allow untested relocations. If you tested one and it
> + * works or you fixed the relocation please remove the guard.
> + */
> +#define ALLOW_UNTESTED_RELOCS 1
> +
> +static void*
> +set_veneer(void* tramopline, Elf_Addr target)
> +{
> + /*
> + * http://shell-storm.org/online/Online-Assembler-and-Disassembler/
> + *
> + * ldr x9, #8
> + * br x9
> + *
> + */
> + uint64_t* tramp = (uint64_t*) tramopline;
> +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
> + *tramp++ = 0xd61f012058000049;
> +#else
> + *tramp++ = 0xd61f012058000049; /* not tested */
> +#endif
> + *tramp++ = (uint64_t) target;
> + return tramp;
> +}
> +
> +static size_t
> +get_veneer_size(int type)
> +{
> + (void) type;
> + return 16;
> +}
> +
> +size_t
> +rtems_rtl_elf_relocate_tramp_max_size (void)
> +{
> + return 16;
> +}
> +
> +uint32_t
> +rtems_rtl_elf_section_flags (const rtems_rtl_obj* obj,
> + const Elf_Shdr* shdr)
> +{
> + return 0;
> +}
> +
> +uint32_t
> +rtems_rtl_elf_arch_parse_section (const rtems_rtl_obj* obj,
> + int section,
> + const char* name,
> + const Elf_Shdr* shdr,
> + const uint32_t flags)
> +{
> + (void) obj;
> + (void) section;
> + (void) name;
> + (void) shdr;
> + return flags;
> +}
> +
> +bool
> +rtems_rtl_elf_arch_section_alloc (const rtems_rtl_obj* obj,
> + rtems_rtl_obj_sect* sect)
> +{
> + (void) obj;
> + (void) sect;
> + return false;
> +}
> +
> +bool
> +rtems_rtl_elf_arch_section_free (const rtems_rtl_obj* obj,
> + rtems_rtl_obj_sect* sect)
> +{
> + (void) obj;
> + (void) sect;
> + return false;
> +}
> +
> +bool
> +rtems_rtl_elf_rel_resolve_sym (Elf_Word type)
> +{
> + return true;
> +}
> +
> +rtems_rtl_elf_rel_status
> +rtems_rtl_elf_reloc_rela (rtems_rtl_obj* obj,
> + const Elf_Rela* rela,
> + const rtems_rtl_obj_sect* sect,
> + const char* symname,
> + const Elf_Byte syminfo,
> + const Elf_Word symvalue,
> + const bool parsing)
> +{
> + Elf64_Addr *where;
> + Elf32_Addr *where32;
> + Elf_Addr off = rela->r_offset;
> + Elf_Addr target;
> + Elf_Addr raddr;
> + uint32_t *insn, immhi, immlo, shift;
> +
> + where = (Elf_Addr *)(sect->base + rela->r_offset);
> + where32 = (void *)where;
> +
> + insn = (uint32_t *)where;
> +
> + /*
> + * S - the address of the symbol
> + * A - the addend of the reolcation
> + * P - the address of the place being relocated (derived from r_offset)
> + * Page(expr) - the page address of the expression expr, defined as (expr & ~0xFFF).
> + */
> + switch (ELF_R_TYPE(rela->r_info)) {
> + case R_TYPE(NONE):
> + if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) {
> + printf ("rtl: NONE %p in %s\n", where, rtems_rtl_obj_oname (obj));
> + }
> + break;
> +
> + case R_TYPE(ABS64): /* word S + A */
> + case R_TYPE(GLOB_DAT): /* word S + A */
> + if (!parsing) {
> + target = (Elf_Addr)symvalue + rela->r_addend;
> +
> + if (*where != target)
> + *where = target;
> +
> + if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
> + printf ("rtl: reloc 64/GLOB_DAT in %s --> %p in %s\n",
> + sect->name, (void *)*where,
> + rtems_rtl_obj_oname (obj));
> + }
> + break;
> +
> + /*
> + * If S is a normal symbol, resolves to the difference between the static
> + * link address of S and the execution address of S. If S is the null symbol
> + * (ELF symbol index 0), resolves to the difference between the static link
> + * address of P and the execution address of P.
> + */
> + case R_TYPE(RELATIVE): /* Delta(S) + A */
> + if (!parsing) {
> + *where = (Elf_Addr)(sect->base + rela->r_addend);
> + if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
> + printf ("rtl: reloc RELATIVE in %s --> %p in %s\n",
> + sect->name, (void *)*where,
> + rtems_rtl_obj_oname (obj));
> + }
> + break;
> +
> + case R_TYPE(COPY):
> + /*
> + * These are deferred until all other relocations have
> + * been done. All we do here is make sure that the
> + * COPY relocation is not in a shared library. They
> + * are allowed only in executable files.
> + */
> + printf("rtl: reloc COPY (please report)\n");
> + break;
> +
> + case R_AARCH64_ADD_ABS_LO12_NC: /* S + A */
> + case R_AARCH64_LDST8_ABS_LO12_NC:
> + case R_AARCH_LDST16_ABS_LO12_NC:
> + case R_AARCH_LDST32_ABS_LO12_NC:
> + case R_AARCH_LDST64_ABS_LO12_NC:
> + switch (ELF_R_TYPE(rela->r_info)) {
> + case R_AARCH64_ADD_ABS_LO12_NC:
> + case R_AARCH64_LDST8_ABS_LO12_NC:
> + shift = 0;
> + break;
> + case R_AARCH_LDST16_ABS_LO12_NC:
> + shift = 1;
> + break;
> + case R_AARCH_LDST32_ABS_LO12_NC:
> + shift = 2;
> + break;
> + case R_AARCH_LDST64_ABS_LO12_NC:
> + shift = 3;
> + break;
> + default:
> + printf("illegal rtype: %ld\n", ELF_R_TYPE(rela->r_info));
> + break;
> + }
> +
> + /*
> + * S + A
> + * e.g.) add x0,x0,#:lo12:<sym>+<addend>
> + * ldrb w0,[x0,#:lo12:<sym>+<addend>]
> + * ldrh w0,[x0,#:lo12:<sym>+<addend>]
> + * ldr w0,[x0,#:lo12:<sym>+<addend>]
> + * ldr x0,[x0,#:lo12:<sym>+<addend>]
> + */
> + if (!parsing) {
> + target = (Elf_Addr)symvalue + rela->r_addend;
> + if (checkalign(target, 1 << shift, where, off)) {
> + printf ("rtl: reloc checkalign failed in %s --> %p in %s\n",
> + sect->name, (void *)*where,
> + rtems_rtl_obj_oname (obj));
> + printf("ELF_R_TYPE is : %ld\n", ELF_R_TYPE(rela->r_info));
> + break;
> + }
> + target &= WIDTHMASK(12);
> + target >>= shift;
> + *insn = htole32(
> + (le32toh(*insn) & ~__BITS(21,10)) | (target << 10));
> + }
> + break;
> +
> + case R_AARCH64_ADR_PREL_PG_HI21:
> + /*
> + * Page(S + A) - Page(P)
> + * e.g.) adrp x0,<sym>+<addend>
> + */
> + if (!parsing) {
> + target = (Elf_Addr)symvalue + rela->r_addend;
> + target = target >> 12;
> + raddr = target << 12;
> + target -= (uintptr_t)where >> 12;
> +
> + if (checkoverflow(target, 21, raddr, " x 4k", where, off)) {
> + return rtems_rtl_elf_rel_failure;
> + }
> +
> + immlo = target & WIDTHMASK(2);
> + immhi = (target >> 2) & WIDTHMASK(19);
> + *insn = htole32((le32toh(*insn) &
> + ~(__BITS(30,29) | __BITS(23,5))) |
> + (immlo << 29) | (immhi << 5));
> + }
> + break;
> +
> + case R_AARCH_JUMP26:
> + case R_AARCH_CALL26:
> + /*
> + * S + A - P
> + * e.g.) b <sym>+<addend>
> + * bl <sym>+<addend>
> + */
> + if (parsing && sect->base == 0) {
> + if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
> + printf ("rtl: JUMP26/PC26/CALL tramp cache\n");
> + return rtems_rtl_elf_rel_tramp_cache;
> + }
> +
> + raddr = (Elf_Addr)symvalue + rela->r_addend;
> + target = raddr - (uintptr_t)where;
> + if (checkalign(target, 4, where, off)) {
> + return rtems_rtl_elf_rel_failure;
> + }
> +
> + target = (intptr_t)target >> 2;
> +
> + if (((Elf_Sword)target > 0x1FFFFFF) || ((Elf_Sword)target < -0x2000000)) {
> + Elf_Word tramp_addr;
> + size_t tramp_size = get_veneer_size(ELF_R_TYPE(rela->r_info));
> +
> + if (parsing) {
> + if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
> + printf ("rtl: JUMP26/PC26/CALL tramp add\n");
> + return rtems_rtl_elf_rel_tramp_add;
> + }
> +
> + if (!rtems_rtl_obj_has_tramp_space (obj, tramp_size)) {
> + rtems_rtl_set_error (EINVAL,
> + "%s: CALL/JUMP26: overflow: no tramp memory",
> + sect->name);
> + return rtems_rtl_elf_rel_failure;
> + }
> +
> + tramp_addr = ((Elf_Addr) obj->tramp_brk) | (symvalue & 1);
> + obj->tramp_brk = set_veneer(obj->tramp_brk, symvalue);
> +
> + target = tramp_addr + rela->r_addend - (uintptr_t)where;
> + target = (uintptr_t)target >> 2;
> + }
> +
> + if (checkoverflow(target, 26, raddr, " word", where, off)) {
> + return rtems_rtl_elf_rel_failure;
> + }
> +
> + if (!parsing) {
> + target &= WIDTHMASK(26);
> + *insn = htole32((le32toh(*insn) & ~__BITS(25,0)) | target);
> + }
> +
> + break;
> +
> + case R_AARCH64_PREL32:
> + /*
> + * S + A - P
> + * e.g.) 1: .word <sym>+<addend>-1b
> + */
> + if (!parsing) {
> + raddr = (Elf_Addr)symvalue + rela->r_addend;
> + target = raddr - (uintptr_t)where;
> + if (checkoverflow(target, 32, raddr, "", where, off)) {
> + return rtems_rtl_elf_rel_failure;
> + }
> + *where32 = target;
> + }
> + break;
> +
> + case R_TYPE(TLSDESC):
> + printf ("rtl: reloc TLSDESC in %s --> %p in %s\n",
> + sect->name, (void *)*where,
> + rtems_rtl_obj_oname (obj));
> + break;
> +
> + case R_TLS_TYPE(TLS_DTPREL):
> + printf ("rtl: reloc TLS_DTPREL in %s --> %p in %s\n",
> + sect->name, (void *)*where,
> + rtems_rtl_obj_oname (obj));
> + break;
> + case R_TLS_TYPE(TLS_DTPMOD):
> + printf ("rtl: reloc TLS_DTPMOD in %s --> %p in %s\n",
> + sect->name, (void *)*where,
> + rtems_rtl_obj_oname (obj));
> + break;
> +
> + case R_TLS_TYPE(TLS_TPREL):
> + printf ("rtl: reloc TLS_TPREL in %s --> %p in %s\n",
> + sect->name, (void *)*where,
> + rtems_rtl_obj_oname (obj));
> + break;
> +
> + default:
> + printf ("rtl: Unsupported relocation type in %s --> %p in %s\n",
> + sect->name, (void *)where,
> + rtems_rtl_obj_oname (obj));
> + return rtems_rtl_elf_rel_failure;
> + }
> +
> + return rtems_rtl_elf_rel_no_error;
> +}
> +
> +rtems_rtl_elf_rel_status
> +rtems_rtl_elf_relocate_rela_tramp (rtems_rtl_obj* obj,
> + const Elf_Rela* rela,
> + const rtems_rtl_obj_sect* sect,
> + const char* symname,
> + const Elf_Byte syminfo,
> + const Elf_Word symvalue)
> +{
> + return rtems_rtl_elf_reloc_rela (obj,
> + rela,
> + sect,
> + symname,
> + syminfo,
> + symvalue,
> + true);
> +}
> +
> +rtems_rtl_elf_rel_status
> +rtems_rtl_elf_relocate_rela (rtems_rtl_obj* obj,
> + const Elf_Rela* rela,
> + const rtems_rtl_obj_sect* sect,
> + const char* symname,
> + const Elf_Byte syminfo,
> + const Elf_Word symvalue)
> +{
> + return rtems_rtl_elf_reloc_rela (obj,
> + rela,
> + sect,
> + symname,
> + syminfo,
> + symvalue,
> + false);
> +}
> +
> +rtems_rtl_elf_rel_status
> +rtems_rtl_elf_relocate_rel_tramp (rtems_rtl_obj* obj,
> + const Elf_Rel* rel,
> + const rtems_rtl_obj_sect* sect,
> + const char* symname,
> + const Elf_Byte syminfo,
> + const Elf_Word symvalue)
> +{
> + rtems_rtl_set_error (EINVAL, "rela type record not supported");
> + return rtems_rtl_elf_rel_failure;
> +}
> +
> +rtems_rtl_elf_rel_status
> +rtems_rtl_elf_relocate_rel (rtems_rtl_obj* obj,
> + const Elf_Rel* rel,
> + const rtems_rtl_obj_sect* sect,
> + const char* symname,
> + const Elf_Byte syminfo,
> + const Elf_Word symvalue)
> +{
> + rtems_rtl_set_error (EINVAL, "rela type record not supported");
> + return rtems_rtl_elf_rel_failure;
> +}
> +
> +bool
> +rtems_rtl_elf_unwind_parse (const rtems_rtl_obj* obj,
> + const char* name,
> + uint32_t flags)
> +{
> + /*
> + * We location the EH sections in section flags.
> + */
> + return false;
> +}
> +
> +bool
> +rtems_rtl_elf_unwind_register (rtems_rtl_obj* obj)
> +{
> + return true;
> +}
> +
> +bool
> +rtems_rtl_elf_unwind_deregister (rtems_rtl_obj* obj)
> +{
> + obj->loader = NULL;
Did you test the code with this removed?
I think it is a bug and a bug in the ARM implementation as well.
Chris
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