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[/] [hf-risc/] [trunk/] [tools/] [riscv-gnu-toolchain-master/] [binutils/] [bfd/] [elfnn-riscv.c] - Rev 13
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/* RISC-V-specific support for NN-bit ELF. Copyright 2011-2015 Free Software Foundation, Inc. Contributed by Andrew Waterman (waterman@cs.berkeley.edu) at UC Berkeley. 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" #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 /* The RISC-V linker needs to keep track of the number of relocs that it decides to copy as dynamic relocs in check_relocs for each symbol. This is so that it can later discard them if they are found to be unnecessary. We store the information in a field extending the regular ELF linker hash table. */ struct riscv_elf_dyn_relocs { struct riscv_elf_dyn_relocs *next; /* The input section of the reloc. */ asection *sec; /* Total number of relocs copied for the input section. */ bfd_size_type count; /* Number of pc-relative relocs copied for the input section. */ bfd_size_type pc_count; }; /* 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 riscv_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 *sdynbss; asection *srelbss; asection *sdyntdata; /* Small local sym to section mapping cache. */ struct sym_cache sym_cache; }; /* 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 void riscv_info_to_howto_rela (bfd *abfd ATTRIBUTE_UNUSED, arelent *cache_ptr, Elf_Internal_Rela *dst) { cache_ptr->howto = riscv_elf_rtype_to_howto (ELFNN_R_TYPE (dst->r_info)); } 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; } 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. */ s = bfd_get_linker_section (abfd, ".got"); if (s != 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; htab->sdynbss = bfd_get_linker_section (dynobj, ".dynbss"); if (!info->shared) { htab->srelbss = bfd_get_linker_section (dynobj, ".rela.bss"); htab->sdyntdata = bfd_make_section_anyway_with_flags (dynobj, ".tdata.dyn", SEC_ALLOC | SEC_THREAD_LOCAL); } if (!htab->elf.splt || !htab->elf.srelplt || !htab->sdynbss || (!info->shared && (!htab->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 riscv_elf_dyn_relocs **pp; struct riscv_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 riscv_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) (_("%B: `%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) { (*_bfd_error_handler) (_("%B: relocation %s against `%s' can not be used when making a shared " "object; recompile with -fPIC"), abfd, riscv_elf_rtype_to_howto (r_type)->name, 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 (info->relocatable) 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 long 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) (_("%B: 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; /* PR15323, ref flags aren't set for references in the same object. */ h->root.non_ir_ref = 1; } switch (r_type) { case R_RISCV_TLS_GD_HI20: if (!riscv_elf_record_got_reference (abfd, info, h, r_symndx) || !riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_TLS_GD)) return FALSE; break; case R_RISCV_TLS_GOT_HI20: if (info->shared) 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 (info->shared) break; goto static_reloc; case R_RISCV_TPREL_HI20: if (!info->executable) 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 (info->shared) 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 && !info->shared) { /* 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. */ if ((info->shared && (sec->flags & SEC_ALLOC) != 0 && (! riscv_elf_rtype_to_howto (r_type)->pc_relative || (h != NULL && (! info->symbolic || h->root.type == bfd_link_hash_defweak || !h->def_regular)))) || (!info->shared && (sec->flags & SEC_ALLOC) != 0 && h != NULL && (h->root.type == bfd_link_hash_defweak || !h->def_regular))) { struct riscv_elf_dyn_relocs *p; struct riscv_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 riscv_elf_dyn_relocs **) vpp; } p = *head; if (p == NULL || p->sec != sec) { bfd_size_type amt = sizeof *p; p = ((struct riscv_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 += riscv_elf_rtype_to_howto (r_type)->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); } /* Update the got entry reference counts for the section being removed. */ static bfd_boolean riscv_elf_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info, asection *sec, const Elf_Internal_Rela *relocs) { const Elf_Internal_Rela *rel, *relend; Elf_Internal_Shdr *symtab_hdr = &elf_symtab_hdr (abfd); struct elf_link_hash_entry **sym_hashes = elf_sym_hashes (abfd); bfd_signed_vma *local_got_refcounts = elf_local_got_refcounts (abfd); if (info->relocatable) return TRUE; elf_section_data (sec)->local_dynrel = NULL; for (rel = relocs, relend = relocs + sec->reloc_count; rel < relend; rel++) { unsigned long r_symndx; struct elf_link_hash_entry *h = NULL; r_symndx = ELFNN_R_SYM (rel->r_info); if (r_symndx >= symtab_hdr->sh_info) { struct riscv_elf_link_hash_entry *eh; struct riscv_elf_dyn_relocs **pp; struct riscv_elf_dyn_relocs *p; 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; eh = (struct riscv_elf_link_hash_entry *) h; for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next) if (p->sec == sec) { /* Everything must go for SEC. */ *pp = p->next; break; } } switch (ELFNN_R_TYPE (rel->r_info)) { case R_RISCV_GOT_HI20: case R_RISCV_TLS_GOT_HI20: case R_RISCV_TLS_GD_HI20: if (h != NULL) { if (h->got.refcount > 0) h->got.refcount--; } else { if (local_got_refcounts && local_got_refcounts[r_symndx] > 0) local_got_refcounts[r_symndx]--; } break; case R_RISCV_HI20: case R_RISCV_PCREL_HI20: case R_RISCV_COPY: case R_RISCV_JUMP_SLOT: case R_RISCV_RELATIVE: case R_RISCV_64: case R_RISCV_32: case R_RISCV_BRANCH: case R_RISCV_CALL: case R_RISCV_JAL: case R_RISCV_RVC_BRANCH: case R_RISCV_RVC_JUMP: if (info->shared) break; /* Fall through. */ case R_RISCV_CALL_PLT: if (h != NULL) { if (h->plt.refcount > 0) h->plt.refcount--; } break; default: break; } } return TRUE; } /* 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; struct riscv_elf_dyn_relocs *p; bfd *dynobj; asection *s; 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->u.weakdef != NULL || (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->u.weakdef != NULL) { BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined || h->u.weakdef->root.type == bfd_link_hash_defweak); h->root.u.def.section = h->u.weakdef->root.u.def.section; h->root.u.def.value = h->u.weakdef->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 (info->shared) 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; } eh = (struct riscv_elf_link_hash_entry *) h; for (p = eh->dyn_relocs; p != NULL; p = p->next) { s = p->sec->output_section; if (s != NULL && (s->flags & SEC_READONLY) != 0) break; } /* If we didn't find any dynamic relocs in read-only sections, then we'll be keeping the dynamic relocs and avoiding the copy reloc. */ if (p == NULL) { 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. */ if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0) { htab->srelbss->size += sizeof (ElfNN_External_Rela); h->needs_copy = 1; } if (eh->tls_type & ~GOT_NORMAL) return _bfd_elf_adjust_dynamic_copy (info, h, htab->sdyntdata); return _bfd_elf_adjust_dynamic_copy (info, h, htab->sdynbss); } /* 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 riscv_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, info->shared, 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 (! info->shared && !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, info->shared, 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 (info->shared) { if (SYMBOL_CALLS_LOCAL (info, h)) { struct riscv_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) 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; } /* Find any dynamic relocs that apply to read-only sections. */ static bfd_boolean readonly_dynrelocs (struct elf_link_hash_entry *h, void *inf) { struct riscv_elf_link_hash_entry *eh; struct riscv_elf_dyn_relocs *p; eh = (struct riscv_elf_link_hash_entry *) h; for (p = eh->dyn_relocs; p != NULL; p = p->next) { asection *s = p->sec->output_section; if (s != NULL && (s->flags & SEC_READONLY) != 0) { ((struct bfd_link_info *) inf)->flags |= DF_TEXTREL; 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 (info->executable) { 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 riscv_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 (info->shared || (*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->sdynbss) { /* 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 (info->executable) { 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, readonly_dynrelocs, 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, "_gp", 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_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_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_SUB8: case R_RISCV_SUB16: case R_RISCV_SUB32: case R_RISCV_SUB64: case R_RISCV_TLS_DTPREL32: case R_RISCV_TLS_DTPREL64: break; 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_record_pcrel_hi_reloc (riscv_pcrel_relocs *p, bfd_vma addr, bfd_vma value) { riscv_pcrel_hi_reloc entry = {addr, value - addr}; 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) return ((*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)); 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); 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 (r_type); const char *msg = NULL; if (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 (info->relocatable) 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); } switch (r_type) { case R_RISCV_NONE: 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: /* These require no special handling beyond perform_relocation. */ break; case R_RISCV_GOT_HI20: if (h != NULL) { bfd_boolean dyn; off = h->got.offset; BFD_ASSERT (off != (bfd_vma) -1); dyn = elf_hash_table (info)->dynamic_sections_created; if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h) || (info->shared && 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 (info->shared) { 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; if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc, relocation)) 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_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_PLT: case R_RISCV_CALL: case R_RISCV_JAL: case R_RISCV_RVC_JUMP: if (info->shared && 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); 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); } 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: if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc, relocation + rel->r_addend)) r = bfd_reloc_overflow; break; case R_RISCV_PCREL_LO12_I: case R_RISCV_PCREL_LO12_S: 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 ((info->shared && (h == NULL || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT || h->root.type != bfd_link_hash_undefweak) && (! howto->pc_relative || !SYMBOL_CALLS_LOCAL (info, h))) || (!info->shared && 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 && !(info->shared && 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; dyn = htab->elf.dynamic_sections_created; if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h) && (!info->shared || !SYMBOL_REFERENCES_LOCAL (info, h))) { indx = h->dynindx; } } /* The GOT entries have not been initialized yet. Do it now, and emit any relocations. */ if ((info->shared || indx != 0) && (h == NULL || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT || h->root.type != bfd_link_hash_undefweak)) need_relocs = TRUE; if (tls_type & GOT_TLS_GD) { if (need_relocs) { outrel.r_offset = sec_addr (htab->elf.sgot) + off; outrel.r_addend = 0; outrel.r_info = ELFNN_R_INFO (indx, R_RISCV_TLS_DTPMODNN); bfd_put_NN (output_bfd, 0, htab->elf.sgot->contents + off); riscv_elf_append_rela (output_bfd, htab->elf.srelgot, &outrel); if (indx == 0) { BFD_ASSERT (! unresolved_reloc); bfd_put_NN (output_bfd, dtpoff (info, relocation), (htab->elf.sgot->contents + off + RISCV_ELF_WORD_BYTES)); } else { bfd_put_NN (output_bfd, 0, (htab->elf.sgot->contents + off + RISCV_ELF_WORD_BYTES)); outrel.r_info = ELFNN_R_INFO (indx, R_RISCV_TLS_DTPRELNN); outrel.r_offset += RISCV_ELF_WORD_BYTES; riscv_elf_append_rela (output_bfd, htab->elf.srelgot, &outrel); } } else { /* If we are not emitting relocations for a general dynamic reference, then we must be in a static link or an executable link with the symbol binding locally. Mark it as belonging to module 1, the executable. */ bfd_put_NN (output_bfd, 1, htab->elf.sgot->contents + off); bfd_put_NN (output_bfd, dtpoff (info, relocation), (htab->elf.sgot->contents + off + RISCV_ELF_WORD_BYTES)); } } if (tls_type & GOT_TLS_IE) { if (need_relocs) { bfd_put_NN (output_bfd, 0, htab->elf.sgot->contents + off + ie_off); outrel.r_offset = sec_addr (htab->elf.sgot) + off + ie_off; outrel.r_addend = 0; if (indx == 0) outrel.r_addend = tpoff (info, relocation); outrel.r_info = ELFNN_R_INFO (indx, R_RISCV_TLS_TPRELNN); riscv_elf_append_rela (output_bfd, htab->elf.srelgot, &outrel); } else { bfd_put_NN (output_bfd, tpoff (info, relocation), htab->elf.sgot->contents + off + ie_off); } } } BFD_ASSERT (off < (bfd_vma) -2); relocation = sec_addr (htab->elf.sgot) + off + (is_ie ? ie_off : 0); if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc, relocation)) r = 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) (_("%B(%A+0x%lx): unresolvable %s relocation against symbol `%s'"), input_bfd, input_section, (long) 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: r = 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: r = info->callbacks->undefined_symbol (info, name, input_bfd, input_section, rel->r_offset, TRUE); break; case bfd_reloc_outofrange: msg = _("internal error: out of range error"); break; case bfd_reloc_notsupported: msg = _("internal error: unsupported relocation error"); break; case bfd_reloc_dangerous: msg = _("internal error: dangerous relocation"); break; default: msg = _("internal error: unknown error"); break; } if (msg) r = info->callbacks->warning (info, msg, name, input_bfd, input_section, rel->r_offset); 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))) { 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 -Bsymbolic link, and the symbol is defined locally, we just want to emit a RELATIVE reloc. Likewise if 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 (info->shared && (info->symbolic || h->dynindx == -1) && h->def_regular) { 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->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; /* 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; riscv_elf_append_rela (output_bfd, htab->srelbss, &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 != TRUE) 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: `%A'"), 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, bfd *obfd) { 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) (_("%B: ABI is incompatible with that of the selected emulation"), ibfd); return FALSE; } if (!_bfd_elf_merge_object_attributes (ibfd, obfd)) return FALSE; if (! elf_flags_init (obfd)) { elf_flags_init (obfd) = TRUE; elf_elfheader (obfd)->e_flags = new_flags; return TRUE; } /* Disallow linking soft-float and hard-float. */ if ((old_flags ^ new_flags) & EF_RISCV_SOFT_FLOAT) { (*_bfd_error_handler) (_("%B: can't link hard-float modules with soft-float modules"), 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) { 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. */ 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]; 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. */ 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; } /* 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_boolean *again) { 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. Assume at most page-alignment, and account for this by adding some slop. */ if (VALID_UJTYPE_IMM (foff) && sym_sec->output_section != sec->output_section) foff += (foff < 0 ? -ELF_MAXPAGESIZE : ELF_MAXPAGESIZE); /* See if this function call can be shortened. */ if (!VALID_UJTYPE_IMM (foff) && !(!link_info->shared && 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); } /* 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_boolean *again) { 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 might later move out of range. */ if (sym_sec->flags & SEC_MERGE) return TRUE; BFD_ASSERT (rel->r_offset + 4 <= sec->size); /* Is the reference in range of x0 or gp? */ if (VALID_ITYPE_IMM (symval) || VALID_ITYPE_IMM (symval - gp)) { 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); 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 != x2/sp). */ bfd_vma lui = bfd_get_32 (abfd, contents + rel->r_offset); if (((lui >> OP_SH_RD) & OP_MASK_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); } 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_boolean *again) { /* See if this symbol is in range of tp. */ if (RISCV_CONST_HIGH_PART (tpoff (link_info, symval)) != 0) return TRUE; /* We can delete the unnecessary LUI and tp add. The LO12 reloc will be made directly tp-relative. */ BFD_ASSERT (rel->r_offset + 4 <= sec->size); rel->r_info = ELFNN_R_INFO (0, R_RISCV_NONE); *again = TRUE; return riscv_relax_delete_bytes (abfd, sec, rel->r_offset, 4); } /* Implement R_RISCV_ALIGN by deleting excess alignment NOPs. */ static bfd_boolean _bfd_riscv_relax_align (bfd *abfd, asection *sec, asection *sym_sec ATTRIBUTE_UNUSED, struct bfd_link_info *link_info ATTRIBUTE_UNUSED, Elf_Internal_Rela *rel, bfd_vma symval, bfd_boolean *again 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) 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); } /* Relax a section. Pass 0 shortens code sequences unless disabled. Pass 1, 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; *again = FALSE; if (info->relocatable || sec->sec_flg0 || (sec->flags & SEC_RELOC) == 0 || sec->reloc_count == 0 || (info->disable_target_specific_optimizations && info->relax_pass == 0)) return TRUE; /* 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; /* Examine and consider relaxing each reloc. */ for (i = 0; i < sec->reloc_count; i++) { asection *sym_sec; Elf_Internal_Rela *rel = relocs + i; typeof (&_bfd_riscv_relax_call) relax_func = NULL; int type = ELFNN_R_TYPE (rel->r_info); bfd_vma symval; 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 (type == R_RISCV_TPREL_HI20 || type == R_RISCV_TPREL_ADD) relax_func = _bfd_riscv_relax_tls_le; } else if (type == R_RISCV_ALIGN) relax_func = _bfd_riscv_relax_align; if (!relax_func) 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)); 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 (sec_addr (sym_sec) == 0) continue; 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; sym_sec = h->root.u.def.section; } symval += rel->r_addend; if (!relax_func (abfd, sec, sym_sec, info, rel, symval, again)) goto fail; } ret = TRUE; fail: if (relocs != data->relocs) free (relocs); return ret; } #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_gc_sweep_hook riscv_elf_gc_sweep_hook #define elf_backend_plt_sym_val riscv_elf_plt_sym_val #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_rela_normal 1 #define elf_backend_default_execstack 0 #include "elfNN-target.h"