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binutils-gdb/bfd/elfnn-riscv.c
Jim Wilson 13755f406d RISC-V: Fix TLS and --gc-sections conflict. 
bfd/
	* elfnn-riscv.c (riscv_elf_create_dynamic_sections): For .tdata.dyn,
	add SEC_LINKER_CREATED flag.
2018-08-02 16:13:49 -07:00

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/* RISC-V-specific support for NN-bit ELF.
Copyright (C) 2011-2018 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"
/* 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
/* RISC-V ELF linker hash entry. */
struct riscv_elf_link_hash_entry
{
struct elf_link_hash_entry elf;
/* Track dynamic relocs copied for this symbol. */
struct elf_dyn_relocs *dyn_relocs;
#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)
#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;
/* Small local sym to section mapping cache. */
struct sym_cache sym_cache;
/* The max alignment of output sections. */
bfd_vma max_alignment;
};
/* Get the RISC-V ELF linker hash table from a link_info structure. */
#define riscv_elf_hash_table(p) \
(elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \
== RISCV_ELF_DATA ? ((struct riscv_elf_link_hash_table *) ((p)->hash)) : NULL)
static bfd_boolean
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);
}
/* 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
#define GOTPLT_HEADER_SIZE (2 * GOT_ENTRY_SIZE)
#define sec_addr(sec) ((sec)->output_section->vma + (sec)->output_offset)
static bfd_vma
riscv_elf_got_plt_val (bfd_vma plt_index, struct bfd_link_info *info)
{
return sec_addr (riscv_elf_hash_table (info)->elf.sgotplt)
+ GOTPLT_HEADER_SIZE + (plt_index * GOT_ENTRY_SIZE);
}
#if ARCH_SIZE == 32
# define MATCH_LREG MATCH_LW
#else
# define MATCH_LREG MATCH_LD
#endif
/* Generate a PLT header. */
static void
riscv_make_plt_header (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);
/* 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, -(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);
}
/* Generate a PLT entry. */
static void
riscv_make_plt_entry (bfd_vma got, bfd_vma addr, uint32_t *entry)
{
/* 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;
}
/* 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->dyn_relocs = NULL;
eh->tls_type = GOT_UNKNOWN;
}
return entry;
}
/* 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;
bfd_size_type 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;
return &ret->elf.root;
}
/* Create the .got section. */
static bfd_boolean
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 (abfd, 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 (abfd, 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 (abfd, 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 bfd_boolean
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))
{
htab->sdyntdata =
bfd_make_section_anyway_with_flags (dynobj, ".tdata.dyn",
(SEC_ALLOC | SEC_THREAD_LOCAL
| 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 (eind->dyn_relocs != NULL)
{
if (edir->dyn_relocs != NULL)
{
struct elf_dyn_relocs **pp;
struct elf_dyn_relocs *p;
/* Add reloc counts against the indirect sym to the direct sym
list. Merge any entries against the same section. */
for (pp = &eind->dyn_relocs; (p = *pp) != NULL; )
{
struct elf_dyn_relocs *q;
for (q = edir->dyn_relocs; q != NULL; q = q->next)
if (q->sec == p->sec)
{
q->pc_count += p->pc_count;
q->count += p->count;
*pp = p->next;
break;
}
if (q == NULL)
pp = &p->next;
}
*pp = edir->dyn_relocs;
}
edir->dyn_relocs = eind->dyn_relocs;
eind->dyn_relocs = NULL;
}
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 bfd_boolean
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 bfd_boolean
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 bfd_boolean
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);
(*_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 bfd_boolean
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)
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;
}
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_PLT:
/* This symbol requires a procedure linkage table entry. We
actually build the entry in adjust_dynamic_symbol,
because this 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 (h != NULL)
{
h->needs_plt = 1;
h->plt.refcount += 1;
}
break;
case R_RISCV_CALL:
case R_RISCV_JAL:
case R_RISCV_BRANCH:
case R_RISCV_RVC_BRANCH:
case R_RISCV_RVC_JUMP:
case R_RISCV_PCREL_HI20:
/* In shared libraries, 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:
/* This reloc might not bind locally. */
if (h != NULL)
h->non_got_ref = 1;
if (h != NULL && !bfd_link_pic (info))
{
/* We may need a .plt entry if the function this reloc
refers to is in a shared lib. */
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. */
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)))
{
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 = &((struct riscv_elf_link_hash_entry *) 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->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)
{
bfd_size_type 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);
}
/* Find dynamic relocs for H that apply to read-only sections. */
static asection *
readonly_dynrelocs (struct elf_link_hash_entry *h)
{
struct elf_dyn_relocs *p;
for (p = riscv_elf_hash_entry (h)->dyn_relocs; p != NULL; p = p->next)
{
asection *s = p->sec->output_section;
if (s != NULL && (s->flags & SEC_READONLY) != 0)
return p->sec;
}
return NULL;
}
/* 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 bfd_boolean
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
|| 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 (!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 bfd_boolean
allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
{
struct bfd_link_info *info;
struct riscv_elf_link_hash_table *htab;
struct riscv_elf_link_hash_entry *eh;
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);
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;
bfd_boolean 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;
eh = (struct riscv_elf_link_hash_entry *) h;
if (eh->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 = &eh->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 (eh->dyn_relocs != NULL
&& h->root.type == bfd_link_hash_undefweak)
{
if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
|| UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
eh->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;
}
eh->dyn_relocs = NULL;
keep: ;
}
/* Finally, allocate space. */
for (p = eh->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;
}
/* Set DF_TEXTREL if we find any dynamic relocs that apply to
read-only sections. */
static bfd_boolean
maybe_set_textrel (struct elf_link_hash_entry *h, void *info_p)
{
asection *sec;
if (h->root.type == bfd_link_hash_indirect)
return TRUE;
sec = readonly_dynrelocs (h);
if (sec != NULL)
{
struct bfd_link_info *info = (struct bfd_link_info *) info_p;
info->flags |= DF_TEXTREL;
info->callbacks->minfo
(_("%pB: dynamic relocation against `%pT' in read-only section `%pA'\n"),
sec->owner, h->root.root.string, sec);
/* Not an error, just cut short the traversal. */
return FALSE;
}
return TRUE;
}
static bfd_boolean
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 global sym .plt and .got entries, and space for global
sym dynamic relocs. */
elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, info);
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.sdynbss
|| s == htab->elf.sdynrelro)
{
/* Strip this section if we don't need it; see the
comment below. */
}
else if (strncmp (s->name, ".rela", 5) == 0)
{
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;
}
if (elf_hash_table (info)->dynamic_sections_created)
{
/* Add some entries to the .dynamic section. We fill in the
values later, in riscv_elf_finish_dynamic_sections, but we
must add the entries now so that we get the correct size for
the .dynamic section. The DT_DEBUG entry is filled in by the
dynamic linker and used by the debugger. */
#define add_dynamic_entry(TAG, VAL) \
_bfd_elf_add_dynamic_entry (info, TAG, VAL)
if (bfd_link_executable (info))
{
if (!add_dynamic_entry (DT_DEBUG, 0))
return FALSE;
}
if (htab->elf.srelplt->size != 0)
{
if (!add_dynamic_entry (DT_PLTGOT, 0)
|| !add_dynamic_entry (DT_PLTRELSZ, 0)
|| !add_dynamic_entry (DT_PLTREL, DT_RELA)
|| !add_dynamic_entry (DT_JMPREL, 0))
return FALSE;
}
if (!add_dynamic_entry (DT_RELA, 0)
|| !add_dynamic_entry (DT_RELASZ, 0)
|| !add_dynamic_entry (DT_RELAENT, sizeof (ElfNN_External_Rela)))
return FALSE;
/* If any dynamic relocs apply to a read-only section,
then we need a DT_TEXTREL entry. */
if ((info->flags & DF_TEXTREL) == 0)
elf_link_hash_traverse (&htab->elf, maybe_set_textrel, info);
if (info->flags & DF_TEXTREL)
{
if (!add_dynamic_entry (DT_TEXTREL, 0))
return FALSE;
}
}
#undef add_dynamic_entry
return 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_UJTYPE_IMM (value))
return bfd_reloc_overflow;
value = ENCODE_UJTYPE_IMM (value);
break;
case R_RISCV_BRANCH:
if (!VALID_SBTYPE_IMM (value))
return bfd_reloc_overflow;
value = ENCODE_SBTYPE_IMM (value);
break;
case R_RISCV_RVC_BRANCH:
if (!VALID_RVC_B_IMM (value))
return bfd_reloc_overflow;
value = ENCODE_RVC_B_IMM (value);
break;
case R_RISCV_RVC_JUMP:
if (!VALID_RVC_J_IMM (value))
return bfd_reloc_overflow;
value = ENCODE_RVC_J_IMM (value);
break;
case R_RISCV_RVC_LUI:
if (!VALID_RVC_LUI_IMM (RISCV_CONST_HIGH_PART (value)))
return bfd_reloc_overflow;
value = ENCODE_RVC_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 = bfd_get (howto->bitsize, input_bfd, contents + rel->r_offset);
word = (word & ~howto->dst_mask) | (value & howto->dst_mask);
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
{
bfd_vma address;
bfd_vma value;
} riscv_pcrel_hi_reloc;
typedef struct riscv_pcrel_lo_reloc
{
asection * input_section;
struct bfd_link_info * info;
reloc_howto_type * howto;
const Elf_Internal_Rela * reloc;
bfd_vma addr;
const char * name;
bfd_byte * contents;
struct riscv_pcrel_lo_reloc * next;
} riscv_pcrel_lo_reloc;
typedef struct
{
htab_t hi_relocs;
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 bfd_boolean
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 bfd_boolean
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 bfd_boolean
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,
bfd *input_bfd)
{
/* 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 = bfd_get(howto->bitsize, input_bfd, contents + rel->r_offset);
insn = (insn & ~MASK_AUIPC) | MATCH_LUI;
bfd_put(howto->bitsize, input_bfd, insn, contents + rel->r_offset);
return TRUE;
}
static bfd_boolean
riscv_record_pcrel_hi_reloc (riscv_pcrel_relocs *p, bfd_vma addr,
bfd_vma value, bfd_boolean absolute)
{
bfd_vma offset = absolute ? value : value - addr;
riscv_pcrel_hi_reloc entry = {addr, offset};
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 bfd_boolean
riscv_record_pcrel_lo_reloc (riscv_pcrel_relocs *p,
asection *input_section,
struct bfd_link_info *info,
reloc_howto_type *howto,
const Elf_Internal_Rela *reloc,
bfd_vma addr,
const char *name,
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) {input_section, info, howto, reloc, addr,
name, contents, p->lo_relocs};
p->lo_relocs = entry;
return TRUE;
}
static bfd_boolean
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->addr, 0};
riscv_pcrel_hi_reloc *entry = htab_find (p->hi_relocs, &search);
if (entry == NULL)
{
((*r->info->callbacks->reloc_overflow)
(r->info, NULL, r->name, r->howto->name, (bfd_vma) 0,
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 bfd_boolean
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;
bfd_boolean ret = FALSE;
asection *sreloc = elf_section_data (input_section)->sreloc;
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);
bfd_boolean 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;
bfd_vma off, ie_off;
bfd_boolean 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;
bfd_boolean 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);
}
else
{
bfd_boolean 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;
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 (input_bfd, 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)
{
bfd_boolean 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;
}
}
relocation = sec_addr (htab->elf.sgot) + off;
absolute = riscv_zero_pcrel_hi_reloc (rel,
info,
pc,
relocation,
contents,
howto,
input_bfd);
r_type = ELFNN_R_TYPE (rel->r_info);
howto = riscv_elf_rtype_to_howto (input_bfd, r_type);
if (howto == NULL)
r = bfd_reloc_notsupported;
else if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
relocation, 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:
/* 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
&& h->plt.offset == MINUS_ONE)
{
/* We can use x0 as the base register. */
bfd_vma insn = bfd_get_32 (input_bfd,
contents + rel->r_offset + 4);
insn &= ~(OP_MASK_RS1 << OP_SH_RS1);
bfd_put_32 (input_bfd, 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_CALL_PLT:
case R_RISCV_JAL:
case R_RISCV_RVC_JUMP:
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_get_32 (input_bfd, contents + rel->r_offset);
insn &= ~(OP_MASK_RS1 << OP_SH_RS1);
insn |= X_TP << OP_SH_RS1;
bfd_put_32 (input_bfd, 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);
bfd_boolean 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_get_32 (input_bfd, 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_put_32 (input_bfd, 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,
input_bfd);
r_type = ELFNN_R_TYPE (rel->r_info);
howto = riscv_elf_rtype_to_howto (input_bfd, r_type);
if (howto == NULL)
r = bfd_reloc_notsupported;
else if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
relocation + rel->r_addend,
absolute))
r = bfd_reloc_overflow;
break;
case R_RISCV_PCREL_LO12_I:
case R_RISCV_PCREL_LO12_S:
/* Addends are not allowed, because then riscv_relax_delete_bytes
would have to search through all relocs to update the addends.
Also, riscv_resolve_pcrel_lo_relocs does not support addends
when searching for a matching hi reloc. */
if (rel->r_addend)
{
r = bfd_reloc_dangerous;
break;
}
if (riscv_record_pcrel_lo_reloc (&pcrel_relocs, input_section, info,
howto, rel, relocation, name,
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;
bfd_boolean 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;
}
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;
bfd_boolean need_relocs = FALSE;
if (htab->elf.srelgot == NULL)
abort ();
if (h != NULL)
{
bfd_boolean 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, 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)
{
(*_bfd_error_handler)
(_("%pB(%pA+%#" PRIx64 "): "
"unresolvable %s relocation against symbol `%s'"),
input_bfd,
input_section,
(uint64_t) rel->r_offset,
howto->name,
h->root.root.string);
continue;
}
if (r == bfd_reloc_ok)
r = perform_relocation (howto, rel, relocation, input_section,
input_bfd, contents);
switch (r)
{
case bfd_reloc_ok:
continue;
case bfd_reloc_overflow:
info->callbacks->reloc_overflow
(info, (h ? &h->root : NULL), name, howto->name,
(bfd_vma) 0, input_bfd, input_section, rel->r_offset);
break;
case bfd_reloc_undefined:
info->callbacks->undefined_symbol
(info, name, input_bfd, input_section, rel->r_offset,
TRUE);
break;
case bfd_reloc_outofrange:
msg = _("%X%P: internal error: out of range error\n");
break;
case bfd_reloc_notsupported:
msg = _("%X%P: internal error: unsupported relocation error\n");
break;
case bfd_reloc_dangerous:
info->callbacks->reloc_dangerous
(info, "%pcrel_lo with addend", input_bfd, input_section,
rel->r_offset);
break;
default:
msg = _("%X%P: internal error: unknown error\n");
break;
}
if (msg)
info->callbacks->einfo (msg);
/* We already reported the error via a callback, so don't try to report
it again by returning false. That leads to spurious errors. */
ret = TRUE;
goto out;
}
ret = riscv_resolve_pcrel_lo_relocs (&pcrel_relocs);
out:
riscv_free_pcrel_relocs (&pcrel_relocs);
return ret;
}
/* Finish up dynamic symbol handling. We set the contents of various
dynamic sections here. */
static bfd_boolean
riscv_elf_finish_dynamic_symbol (bfd *output_bfd,
struct bfd_link_info *info,
struct elf_link_hash_entry *h,
Elf_Internal_Sym *sym)
{
struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
if (h->plt.offset != (bfd_vma) -1)
{
/* We've decided to create a PLT entry for this symbol. */
bfd_byte *loc;
bfd_vma i, header_address, plt_idx, got_address;
uint32_t plt_entry[PLT_ENTRY_INSNS];
Elf_Internal_Rela rela;
BFD_ASSERT (h->dynindx != -1);
/* Calculate the address of the PLT header. */
header_address = sec_addr (htab->elf.splt);
/* Calculate the index of the entry. */
plt_idx = (h->plt.offset - PLT_HEADER_SIZE) / PLT_ENTRY_SIZE;
/* Calculate the address of the .got.plt entry. */
got_address = riscv_elf_got_plt_val (plt_idx, info);
/* Find out where the .plt entry should go. */
loc = htab->elf.splt->contents + h->plt.offset;
/* Fill in the PLT entry itself. */
riscv_make_plt_entry (got_address, header_address + h->plt.offset,
plt_entry);
for (i = 0; i < PLT_ENTRY_INSNS; i++)
bfd_put_32 (output_bfd, plt_entry[i], loc + 4*i);
/* Fill in the initial value of the .got.plt entry. */
loc = htab->elf.sgotplt->contents
+ (got_address - sec_addr (htab->elf.sgotplt));
bfd_put_NN (output_bfd, sec_addr (htab->elf.splt), loc);
/* Fill in the entry in the .rela.plt section. */
rela.r_offset = got_address;
rela.r_addend = 0;
rela.r_info = ELFNN_R_INFO (h->dynindx, R_RISCV_JUMP_SLOT);
loc = htab->elf.srelplt->contents + plt_idx * sizeof (ElfNN_External_Rela);
bed->s->swap_reloca_out (output_bfd, &rela, loc);
if (!h->def_regular)
{
/* Mark the symbol as undefined, rather than as defined in
the .plt section. Leave the value alone. */
sym->st_shndx = SHN_UNDEF;
/* If the symbol is weak, we do need to clear the value.
Otherwise, the PLT entry would provide a definition for
the symbol even if the symbol wasn't defined anywhere,
and so the symbol would never be NULL. */
if (!h->ref_regular_nonweak)
sym->st_value = 0;
}
}
if (h->got.offset != (bfd_vma) -1
&& !(riscv_elf_hash_entry (h)->tls_type & (GOT_TLS_GD | GOT_TLS_IE))
&& !UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
{
asection *sgot;
asection *srela;
Elf_Internal_Rela rela;
/* This symbol has an entry in the GOT. Set it up. */
sgot = htab->elf.sgot;
srela = htab->elf.srelgot;
BFD_ASSERT (sgot != NULL && srela != NULL);
rela.r_offset = sec_addr (sgot) + (h->got.offset &~ (bfd_vma) 1);
/* If this is a local symbol reference, we just want to emit a RELATIVE
reloc. This can happen if it is a -Bsymbolic link, or a pie link, or
the symbol was forced to be local because of a version file.
The entry in the global offset table will already have been
initialized in the relocate_section function. */
if (bfd_link_pic (info)
&& SYMBOL_REFERENCES_LOCAL (info, h))
{
BFD_ASSERT((h->got.offset & 1) != 0);
asection *sec = h->root.u.def.section;
rela.r_info = ELFNN_R_INFO (0, R_RISCV_RELATIVE);
rela.r_addend = (h->root.u.def.value
+ sec->output_section->vma
+ sec->output_offset);
}
else
{
BFD_ASSERT((h->got.offset & 1) == 0);
BFD_ASSERT (h->dynindx != -1);
rela.r_info = ELFNN_R_INFO (h->dynindx, R_RISCV_NN);
rela.r_addend = 0;
}
bfd_put_NN (output_bfd, 0,
sgot->contents + (h->got.offset & ~(bfd_vma) 1));
riscv_elf_append_rela (output_bfd, srela, &rela);
}
if (h->needs_copy)
{
Elf_Internal_Rela rela;
asection *s;
/* This symbols needs a copy reloc. Set it up. */
BFD_ASSERT (h->dynindx != -1);
rela.r_offset = sec_addr (h->root.u.def.section) + h->root.u.def.value;
rela.r_info = ELFNN_R_INFO (h->dynindx, R_RISCV_COPY);
rela.r_addend = 0;
if (h->root.u.def.section == htab->elf.sdynrelro)
s = htab->elf.sreldynrelro;
else
s = htab->elf.srelbss;
riscv_elf_append_rela (output_bfd, s, &rela);
}
/* Mark some specially defined symbols as absolute. */
if (h == htab->elf.hdynamic
|| (h == htab->elf.hgot || h == htab->elf.hplt))
sym->st_shndx = SHN_ABS;
return TRUE;
}
/* Finish up the dynamic sections. */
static bfd_boolean
riscv_finish_dyn (bfd *output_bfd, struct bfd_link_info *info,
bfd *dynobj, asection *sdyn)
{
struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
size_t dynsize = bed->s->sizeof_dyn;
bfd_byte *dyncon, *dynconend;
dynconend = sdyn->contents + sdyn->size;
for (dyncon = sdyn->contents; dyncon < dynconend; dyncon += dynsize)
{
Elf_Internal_Dyn dyn;
asection *s;
bed->s->swap_dyn_in (dynobj, dyncon, &dyn);
switch (dyn.d_tag)
{
case DT_PLTGOT:
s = htab->elf.sgotplt;
dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
break;
case DT_JMPREL:
s = htab->elf.srelplt;
dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
break;
case DT_PLTRELSZ:
s = htab->elf.srelplt;
dyn.d_un.d_val = s->size;
break;
default:
continue;
}
bed->s->swap_dyn_out (output_bfd, &dyn, dyncon);
}
return TRUE;
}
static bfd_boolean
riscv_elf_finish_dynamic_sections (bfd *output_bfd,
struct bfd_link_info *info)
{
bfd *dynobj;
asection *sdyn;
struct riscv_elf_link_hash_table *htab;
htab = riscv_elf_hash_table (info);
BFD_ASSERT (htab != NULL);
dynobj = htab->elf.dynobj;
sdyn = bfd_get_linker_section (dynobj, ".dynamic");
if (elf_hash_table (info)->dynamic_sections_created)
{
asection *splt;
bfd_boolean ret;
splt = htab->elf.splt;
BFD_ASSERT (splt != NULL && sdyn != NULL);
ret = riscv_finish_dyn (output_bfd, info, dynobj, sdyn);
if (!ret)
return ret;
/* Fill in the head and tail entries in the procedure linkage table. */
if (splt->size > 0)
{
int i;
uint32_t plt_header[PLT_HEADER_INSNS];
riscv_make_plt_header (sec_addr (htab->elf.sgotplt),
sec_addr (splt), plt_header);
for (i = 0; i < PLT_HEADER_INSNS; i++)
bfd_put_32 (output_bfd, plt_header[i], splt->contents + 4*i);
elf_section_data (splt->output_section)->this_hdr.sh_entsize
= PLT_ENTRY_SIZE;
}
}
if (htab->elf.sgotplt)
{
asection *output_section = htab->elf.sgotplt->output_section;
if (bfd_is_abs_section (output_section))
{
(*_bfd_error_handler)
(_("discarded output section: `%pA'"), htab->elf.sgotplt);
return FALSE;
}
if (htab->elf.sgotplt->size > 0)
{
/* Write the first two entries in .got.plt, needed for the dynamic
linker. */
bfd_put_NN (output_bfd, (bfd_vma) -1, htab->elf.sgotplt->contents);
bfd_put_NN (output_bfd, (bfd_vma) 0,
htab->elf.sgotplt->contents + GOT_ENTRY_SIZE);
}
elf_section_data (output_section)->this_hdr.sh_entsize = GOT_ENTRY_SIZE;
}
if (htab->elf.sgot)
{
asection *output_section = htab->elf.sgot->output_section;
if (htab->elf.sgot->size > 0)
{
/* Set the first entry in the global offset table to the address of
the dynamic section. */
bfd_vma val = sdyn ? sec_addr (sdyn) : 0;
bfd_put_NN (output_bfd, val, htab->elf.sgot->contents);
}
elf_section_data (output_section)->this_hdr.sh_entsize = GOT_ENTRY_SIZE;
}
return TRUE;
}
/* Return address for Ith PLT stub in section PLT, for relocation REL
or (bfd_vma) -1 if it should not be included. */
static bfd_vma
riscv_elf_plt_sym_val (bfd_vma i, const asection *plt,
const arelent *rel ATTRIBUTE_UNUSED)
{
return plt->vma + PLT_HEADER_SIZE + i * PLT_ENTRY_SIZE;
}
static enum elf_reloc_type_class
riscv_reloc_type_class (const struct bfd_link_info *info ATTRIBUTE_UNUSED,
const asection *rel_sec ATTRIBUTE_UNUSED,
const Elf_Internal_Rela *rela)
{
switch (ELFNN_R_TYPE (rela->r_info))
{
case R_RISCV_RELATIVE:
return reloc_class_relative;
case R_RISCV_JUMP_SLOT:
return reloc_class_plt;
case R_RISCV_COPY:
return reloc_class_copy;
default:
return reloc_class_normal;
}
}
/* Merge backend specific data from an object file to the output
object file when linking. */
static bfd_boolean
_bfd_riscv_elf_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
{
bfd *obfd = info->output_bfd;
flagword new_flags = elf_elfheader (ibfd)->e_flags;
flagword old_flags = elf_elfheader (obfd)->e_flags;
if (!is_riscv_elf (ibfd) || !is_riscv_elf (obfd))
return TRUE;
if (strcmp (bfd_get_target (ibfd), bfd_get_target (obfd)) != 0)
{
(*_bfd_error_handler)
(_("%pB: ABI is incompatible with that of the selected emulation:\n"
" target emulation `%s' does not match `%s'"),
ibfd, bfd_get_target (ibfd), bfd_get_target (obfd));
return FALSE;
}
if (!_bfd_elf_merge_object_attributes (ibfd, info))
return FALSE;
if (! elf_flags_init (obfd))
{
elf_flags_init (obfd) = TRUE;
elf_elfheader (obfd)->e_flags = new_flags;
return TRUE;
}
/* Disallow linking different float ABIs. */
if ((old_flags ^ new_flags) & EF_RISCV_FLOAT_ABI)
{
(*_bfd_error_handler)
(_("%pB: can't link hard-float modules with soft-float modules"), ibfd);
goto fail;
}
/* Disallow linking RVE and non-RVE. */
if ((old_flags ^ new_flags) & EF_RISCV_RVE)
{
(*_bfd_error_handler)
(_("%pB: can't link RVE with other target"), ibfd);
goto fail;
}
/* Allow linking RVC and non-RVC, and keep the RVC flag. */
elf_elfheader (obfd)->e_flags |= new_flags & EF_RISCV_RVC;
return TRUE;
fail:
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
/* Delete some bytes from a section while relaxing. */
static bfd_boolean
riscv_relax_delete_bytes (bfd *abfd, asection *sec, bfd_vma addr, size_t count,
struct bfd_link_info *link_info)
{
unsigned int i, symcount;
bfd_vma toaddr = sec->size;
struct elf_link_hash_entry **sym_hashes = elf_sym_hashes (abfd);
Elf_Internal_Shdr *symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
unsigned int sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec);
struct bfd_elf_section_data *data = elf_section_data (sec);
bfd_byte *contents = data->this_hdr.contents;
/* Actually delete the bytes. */
sec->size -= count;
memmove (contents + addr, contents + addr + count, toaddr - addr - count);
/* Adjust the location of all of the relocs. Note that we need not
adjust the addends, since all PC-relative references must be against
symbols, which we will adjust below. */
for (i = 0; i < sec->reloc_count; i++)
if (data->relocs[i].r_offset > addr && data->relocs[i].r_offset < toaddr)
data->relocs[i].r_offset -= count;
/* Adjust the local symbols defined in this section. */
for (i = 0; i < symtab_hdr->sh_info; i++)
{
Elf_Internal_Sym *sym = (Elf_Internal_Sym *) symtab_hdr->contents + i;
if (sym->st_shndx == sec_shndx)
{
/* If the symbol is in the range of memory we just moved, we
have to adjust its value. */
if (sym->st_value > addr && sym->st_value <= toaddr)
sym->st_value -= count;
/* If the symbol *spans* the bytes we just deleted (i.e. its
*end* is in the moved bytes but its *start* isn't), then we
must adjust its size.
This test needs to use the original value of st_value, otherwise
we might accidentally decrease size when deleting bytes right
before the symbol. But since deleted relocs can't span across
symbols, we can't have both a st_value and a st_size decrease,
so it is simpler to just use an else. */
else if (sym->st_value <= addr
&& sym->st_value + sym->st_size > addr
&& sym->st_value + sym->st_size <= toaddr)
sym->st_size -= count;
}
}
/* Now adjust the global symbols defined in this section. */
symcount = ((symtab_hdr->sh_size / sizeof (ElfNN_External_Sym))
- symtab_hdr->sh_info);
for (i = 0; i < symcount; i++)
{
struct elf_link_hash_entry *sym_hash = sym_hashes[i];
/* The '--wrap SYMBOL' option is causing a pain when the object file,
containing the definition of __wrap_SYMBOL, includes a direct
call to SYMBOL as well. Since both __wrap_SYMBOL and SYMBOL reference
the same symbol (which is __wrap_SYMBOL), but still exist as two
different symbols in 'sym_hashes', we don't want to adjust
the global symbol __wrap_SYMBOL twice. */
/* The same problem occurs with symbols that are versioned_hidden, as
foo becomes an alias for foo@BAR, and hence they need the same
treatment. */
if (link_info->wrap_hash != NULL
|| sym_hash->versioned == versioned_hidden)
{
struct elf_link_hash_entry **cur_sym_hashes;
/* Loop only over the symbols which have already been checked. */
for (cur_sym_hashes = sym_hashes; cur_sym_hashes < &sym_hashes[i];
cur_sym_hashes++)
{
/* If the current symbol is identical to 'sym_hash', that means
the symbol was already adjusted (or at least checked). */
if (*cur_sym_hashes == sym_hash)
break;
}
/* Don't adjust the symbol again. */
if (cur_sym_hashes < &sym_hashes[i])
continue;
}
if ((sym_hash->root.type == bfd_link_hash_defined
|| sym_hash->root.type == bfd_link_hash_defweak)
&& sym_hash->root.u.def.section == sec)
{
/* As above, adjust the value if needed. */
if (sym_hash->root.u.def.value > addr
&& sym_hash->root.u.def.value <= toaddr)
sym_hash->root.u.def.value -= count;
/* As above, adjust the size if needed. */
else if (sym_hash->root.u.def.value <= addr
&& sym_hash->root.u.def.value + sym_hash->size > addr
&& sym_hash->root.u.def.value + sym_hash->size <= toaddr)
sym_hash->size -= count;
}
}
return TRUE;
}
/* A second format for recording PC-relative hi relocations. This stores the
information required to relax them to GP-relative addresses. */
typedef struct riscv_pcgp_hi_reloc riscv_pcgp_hi_reloc;
struct riscv_pcgp_hi_reloc
{
bfd_vma hi_sec_off;
bfd_vma hi_addend;
bfd_vma hi_addr;
unsigned hi_sym;
asection *sym_sec;
riscv_pcgp_hi_reloc *next;
};
typedef struct riscv_pcgp_lo_reloc riscv_pcgp_lo_reloc;
struct riscv_pcgp_lo_reloc
{
bfd_vma hi_sec_off;
riscv_pcgp_lo_reloc *next;
};
typedef struct
{
riscv_pcgp_hi_reloc *hi;
riscv_pcgp_lo_reloc *lo;
} riscv_pcgp_relocs;
static bfd_boolean
riscv_init_pcgp_relocs (riscv_pcgp_relocs *p)
{
p->hi = NULL;
p->lo = NULL;
return TRUE;
}
static void
riscv_free_pcgp_relocs (riscv_pcgp_relocs *p,
bfd *abfd ATTRIBUTE_UNUSED,
asection *sec ATTRIBUTE_UNUSED)
{
riscv_pcgp_hi_reloc *c;
riscv_pcgp_lo_reloc *l;
for (c = p->hi; c != NULL;)
{
riscv_pcgp_hi_reloc *next = c->next;
free (c);
c = next;
}
for (l = p->lo; l != NULL;)
{
riscv_pcgp_lo_reloc *next = l->next;
free (l);
l = next;
}
}
static bfd_boolean
riscv_record_pcgp_hi_reloc (riscv_pcgp_relocs *p, bfd_vma hi_sec_off,
bfd_vma hi_addend, bfd_vma hi_addr,
unsigned hi_sym, asection *sym_sec)
{
riscv_pcgp_hi_reloc *new = bfd_malloc (sizeof(*new));
if (!new)
return FALSE;
new->hi_sec_off = hi_sec_off;
new->hi_addend = hi_addend;
new->hi_addr = hi_addr;
new->hi_sym = hi_sym;
new->sym_sec = sym_sec;
new->next = p->hi;
p->hi = new;
return TRUE;
}
static riscv_pcgp_hi_reloc *
riscv_find_pcgp_hi_reloc(riscv_pcgp_relocs *p, bfd_vma hi_sec_off)
{
riscv_pcgp_hi_reloc *c;
for (c = p->hi; c != NULL; c = c->next)
if (c->hi_sec_off == hi_sec_off)
return c;
return NULL;
}
static bfd_boolean
riscv_delete_pcgp_hi_reloc(riscv_pcgp_relocs *p, bfd_vma hi_sec_off)
{
bfd_boolean out = FALSE;
riscv_pcgp_hi_reloc *c;
for (c = p->hi; c != NULL; c = c->next)
if (c->hi_sec_off == hi_sec_off)
out = TRUE;
return out;
}
static bfd_boolean
riscv_use_pcgp_hi_reloc(riscv_pcgp_relocs *p, bfd_vma hi_sec_off)
{
bfd_boolean out = FALSE;
riscv_pcgp_hi_reloc *c;
for (c = p->hi; c != NULL; c = c->next)
if (c->hi_sec_off == hi_sec_off)
out = TRUE;
return out;
}
static bfd_boolean
riscv_record_pcgp_lo_reloc (riscv_pcgp_relocs *p, bfd_vma hi_sec_off)
{
riscv_pcgp_lo_reloc *new = bfd_malloc (sizeof(*new));
if (!new)
return FALSE;
new->hi_sec_off = hi_sec_off;
new->next = p->lo;
p->lo = new;
return TRUE;
}
static bfd_boolean
riscv_find_pcgp_lo_reloc (riscv_pcgp_relocs *p, bfd_vma hi_sec_off)
{
riscv_pcgp_lo_reloc *c;
for (c = p->lo; c != NULL; c = c->next)
if (c->hi_sec_off == hi_sec_off)
return TRUE;
return FALSE;
}
static bfd_boolean
riscv_delete_pcgp_lo_reloc (riscv_pcgp_relocs *p ATTRIBUTE_UNUSED,
bfd_vma lo_sec_off ATTRIBUTE_UNUSED,
size_t bytes ATTRIBUTE_UNUSED)
{
return TRUE;
}
typedef bfd_boolean (*relax_func_t) (bfd *, asection *, asection *,
struct bfd_link_info *,
Elf_Internal_Rela *,
bfd_vma, bfd_vma, bfd_vma, bfd_boolean *,
riscv_pcgp_relocs *);
/* Relax AUIPC + JALR into JAL. */
static bfd_boolean
_bfd_riscv_relax_call (bfd *abfd, asection *sec, asection *sym_sec,
struct bfd_link_info *link_info,
Elf_Internal_Rela *rel,
bfd_vma symval,
bfd_vma max_alignment,
bfd_vma reserve_size ATTRIBUTE_UNUSED,
bfd_boolean *again,
riscv_pcgp_relocs *pcgp_relocs ATTRIBUTE_UNUSED)
{
bfd_byte *contents = elf_section_data (sec)->this_hdr.contents;
bfd_signed_vma foff = symval - (sec_addr (sec) + rel->r_offset);
bfd_boolean near_zero = (symval + RISCV_IMM_REACH/2) < RISCV_IMM_REACH;
bfd_vma auipc, jalr;
int rd, r_type, len = 4, rvc = elf_elfheader (abfd)->e_flags & EF_RISCV_RVC;
/* If the call crosses section boundaries, an alignment directive could
cause the PC-relative offset to later increase. */
if (VALID_UJTYPE_IMM (foff) && sym_sec->output_section != sec->output_section)
foff += (foff < 0 ? -max_alignment : max_alignment);
/* See if this function call can be shortened. */
if (!VALID_UJTYPE_IMM (foff) && !(!bfd_link_pic (link_info) && near_zero))
return TRUE;
/* Shorten the function call. */
BFD_ASSERT (rel->r_offset + 8 <= sec->size);
auipc = bfd_get_32 (abfd, contents + rel->r_offset);
jalr = bfd_get_32 (abfd, contents + rel->r_offset + 4);
rd = (jalr >> OP_SH_RD) & OP_MASK_RD;
rvc = rvc && VALID_RVC_J_IMM (foff) && ARCH_SIZE == 32;
if (rvc && (rd == 0 || rd == X_RA))
{
/* Relax to C.J[AL] rd, addr. */
r_type = R_RISCV_RVC_JUMP;
auipc = rd == 0 ? MATCH_C_J : MATCH_C_JAL;
len = 2;
}
else if (VALID_UJTYPE_IMM (foff))
{
/* Relax to JAL rd, addr. */
r_type = R_RISCV_JAL;
auipc = MATCH_JAL | (rd << OP_SH_RD);
}
else /* near_zero */
{
/* Relax to JALR rd, x0, addr. */
r_type = R_RISCV_LO12_I;
auipc = MATCH_JALR | (rd << OP_SH_RD);
}
/* Replace the R_RISCV_CALL reloc. */
rel->r_info = ELFNN_R_INFO (ELFNN_R_SYM (rel->r_info), r_type);
/* Replace the AUIPC. */
bfd_put (8 * len, abfd, auipc, contents + rel->r_offset);
/* Delete unnecessary JALR. */
*again = TRUE;
return riscv_relax_delete_bytes (abfd, sec, rel->r_offset + len, 8 - len,
link_info);
}
/* Traverse all output sections and return the max alignment. */
static bfd_vma
_bfd_riscv_get_max_alignment (asection *sec)
{
unsigned int max_alignment_power = 0;
asection *o;
for (o = sec->output_section->owner->sections; o != NULL; o = o->next)
{
if (o->alignment_power > max_alignment_power)
max_alignment_power = o->alignment_power;
}
return (bfd_vma) 1 << max_alignment_power;
}
/* Relax non-PIC global variable references. */
static bfd_boolean
_bfd_riscv_relax_lui (bfd *abfd,
asection *sec,
asection *sym_sec,
struct bfd_link_info *link_info,
Elf_Internal_Rela *rel,
bfd_vma symval,
bfd_vma max_alignment,
bfd_vma reserve_size,
bfd_boolean *again,
riscv_pcgp_relocs *pcgp_relocs ATTRIBUTE_UNUSED)
{
bfd_byte *contents = elf_section_data (sec)->this_hdr.contents;
bfd_vma gp = riscv_global_pointer_value (link_info);
int use_rvc = elf_elfheader (abfd)->e_flags & EF_RISCV_RVC;
/* Mergeable symbols and code might later move out of range. */
if (sym_sec->flags & (SEC_MERGE | SEC_CODE))
return TRUE;
BFD_ASSERT (rel->r_offset + 4 <= sec->size);
if (gp)
{
/* If gp and the symbol are in the same output section, then
consider only that section's alignment. */
struct bfd_link_hash_entry *h =
bfd_link_hash_lookup (link_info->hash, RISCV_GP_SYMBOL, FALSE, FALSE,
TRUE);
if (h->u.def.section->output_section == sym_sec->output_section)
max_alignment = (bfd_vma) 1 << sym_sec->output_section->alignment_power;
}
/* Is the reference in range of x0 or gp?
Valid gp range conservatively because of alignment issue. */
if (VALID_ITYPE_IMM (symval)
|| (symval >= gp
&& VALID_ITYPE_IMM (symval - gp + max_alignment + reserve_size))
|| (symval < gp
&& VALID_ITYPE_IMM (symval - gp - max_alignment - reserve_size)))
{
unsigned sym = ELFNN_R_SYM (rel->r_info);
switch (ELFNN_R_TYPE (rel->r_info))
{
case R_RISCV_LO12_I:
rel->r_info = ELFNN_R_INFO (sym, R_RISCV_GPREL_I);
return TRUE;
case R_RISCV_LO12_S:
rel->r_info = ELFNN_R_INFO (sym, R_RISCV_GPREL_S);
return TRUE;
case R_RISCV_HI20:
/* We can delete the unnecessary LUI and reloc. */
rel->r_info = ELFNN_R_INFO (0, R_RISCV_NONE);
*again = TRUE;
return riscv_relax_delete_bytes (abfd, sec, rel->r_offset, 4,
link_info);
default:
abort ();
}
}
/* Can we relax LUI to C.LUI? Alignment might move the section forward;
account for this assuming page alignment at worst. */
if (use_rvc
&& ELFNN_R_TYPE (rel->r_info) == R_RISCV_HI20
&& VALID_RVC_LUI_IMM (RISCV_CONST_HIGH_PART (symval))
&& VALID_RVC_LUI_IMM (RISCV_CONST_HIGH_PART (symval + ELF_MAXPAGESIZE)))
{
/* Replace LUI with C.LUI if legal (i.e., rd != x0 and rd != x2/sp). */
bfd_vma lui = bfd_get_32 (abfd, contents + rel->r_offset);
unsigned rd = ((unsigned)lui >> OP_SH_RD) & OP_MASK_RD;
if (rd == 0 || rd == X_SP)
return TRUE;
lui = (lui & (OP_MASK_RD << OP_SH_RD)) | MATCH_C_LUI;
bfd_put_32 (abfd, lui, contents + rel->r_offset);
/* Replace the R_RISCV_HI20 reloc. */
rel->r_info = ELFNN_R_INFO (ELFNN_R_SYM (rel->r_info), R_RISCV_RVC_LUI);
*again = TRUE;
return riscv_relax_delete_bytes (abfd, sec, rel->r_offset + 2, 2,
link_info);
}
return TRUE;
}
/* Relax non-PIC TLS references. */
static bfd_boolean
_bfd_riscv_relax_tls_le (bfd *abfd,
asection *sec,
asection *sym_sec ATTRIBUTE_UNUSED,
struct bfd_link_info *link_info,
Elf_Internal_Rela *rel,
bfd_vma symval,
bfd_vma max_alignment ATTRIBUTE_UNUSED,
bfd_vma reserve_size ATTRIBUTE_UNUSED,
bfd_boolean *again,
riscv_pcgp_relocs *prcel_relocs ATTRIBUTE_UNUSED)
{
/* See if this symbol is in range of tp. */
if (RISCV_CONST_HIGH_PART (tpoff (link_info, symval)) != 0)
return TRUE;
BFD_ASSERT (rel->r_offset + 4 <= sec->size);
switch (ELFNN_R_TYPE (rel->r_info))
{
case R_RISCV_TPREL_LO12_I:
rel->r_info = ELFNN_R_INFO (ELFNN_R_SYM (rel->r_info), R_RISCV_TPREL_I);
return TRUE;
case R_RISCV_TPREL_LO12_S:
rel->r_info = ELFNN_R_INFO (ELFNN_R_SYM (rel->r_info), R_RISCV_TPREL_S);
return TRUE;
case R_RISCV_TPREL_HI20:
case R_RISCV_TPREL_ADD:
/* We can delete the unnecessary instruction and reloc. */
rel->r_info = ELFNN_R_INFO (0, R_RISCV_NONE);
*again = TRUE;
return riscv_relax_delete_bytes (abfd, sec, rel->r_offset, 4, link_info);
default:
abort ();
}
}
/* Implement R_RISCV_ALIGN by deleting excess alignment NOPs. */
static bfd_boolean
_bfd_riscv_relax_align (bfd *abfd, asection *sec,
asection *sym_sec,
struct bfd_link_info *link_info,
Elf_Internal_Rela *rel,
bfd_vma symval,
bfd_vma max_alignment ATTRIBUTE_UNUSED,
bfd_vma reserve_size ATTRIBUTE_UNUSED,
bfd_boolean *again ATTRIBUTE_UNUSED,
riscv_pcgp_relocs *pcrel_relocs ATTRIBUTE_UNUSED)
{
bfd_byte *contents = elf_section_data (sec)->this_hdr.contents;
bfd_vma alignment = 1, pos;
while (alignment <= rel->r_addend)
alignment *= 2;
symval -= rel->r_addend;
bfd_vma aligned_addr = ((symval - 1) & ~(alignment - 1)) + alignment;
bfd_vma nop_bytes = aligned_addr - symval;
/* Once we've handled an R_RISCV_ALIGN, we can't relax anything else. */
sec->sec_flg0 = TRUE;
/* Make sure there are enough NOPs to actually achieve the alignment. */
if (rel->r_addend < nop_bytes)
{
_bfd_error_handler
(_("%pB(%pA+%#" PRIx64 "): %" PRId64 " bytes required for alignment "
"to %" PRId64 "-byte boundary, but only %" PRId64 " present"),
abfd, sym_sec, (uint64_t) rel->r_offset,
(int64_t) nop_bytes, (int64_t) alignment, (int64_t) rel->r_addend);
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
/* Delete the reloc. */
rel->r_info = ELFNN_R_INFO (0, R_RISCV_NONE);
/* If the number of NOPs is already correct, there's nothing to do. */
if (nop_bytes == rel->r_addend)
return TRUE;
/* Write as many RISC-V NOPs as we need. */
for (pos = 0; pos < (nop_bytes & -4); pos += 4)
bfd_put_32 (abfd, RISCV_NOP, contents + rel->r_offset + pos);
/* Write a final RVC NOP if need be. */
if (nop_bytes % 4 != 0)
bfd_put_16 (abfd, RVC_NOP, contents + rel->r_offset + pos);
/* Delete the excess bytes. */
return riscv_relax_delete_bytes (abfd, sec, rel->r_offset + nop_bytes,
rel->r_addend - nop_bytes, link_info);
}
/* Relax PC-relative references to GP-relative references. */
static bfd_boolean
_bfd_riscv_relax_pc (bfd *abfd,
asection *sec,
asection *sym_sec,
struct bfd_link_info *link_info,
Elf_Internal_Rela *rel,
bfd_vma symval,
bfd_vma max_alignment,
bfd_vma reserve_size,
bfd_boolean *again ATTRIBUTE_UNUSED,
riscv_pcgp_relocs *pcgp_relocs)
{
bfd_vma gp = riscv_global_pointer_value (link_info);
BFD_ASSERT (rel->r_offset + 4 <= sec->size);
/* Chain the _LO relocs to their cooresponding _HI reloc to compute the
* actual target address. */
riscv_pcgp_hi_reloc hi_reloc;
memset (&hi_reloc, 0, sizeof (hi_reloc));
switch (ELFNN_R_TYPE (rel->r_info))
{
case R_RISCV_PCREL_LO12_I:
case R_RISCV_PCREL_LO12_S:
{
riscv_pcgp_hi_reloc *hi = riscv_find_pcgp_hi_reloc (pcgp_relocs,
symval - sec_addr(sym_sec));
if (hi == NULL)
{
riscv_record_pcgp_lo_reloc (pcgp_relocs, symval - sec_addr(sym_sec));
return TRUE;
}
hi_reloc = *hi;
symval = hi_reloc.hi_addr;
sym_sec = hi_reloc.sym_sec;
if (!riscv_use_pcgp_hi_reloc(pcgp_relocs, hi->hi_sec_off))
_bfd_error_handler
(_("%pB(%pA+%#" PRIx64 "): Unable to clear RISCV_PCREL_HI20 reloc "
"for corresponding RISCV_PCREL_LO12 reloc"),
abfd, sec, (uint64_t) rel->r_offset);
}
break;
case R_RISCV_PCREL_HI20:
/* Mergeable symbols and code might later move out of range. */
if (sym_sec->flags & (SEC_MERGE | SEC_CODE))
return TRUE;
/* If the cooresponding lo relocation has already been seen then it's not
* safe to relax this relocation. */
if (riscv_find_pcgp_lo_reloc (pcgp_relocs, rel->r_offset))
return TRUE;
break;
default:
abort ();
}
if (gp)
{
/* If gp and the symbol are in the same output section, then
consider only that section's alignment. */
struct bfd_link_hash_entry *h =
bfd_link_hash_lookup (link_info->hash, RISCV_GP_SYMBOL, FALSE, FALSE, TRUE);
if (h->u.def.section->output_section == sym_sec->output_section)
max_alignment = (bfd_vma) 1 << sym_sec->output_section->alignment_power;
}
/* Is the reference in range of x0 or gp?
Valid gp range conservatively because of alignment issue. */
if (VALID_ITYPE_IMM (symval)
|| (symval >= gp
&& VALID_ITYPE_IMM (symval - gp + max_alignment + reserve_size))
|| (symval < gp
&& VALID_ITYPE_IMM (symval - gp - max_alignment - reserve_size)))
{
unsigned sym = hi_reloc.hi_sym;
switch (ELFNN_R_TYPE (rel->r_info))
{
case R_RISCV_PCREL_LO12_I:
rel->r_info = ELFNN_R_INFO (sym, R_RISCV_GPREL_I);
rel->r_addend += hi_reloc.hi_addend;
return riscv_delete_pcgp_lo_reloc (pcgp_relocs, rel->r_offset, 4);
case R_RISCV_PCREL_LO12_S:
rel->r_info = ELFNN_R_INFO (sym, R_RISCV_GPREL_S);
rel->r_addend += hi_reloc.hi_addend;
return riscv_delete_pcgp_lo_reloc (pcgp_relocs, rel->r_offset, 4);
case R_RISCV_PCREL_HI20:
riscv_record_pcgp_hi_reloc (pcgp_relocs,
rel->r_offset,
rel->r_addend,
symval,
ELFNN_R_SYM(rel->r_info),
sym_sec);
/* We can delete the unnecessary AUIPC and reloc. */
rel->r_info = ELFNN_R_INFO (0, R_RISCV_DELETE);
rel->r_addend = 4;
return riscv_delete_pcgp_hi_reloc (pcgp_relocs, rel->r_offset);
default:
abort ();
}
}
return TRUE;
}
/* Relax PC-relative references to GP-relative references. */
static bfd_boolean
_bfd_riscv_relax_delete (bfd *abfd,
asection *sec,
asection *sym_sec ATTRIBUTE_UNUSED,
struct bfd_link_info *link_info,
Elf_Internal_Rela *rel,
bfd_vma symval ATTRIBUTE_UNUSED,
bfd_vma max_alignment ATTRIBUTE_UNUSED,
bfd_vma reserve_size ATTRIBUTE_UNUSED,
bfd_boolean *again ATTRIBUTE_UNUSED,
riscv_pcgp_relocs *pcgp_relocs ATTRIBUTE_UNUSED)
{
if (!riscv_relax_delete_bytes(abfd, sec, rel->r_offset, rel->r_addend,
link_info))
return FALSE;
rel->r_info = ELFNN_R_INFO(0, R_RISCV_NONE);
return TRUE;
}
/* Relax a section. Pass 0 shortens code sequences unless disabled. Pass 1
deletes the bytes that pass 0 made obselete. Pass 2, which cannot be
disabled, handles code alignment directives. */
static bfd_boolean
_bfd_riscv_relax_section (bfd *abfd, asection *sec,
struct bfd_link_info *info,
bfd_boolean *again)
{
Elf_Internal_Shdr *symtab_hdr = &elf_symtab_hdr (abfd);
struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
struct bfd_elf_section_data *data = elf_section_data (sec);
Elf_Internal_Rela *relocs;
bfd_boolean ret = FALSE;
unsigned int i;
bfd_vma max_alignment, reserve_size = 0;
riscv_pcgp_relocs pcgp_relocs;
*again = FALSE;
if (bfd_link_relocatable (info)
|| sec->sec_flg0
|| (sec->flags & SEC_RELOC) == 0
|| sec->reloc_count == 0
|| (info->disable_target_specific_optimizations
&& info->relax_pass == 0))
return TRUE;
riscv_init_pcgp_relocs (&pcgp_relocs);
/* Read this BFD's relocs if we haven't done so already. */
if (data->relocs)
relocs = data->relocs;
else if (!(relocs = _bfd_elf_link_read_relocs (abfd, sec, NULL, NULL,
info->keep_memory)))
goto fail;
if (htab)
{
max_alignment = htab->max_alignment;
if (max_alignment == (bfd_vma) -1)
{
max_alignment = _bfd_riscv_get_max_alignment (sec);
htab->max_alignment = max_alignment;
}
}
else
max_alignment = _bfd_riscv_get_max_alignment (sec);
/* Examine and consider relaxing each reloc. */
for (i = 0; i < sec->reloc_count; i++)
{
asection *sym_sec;
Elf_Internal_Rela *rel = relocs + i;
relax_func_t relax_func;
int type = ELFNN_R_TYPE (rel->r_info);
bfd_vma symval;
relax_func = NULL;
if (info->relax_pass == 0)
{
if (type == R_RISCV_CALL || type == R_RISCV_CALL_PLT)
relax_func = _bfd_riscv_relax_call;
else if (type == R_RISCV_HI20
|| type == R_RISCV_LO12_I
|| type == R_RISCV_LO12_S)
relax_func = _bfd_riscv_relax_lui;
else if (!bfd_link_pic(info)
&& (type == R_RISCV_PCREL_HI20
|| type == R_RISCV_PCREL_LO12_I
|| type == R_RISCV_PCREL_LO12_S))
relax_func = _bfd_riscv_relax_pc;
else if (type == R_RISCV_TPREL_HI20
|| type == R_RISCV_TPREL_ADD
|| type == R_RISCV_TPREL_LO12_I
|| type == R_RISCV_TPREL_LO12_S)
relax_func = _bfd_riscv_relax_tls_le;
else
continue;
/* Only relax this reloc if it is paired with R_RISCV_RELAX. */
if (i == sec->reloc_count - 1
|| ELFNN_R_TYPE ((rel + 1)->r_info) != R_RISCV_RELAX
|| rel->r_offset != (rel + 1)->r_offset)
continue;
/* Skip over the R_RISCV_RELAX. */
i++;
}
else if (info->relax_pass == 1 && type == R_RISCV_DELETE)
relax_func = _bfd_riscv_relax_delete;
else if (info->relax_pass == 2 && type == R_RISCV_ALIGN)
relax_func = _bfd_riscv_relax_align;
else
continue;
data->relocs = relocs;
/* Read this BFD's contents if we haven't done so already. */
if (!data->this_hdr.contents
&& !bfd_malloc_and_get_section (abfd, sec, &data->this_hdr.contents))
goto fail;
/* Read this BFD's symbols if we haven't done so already. */
if (symtab_hdr->sh_info != 0
&& !symtab_hdr->contents
&& !(symtab_hdr->contents =
(unsigned char *) bfd_elf_get_elf_syms (abfd, symtab_hdr,
symtab_hdr->sh_info,
0, NULL, NULL, NULL)))
goto fail;
/* Get the value of the symbol referred to by the reloc. */
if (ELFNN_R_SYM (rel->r_info) < symtab_hdr->sh_info)
{
/* A local symbol. */
Elf_Internal_Sym *isym = ((Elf_Internal_Sym *) symtab_hdr->contents
+ ELFNN_R_SYM (rel->r_info));
reserve_size = (isym->st_size - rel->r_addend) > isym->st_size
? 0 : isym->st_size - rel->r_addend;
if (isym->st_shndx == SHN_UNDEF)
sym_sec = sec, symval = sec_addr (sec) + rel->r_offset;
else
{
BFD_ASSERT (isym->st_shndx < elf_numsections (abfd));
sym_sec = elf_elfsections (abfd)[isym->st_shndx]->bfd_section;
#if 0
/* The purpose of this code is unknown. It breaks linker scripts
for embedded development that place sections at address zero.
This code is believed to be unnecessary. Disabling it but not
yet removing it, in case something breaks. */
if (sec_addr (sym_sec) == 0)
continue;
#endif
symval = sec_addr (sym_sec) + isym->st_value;
}
}
else
{
unsigned long indx;
struct elf_link_hash_entry *h;
indx = ELFNN_R_SYM (rel->r_info) - symtab_hdr->sh_info;
h = elf_sym_hashes (abfd)[indx];
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->plt.offset != MINUS_ONE)
symval = sec_addr (htab->elf.splt) + h->plt.offset;
else if (h->root.u.def.section->output_section == NULL
|| (h->root.type != bfd_link_hash_defined
&& h->root.type != bfd_link_hash_defweak))
continue;
else
symval = sec_addr (h->root.u.def.section) + h->root.u.def.value;
if (h->type != STT_FUNC)
reserve_size =
(h->size - rel->r_addend) > h->size ? 0 : h->size - rel->r_addend;
sym_sec = h->root.u.def.section;
}
symval += rel->r_addend;
if (!relax_func (abfd, sec, sym_sec, info, rel, symval,
max_alignment, reserve_size, again,
&pcgp_relocs))
goto fail;
}
ret = TRUE;
fail:
if (relocs != data->relocs)
free (relocs);
riscv_free_pcgp_relocs(&pcgp_relocs, abfd, sec);
return ret;
}
#if ARCH_SIZE == 32
# define PRSTATUS_SIZE 0 /* FIXME */
# define PRSTATUS_OFFSET_PR_CURSIG 12
# define PRSTATUS_OFFSET_PR_PID 24
# define PRSTATUS_OFFSET_PR_REG 72
# define ELF_GREGSET_T_SIZE 128
# define PRPSINFO_SIZE 128
# define PRPSINFO_OFFSET_PR_PID 16
# define PRPSINFO_OFFSET_PR_FNAME 32
# define PRPSINFO_OFFSET_PR_PSARGS 48
#else
# define PRSTATUS_SIZE 376
# define PRSTATUS_OFFSET_PR_CURSIG 12
# define PRSTATUS_OFFSET_PR_PID 32
# define PRSTATUS_OFFSET_PR_REG 112
# define ELF_GREGSET_T_SIZE 256
# define PRPSINFO_SIZE 136
# define PRPSINFO_OFFSET_PR_PID 24
# define PRPSINFO_OFFSET_PR_FNAME 40
# define PRPSINFO_OFFSET_PR_PSARGS 56
#endif
/* Support for core dump NOTE sections. */
static bfd_boolean
riscv_elf_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
{
switch (note->descsz)
{
default:
return FALSE;
case PRSTATUS_SIZE: /* sizeof(struct elf_prstatus) on Linux/RISC-V. */
/* pr_cursig */
elf_tdata (abfd)->core->signal
= bfd_get_16 (abfd, note->descdata + PRSTATUS_OFFSET_PR_CURSIG);
/* pr_pid */
elf_tdata (abfd)->core->lwpid
= bfd_get_32 (abfd, note->descdata + PRSTATUS_OFFSET_PR_PID);
break;
}
/* Make a ".reg/999" section. */
return _bfd_elfcore_make_pseudosection (abfd, ".reg", ELF_GREGSET_T_SIZE,
note->descpos + PRSTATUS_OFFSET_PR_REG);
}
static bfd_boolean
riscv_elf_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
{
switch (note->descsz)
{
default:
return FALSE;
case PRPSINFO_SIZE: /* sizeof(struct elf_prpsinfo) on Linux/RISC-V. */
/* pr_pid */
elf_tdata (abfd)->core->pid
= bfd_get_32 (abfd, note->descdata + PRPSINFO_OFFSET_PR_PID);
/* pr_fname */
elf_tdata (abfd)->core->program = _bfd_elfcore_strndup
(abfd, note->descdata + PRPSINFO_OFFSET_PR_FNAME, 16);
/* pr_psargs */
elf_tdata (abfd)->core->command = _bfd_elfcore_strndup
(abfd, note->descdata + PRPSINFO_OFFSET_PR_PSARGS, 80);
break;
}
/* Note that for some reason, a spurious space is tacked
onto the end of the args in some (at least one anyway)
implementations, so strip it off if it exists. */
{
char *command = elf_tdata (abfd)->core->command;
int n = strlen (command);
if (0 < n && command[n - 1] == ' ')
command[n - 1] = '\0';
}
return TRUE;
}
/* Set the right mach type. */
static bfd_boolean
riscv_elf_object_p (bfd *abfd)
{
/* There are only two mach types in RISCV currently. */
if (strcmp (abfd->xvec->name, "elf32-littleriscv") == 0)
bfd_default_set_arch_mach (abfd, bfd_arch_riscv, bfd_mach_riscv32);
else
bfd_default_set_arch_mach (abfd, bfd_arch_riscv, bfd_mach_riscv64);
return TRUE;
}
#define TARGET_LITTLE_SYM riscv_elfNN_vec
#define TARGET_LITTLE_NAME "elfNN-littleriscv"
#define elf_backend_reloc_type_class riscv_reloc_type_class
#define bfd_elfNN_bfd_reloc_name_lookup riscv_reloc_name_lookup
#define bfd_elfNN_bfd_link_hash_table_create riscv_elf_link_hash_table_create
#define bfd_elfNN_bfd_reloc_type_lookup riscv_reloc_type_lookup
#define bfd_elfNN_bfd_merge_private_bfd_data \
_bfd_riscv_elf_merge_private_bfd_data
#define elf_backend_copy_indirect_symbol riscv_elf_copy_indirect_symbol
#define elf_backend_create_dynamic_sections riscv_elf_create_dynamic_sections
#define elf_backend_check_relocs riscv_elf_check_relocs
#define elf_backend_adjust_dynamic_symbol riscv_elf_adjust_dynamic_symbol
#define elf_backend_size_dynamic_sections riscv_elf_size_dynamic_sections
#define elf_backend_relocate_section riscv_elf_relocate_section
#define elf_backend_finish_dynamic_symbol riscv_elf_finish_dynamic_symbol
#define elf_backend_finish_dynamic_sections riscv_elf_finish_dynamic_sections
#define elf_backend_gc_mark_hook riscv_elf_gc_mark_hook
#define elf_backend_plt_sym_val riscv_elf_plt_sym_val
#define elf_backend_grok_prstatus riscv_elf_grok_prstatus
#define elf_backend_grok_psinfo riscv_elf_grok_psinfo
#define elf_backend_object_p riscv_elf_object_p
#define elf_info_to_howto_rel NULL
#define elf_info_to_howto riscv_info_to_howto_rela
#define bfd_elfNN_bfd_relax_section _bfd_riscv_relax_section
#define elf_backend_init_index_section _bfd_elf_init_1_index_section
#define elf_backend_can_gc_sections 1
#define elf_backend_can_refcount 1
#define elf_backend_want_got_plt 1
#define elf_backend_plt_readonly 1
#define elf_backend_plt_alignment 4
#define elf_backend_want_plt_sym 1
#define elf_backend_got_header_size (ARCH_SIZE / 8)
#define elf_backend_want_dynrelro 1
#define elf_backend_rela_normal 1
#define elf_backend_default_execstack 0
#include "elfNN-target.h"
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