blob: a10384cd4d3695415c5b5ed416c236afc329ace1 [file] [log] [blame]
/* RISC-V-specific support for NN-bit ELF.
Copyright (C) 2011-2021 Free Software Foundation, Inc.
Contributed by Andrew Waterman (andrew@sifive.com).
Based on TILE-Gx and MIPS targets.
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/>. */
/* This file handles RISC-V ELF targets. */
#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
#include "bfdlink.h"
#include "genlink.h"
#include "elf-bfd.h"
#include "elfxx-riscv.h"
#include "elf/riscv.h"
#include "opcode/riscv.h"
#include "objalloc.h"
#include "cpu-riscv.h"
#include <limits.h>
#ifndef CHAR_BIT
#define CHAR_BIT 8
#endif
/* Internal relocations used exclusively by the relaxation pass. */
#define R_RISCV_DELETE (R_RISCV_max + 1)
#define ARCH_SIZE NN
#define MINUS_ONE ((bfd_vma)0 - 1)
#define RISCV_ELF_LOG_WORD_BYTES (ARCH_SIZE == 32 ? 2 : 3)
#define RISCV_ELF_WORD_BYTES (1 << RISCV_ELF_LOG_WORD_BYTES)
/* The name of the dynamic interpreter. This is put in the .interp
section. */
#define ELF64_DYNAMIC_INTERPRETER "/lib/ld.so.1"
#define ELF32_DYNAMIC_INTERPRETER "/lib32/ld.so.1"
#define ELF_ARCH bfd_arch_riscv
#define ELF_TARGET_ID RISCV_ELF_DATA
#define ELF_MACHINE_CODE EM_RISCV
#define ELF_MAXPAGESIZE 0x1000
#define ELF_COMMONPAGESIZE 0x1000
#define RISCV_ATTRIBUTES_SECTION_NAME ".riscv.attributes"
/* RISC-V ELF linker hash entry. */
struct riscv_elf_link_hash_entry
{
struct elf_link_hash_entry elf;
#define GOT_UNKNOWN 0
#define GOT_NORMAL 1
#define GOT_TLS_GD 2
#define GOT_TLS_IE 4
#define GOT_TLS_LE 8
char tls_type;
};
#define riscv_elf_hash_entry(ent) \
((struct riscv_elf_link_hash_entry *) (ent))
struct _bfd_riscv_elf_obj_tdata
{
struct elf_obj_tdata root;
/* tls_type for each local got entry. */
char *local_got_tls_type;
};
#define _bfd_riscv_elf_tdata(abfd) \
((struct _bfd_riscv_elf_obj_tdata *) (abfd)->tdata.any)
#define _bfd_riscv_elf_local_got_tls_type(abfd) \
(_bfd_riscv_elf_tdata (abfd)->local_got_tls_type)
#define _bfd_riscv_elf_tls_type(abfd, h, symndx) \
(*((h) != NULL ? &riscv_elf_hash_entry (h)->tls_type \
: &_bfd_riscv_elf_local_got_tls_type (abfd) [symndx]))
#define is_riscv_elf(bfd) \
(bfd_get_flavour (bfd) == bfd_target_elf_flavour \
&& elf_tdata (bfd) != NULL \
&& elf_object_id (bfd) == RISCV_ELF_DATA)
static bool
elfNN_riscv_mkobject (bfd *abfd)
{
return bfd_elf_allocate_object (abfd,
sizeof (struct _bfd_riscv_elf_obj_tdata),
RISCV_ELF_DATA);
}
#include "elf/common.h"
#include "elf/internal.h"
struct riscv_elf_link_hash_table
{
struct elf_link_hash_table elf;
/* Short-cuts to get to dynamic linker sections. */
asection *sdyntdata;
/* The max alignment of output sections. */
bfd_vma max_alignment;
/* Used by local STT_GNU_IFUNC symbols. */
htab_t loc_hash_table;
void * loc_hash_memory;
/* The index of the last unused .rel.iplt slot. */
bfd_vma last_iplt_index;
/* Re-run the relaxations from relax pass 0 if TRUE. */
bool restart_relax;
/* The data segment phase, don't relax the section
when it is exp_seg_relro_adjust. */
int *data_segment_phase;
};
/* Instruction access functions. */
#define riscv_get_insn(bits, ptr) \
((bits) == 16 ? bfd_getl16 (ptr) \
: (bits) == 32 ? bfd_getl32 (ptr) \
: (bits) == 64 ? bfd_getl64 (ptr) \
: (abort (), (bfd_vma) - 1))
#define riscv_put_insn(bits, val, ptr) \
((bits) == 16 ? bfd_putl16 (val, ptr) \
: (bits) == 32 ? bfd_putl32 (val, ptr) \
: (bits) == 64 ? bfd_putl64 (val, ptr) \
: (abort (), (void) 0))
/* Get the RISC-V ELF linker hash table from a link_info structure. */
#define riscv_elf_hash_table(p) \
((is_elf_hash_table ((p)->hash) \
&& elf_hash_table_id (elf_hash_table (p)) == RISCV_ELF_DATA) \
? (struct riscv_elf_link_hash_table *) (p)->hash : NULL)
static bool
riscv_info_to_howto_rela (bfd *abfd,
arelent *cache_ptr,
Elf_Internal_Rela *dst)
{
cache_ptr->howto = riscv_elf_rtype_to_howto (abfd, ELFNN_R_TYPE (dst->r_info));
return cache_ptr->howto != NULL;
}
static void
riscv_elf_append_rela (bfd *abfd, asection *s, Elf_Internal_Rela *rel)
{
const struct elf_backend_data *bed;
bfd_byte *loc;
bed = get_elf_backend_data (abfd);
loc = s->contents + (s->reloc_count++ * bed->s->sizeof_rela);
bed->s->swap_reloca_out (abfd, rel, loc);
}
/* Return true if a relocation is modifying an instruction. */
static bool
riscv_is_insn_reloc (const reloc_howto_type *howto)
{
/* Heuristic: A multibyte destination with a nontrivial mask
is an instruction */
return (howto->bitsize > 8
&& howto->dst_mask != 0
&& ~(howto->dst_mask | (howto->bitsize < sizeof(bfd_vma) * CHAR_BIT
? (MINUS_ONE << howto->bitsize) : (bfd_vma)0)) != 0);
}
/* PLT/GOT stuff. */
#define PLT_HEADER_INSNS 8
#define PLT_ENTRY_INSNS 4
#define PLT_HEADER_SIZE (PLT_HEADER_INSNS * 4)
#define PLT_ENTRY_SIZE (PLT_ENTRY_INSNS * 4)
#define GOT_ENTRY_SIZE RISCV_ELF_WORD_BYTES
/* Reserve two entries of GOTPLT for ld.so, one is used for PLT resolver,
the other is used for link map. Other targets also reserve one more
entry used for runtime profile? */
#define GOTPLT_HEADER_SIZE (2 * GOT_ENTRY_SIZE)
#define sec_addr(sec) ((sec)->output_section->vma + (sec)->output_offset)
#if ARCH_SIZE == 32
# define MATCH_LREG MATCH_LW
#else
# define MATCH_LREG MATCH_LD
#endif
/* Generate a PLT header. */
static bool
riscv_make_plt_header (bfd *output_bfd, bfd_vma gotplt_addr, bfd_vma addr,
uint32_t *entry)
{
bfd_vma gotplt_offset_high = RISCV_PCREL_HIGH_PART (gotplt_addr, addr);
bfd_vma gotplt_offset_low = RISCV_PCREL_LOW_PART (gotplt_addr, addr);
/* RVE has no t3 register, so this won't work, and is not supported. */
if (elf_elfheader (output_bfd)->e_flags & EF_RISCV_RVE)
{
_bfd_error_handler (_("%pB: warning: RVE PLT generation not supported"),
output_bfd);
return false;
}
/* auipc t2, %hi(.got.plt)
sub t1, t1, t3 # shifted .got.plt offset + hdr size + 12
l[w|d] t3, %lo(.got.plt)(t2) # _dl_runtime_resolve
addi t1, t1, -(hdr size + 12) # shifted .got.plt offset
addi t0, t2, %lo(.got.plt) # &.got.plt
srli t1, t1, log2(16/PTRSIZE) # .got.plt offset
l[w|d] t0, PTRSIZE(t0) # link map
jr t3 */
entry[0] = RISCV_UTYPE (AUIPC, X_T2, gotplt_offset_high);
entry[1] = RISCV_RTYPE (SUB, X_T1, X_T1, X_T3);
entry[2] = RISCV_ITYPE (LREG, X_T3, X_T2, gotplt_offset_low);
entry[3] = RISCV_ITYPE (ADDI, X_T1, X_T1, (uint32_t) -(PLT_HEADER_SIZE + 12));
entry[4] = RISCV_ITYPE (ADDI, X_T0, X_T2, gotplt_offset_low);
entry[5] = RISCV_ITYPE (SRLI, X_T1, X_T1, 4 - RISCV_ELF_LOG_WORD_BYTES);
entry[6] = RISCV_ITYPE (LREG, X_T0, X_T0, RISCV_ELF_WORD_BYTES);
entry[7] = RISCV_ITYPE (JALR, 0, X_T3, 0);
return true;
}
/* Generate a PLT entry. */
static bool
riscv_make_plt_entry (bfd *output_bfd, bfd_vma got, bfd_vma addr,
uint32_t *entry)
{
/* RVE has no t3 register, so this won't work, and is not supported. */
if (elf_elfheader (output_bfd)->e_flags & EF_RISCV_RVE)
{
_bfd_error_handler (_("%pB: warning: RVE PLT generation not supported"),
output_bfd);
return false;
}
/* auipc t3, %hi(.got.plt entry)
l[w|d] t3, %lo(.got.plt entry)(t3)
jalr t1, t3
nop */
entry[0] = RISCV_UTYPE (AUIPC, X_T3, RISCV_PCREL_HIGH_PART (got, addr));
entry[1] = RISCV_ITYPE (LREG, X_T3, X_T3, RISCV_PCREL_LOW_PART (got, addr));
entry[2] = RISCV_ITYPE (JALR, X_T1, X_T3, 0);
entry[3] = RISCV_NOP;
return true;
}
/* Create an entry in an RISC-V ELF linker hash table. */
static struct bfd_hash_entry *
link_hash_newfunc (struct bfd_hash_entry *entry,
struct bfd_hash_table *table, const char *string)
{
/* Allocate the structure if it has not already been allocated by a
subclass. */
if (entry == NULL)
{
entry =
bfd_hash_allocate (table,
sizeof (struct riscv_elf_link_hash_entry));
if (entry == NULL)
return entry;
}
/* Call the allocation method of the superclass. */
entry = _bfd_elf_link_hash_newfunc (entry, table, string);
if (entry != NULL)
{
struct riscv_elf_link_hash_entry *eh;
eh = (struct riscv_elf_link_hash_entry *) entry;
eh->tls_type = GOT_UNKNOWN;
}
return entry;
}
/* Compute a hash of a local hash entry. We use elf_link_hash_entry
for local symbol so that we can handle local STT_GNU_IFUNC symbols
as global symbol. We reuse indx and dynstr_index for local symbol
hash since they aren't used by global symbols in this backend. */
static hashval_t
riscv_elf_local_htab_hash (const void *ptr)
{
struct elf_link_hash_entry *h = (struct elf_link_hash_entry *) ptr;
return ELF_LOCAL_SYMBOL_HASH (h->indx, h->dynstr_index);
}
/* Compare local hash entries. */
static int
riscv_elf_local_htab_eq (const void *ptr1, const void *ptr2)
{
struct elf_link_hash_entry *h1 = (struct elf_link_hash_entry *) ptr1;
struct elf_link_hash_entry *h2 = (struct elf_link_hash_entry *) ptr2;
return h1->indx == h2->indx && h1->dynstr_index == h2->dynstr_index;
}
/* Find and/or create a hash entry for local symbol. */
static struct elf_link_hash_entry *
riscv_elf_get_local_sym_hash (struct riscv_elf_link_hash_table *htab,
bfd *abfd, const Elf_Internal_Rela *rel,
bool create)
{
struct riscv_elf_link_hash_entry eh, *ret;
asection *sec = abfd->sections;
hashval_t h = ELF_LOCAL_SYMBOL_HASH (sec->id,
ELFNN_R_SYM (rel->r_info));
void **slot;
eh.elf.indx = sec->id;
eh.elf.dynstr_index = ELFNN_R_SYM (rel->r_info);
slot = htab_find_slot_with_hash (htab->loc_hash_table, &eh, h,
create ? INSERT : NO_INSERT);
if (!slot)
return NULL;
if (*slot)
{
ret = (struct riscv_elf_link_hash_entry *) *slot;
return &ret->elf;
}
ret = (struct riscv_elf_link_hash_entry *)
objalloc_alloc ((struct objalloc *) htab->loc_hash_memory,
sizeof (struct riscv_elf_link_hash_entry));
if (ret)
{
memset (ret, 0, sizeof (*ret));
ret->elf.indx = sec->id;
ret->elf.dynstr_index = ELFNN_R_SYM (rel->r_info);
ret->elf.dynindx = -1;
*slot = ret;
}
return &ret->elf;
}
/* Destroy a RISC-V elf linker hash table. */
static void
riscv_elf_link_hash_table_free (bfd *obfd)
{
struct riscv_elf_link_hash_table *ret
= (struct riscv_elf_link_hash_table *) obfd->link.hash;
if (ret->loc_hash_table)
htab_delete (ret->loc_hash_table);
if (ret->loc_hash_memory)
objalloc_free ((struct objalloc *) ret->loc_hash_memory);
_bfd_elf_link_hash_table_free (obfd);
}
/* Create a RISC-V ELF linker hash table. */
static struct bfd_link_hash_table *
riscv_elf_link_hash_table_create (bfd *abfd)
{
struct riscv_elf_link_hash_table *ret;
size_t amt = sizeof (struct riscv_elf_link_hash_table);
ret = (struct riscv_elf_link_hash_table *) bfd_zmalloc (amt);
if (ret == NULL)
return NULL;
if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd, link_hash_newfunc,
sizeof (struct riscv_elf_link_hash_entry),
RISCV_ELF_DATA))
{
free (ret);
return NULL;
}
ret->max_alignment = (bfd_vma) -1;
ret->restart_relax = false;
/* Create hash table for local ifunc. */
ret->loc_hash_table = htab_try_create (1024,
riscv_elf_local_htab_hash,
riscv_elf_local_htab_eq,
NULL);
ret->loc_hash_memory = objalloc_create ();
if (!ret->loc_hash_table || !ret->loc_hash_memory)
{
riscv_elf_link_hash_table_free (abfd);
return NULL;
}
ret->elf.root.hash_table_free = riscv_elf_link_hash_table_free;
return &ret->elf.root;
}
/* Create the .got section. */
static bool
riscv_elf_create_got_section (bfd *abfd, struct bfd_link_info *info)
{
flagword flags;
asection *s, *s_got;
struct elf_link_hash_entry *h;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
struct elf_link_hash_table *htab = elf_hash_table (info);
/* This function may be called more than once. */
if (htab->sgot != NULL)
return true;
flags = bed->dynamic_sec_flags;
s = bfd_make_section_anyway_with_flags (abfd,
(bed->rela_plts_and_copies_p
? ".rela.got" : ".rel.got"),
(bed->dynamic_sec_flags
| SEC_READONLY));
if (s == NULL
|| !bfd_set_section_alignment (s, bed->s->log_file_align))
return false;
htab->srelgot = s;
s = s_got = bfd_make_section_anyway_with_flags (abfd, ".got", flags);
if (s == NULL
|| !bfd_set_section_alignment (s, bed->s->log_file_align))
return false;
htab->sgot = s;
/* The first bit of the global offset table is the header. */
s->size += bed->got_header_size;
if (bed->want_got_plt)
{
s = bfd_make_section_anyway_with_flags (abfd, ".got.plt", flags);
if (s == NULL
|| !bfd_set_section_alignment (s, bed->s->log_file_align))
return false;
htab->sgotplt = s;
/* Reserve room for the header. */
s->size += GOTPLT_HEADER_SIZE;
}
if (bed->want_got_sym)
{
/* Define the symbol _GLOBAL_OFFSET_TABLE_ at the start of the .got
section. We don't do this in the linker script because we don't want
to define the symbol if we are not creating a global offset
table. */
h = _bfd_elf_define_linkage_sym (abfd, info, s_got,
"_GLOBAL_OFFSET_TABLE_");
elf_hash_table (info)->hgot = h;
if (h == NULL)
return false;
}
return true;
}
/* Create .plt, .rela.plt, .got, .got.plt, .rela.got, .dynbss, and
.rela.bss sections in DYNOBJ, and set up shortcuts to them in our
hash table. */
static bool
riscv_elf_create_dynamic_sections (bfd *dynobj,
struct bfd_link_info *info)
{
struct riscv_elf_link_hash_table *htab;
htab = riscv_elf_hash_table (info);
BFD_ASSERT (htab != NULL);
if (!riscv_elf_create_got_section (dynobj, info))
return false;
if (!_bfd_elf_create_dynamic_sections (dynobj, info))
return false;
if (!bfd_link_pic (info))
{
/* Technically, this section doesn't have contents. It is used as the
target of TLS copy relocs, to copy TLS data from shared libraries into
the executable. However, if we don't mark it as loadable, then it
matches the IS_TBSS test in ldlang.c, and there is no run-time address
space allocated for it even though it has SEC_ALLOC. That test is
correct for .tbss, but not correct for this section. There is also
a second problem that having a section with no contents can only work
if it comes after all sections with contents in the same segment,
but the linker script does not guarantee that. This is just mixed in
with other .tdata.* sections. We can fix both problems by lying and
saying that there are contents. This section is expected to be small
so this should not cause a significant extra program startup cost. */
htab->sdyntdata =
bfd_make_section_anyway_with_flags (dynobj, ".tdata.dyn",
(SEC_ALLOC | SEC_THREAD_LOCAL
| SEC_LOAD | SEC_DATA
| SEC_HAS_CONTENTS
| SEC_LINKER_CREATED));
}
if (!htab->elf.splt || !htab->elf.srelplt || !htab->elf.sdynbss
|| (!bfd_link_pic (info) && (!htab->elf.srelbss || !htab->sdyntdata)))
abort ();
return true;
}
/* Copy the extra info we tack onto an elf_link_hash_entry. */
static void
riscv_elf_copy_indirect_symbol (struct bfd_link_info *info,
struct elf_link_hash_entry *dir,
struct elf_link_hash_entry *ind)
{
struct riscv_elf_link_hash_entry *edir, *eind;
edir = (struct riscv_elf_link_hash_entry *) dir;
eind = (struct riscv_elf_link_hash_entry *) ind;
if (ind->root.type == bfd_link_hash_indirect
&& dir->got.refcount <= 0)
{
edir->tls_type = eind->tls_type;
eind->tls_type = GOT_UNKNOWN;
}
_bfd_elf_link_hash_copy_indirect (info, dir, ind);
}
static bool
riscv_elf_record_tls_type (bfd *abfd, struct elf_link_hash_entry *h,
unsigned long symndx, char tls_type)
{
char *new_tls_type = &_bfd_riscv_elf_tls_type (abfd, h, symndx);
*new_tls_type |= tls_type;
if ((*new_tls_type & GOT_NORMAL) && (*new_tls_type & ~GOT_NORMAL))
{
(*_bfd_error_handler)
(_("%pB: `%s' accessed both as normal and thread local symbol"),
abfd, h ? h->root.root.string : "<local>");
return false;
}
return true;
}
static bool
riscv_elf_record_got_reference (bfd *abfd, struct bfd_link_info *info,
struct elf_link_hash_entry *h, long symndx)
{
struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
Elf_Internal_Shdr *symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
if (htab->elf.sgot == NULL)
{
if (!riscv_elf_create_got_section (htab->elf.dynobj, info))
return false;
}
if (h != NULL)
{
h->got.refcount += 1;
return true;
}
/* This is a global offset table entry for a local symbol. */
if (elf_local_got_refcounts (abfd) == NULL)
{
bfd_size_type size = symtab_hdr->sh_info * (sizeof (bfd_vma) + 1);
if (!(elf_local_got_refcounts (abfd) = bfd_zalloc (abfd, size)))
return false;
_bfd_riscv_elf_local_got_tls_type (abfd)
= (char *) (elf_local_got_refcounts (abfd) + symtab_hdr->sh_info);
}
elf_local_got_refcounts (abfd) [symndx] += 1;
return true;
}
static bool
bad_static_reloc (bfd *abfd, unsigned r_type, struct elf_link_hash_entry *h)
{
reloc_howto_type * r = riscv_elf_rtype_to_howto (abfd, r_type);
/* We propably can improve the information to tell users that they
should be recompile the code with -fPIC or -fPIE, just like what
x86 does. */
(*_bfd_error_handler)
(_("%pB: relocation %s against `%s' can not be used when making a shared "
"object; recompile with -fPIC"),
abfd, r ? r->name : _("<unknown>"),
h != NULL ? h->root.root.string : "a local symbol");
bfd_set_error (bfd_error_bad_value);
return false;
}
/* Look through the relocs for a section during the first phase, and
allocate space in the global offset table or procedure linkage
table. */
static bool
riscv_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
asection *sec, const Elf_Internal_Rela *relocs)
{
struct riscv_elf_link_hash_table *htab;
Elf_Internal_Shdr *symtab_hdr;
struct elf_link_hash_entry **sym_hashes;
const Elf_Internal_Rela *rel;
asection *sreloc = NULL;
if (bfd_link_relocatable (info))
return true;
htab = riscv_elf_hash_table (info);
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
sym_hashes = elf_sym_hashes (abfd);
if (htab->elf.dynobj == NULL)
htab->elf.dynobj = abfd;
for (rel = relocs; rel < relocs + sec->reloc_count; rel++)
{
unsigned int r_type;
unsigned int r_symndx;
struct elf_link_hash_entry *h;
r_symndx = ELFNN_R_SYM (rel->r_info);
r_type = ELFNN_R_TYPE (rel->r_info);
if (r_symndx >= NUM_SHDR_ENTRIES (symtab_hdr))
{
(*_bfd_error_handler) (_("%pB: bad symbol index: %d"),
abfd, r_symndx);
return false;
}
if (r_symndx < symtab_hdr->sh_info)
{
/* A local symbol. */
Elf_Internal_Sym *isym = bfd_sym_from_r_symndx (&htab->elf.sym_cache,
abfd, r_symndx);
if (isym == NULL)
return false;
/* Check relocation against local STT_GNU_IFUNC symbol. */
if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC)
{
h = riscv_elf_get_local_sym_hash (htab, abfd, rel, true);
if (h == NULL)
return false;
/* Fake STT_GNU_IFUNC global symbol. */
h->root.root.string = bfd_elf_sym_name (abfd, symtab_hdr,
isym, NULL);
h->type = STT_GNU_IFUNC;
h->def_regular = 1;
h->ref_regular = 1;
h->forced_local = 1;
h->root.type = bfd_link_hash_defined;
}
else
h = NULL;
}
else
{
h = sym_hashes[r_symndx - symtab_hdr->sh_info];
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
}
if (h != NULL)
{
switch (r_type)
{
case R_RISCV_32:
case R_RISCV_64:
case R_RISCV_CALL:
case R_RISCV_CALL_PLT:
case R_RISCV_HI20:
case R_RISCV_GOT_HI20:
case R_RISCV_PCREL_HI20:
/* Create the ifunc sections, iplt and ipltgot, for static
executables. */
if (h->type == STT_GNU_IFUNC
&& !_bfd_elf_create_ifunc_sections (htab->elf.dynobj, info))
return false;
break;
default:
break;
}
/* It is referenced by a non-shared object. */
h->ref_regular = 1;
}
switch (r_type)
{
case R_RISCV_TLS_GD_HI20:
if (!riscv_elf_record_got_reference (abfd, info, h, r_symndx)
|| !riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_TLS_GD))
return false;
break;
case R_RISCV_TLS_GOT_HI20:
if (bfd_link_pic (info))
info->flags |= DF_STATIC_TLS;
if (!riscv_elf_record_got_reference (abfd, info, h, r_symndx)
|| !riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_TLS_IE))
return false;
break;
case R_RISCV_GOT_HI20:
if (!riscv_elf_record_got_reference (abfd, info, h, r_symndx)
|| !riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_NORMAL))
return false;
break;
case R_RISCV_CALL:
case R_RISCV_CALL_PLT:
/* These symbol requires a procedure linkage table entry.
We actually build the entry in adjust_dynamic_symbol,
because these might be a case of linking PIC code without
linking in any dynamic objects, in which case we don't
need to generate a procedure linkage table after all. */
/* If it is a local symbol, then we resolve it directly
without creating a PLT entry. */
if (h == NULL)
continue;
h->needs_plt = 1;
h->plt.refcount += 1;
break;
case R_RISCV_PCREL_HI20:
if (h != NULL
&& h->type == STT_GNU_IFUNC)
{
h->non_got_ref = 1;
h->pointer_equality_needed = 1;
/* We don't use the PCREL_HI20 in the data section,
so we always need the plt when it refers to
ifunc symbol. */
h->plt.refcount += 1;
}
/* Fall through. */
case R_RISCV_JAL:
case R_RISCV_BRANCH:
case R_RISCV_RVC_BRANCH:
case R_RISCV_RVC_JUMP:
/* In shared libraries and pie, these relocs are known
to bind locally. */
if (bfd_link_pic (info))
break;
goto static_reloc;
case R_RISCV_TPREL_HI20:
if (!bfd_link_executable (info))
return bad_static_reloc (abfd, r_type, h);
if (h != NULL)
riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_TLS_LE);
goto static_reloc;
case R_RISCV_HI20:
if (bfd_link_pic (info))
return bad_static_reloc (abfd, r_type, h);
/* Fall through. */
case R_RISCV_COPY:
case R_RISCV_JUMP_SLOT:
case R_RISCV_RELATIVE:
case R_RISCV_64:
case R_RISCV_32:
/* Fall through. */
static_reloc:
if (h != NULL
&& (!bfd_link_pic (info)
|| h->type == STT_GNU_IFUNC))
{
/* This reloc might not bind locally. */
h->non_got_ref = 1;
h->pointer_equality_needed = 1;
if (!h->def_regular
|| (sec->flags & (SEC_CODE | SEC_READONLY)) != 0)
{
/* We may need a .plt entry if the symbol is a function
defined in a shared lib or is a function referenced
from the code or read-only section. */
h->plt.refcount += 1;
}
}
/* If we are creating a shared library, and this is a reloc
against a global symbol, or a non PC relative reloc
against a local symbol, then we need to copy the reloc
into the shared library. However, if we are linking with
-Bsymbolic, we do not need to copy a reloc against a
global symbol which is defined in an object we are
including in the link (i.e., DEF_REGULAR is set). At
this point we have not seen all the input files, so it is
possible that DEF_REGULAR is not set now but will be set
later (it is never cleared). In case of a weak definition,
DEF_REGULAR may be cleared later by a strong definition in
a shared library. We account for that possibility below by
storing information in the relocs_copied field of the hash
table entry. A similar situation occurs when creating
shared libraries and symbol visibility changes render the
symbol local.
If on the other hand, we are creating an executable, we
may need to keep relocations for symbols satisfied by a
dynamic library if we manage to avoid copy relocs for the
symbol.
Generate dynamic pointer relocation against STT_GNU_IFUNC
symbol in the non-code section (R_RISCV_32/R_RISCV_64). */
reloc_howto_type * r = riscv_elf_rtype_to_howto (abfd, r_type);
if ((bfd_link_pic (info)
&& (sec->flags & SEC_ALLOC) != 0
&& ((r != NULL && !r->pc_relative)
|| (h != NULL
&& (!info->symbolic
|| h->root.type == bfd_link_hash_defweak
|| !h->def_regular))))
|| (!bfd_link_pic (info)
&& (sec->flags & SEC_ALLOC) != 0
&& h != NULL
&& (h->root.type == bfd_link_hash_defweak
|| !h->def_regular))
|| (!bfd_link_pic (info)
&& h != NULL
&& h->type == STT_GNU_IFUNC
&& (sec->flags & SEC_CODE) == 0))
{
struct elf_dyn_relocs *p;
struct elf_dyn_relocs **head;
/* When creating a shared object, we must copy these
relocs into the output file. We create a reloc
section in dynobj and make room for the reloc. */
if (sreloc == NULL)
{
sreloc = _bfd_elf_make_dynamic_reloc_section
(sec, htab->elf.dynobj, RISCV_ELF_LOG_WORD_BYTES,
abfd, /*rela?*/ true);
if (sreloc == NULL)
return false;
}
/* If this is a global symbol, we count the number of
relocations we need for this symbol. */
if (h != NULL)
head = &h->dyn_relocs;
else
{
/* Track dynamic relocs needed for local syms too.
We really need local syms available to do this
easily. Oh well. */
asection *s;
void *vpp;
Elf_Internal_Sym *isym;
isym = bfd_sym_from_r_symndx (&htab->elf.sym_cache,
abfd, r_symndx);
if (isym == NULL)
return false;
s = bfd_section_from_elf_index (abfd, isym->st_shndx);
if (s == NULL)
s = sec;
vpp = &elf_section_data (s)->local_dynrel;
head = (struct elf_dyn_relocs **) vpp;
}
p = *head;
if (p == NULL || p->sec != sec)
{
size_t amt = sizeof *p;
p = ((struct elf_dyn_relocs *)
bfd_alloc (htab->elf.dynobj, amt));
if (p == NULL)
return false;
p->next = *head;
*head = p;
p->sec = sec;
p->count = 0;
p->pc_count = 0;
}
p->count += 1;
p->pc_count += r == NULL ? 0 : r->pc_relative;
}
break;
case R_RISCV_GNU_VTINHERIT:
if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
return false;
break;
case R_RISCV_GNU_VTENTRY:
if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
return false;
break;
default:
break;
}
}
return true;
}
static asection *
riscv_elf_gc_mark_hook (asection *sec,
struct bfd_link_info *info,
Elf_Internal_Rela *rel,
struct elf_link_hash_entry *h,
Elf_Internal_Sym *sym)
{
if (h != NULL)
switch (ELFNN_R_TYPE (rel->r_info))
{
case R_RISCV_GNU_VTINHERIT:
case R_RISCV_GNU_VTENTRY:
return NULL;
}
return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
}
/* Adjust a symbol defined by a dynamic object and referenced by a
regular object. The current definition is in some section of the
dynamic object, but we're not including those sections. We have to
change the definition to something the rest of the link can
understand. */
static bool
riscv_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
struct elf_link_hash_entry *h)
{
struct riscv_elf_link_hash_table *htab;
struct riscv_elf_link_hash_entry * eh;
bfd *dynobj;
asection *s, *srel;
htab = riscv_elf_hash_table (info);
BFD_ASSERT (htab != NULL);
dynobj = htab->elf.dynobj;
/* Make sure we know what is going on here. */
BFD_ASSERT (dynobj != NULL
&& (h->needs_plt
|| h->type == STT_GNU_IFUNC
|| h->is_weakalias
|| (h->def_dynamic
&& h->ref_regular
&& !h->def_regular)));
/* If this is a function, put it in the procedure linkage table. We
will fill in the contents of the procedure linkage table later
(although we could actually do it here). */
if (h->type == STT_FUNC || h->type == STT_GNU_IFUNC || h->needs_plt)
{
if (h->plt.refcount <= 0
|| (h->type != STT_GNU_IFUNC
&& (SYMBOL_CALLS_LOCAL (info, h)
|| (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
&& h->root.type == bfd_link_hash_undefweak))))
{
/* This case can occur if we saw a R_RISCV_CALL_PLT reloc in an
input file, but the symbol was never referred to by a dynamic
object, or if all references were garbage collected. In such
a case, we don't actually need to build a PLT entry. */
h->plt.offset = (bfd_vma) -1;
h->needs_plt = 0;
}
return true;
}
else
h->plt.offset = (bfd_vma) -1;
/* If this is a weak symbol, and there is a real definition, the
processor independent code will have arranged for us to see the
real definition first, and we can just use the same value. */
if (h->is_weakalias)
{
struct elf_link_hash_entry *def = weakdef (h);
BFD_ASSERT (def->root.type == bfd_link_hash_defined);
h->root.u.def.section = def->root.u.def.section;
h->root.u.def.value = def->root.u.def.value;
return true;
}
/* This is a reference to a symbol defined by a dynamic object which
is not a function. */
/* If we are creating a shared library, we must presume that the
only references to the symbol are via the global offset table.
For such cases we need not do anything here; the relocations will
be handled correctly by relocate_section. */
if (bfd_link_pic (info))
return true;
/* If there are no references to this symbol that do not use the
GOT, we don't need to generate a copy reloc. */
if (!h->non_got_ref)
return true;
/* If -z nocopyreloc was given, we won't generate them either. */
if (info->nocopyreloc)
{
h->non_got_ref = 0;
return true;
}
/* If we don't find any dynamic relocs in read-only sections, then
we'll be keeping the dynamic relocs and avoiding the copy reloc. */
if (!_bfd_elf_readonly_dynrelocs (h))
{
h->non_got_ref = 0;
return true;
}
/* We must allocate the symbol in our .dynbss section, which will
become part of the .bss section of the executable. There will be
an entry for this symbol in the .dynsym section. The dynamic
object will contain position independent code, so all references
from the dynamic object to this symbol will go through the global
offset table. The dynamic linker will use the .dynsym entry to
determine the address it must put in the global offset table, so
both the dynamic object and the regular object will refer to the
same memory location for the variable. */
/* We must generate a R_RISCV_COPY reloc to tell the dynamic linker
to copy the initial value out of the dynamic object and into the
runtime process image. We need to remember the offset into the
.rel.bss section we are going to use. */
eh = (struct riscv_elf_link_hash_entry *) h;
if (eh->tls_type & ~GOT_NORMAL)
{
s = htab->sdyntdata;
srel = htab->elf.srelbss;
}
else if ((h->root.u.def.section->flags & SEC_READONLY) != 0)
{
s = htab->elf.sdynrelro;
srel = htab->elf.sreldynrelro;
}
else
{
s = htab->elf.sdynbss;
srel = htab->elf.srelbss;
}
if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0)
{
srel->size += sizeof (ElfNN_External_Rela);
h->needs_copy = 1;
}
return _bfd_elf_adjust_dynamic_copy (info, h, s);
}
/* Allocate space in .plt, .got and associated reloc sections for
dynamic relocs. */
static bool
allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
{
struct bfd_link_info *info;
struct riscv_elf_link_hash_table *htab;
struct elf_dyn_relocs *p;
if (h->root.type == bfd_link_hash_indirect)
return true;
info = (struct bfd_link_info *) inf;
htab = riscv_elf_hash_table (info);
BFD_ASSERT (htab != NULL);
/* When we are generating pde, make sure gp symbol is output as a
dynamic symbol. Then ld.so can set the gp register earlier, before
resolving the ifunc. */
if (!bfd_link_pic (info)
&& htab->elf.dynamic_sections_created
&& strcmp (h->root.root.string, RISCV_GP_SYMBOL) == 0
&& !bfd_elf_link_record_dynamic_symbol (info, h))
return false;
/* Since STT_GNU_IFUNC symbols must go through PLT, we handle them
in the allocate_ifunc_dynrelocs and allocate_local_ifunc_dynrelocs,
if they are defined and referenced in a non-shared object. */
if (h->type == STT_GNU_IFUNC
&& h->def_regular)
return true;
else if (htab->elf.dynamic_sections_created
&& h->plt.refcount > 0)
{
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
&& !h->forced_local)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return false;
}
if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, bfd_link_pic (info), h))
{
asection *s = htab->elf.splt;
if (s->size == 0)
s->size = PLT_HEADER_SIZE;
h->plt.offset = s->size;
/* Make room for this entry. */
s->size += PLT_ENTRY_SIZE;
/* We also need to make an entry in the .got.plt section. */
htab->elf.sgotplt->size += GOT_ENTRY_SIZE;
/* We also need to make an entry in the .rela.plt section. */
htab->elf.srelplt->size += sizeof (ElfNN_External_Rela);
/* If this symbol is not defined in a regular file, and we are
not generating a shared library, then set the symbol to this
location in the .plt. This is required to make function
pointers compare as equal between the normal executable and
the shared library. */
if (! bfd_link_pic (info)
&& !h->def_regular)
{
h->root.u.def.section = s;
h->root.u.def.value = h->plt.offset;
}
}
else
{
h->plt.offset = (bfd_vma) -1;
h->needs_plt = 0;
}
}
else
{
h->plt.offset = (bfd_vma) -1;
h->needs_plt = 0;
}
if (h->got.refcount > 0)
{
asection *s;
bool dyn;
int tls_type = riscv_elf_hash_entry (h)->tls_type;
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
&& !h->forced_local)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return false;
}
s = htab->elf.sgot;
h->got.offset = s->size;
dyn = htab->elf.dynamic_sections_created;
if (tls_type & (GOT_TLS_GD | GOT_TLS_IE))
{
/* TLS_GD needs two dynamic relocs and two GOT slots. */
if (tls_type & GOT_TLS_GD)
{
s->size += 2 * RISCV_ELF_WORD_BYTES;
htab->elf.srelgot->size += 2 * sizeof (ElfNN_External_Rela);
}
/* TLS_IE needs one dynamic reloc and one GOT slot. */
if (tls_type & GOT_TLS_IE)
{
s->size += RISCV_ELF_WORD_BYTES;
htab->elf.srelgot->size += sizeof (ElfNN_External_Rela);
}
}
else
{
s->size += RISCV_ELF_WORD_BYTES;
if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, bfd_link_pic (info), h)
&& ! UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
htab->elf.srelgot->size += sizeof (ElfNN_External_Rela);
}
}
else
h->got.offset = (bfd_vma) -1;
if (h->dyn_relocs == NULL)
return true;
/* In the shared -Bsymbolic case, discard space allocated for
dynamic pc-relative relocs against symbols which turn out to be
defined in regular objects. For the normal shared case, discard
space for pc-relative relocs that have become local due to symbol
visibility changes. */
if (bfd_link_pic (info))
{
if (SYMBOL_CALLS_LOCAL (info, h))
{
struct elf_dyn_relocs **pp;
for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
{
p->count -= p->pc_count;
p->pc_count = 0;
if (p->count == 0)
*pp = p->next;
else
pp = &p->next;
}
}
/* Also discard relocs on undefined weak syms with non-default
visibility. */
if (h->dyn_relocs != NULL
&& h->root.type == bfd_link_hash_undefweak)
{
if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
|| UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
h->dyn_relocs = NULL;
/* Make sure undefined weak symbols are output as a dynamic
symbol in PIEs. */
else if (h->dynindx == -1
&& !h->forced_local)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return false;
}
}
}
else
{
/* For the non-shared case, discard space for relocs against
symbols which turn out to need copy relocs or are not
dynamic. */
if (!h->non_got_ref
&& ((h->def_dynamic
&& !h->def_regular)
|| (htab->elf.dynamic_sections_created
&& (h->root.type == bfd_link_hash_undefweak
|| h->root.type == bfd_link_hash_undefined))))
{
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
&& !h->forced_local)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return false;
}
/* If that succeeded, we know we'll be keeping all the
relocs. */
if (h->dynindx != -1)
goto keep;
}
h->dyn_relocs = NULL;
keep: ;
}
/* Finally, allocate space. */
for (p = h->dyn_relocs; p != NULL; p = p->next)
{
asection *sreloc = elf_section_data (p->sec)->sreloc;
sreloc->size += p->count * sizeof (ElfNN_External_Rela);
}
return true;
}
/* Allocate space in .plt, .got and associated reloc sections for
ifunc dynamic relocs. */
static bool
allocate_ifunc_dynrelocs (struct elf_link_hash_entry *h,
void *inf)
{
struct bfd_link_info *info;
if (h->root.type == bfd_link_hash_indirect)
return true;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
info = (struct bfd_link_info *) inf;
/* Since STT_GNU_IFUNC symbol must go through PLT, we handle it
here if it is defined and referenced in a non-shared object. */
if (h->type == STT_GNU_IFUNC
&& h->def_regular)
return _bfd_elf_allocate_ifunc_dyn_relocs (info, h,
&h->dyn_relocs,
PLT_ENTRY_SIZE,
PLT_HEADER_SIZE,
GOT_ENTRY_SIZE,
true);
return true;
}
/* Allocate space in .plt, .got and associated reloc sections for
local ifunc dynamic relocs. */
static int
allocate_local_ifunc_dynrelocs (void **slot, void *inf)
{
struct elf_link_hash_entry *h
= (struct elf_link_hash_entry *) *slot;
if (h->type != STT_GNU_IFUNC
|| !h->def_regular
|| !h->ref_regular
|| !h->forced_local
|| h->root.type != bfd_link_hash_defined)
abort ();
return allocate_ifunc_dynrelocs (h, inf);
}
static bool
riscv_elf_size_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info)
{
struct riscv_elf_link_hash_table *htab;
bfd *dynobj;
asection *s;
bfd *ibfd;
htab = riscv_elf_hash_table (info);
BFD_ASSERT (htab != NULL);
dynobj = htab->elf.dynobj;
BFD_ASSERT (dynobj != NULL);
if (elf_hash_table (info)->dynamic_sections_created)
{
/* Set the contents of the .interp section to the interpreter. */
if (bfd_link_executable (info) && !info->nointerp)
{
s = bfd_get_linker_section (dynobj, ".interp");
BFD_ASSERT (s != NULL);
s->size = strlen (ELFNN_DYNAMIC_INTERPRETER) + 1;
s->contents = (unsigned char *) ELFNN_DYNAMIC_INTERPRETER;
}
}
/* Set up .got offsets for local syms, and space for local dynamic
relocs. */
for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
{
bfd_signed_vma *local_got;
bfd_signed_vma *end_local_got;
char *local_tls_type;
bfd_size_type locsymcount;
Elf_Internal_Shdr *symtab_hdr;
asection *srel;
if (! is_riscv_elf (ibfd))
continue;
for (s = ibfd->sections; s != NULL; s = s->next)
{
struct elf_dyn_relocs *p;
for (p = elf_section_data (s)->local_dynrel; p != NULL; p = p->next)
{
if (!bfd_is_abs_section (p->sec)
&& bfd_is_abs_section (p->sec->output_section))
{
/* Input section has been discarded, either because
it is a copy of a linkonce section or due to
linker script /DISCARD/, so we'll be discarding
the relocs too. */
}
else if (p->count != 0)
{
srel = elf_section_data (p->sec)->sreloc;
srel->size += p->count * sizeof (ElfNN_External_Rela);
if ((p->sec->output_section->flags & SEC_READONLY) != 0)
info->flags |= DF_TEXTREL;
}
}
}
local_got = elf_local_got_refcounts (ibfd);
if (!local_got)
continue;
symtab_hdr = &elf_symtab_hdr (ibfd);
locsymcount = symtab_hdr->sh_info;
end_local_got = local_got + locsymcount;
local_tls_type = _bfd_riscv_elf_local_got_tls_type (ibfd);
s = htab->elf.sgot;
srel = htab->elf.srelgot;
for (; local_got < end_local_got; ++local_got, ++local_tls_type)
{
if (*local_got > 0)
{
*local_got = s->size;
s->size += RISCV_ELF_WORD_BYTES;
if (*local_tls_type & GOT_TLS_GD)
s->size += RISCV_ELF_WORD_BYTES;
if (bfd_link_pic (info)
|| (*local_tls_type & (GOT_TLS_GD | GOT_TLS_IE)))
srel->size += sizeof (ElfNN_External_Rela);
}
else
*local_got = (bfd_vma) -1;
}
}
/* Allocate .plt and .got entries and space dynamic relocs for
global symbols. */
elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, info);
/* Allocate .plt and .got entries and space dynamic relocs for
global ifunc symbols. */
elf_link_hash_traverse (&htab->elf, allocate_ifunc_dynrelocs, info);
/* Allocate .plt and .got entries and space dynamic relocs for
local ifunc symbols. */
htab_traverse (htab->loc_hash_table, allocate_local_ifunc_dynrelocs, info);
/* Used to resolve the dynamic relocs overwite problems when
generating static executable. */
if (htab->elf.irelplt)
htab->last_iplt_index = htab->elf.irelplt->reloc_count - 1;
if (htab->elf.sgotplt)
{
struct elf_link_hash_entry *got;
got = elf_link_hash_lookup (elf_hash_table (info),
"_GLOBAL_OFFSET_TABLE_",
false, false, false);
/* Don't allocate .got.plt section if there are no GOT nor PLT
entries and there is no refeence to _GLOBAL_OFFSET_TABLE_. */
if ((got == NULL
|| !got->ref_regular_nonweak)
&& (htab->elf.sgotplt->size == GOTPLT_HEADER_SIZE)
&& (htab->elf.splt == NULL
|| htab->elf.splt->size == 0)
&& (htab->elf.sgot == NULL
|| (htab->elf.sgot->size
== get_elf_backend_data (output_bfd)->got_header_size)))
htab->elf.sgotplt->size = 0;
}
/* The check_relocs and adjust_dynamic_symbol entry points have
determined the sizes of the various dynamic sections. Allocate
memory for them. */
for (s = dynobj->sections; s != NULL; s = s->next)
{
if ((s->flags & SEC_LINKER_CREATED) == 0)
continue;
if (s == htab->elf.splt
|| s == htab->elf.sgot
|| s == htab->elf.sgotplt
|| s == htab->elf.iplt
|| s == htab->elf.igotplt
|| s == htab->elf.sdynbss
|| s == htab->elf.sdynrelro
|| s == htab->sdyntdata)
{
/* Strip this section if we don't need it; see the
comment below. */
}
else if (startswith (s->name, ".rela"))
{
if (s->size != 0)
{
/* We use the reloc_count field as a counter if we need
to copy relocs into the output file. */
s->reloc_count = 0;
}
}
else
{
/* It's not one of our sections. */
continue;
}
if (s->size == 0)
{
/* If we don't need this section, strip it from the
output file. This is mostly to handle .rela.bss and
.rela.plt. We must create both sections in
create_dynamic_sections, because they must be created
before the linker maps input sections to output
sections. The linker does that before
adjust_dynamic_symbol is called, and it is that
function which decides whether anything needs to go
into these sections. */
s->flags |= SEC_EXCLUDE;
continue;
}
if ((s->flags & SEC_HAS_CONTENTS) == 0)
continue;
/* Allocate memory for the section contents. Zero the memory
for the benefit of .rela.plt, which has 4 unused entries
at the beginning, and we don't want garbage. */
s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->size);
if (s->contents == NULL)
return false;
}
return _bfd_elf_add_dynamic_tags (output_bfd, info, true);
}
#define TP_OFFSET 0
#define DTP_OFFSET 0x800
/* Return the relocation value for a TLS dtp-relative reloc. */
static bfd_vma
dtpoff (struct bfd_link_info *info, bfd_vma address)
{
/* If tls_sec is NULL, we should have signalled an error already. */
if (elf_hash_table (info)->tls_sec == NULL)
return 0;
return address - elf_hash_table (info)->tls_sec->vma - DTP_OFFSET;
}
/* Return the relocation value for a static TLS tp-relative relocation. */
static bfd_vma
tpoff (struct bfd_link_info *info, bfd_vma address)
{
/* If tls_sec is NULL, we should have signalled an error already. */
if (elf_hash_table (info)->tls_sec == NULL)
return 0;
return address - elf_hash_table (info)->tls_sec->vma - TP_OFFSET;
}
/* Return the global pointer's value, or 0 if it is not in use. */
static bfd_vma
riscv_global_pointer_value (struct bfd_link_info *info)
{
struct bfd_link_hash_entry *h;
h = bfd_link_hash_lookup (info->hash, RISCV_GP_SYMBOL, false, false, true);
if (h == NULL || h->type != bfd_link_hash_defined)
return 0;
return h->u.def.value + sec_addr (h->u.def.section);
}
/* Emplace a static relocation. */
static bfd_reloc_status_type
perform_relocation (const reloc_howto_type *howto,
const Elf_Internal_Rela *rel,
bfd_vma value,
asection *input_section,
bfd *input_bfd,
bfd_byte *contents)
{
if (howto->pc_relative)
value -= sec_addr (input_section) + rel->r_offset;
value += rel->r_addend;
switch (ELFNN_R_TYPE (rel->r_info))
{
case R_RISCV_HI20:
case R_RISCV_TPREL_HI20:
case R_RISCV_PCREL_HI20:
case R_RISCV_GOT_HI20:
case R_RISCV_TLS_GOT_HI20:
case R_RISCV_TLS_GD_HI20:
if (ARCH_SIZE > 32 && !VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (value)))
return bfd_reloc_overflow;
value = ENCODE_UTYPE_IMM (RISCV_CONST_HIGH_PART (value));
break;
case R_RISCV_LO12_I:
case R_RISCV_GPREL_I:
case R_RISCV_TPREL_LO12_I:
case R_RISCV_TPREL_I:
case R_RISCV_PCREL_LO12_I:
value = ENCODE_ITYPE_IMM (value);
break;
case R_RISCV_LO12_S:
case R_RISCV_GPREL_S:
case R_RISCV_TPREL_LO12_S:
case R_RISCV_TPREL_S:
case R_RISCV_PCREL_LO12_S:
value = ENCODE_STYPE_IMM (value);
break;
case R_RISCV_CALL:
case R_RISCV_CALL_PLT:
if (ARCH_SIZE > 32 && !VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (value)))
return bfd_reloc_overflow;
value = ENCODE_UTYPE_IMM (RISCV_CONST_HIGH_PART (value))
| (ENCODE_ITYPE_IMM (value) << 32);
break;
case R_RISCV_JAL:
if (!VALID_JTYPE_IMM (value))
return bfd_reloc_overflow;
value = ENCODE_JTYPE_IMM (value);
break;
case R_RISCV_BRANCH:
if (!VALID_BTYPE_IMM (value))
return bfd_reloc_overflow;
value = ENCODE_BTYPE_IMM (value);
break;
case R_RISCV_RVC_BRANCH:
if (!VALID_CBTYPE_IMM (value))
return bfd_reloc_overflow;
value = ENCODE_CBTYPE_IMM (value);
break;
case R_RISCV_RVC_JUMP:
if (!VALID_CJTYPE_IMM (value))
return bfd_reloc_overflow;
value = ENCODE_CJTYPE_IMM (value);
break;
case R_RISCV_RVC_LUI:
if (RISCV_CONST_HIGH_PART (value) == 0)
{
/* Linker relaxation can convert an address equal to or greater than
0x800 to slightly below 0x800. C.LUI does not accept zero as a
valid immediate. We can fix this by converting it to a C.LI. */
bfd_vma insn = riscv_get_insn (howto->bitsize,
contents + rel->r_offset);
insn = (insn & ~MATCH_C_LUI) | MATCH_C_LI;
riscv_put_insn (howto->bitsize, insn, contents + rel->r_offset);
value = ENCODE_CITYPE_IMM (0);
}
else if (!VALID_CITYPE_LUI_IMM (RISCV_CONST_HIGH_PART (value)))
return bfd_reloc_overflow;
else
value = ENCODE_CITYPE_LUI_IMM (RISCV_CONST_HIGH_PART (value));
break;
case R_RISCV_32:
case R_RISCV_64:
case R_RISCV_ADD8:
case R_RISCV_ADD16:
case R_RISCV_ADD32:
case R_RISCV_ADD64:
case R_RISCV_SUB6:
case R_RISCV_SUB8:
case R_RISCV_SUB16:
case R_RISCV_SUB32:
case R_RISCV_SUB64:
case R_RISCV_SET6:
case R_RISCV_SET8:
case R_RISCV_SET16:
case R_RISCV_SET32:
case R_RISCV_32_PCREL:
case R_RISCV_TLS_DTPREL32:
case R_RISCV_TLS_DTPREL64:
break;
case R_RISCV_DELETE:
return bfd_reloc_ok;
default:
return bfd_reloc_notsupported;
}
bfd_vma word;
if (riscv_is_insn_reloc (howto))
word = riscv_get_insn (howto->bitsize, contents + rel->r_offset);
else
word = bfd_get (howto->bitsize, input_bfd, contents + rel->r_offset);
word = (word & ~howto->dst_mask) | (value & howto->dst_mask);
if (riscv_is_insn_reloc (howto))
riscv_put_insn (howto->bitsize, word, contents + rel->r_offset);
else
bfd_put (howto->bitsize, input_bfd, word, contents + rel->r_offset);
return bfd_reloc_ok;
}
/* Remember all PC-relative high-part relocs we've encountered to help us
later resolve the corresponding low-part relocs. */
typedef struct
{
/* PC value. */
bfd_vma address;
/* Relocation value with addend. */
bfd_vma value;
/* Original reloc type. */
int type;
} riscv_pcrel_hi_reloc;
typedef struct riscv_pcrel_lo_reloc
{
/* PC value of auipc. */
bfd_vma address;
/* Internal relocation. */
const Elf_Internal_Rela *reloc;
/* Record the following information helps to resolve the %pcrel
which cross different input section. For now we build a hash
for pcrel at the start of riscv_elf_relocate_section, and then
free the hash at the end. But riscv_elf_relocate_section only
handles an input section at a time, so that means we can only
resolve the %pcrel_hi and %pcrel_lo which are in the same input
section. Otherwise, we will report dangerous relocation errors
for those %pcrel which are not in the same input section. */
asection *input_section;
struct bfd_link_info *info;
reloc_howto_type *howto;
bfd_byte *contents;
/* The next riscv_pcrel_lo_reloc. */
struct riscv_pcrel_lo_reloc *next;
} riscv_pcrel_lo_reloc;
typedef struct
{
/* Hash table for riscv_pcrel_hi_reloc. */
htab_t hi_relocs;
/* Linked list for riscv_pcrel_lo_reloc. */
riscv_pcrel_lo_reloc *lo_relocs;
} riscv_pcrel_relocs;
static hashval_t
riscv_pcrel_reloc_hash (const void *entry)
{
const riscv_pcrel_hi_reloc *e = entry;
return (hashval_t)(e->address >> 2);
}
static int
riscv_pcrel_reloc_eq (const void *entry1, const void *entry2)
{
const riscv_pcrel_hi_reloc *e1 = entry1, *e2 = entry2;
return e1->address == e2->address;
}
static bool
riscv_init_pcrel_relocs (riscv_pcrel_relocs *p)
{
p->lo_relocs = NULL;
p->hi_relocs = htab_create (1024, riscv_pcrel_reloc_hash,
riscv_pcrel_reloc_eq, free);
return p->hi_relocs != NULL;
}
static void
riscv_free_pcrel_relocs (riscv_pcrel_relocs *p)
{
riscv_pcrel_lo_reloc *cur = p->lo_relocs;
while (cur != NULL)
{
riscv_pcrel_lo_reloc *next = cur->next;
free (cur);
cur = next;
}
htab_delete (p->hi_relocs);
}
static bool
riscv_zero_pcrel_hi_reloc (Elf_Internal_Rela *rel,
struct bfd_link_info *info,
bfd_vma pc,
bfd_vma addr,
bfd_byte *contents,
const reloc_howto_type *howto)
{
/* We may need to reference low addreses in PC-relative modes even when the
PC is far away from these addresses. For example, undefweak references
need to produce the address 0 when linked. As 0 is far from the arbitrary
addresses that we can link PC-relative programs at, the linker can't
actually relocate references to those symbols. In order to allow these
programs to work we simply convert the PC-relative auipc sequences to
0-relative lui sequences. */
if (bfd_link_pic (info))
return false;
/* If it's possible to reference the symbol using auipc we do so, as that's
more in the spirit of the PC-relative relocations we're processing. */
bfd_vma offset = addr - pc;
if (ARCH_SIZE == 32 || VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (offset)))
return false;
/* If it's impossible to reference this with a LUI-based offset then don't
bother to convert it at all so users still see the PC-relative relocation
in the truncation message. */
if (ARCH_SIZE > 32 && !VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (addr)))
return false;
rel->r_info = ELFNN_R_INFO (addr, R_RISCV_HI20);
bfd_vma insn = riscv_get_insn (howto->bitsize, contents + rel->r_offset);
insn = (insn & ~MASK_AUIPC) | MATCH_LUI;
riscv_put_insn (howto->bitsize, insn, contents + rel->r_offset);
return true;
}
static bool
riscv_record_pcrel_hi_reloc (riscv_pcrel_relocs *p,
bfd_vma addr,
bfd_vma value,
int type,
bool absolute)
{
bfd_vma offset = absolute ? value : value - addr;
riscv_pcrel_hi_reloc entry = {addr, offset, type};
riscv_pcrel_hi_reloc **slot =
(riscv_pcrel_hi_reloc **) htab_find_slot (p->hi_relocs, &entry, INSERT);
BFD_ASSERT (*slot == NULL);
*slot = (riscv_pcrel_hi_reloc *) bfd_malloc (sizeof (riscv_pcrel_hi_reloc));
if (*slot == NULL)
return false;
**slot = entry;
return true;
}
static bool
riscv_record_pcrel_lo_reloc (riscv_pcrel_relocs *p,
bfd_vma addr,
const Elf_Internal_Rela *reloc,
asection *input_section,
struct bfd_link_info *info,
reloc_howto_type *howto,
bfd_byte *contents)
{
riscv_pcrel_lo_reloc *entry;
entry = (riscv_pcrel_lo_reloc *) bfd_malloc (sizeof (riscv_pcrel_lo_reloc));
if (entry == NULL)
return false;
*entry = (riscv_pcrel_lo_reloc) {addr, reloc, input_section, info,
howto, contents, p->lo_relocs};
p->lo_relocs = entry;
return true;
}
static bool
riscv_resolve_pcrel_lo_relocs (riscv_pcrel_relocs *p)
{
riscv_pcrel_lo_reloc *r;
for (r = p->lo_relocs; r != NULL; r = r->next)
{
bfd *input_bfd = r->input_section->owner;
riscv_pcrel_hi_reloc search = {r->address, 0, 0};
riscv_pcrel_hi_reloc *entry = htab_find (p->hi_relocs, &search);
/* There may be a risk if the %pcrel_lo with addend refers to
an IFUNC symbol. The %pcrel_hi has been relocated to plt,
so the corresponding %pcrel_lo with addend looks wrong. */
char *string = NULL;
if (entry == NULL)
string = _("%pcrel_lo missing matching %pcrel_hi");
else if (entry->type == R_RISCV_GOT_HI20
&& r->reloc->r_addend != 0)
string = _("%pcrel_lo with addend isn't allowed for R_RISCV_GOT_HI20");
else if (RISCV_CONST_HIGH_PART (entry->value)
!= RISCV_CONST_HIGH_PART (entry->value + r->reloc->r_addend))
{
/* Check the overflow when adding reloc addend. */
if (asprintf (&string,
_("%%pcrel_lo overflow with an addend, the "
"value of %%pcrel_hi is 0x%" PRIx64 " without "
"any addend, but may be 0x%" PRIx64 " after "
"adding the %%pcrel_lo addend"),
(int64_t) RISCV_CONST_HIGH_PART (entry->value),
(int64_t) RISCV_CONST_HIGH_PART
(entry->value + r->reloc->r_addend)) == -1)
string = _("%pcrel_lo overflow with an addend");
}
if (string != NULL)
{
(*r->info->callbacks->reloc_dangerous)
(r->info, string, input_bfd, r->input_section, r->reloc->r_offset);
return true;
}
perform_relocation (r->howto, r->reloc, entry->value, r->input_section,
input_bfd, r->contents);
}
return true;
}
/* Relocate a RISC-V ELF section.
The RELOCATE_SECTION function is called by the new ELF backend linker
to handle the relocations for a section.
The relocs are always passed as Rela structures.
This function is responsible for adjusting the section contents as
necessary, and (if generating a relocatable output file) adjusting
the reloc addend as necessary.
This function does not have to worry about setting the reloc
address or the reloc symbol index.
LOCAL_SYMS is a pointer to the swapped in local symbols.
LOCAL_SECTIONS is an array giving the section in the input file
corresponding to the st_shndx field of each local symbol.
The global hash table entry for the global symbols can be found
via elf_sym_hashes (input_bfd).
When generating relocatable output, this function must handle
STB_LOCAL/STT_SECTION symbols specially. The output symbol is
going to be the section symbol corresponding to the output
section, which means that the addend must be adjusted
accordingly. */
static int
riscv_elf_relocate_section (bfd *output_bfd,
struct bfd_link_info *info,
bfd *input_bfd,
asection *input_section,
bfd_byte *contents,
Elf_Internal_Rela *relocs,
Elf_Internal_Sym *local_syms,
asection **local_sections)
{
Elf_Internal_Rela *rel;
Elf_Internal_Rela *relend;
riscv_pcrel_relocs pcrel_relocs;
bool ret = false;
struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
Elf_Internal_Shdr *symtab_hdr = &elf_symtab_hdr (input_bfd);
struct elf_link_hash_entry **sym_hashes = elf_sym_hashes (input_bfd);
bfd_vma *local_got_offsets = elf_local_got_offsets (input_bfd);
bool absolute;
if (!riscv_init_pcrel_relocs (&pcrel_relocs))
return false;
relend = relocs + input_section->reloc_count;
for (rel = relocs; rel < relend; rel++)
{
unsigned long r_symndx;
struct elf_link_hash_entry *h;
Elf_Internal_Sym *sym;
asection *sec;
bfd_vma relocation;
bfd_reloc_status_type r = bfd_reloc_ok;
const char *name = NULL;
bfd_vma off, ie_off;
bool unresolved_reloc, is_ie = false;
bfd_vma pc = sec_addr (input_section) + rel->r_offset;
int r_type = ELFNN_R_TYPE (rel->r_info), tls_type;
reloc_howto_type *howto = riscv_elf_rtype_to_howto (input_bfd, r_type);
const char *msg = NULL;
char *msg_buf = NULL;
bool resolved_to_zero;
if (howto == NULL
|| r_type == R_RISCV_GNU_VTINHERIT || r_type == R_RISCV_GNU_VTENTRY)
continue;
/* This is a final link. */
r_symndx = ELFNN_R_SYM (rel->r_info);
h = NULL;
sym = NULL;
sec = NULL;
unresolved_reloc = false;
if (r_symndx < symtab_hdr->sh_info)
{
sym = local_syms + r_symndx;
sec = local_sections[r_symndx];
relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
/* Relocate against local STT_GNU_IFUNC symbol. */
if (!bfd_link_relocatable (info)
&& ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC)
{
h = riscv_elf_get_local_sym_hash (htab, input_bfd, rel, false);
if (h == NULL)
abort ();
/* Set STT_GNU_IFUNC symbol value. */
h->root.u.def.value = sym->st_value;
h->root.u.def.section = sec;
}
}
else
{
bool warned, ignored;
RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
r_symndx, symtab_hdr, sym_hashes,
h, sec, relocation,
unresolved_reloc, warned, ignored);
if (warned)
{
/* To avoid generating warning messages about truncated
relocations, set the relocation's address to be the same as
the start of this section. */
if (input_section->output_section != NULL)
relocation = input_section->output_section->vma;
else
relocation = 0;
}
}
if (sec != NULL && discarded_section (sec))
RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
rel, 1, relend, howto, 0, contents);
if (bfd_link_relocatable (info))
continue;
/* Since STT_GNU_IFUNC symbol must go through PLT, we handle
it here if it is defined in a non-shared object. */
if (h != NULL
&& h->type == STT_GNU_IFUNC
&& h->def_regular)
{
asection *plt, *base_got;
if ((input_section->flags & SEC_ALLOC) == 0)
{
/* If this is a SHT_NOTE section without SHF_ALLOC, treat
STT_GNU_IFUNC symbol as STT_FUNC. */
if (elf_section_type (input_section) == SHT_NOTE)
goto skip_ifunc;
/* Dynamic relocs are not propagated for SEC_DEBUGGING
sections because such sections are not SEC_ALLOC and
thus ld.so will not process them. */
if ((input_section->flags & SEC_DEBUGGING) != 0)
continue;
abort ();
}
else if (h->plt.offset == (bfd_vma) -1
/* The following relocation may not need the .plt entries
when all references to a STT_GNU_IFUNC symbols are done
via GOT or static function pointers. */
&& r_type != R_RISCV_32
&& r_type != R_RISCV_64
&& r_type != R_RISCV_HI20
&& r_type != R_RISCV_GOT_HI20
&& r_type != R_RISCV_LO12_I
&& r_type != R_RISCV_LO12_S)
goto bad_ifunc_reloc;
/* STT_GNU_IFUNC symbol must go through PLT. */
plt = htab->elf.splt ? htab->elf.splt : htab->elf.iplt;
relocation = plt->output_section->vma
+ plt->output_offset
+ h->plt.offset;
switch (r_type)
{
case R_RISCV_32:
case R_RISCV_64:
if (rel->r_addend != 0)
{
if (h->root.root.string)
name = h->root.root.string;
else
name = bfd_elf_sym_name (input_bfd, symtab_hdr, sym, NULL);
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: relocation %s against STT_GNU_IFUNC "
"symbol `%s' has non-zero addend: %" PRId64),
input_bfd, howto->name, name, (int64_t) rel->r_addend);
bfd_set_error (bfd_error_bad_value);
return false;
}
/* Generate dynamic relocation only when there is a non-GOT
reference in a shared object or there is no PLT. */
if ((bfd_link_pic (info) && h->non_got_ref)
|| h->plt.offset == (bfd_vma) -1)
{
Elf_Internal_Rela outrel;
asection *sreloc;
/* Need a dynamic relocation to get the real function
address. */
outrel.r_offset = _bfd_elf_section_offset (output_bfd,
info,
input_section,
rel->r_offset);
if (outrel.r_offset == (bfd_vma) -1
|| outrel.r_offset == (bfd_vma) -2)
abort ();
outrel.r_offset += input_section->output_section->vma
+ input_section->output_offset;
if (h->dynindx == -1
|| h->forced_local
|| bfd_link_executable (info))
{
info->callbacks->minfo
(_("Local IFUNC function `%s' in %pB\n"),
h->root.root.string,
h->root.u.def.section->owner);
/* This symbol is resolved locally. */
outrel.r_info = ELFNN_R_INFO (0, R_RISCV_IRELATIVE);
outrel.r_addend = h->root.u.def.value
+ h->root.u.def.section->output_section->vma
+ h->root.u.def.section->output_offset;
}
else
{
outrel.r_info = ELFNN_R_INFO (h->dynindx, r_type);
outrel.r_addend = 0;
}
/* Dynamic relocations are stored in
1. .rela.ifunc section in PIC object.
2. .rela.got section in dynamic executable.
3. .rela.iplt section in static executable. */
if (bfd_link_pic (info))
sreloc = htab->elf.irelifunc;
else if (htab->elf.splt != NULL)
sreloc = htab->elf.srelgot;
else
sreloc = htab->elf.irelplt;
riscv_elf_append_rela (output_bfd, sreloc, &outrel);
/* If this reloc is against an external symbol, we
do not want to fiddle with the addend. Otherwise,
we need to include the symbol value so that it
becomes an addend for the dynamic reloc. For an
internal symbol, we have updated addend. */
continue;
}
goto do_relocation;
case R_RISCV_GOT_HI20:
base_got = htab->elf.sgot;
off = h->got.offset;
if (base_got == NULL)
abort ();
if (off == (bfd_vma) -1)
{
bfd_vma plt_idx;
/* We can't use h->got.offset here to save state, or
even just remember the offset, as finish_dynamic_symbol
would use that as offset into .got. */
if (htab->elf.splt != NULL)
{
plt_idx = (h->plt.offset - PLT_HEADER_SIZE)
/ PLT_ENTRY_SIZE;
off = GOTPLT_HEADER_SIZE + (plt_idx * GOT_ENTRY_SIZE);
base_got = htab->elf.sgotplt;
}
else
{
plt_idx = h->plt.offset / PLT_ENTRY_SIZE;
off = plt_idx * GOT_ENTRY_SIZE;
base_got = htab->elf.igotplt;
}
if (h->dynindx == -1
|| h->forced_local
|| info->symbolic)
{
/* This references the local definition. We must
initialize this entry in the global offset table.
Since the offset must always be a multiple of 8,
we use the least significant bit to record
whether we have initialized it already.
When doing a dynamic link, we create a .rela.got
relocation entry to initialize the value. This
is done in the finish_dynamic_symbol routine. */
if ((off & 1) != 0)
off &= ~1;
else
{
bfd_put_NN (output_bfd, relocation,
base_got->contents + off);
/* Note that this is harmless for the case,
as -1 | 1 still is -1. */
h->got.offset |= 1;
}
}
}
relocation = base_got->output_section->vma
+ base_got->output_offset + off;
if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
relocation, r_type,
false))
r = bfd_reloc_overflow;
goto do_relocation;
case R_RISCV_CALL:
case R_RISCV_CALL_PLT:
case R_RISCV_HI20:
case R_RISCV_LO12_I:
case R_RISCV_LO12_S:
goto do_relocation;
case R_RISCV_PCREL_HI20:
if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
relocation, r_type,
false))
r = bfd_reloc_overflow;
goto do_relocation;
default:
bad_ifunc_reloc:
if (h->root.root.string)
name = h->root.root.string;
else
/* The entry of local ifunc is fake in global hash table,
we should find the name by the original local symbol. */
name = bfd_elf_sym_name (input_bfd, symtab_hdr, sym, NULL);
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: relocation %s against STT_GNU_IFUNC "
"symbol `%s' isn't supported"), input_bfd,
howto->name, name);
bfd_set_error (bfd_error_bad_value);
return false;
}
}
skip_ifunc:
if (h != NULL)
name = h->root.root.string;
else
{
name = (bfd_elf_string_from_elf_section
(input_bfd, symtab_hdr->sh_link, sym->st_name));
if (name == NULL || *name == '\0')
name = bfd_section_name (sec);
}
resolved_to_zero = (h != NULL
&& UNDEFWEAK_NO_DYNAMIC_RELOC (info, h));
switch (r_type)
{
case R_RISCV_NONE:
case R_RISCV_RELAX:
case R_RISCV_TPREL_ADD:
case R_RISCV_COPY:
case R_RISCV_JUMP_SLOT:
case R_RISCV_RELATIVE:
/* These require nothing of us at all. */
continue;
case R_RISCV_HI20:
case R_RISCV_BRANCH:
case R_RISCV_RVC_BRANCH:
case R_RISCV_RVC_LUI:
case R_RISCV_LO12_I:
case R_RISCV_LO12_S:
case R_RISCV_SET6:
case R_RISCV_SET8:
case R_RISCV_SET16:
case R_RISCV_SET32:
case R_RISCV_32_PCREL:
case R_RISCV_DELETE:
/* These require no special handling beyond perform_relocation. */
break;
case R_RISCV_GOT_HI20:
if (h != NULL)
{
bool dyn, pic;
off = h->got.offset;
BFD_ASSERT (off != (bfd_vma) -1);
dyn = elf_hash_table (info)->dynamic_sections_created;
pic = bfd_link_pic (info);
if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, pic, h)
|| (pic && SYMBOL_REFERENCES_LOCAL (info, h)))
{
/* This is actually a static link, or it is a
-Bsymbolic link and the symbol is defined
locally, or the symbol was forced to be local
because of a version file. We must initialize
this entry in the global offset table. Since the
offset must always be a multiple of the word size,
we use the least significant bit to record whether
we have initialized it already.
When doing a dynamic link, we create a .rela.got
relocation entry to initialize the value. This
is done in the finish_dynamic_symbol routine. */
if ((off & 1) != 0)
off &= ~1;
else
{
bfd_put_NN (output_bfd, relocation,
htab->elf.sgot->contents + off);
h->got.offset |= 1;
}
}
else
unresolved_reloc = false;
}
else
{
BFD_ASSERT (local_got_offsets != NULL
&& local_got_offsets[r_symndx] != (bfd_vma) -1);
off = local_got_offsets[r_symndx];
/* The offset must always be a multiple of the word size.
So, we can use the least significant bit to record
whether we have already processed this entry. */
if ((off & 1) != 0)
off &= ~1;
else
{
if (bfd_link_pic (info))
{
asection *s;
Elf_Internal_Rela outrel;
/* We need to generate a R_RISCV_RELATIVE reloc
for the dynamic linker. */
s = htab->elf.srelgot;
BFD_ASSERT (s != NULL);
outrel.r_offset = sec_addr (htab->elf.sgot) + off;
outrel.r_info =
ELFNN_R_INFO (0, R_RISCV_RELATIVE);
outrel.r_addend = relocation;
relocation = 0;
riscv_elf_append_rela (output_bfd, s, &outrel);
}
bfd_put_NN (output_bfd, relocation,
htab->elf.sgot->contents + off);
local_got_offsets[r_symndx] |= 1;
}
}
if (rel->r_addend != 0)
{
msg = _("The addend isn't allowed for R_RISCV_GOT_HI20");
r = bfd_reloc_dangerous;
}
else
{
/* Address of got entry. */
relocation = sec_addr (htab->elf.sgot) + off;
absolute = riscv_zero_pcrel_hi_reloc (rel, info, pc,
relocation, contents,
howto);
/* Update howto if relocation is changed. */
howto = riscv_elf_rtype_to_howto (input_bfd,
ELFNN_R_TYPE (rel->r_info));
if (howto == NULL)
r = bfd_reloc_notsupported;
else if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
relocation, r_type,
absolute))
r = bfd_reloc_overflow;
}
break;
case R_RISCV_ADD8:
case R_RISCV_ADD16:
case R_RISCV_ADD32:
case R_RISCV_ADD64:
{
bfd_vma old_value = bfd_get (howto->bitsize, input_bfd,
contents + rel->r_offset);
relocation = old_value + relocation;
}
break;
case R_RISCV_SUB6:
case R_RISCV_SUB8:
case R_RISCV_SUB16:
case R_RISCV_SUB32:
case R_RISCV_SUB64:
{
bfd_vma old_value = bfd_get (howto->bitsize, input_bfd,
contents + rel->r_offset);
relocation = old_value - relocation;
}
break;
case R_RISCV_CALL:
case R_RISCV_CALL_PLT:
/* Handle a call to an undefined weak function. This won't be
relaxed, so we have to handle it here. */
if (h != NULL && h->root.type == bfd_link_hash_undefweak
&& (!bfd_link_pic (info) || h->plt.offset == MINUS_ONE))
{
/* We can use x0 as the base register. */
bfd_vma insn = bfd_getl32 (contents + rel->r_offset + 4);
insn &= ~(OP_MASK_RS1 << OP_SH_RS1);
bfd_putl32 (insn, contents + rel->r_offset + 4);
/* Set the relocation value so that we get 0 after the pc
relative adjustment. */
relocation = sec_addr (input_section) + rel->r_offset;
}
/* Fall through. */
case R_RISCV_JAL:
case R_RISCV_RVC_JUMP:
/* This line has to match the check in _bfd_riscv_relax_section. */
if (bfd_link_pic (info) && h != NULL && h->plt.offset != MINUS_ONE)
{
/* Refer to the PLT entry. */
relocation = sec_addr (htab->elf.splt) + h->plt.offset;
unresolved_reloc = false;
}
break;
case R_RISCV_TPREL_HI20:
relocation = tpoff (info, relocation);
break;
case R_RISCV_TPREL_LO12_I:
case R_RISCV_TPREL_LO12_S:
relocation = tpoff (info, relocation);
break;
case R_RISCV_TPREL_I:
case R_RISCV_TPREL_S:
relocation = tpoff (info, relocation);
if (VALID_ITYPE_IMM (relocation + rel->r_addend))
{
/* We can use tp as the base register. */
bfd_vma insn = bfd_getl32 (contents + rel->r_offset);
insn &= ~(OP_MASK_RS1 << OP_SH_RS1);
insn |= X_TP << OP_SH_RS1;
bfd_putl32 (insn, contents + rel->r_offset);
}
else
r = bfd_reloc_overflow;
break;
case R_RISCV_GPREL_I:
case R_RISCV_GPREL_S:
{
bfd_vma gp = riscv_global_pointer_value (info);
bool x0_base = VALID_ITYPE_IMM (relocation + rel->r_addend);
if (x0_base || VALID_ITYPE_IMM (relocation + rel->r_addend - gp))
{
/* We can use x0 or gp as the base register. */
bfd_vma insn = bfd_getl32 (contents + rel->r_offset);
insn &= ~(OP_MASK_RS1 << OP_SH_RS1);
if (!x0_base)
{
rel->r_addend -= gp;
insn |= X_GP << OP_SH_RS1;
}
bfd_putl32 (insn, contents + rel->r_offset);
}
else
r = bfd_reloc_overflow;
break;
}
case R_RISCV_PCREL_HI20:
absolute = riscv_zero_pcrel_hi_reloc (rel, info, pc, relocation,
contents, howto);
/* Update howto if relocation is changed. */
howto = riscv_elf_rtype_to_howto (input_bfd,
ELFNN_R_TYPE (rel->r_info));
if (howto == NULL)
r = bfd_reloc_notsupported;
else if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
relocation + rel->r_addend,
r_type, absolute))
r = bfd_reloc_overflow;
break;
case R_RISCV_PCREL_LO12_I:
case R_RISCV_PCREL_LO12_S:
/* We don't allow section symbols plus addends as the auipc address,
because then riscv_relax_delete_bytes would have to search through
all relocs to update these addends. This is also ambiguous, as
we do allow offsets to be added to the target address, which are
not to be used to find the auipc address. */
if (((sym != NULL && (ELF_ST_TYPE (sym->st_info) == STT_SECTION))
|| (h != NULL && h->type == STT_SECTION))
&& rel->r_addend)
{
msg = _("%pcrel_lo section symbol with an addend");
r = bfd_reloc_dangerous;
break;
}
if (riscv_record_pcrel_lo_reloc (&pcrel_relocs, relocation, rel,
input_section, info, howto,
contents))
continue;
r = bfd_reloc_overflow;
break;
case R_RISCV_TLS_DTPREL32:
case R_RISCV_TLS_DTPREL64:
relocation = dtpoff (info, relocation);
break;
case R_RISCV_32:
case R_RISCV_64:
if ((input_section->flags & SEC_ALLOC) == 0)
break;
if ((bfd_link_pic (info)
&& (h == NULL
|| (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
&& !resolved_to_zero)
|| h->root.type != bfd_link_hash_undefweak)
&& (!howto->pc_relative
|| !SYMBOL_CALLS_LOCAL (info, h)))
|| (!bfd_link_pic (info)
&& h != NULL
&& h->dynindx != -1
&& !h->non_got_ref
&& ((h->def_dynamic
&& !h->def_regular)
|| h->root.type == bfd_link_hash_undefweak
|| h->root.type == bfd_link_hash_undefined)))
{
Elf_Internal_Rela outrel;
asection *sreloc;
bool skip_static_relocation, skip_dynamic_relocation;
/* When generating a shared object, these relocations
are copied into the output file to be resolved at run
time. */
outrel.r_offset =
_bfd_elf_section_offset (output_bfd, info, input_section,
rel->r_offset);
skip_static_relocation = outrel.r_offset != (bfd_vma) -2;
skip_dynamic_relocation = outrel.r_offset >= (bfd_vma) -2;
outrel.r_offset += sec_addr (input_section);
if (skip_dynamic_relocation)
memset (&outrel, 0, sizeof outrel);
else if (h != NULL && h->dynindx != -1
&& !(bfd_link_pic (info)
&& SYMBOLIC_BIND (info, h)
&& h->def_regular))
{
outrel.r_info = ELFNN_R_INFO (h->dynindx, r_type);
outrel.r_addend = rel->r_addend;
}
else
{
outrel.r_info = ELFNN_R_INFO (0, R_RISCV_RELATIVE);
outrel.r_addend = relocation + rel->r_addend;
}
sreloc = elf_section_data (input_section)->sreloc;
riscv_elf_append_rela (output_bfd, sreloc, &outrel);
if (skip_static_relocation)
continue;
}
break;
case R_RISCV_TLS_GOT_HI20:
is_ie = true;
/* Fall through. */
case R_RISCV_TLS_GD_HI20:
if (h != NULL)
{
off = h->got.offset;
h->got.offset |= 1;
}
else
{
off = local_got_offsets[r_symndx];
local_got_offsets[r_symndx] |= 1;
}
tls_type = _bfd_riscv_elf_tls_type (input_bfd, h, r_symndx);
BFD_ASSERT (tls_type & (GOT_TLS_IE | GOT_TLS_GD));
/* If this symbol is referenced by both GD and IE TLS, the IE
reference's GOT slot follows the GD reference's slots. */
ie_off = 0;
if ((tls_type & GOT_TLS_GD) && (tls_type & GOT_TLS_IE))
ie_off = 2 * GOT_ENTRY_SIZE;
if ((off & 1) != 0)
off &= ~1;
else
{
Elf_Internal_Rela outrel;
int indx = 0;
bool need_relocs = false;
if (htab->elf.srelgot == NULL)
abort ();
if (h != NULL)
{
bool dyn, pic;
dyn = htab->elf.dynamic_sections_created;
pic = bfd_link_pic (info);
if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, pic, h)
&& (!pic || !SYMBOL_REFERENCES_LOCAL (info, h)))
indx = h->dynindx;
}
/* The GOT entries have not been initialized yet. Do it
now, and emit any relocations. */
if ((bfd_link_pic (info) || indx != 0)
&& (h == NULL
|| ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
|| h->root.type != bfd_link_hash_undefweak))
need_relocs = true;
if (tls_type & GOT_TLS_GD)
{
if (need_relocs)
{
outrel.r_offset = sec_addr (htab->elf.sgot) + off;
outrel.r_addend = 0;
outrel.r_info = ELFNN_R_INFO (indx, R_RISCV_TLS_DTPMODNN);
bfd_put_NN (output_bfd, 0,
htab->elf.sgot->contents + off);
riscv_elf_append_rela (output_bfd, htab->elf.srelgot, &outrel);
if (indx == 0)
{
BFD_ASSERT (! unresolved_reloc);
bfd_put_NN (output_bfd,
dtpoff (info, relocation),
(htab->elf.sgot->contents
+ off + RISCV_ELF_WORD_BYTES));
}
else
{
bfd_put_NN (output_bfd, 0,
(htab->elf.sgot->contents
+ off + RISCV_ELF_WORD_BYTES));
outrel.r_info = ELFNN_R_INFO (indx, R_RISCV_TLS_DTPRELNN);
outrel.r_offset += RISCV_ELF_WORD_BYTES;
riscv_elf_append_rela (output_bfd, htab->elf.srelgot, &outrel);
}
}
else
{
/* If we are not emitting relocations for a
general dynamic reference, then we must be in a
static link or an executable link with the
symbol binding locally. Mark it as belonging
to module 1, the executable. */
bfd_put_NN (output_bfd, 1,
htab->elf.sgot->contents + off);
bfd_put_NN (output_bfd,
dtpoff (info, relocation),
(htab->elf.sgot->contents
+ off + RISCV_ELF_WORD_BYTES));
}
}
if (tls_type & GOT_TLS_IE)
{
if (need_relocs)
{
bfd_put_NN (output_bfd, 0,
htab->elf.sgot->contents + off + ie_off);
outrel.r_offset = sec_addr (htab->elf.sgot)
+ off + ie_off;
outrel.r_addend = 0;
if (indx == 0)
outrel.r_addend = tpoff (info, relocation);
outrel.r_info = ELFNN_R_INFO (indx, R_RISCV_TLS_TPRELNN);
riscv_elf_append_rela (output_bfd, htab->elf.srelgot, &outrel);
}
else
{
bfd_put_NN (output_bfd, tpoff (info, relocation),
htab->elf.sgot->contents + off + ie_off);
}
}
}
BFD_ASSERT (off < (bfd_vma) -2);
relocation = sec_addr (htab->elf.sgot) + off + (is_ie ? ie_off : 0);
if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
relocation, r_type,
false))
r = bfd_reloc_overflow;
unresolved_reloc = false;
break;
default:
r = bfd_reloc_notsupported;
}
/* Dynamic relocs are not propagated for SEC_DEBUGGING sections
because such sections are not SEC_ALLOC and thus ld.so will
not process them. */
if (unresolved_reloc
&& !((input_section->flags & SEC_DEBUGGING) != 0
&& h->def_dynamic)
&& _bfd_elf_section_offset (output_bfd, info, input_section,
rel->r_offset) != (bfd_vma) -1)
{
switch (r_type)
{
case R_RISCV_JAL:
case R_RISCV_RVC_JUMP:
if (asprintf (&msg_buf,
_("%%X%%P: relocation %s against `%s' can "
"not be used when making a shared object; "
"recompile with -fPIC\n"),
howto->name,
h->root.root.string) == -1)
msg_buf = NULL;
break;
default:
if (asprintf (&msg_buf,
_("%%X%%P: unresolvable %s relocation against "
"symbol `%s'\n