Files
binutils-gdb/bfd/elfxx-riscv.h
Nelson Chu 73d931e560 RISC-V: PR31179, The SET/ADD/SUB fix breaks ABI compatibility with 2.41 objects
* Problematic fix commit,
2029e13917
RISC-V: Clarify the behaviors of SET/ADD/SUB relocations

* Bugzilla,
https://sourceware.org/bugzilla/show_bug.cgi?id=31179#c5

The addend of SUB_ULEB128 should be zero if using .uleb128, but we make it
non-zero by accident in assembler before.  This causes troubles by applying
the above commit, since the calculation is changed to support .reloc *SUB*
relocations with non-zero addend.

We encourage people to rebuild their stuff to get the non-zero addend of
SUB_ULEB128, but that might need some times, so report warnings to inform
people need to rebuild their stuff if --check-uleb128 is enabled.

Since the failed .reloc cases for ADD/SET/SUB/ULEB128 are rarely to use,
it may acceptable that stop supproting them until people rebuld their stuff,
maybe half-year or a year later.  Or maybe we should teach people that don't
write the .reloc R_RISCV_SUB* with non-zero constant, and then report
warnings/errors in assembler.

bfd/
	* elfnn-riscv.c (perform_relocation): Ignore the non-zero addend of
	R_RISCV_SUB_ULEB128.
	(riscv_elf_relocate_section): Report warnings to inform people need
	to rebuild their stuff if --check-uleb128 is enabled.  So that can
	get the right non-zero addend of R_RISCV_SUB_ULEB128.
	* elfxx-riscv.h (struct riscv_elf_params): Added bool check_uleb128.
ld/
	* NEWS: Updated.
	* emultempl/riscvelf.em: Added linker risc-v target options,
	--[no-]check-uleb128, to enable/disable checking if the addend of
	uleb128 is non-zero or not.  So that people will know they need to
	rebuild the objects with binutils 2.42 and up, to get the right zero
	addend of SUB_ULEB128 relocation, or they may get troubles if using
	.reloc.
	* ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp: Updated.
	* ld/testsuite/ld-riscv-elf/pr31179*: New test cases.
2023-12-28 14:51:50 +08:00

128 lines
3.4 KiB
C

/* RISC-V ELF specific backend routines.
Copyright (C) 2011-2023 Free Software Foundation, Inc.
Contributed by Andrew Waterman (andrew@sifive.com).
Based on MIPS target.
This file is part of BFD, the Binary File Descriptor library.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING3. If not,
see <http://www.gnu.org/licenses/>. */
#include "elf/common.h"
#include "elf/internal.h"
#include "opcode/riscv.h"
#include "cpu-riscv.h"
#define RISCV_UNKNOWN_VERSION -1
struct riscv_elf_params
{
/* Whether to relax code sequences to GP-relative addressing. */
bool relax_gp;
/* Whether to check if SUB_ULEB128 relocation has non-zero addend. */
bool check_uleb128;
};
extern void riscv_elf32_set_options (struct bfd_link_info *,
struct riscv_elf_params *);
extern void riscv_elf64_set_options (struct bfd_link_info *,
struct riscv_elf_params *);
extern reloc_howto_type *
riscv_reloc_name_lookup (bfd *, const char *);
extern reloc_howto_type *
riscv_reloc_type_lookup (bfd *, bfd_reloc_code_real_type);
extern reloc_howto_type *
riscv_elf_rtype_to_howto (bfd *, unsigned int r_type);
/* The information of architecture attribute. */
struct riscv_subset_t
{
const char *name;
int major_version;
int minor_version;
struct riscv_subset_t *next;
};
typedef struct riscv_subset_t riscv_subset_t;
typedef struct
{
riscv_subset_t *head;
riscv_subset_t *tail;
const char *arch_str;
} riscv_subset_list_t;
extern void
riscv_release_subset_list (riscv_subset_list_t *);
extern void
riscv_add_subset (riscv_subset_list_t *,
const char *,
int, int);
extern bool
riscv_lookup_subset (const riscv_subset_list_t *,
const char *,
riscv_subset_t **);
typedef struct
{
riscv_subset_list_t *subset_list;
void (*error_handler) (const char *,
...) ATTRIBUTE_PRINTF_1;
unsigned *xlen;
enum riscv_spec_class *isa_spec;
bool check_unknown_prefixed_ext;
} riscv_parse_subset_t;
extern bool
riscv_parse_subset (riscv_parse_subset_t *,
const char *);
extern void
riscv_release_subset_list (riscv_subset_list_t *);
extern char *
riscv_arch_str (unsigned, const riscv_subset_list_t *);
extern size_t
riscv_estimate_digit (unsigned);
extern int
riscv_compare_subsets (const char *, const char *);
extern riscv_subset_list_t *
riscv_copy_subset_list (riscv_subset_list_t *);
extern bool
riscv_update_subset (riscv_parse_subset_t *, const char *);
extern bool
riscv_subset_supports (riscv_parse_subset_t *, const char *);
extern bool
riscv_multi_subset_supports (riscv_parse_subset_t *, enum riscv_insn_class);
extern const char *
riscv_multi_subset_supports_ext (riscv_parse_subset_t *, enum riscv_insn_class);
extern void
bfd_elf32_riscv_set_data_segment_info (struct bfd_link_info *, int *);
extern void
bfd_elf64_riscv_set_data_segment_info (struct bfd_link_info *, int *);