diff options
Diffstat (limited to 'bfd/elfxx-mips.c')
| -rw-r--r-- | bfd/elfxx-mips.c | 408 |
1 files changed, 348 insertions, 60 deletions
diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c index 6ca4f06..0c3a5d9 100644 --- a/bfd/elfxx-mips.c +++ b/bfd/elfxx-mips.c @@ -408,6 +408,7 @@ static asection * mips_elf_rel_dyn_section PARAMS ((bfd *, bfd_boolean)); static asection * mips_elf_got_section PARAMS ((bfd *, bfd_boolean)); static struct mips_got_info *mips_elf_got_info PARAMS ((bfd *, asection **)); +static long mips_elf_get_global_gotsym_index PARAMS ((bfd *abfd)); static bfd_vma mips_elf_local_got_index PARAMS ((bfd *, bfd *, struct bfd_link_info *, bfd_vma)); static bfd_vma mips_elf_global_got_index @@ -496,6 +497,7 @@ static struct mips_got_info *mips_elf_got_for_ibfd static bfd *reldyn_sorting_bfd; /* Nonzero if ABFD is using the N32 ABI. */ + #define ABI_N32_P(abfd) \ ((elf_elfheader (abfd)->e_flags & EF_MIPS_ABI2) != 0) @@ -1706,6 +1708,29 @@ mips_elf_got_info (abfd, sgotp) return g; } +/* Obtain the lowest dynamic index of a symbol that was assigned a + global GOT entry. */ +static long +mips_elf_get_global_gotsym_index (abfd) + bfd *abfd; +{ + asection *sgot; + struct mips_got_info *g; + + if (abfd == NULL) + return 0; + + sgot = mips_elf_got_section (abfd, TRUE); + if (sgot == NULL || mips_elf_section_data (sgot) == NULL) + return 0; + + g = mips_elf_section_data (sgot)->u.got_info; + if (g == NULL || g->global_gotsym == NULL) + return 0; + + return g->global_gotsym->dynindx; +} + /* Returns the GOT offset at which the indicated address can be found. If there is not yet a GOT entry for this value, create one. Returns -1 if no satisfactory GOT offset can be found. */ @@ -2129,7 +2154,7 @@ mips_elf_bfd2got_entry_eq (entry1, entry2) return e1->bfd == e2->bfd; } -/* In a multi-got link, determine the GOT to be used for IBFD. G must +/* In a multi-got link, determine the GOT to be used for IBDF. G must be the master GOT data. */ static struct mips_got_info * @@ -3195,6 +3220,18 @@ mips_elf_calculate_relocation (abfd, input_bfd, input_section, info, and we're going to need it, get it now. */ switch (r_type) { + case R_MIPS_GOT_PAGE: + case R_MIPS_GOT_OFST: + /* If this symbol got a global GOT entry, we have to decay + GOT_PAGE/GOT_OFST to GOT_DISP/addend. */ + local_p = local_p || ! h + || (h->root.dynindx + < mips_elf_get_global_gotsym_index (elf_hash_table (info) + ->dynobj)); + if (local_p || r_type == R_MIPS_GOT_OFST) + break; + /* Fall through. */ + case R_MIPS_CALL16: case R_MIPS_GOT16: case R_MIPS_GOT_DISP: @@ -3205,7 +3242,11 @@ mips_elf_calculate_relocation (abfd, input_bfd, input_section, info, /* Find the index into the GOT where this value is located. */ if (!local_p) { - BFD_ASSERT (addend == 0); + /* GOT_PAGE may take a non-zero addend, that is ignored in a + GOT_PAGE relocation that decays to GOT_DISP because the + symbol turns out to be global. The addend is then added + as GOT_OFST. */ + BFD_ASSERT (addend == 0 || r_type == R_MIPS_GOT_PAGE); g = mips_elf_global_got_index (elf_hash_table (info)->dynobj, input_bfd, (struct elf_link_hash_entry *) h); @@ -3219,7 +3260,7 @@ mips_elf_calculate_relocation (abfd, input_bfd, input_section, info, We must initialize this entry in the GOT. */ bfd *tmpbfd = elf_hash_table (info)->dynobj; asection *sgot = mips_elf_got_section (tmpbfd, FALSE); - MIPS_ELF_PUT_WORD (tmpbfd, symbol + addend, sgot->contents + g); + MIPS_ELF_PUT_WORD (tmpbfd, symbol, sgot->contents + g); } } else if (r_type == R_MIPS_GOT16 || r_type == R_MIPS_CALL16) @@ -3315,6 +3356,12 @@ mips_elf_calculate_relocation (abfd, input_bfd, input_section, info, value &= howto->dst_mask; break; + case R_MIPS_GNU_REL16_S2: + value = symbol + mips_elf_sign_extend (addend << 2, 18) - p; + overflowed_p = mips_elf_overflow_p (value, 18); + value = (value >> 2) & howto->dst_mask; + break; + case R_MIPS_GNU_REL_HI16: /* Instead of subtracting 'p' here, we should be subtracting the equivalent value for the LO part of the reloc, since the value @@ -3432,6 +3479,7 @@ mips_elf_calculate_relocation (abfd, input_bfd, input_section, info, /* Fall through. */ case R_MIPS_GOT_DISP: + got_disp: value = g; overflowed_p = mips_elf_overflow_p (value, 16); break; @@ -3443,10 +3491,8 @@ mips_elf_calculate_relocation (abfd, input_bfd, input_section, info, break; case R_MIPS_PC16: - case R_MIPS_GNU_REL16_S2: - value = mips_elf_sign_extend (addend << 2, 18) + symbol - p; - overflowed_p = mips_elf_overflow_p (value, 18); - value = (value >> 2) & howto->dst_mask; + value = mips_elf_sign_extend (addend, 16) + symbol - p; + overflowed_p = mips_elf_overflow_p (value, 16); break; case R_MIPS_GOT_HI16: @@ -3465,6 +3511,11 @@ mips_elf_calculate_relocation (abfd, input_bfd, input_section, info, break; case R_MIPS_GOT_PAGE: + /* GOT_PAGE relocations that reference non-local symbols decay + to GOT_DISP. The corresponding GOT_OFST relocation decays to + 0. */ + if (! local_p) + goto got_disp; value = mips_elf_got_page (abfd, input_bfd, info, symbol + addend, NULL); if (value == MINUS_ONE) return bfd_reloc_outofrange; @@ -3474,7 +3525,10 @@ mips_elf_calculate_relocation (abfd, input_bfd, input_section, info, break; case R_MIPS_GOT_OFST: - mips_elf_got_page (abfd, input_bfd, info, symbol + addend, &value); + if (local_p) + mips_elf_got_page (abfd, input_bfd, info, symbol + addend, &value); + else + value = addend; overflowed_p = mips_elf_overflow_p (value, 16); break; @@ -3832,7 +3886,6 @@ mips_elf_create_dynamic_relocation (output_bfd, info, rel, h, sec, else { long indx; - bfd_vma section_offset; /* We must now calculate the dynamic symbol table index to use in the relocation. */ @@ -3862,15 +3915,18 @@ mips_elf_create_dynamic_relocation (output_bfd, info, rel, h, sec, abort (); } - /* Figure out how far the target of the relocation is from - the beginning of its section. */ - section_offset = symbol - sec->output_section->vma; - /* The relocation we're building is section-relative. - Therefore, the original addend must be adjusted by the - section offset. */ - *addendp += section_offset; - /* Now, the relocation is just against the section. */ - symbol = sec->output_section->vma; + /* Instead of generating a relocation using the section + symbol, we may as well make it a fully relative + relocation. We want to avoid generating relocations to + local symbols because we used to generate them + incorrectly, without adding the original symbol value, + which is mandated by the ABI for section symbols. In + order to give dynamic loaders and applications time to + phase out the incorrect use, we refrain from emitting + section-relative relocations. It's not like they're + useful, after all. This should be a bit more efficient + as well. */ + indx = 0; } /* If the relocation was previously an absolute relocation and @@ -3884,6 +3940,18 @@ mips_elf_create_dynamic_relocation (output_bfd, info, rel, h, sec, know where the shared library will wind up at load-time. */ outrel[0].r_info = ELF_R_INFO (output_bfd, (unsigned long) indx, R_MIPS_REL32); + /* For strict adherence to the ABI specification, we should + generate a R_MIPS_64 relocation record by itself before the + _REL32/_64 record as well, such that the addend is read in as + a 64-bit value (REL32 is a 32-bit relocation, after all). + However, since none of the existing ELF64 MIPS dynamic + loaders seems to care, we don't waste space with these + artificial relocations. If this turns out to not be true, + mips_elf_allocate_dynamic_relocation() should be tweaked so + as to make room for a pair of dynamic relocations per + invocation if ABI_64_P, and here we should generate an + additional relocation record with R_MIPS_64 by itself for a + NULL symbol before this relocation record. */ outrel[1].r_info = ELF_R_INFO (output_bfd, (unsigned long) 0, ABI_64_P (output_bfd) ? R_MIPS_64 @@ -5293,6 +5361,44 @@ _bfd_mips_elf_check_relocs (abfd, info, sec, relocs) } break; + case R_MIPS_GOT_PAGE: + /* If this is a global, overridable symbol, GOT_PAGE will + decay to GOT_DISP, so we'll need a GOT entry for it. */ + if (h == NULL) + break; + else + { + struct mips_elf_link_hash_entry *hmips = + (struct mips_elf_link_hash_entry *) h; + + while (hmips->root.root.type == bfd_link_hash_indirect + || hmips->root.root.type == bfd_link_hash_warning) + hmips = (struct mips_elf_link_hash_entry *) + hmips->root.root.u.i.link; + + if ((hmips->root.root.type == bfd_link_hash_defined + || hmips->root.root.type == bfd_link_hash_defweak) + && hmips->root.root.u.def.section + && ! (info->shared && ! info->symbolic + && ! (hmips->root.elf_link_hash_flags + & ELF_LINK_FORCED_LOCAL)) + /* If we've encountered any other relocation + referencing the symbol, we'll have marked it as + dynamic, and, even though we might be able to get + rid of the GOT entry should we know for sure all + previous relocations were GOT_PAGE ones, at this + point we can't tell, so just keep using the + symbol as dynamic. This is very important in the + multi-got case, since we don't decide whether to + decay GOT_PAGE to GOT_DISP on a per-GOT basis: if + the symbol is dynamic, we'll need a GOT entry for + every GOT in which the symbol is referenced with + a GOT_PAGE relocation. */ + && hmips->root.dynindx == -1) + break; + } + /* Fall through. */ + case R_MIPS_GOT16: case R_MIPS_GOT_HI16: case R_MIPS_GOT_LO16: @@ -5432,6 +5538,185 @@ _bfd_mips_elf_check_relocs (abfd, info, sec, relocs) return TRUE; } +bfd_boolean +_bfd_mips_relax_section (abfd, sec, link_info, again) + bfd *abfd; + asection *sec; + struct bfd_link_info *link_info; + bfd_boolean *again; +{ + Elf_Internal_Rela *internal_relocs; + Elf_Internal_Rela *irel, *irelend; + Elf_Internal_Shdr *symtab_hdr; + bfd_byte *contents = NULL; + bfd_byte *free_contents = NULL; + size_t extsymoff; + bfd_boolean changed_contents = FALSE; + bfd_vma sec_start = sec->output_section->vma + sec->output_offset; + Elf_Internal_Sym *isymbuf = NULL; + + /* We are not currently changing any sizes, so only one pass. */ + *again = FALSE; + + if (link_info->relocateable) + return TRUE; + + internal_relocs = (MNAME(abfd,_bfd_elf,link_read_relocs) + (abfd, sec, (PTR) NULL, (Elf_Internal_Rela *) NULL, + link_info->keep_memory)); + if (internal_relocs == NULL) + return TRUE; + + irelend = internal_relocs + sec->reloc_count + * get_elf_backend_data (abfd)->s->int_rels_per_ext_rel; + symtab_hdr = &elf_tdata (abfd)->symtab_hdr; + extsymoff = (elf_bad_symtab (abfd)) ? 0 : symtab_hdr->sh_info; + + for (irel = internal_relocs; irel < irelend; irel++) + { + bfd_vma symval; + bfd_signed_vma sym_offset; + unsigned int r_type; + unsigned long r_symndx; + asection *sym_sec; + unsigned long instruction; + + /* Turn jalr into bgezal, and jr into beq, if they're marked + with a JALR relocation, that indicate where they jump to. + This saves some pipeline bubbles. */ + r_type = ELF_R_TYPE (abfd, irel->r_info); + if (r_type != R_MIPS_JALR) + continue; + + r_symndx = ELF_R_SYM (abfd, irel->r_info); + /* Compute the address of the jump target. */ + if (r_symndx >= extsymoff) + { + struct mips_elf_link_hash_entry *h + = ((struct mips_elf_link_hash_entry *) + elf_sym_hashes (abfd) [r_symndx - extsymoff]); + + while (h->root.root.type == bfd_link_hash_indirect + || h->root.root.type == bfd_link_hash_warning) + h = (struct mips_elf_link_hash_entry *) h->root.root.u.i.link; + + /* If a symbol is undefined, or if it may be overridden, + skip it. */ + if (! ((h->root.root.type == bfd_link_hash_defined + || h->root.root.type == bfd_link_hash_defweak) + && h->root.root.u.def.section) + || (link_info->shared && ! link_info->symbolic + && ! (h->root.elf_link_hash_flags & ELF_LINK_FORCED_LOCAL))) + continue; + + sym_sec = h->root.root.u.def.section; + if (sym_sec->output_section) + symval = (h->root.root.u.def.value + + sym_sec->output_section->vma + + sym_sec->output_offset); + else + symval = h->root.root.u.def.value; + } + else + { + Elf_Internal_Sym *isym; + + /* Read this BFD's symbols if we haven't done so already. */ + if (isymbuf == NULL && symtab_hdr->sh_info != 0) + { + isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents; + if (isymbuf == NULL) + isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr, + symtab_hdr->sh_info, 0, + NULL, NULL, NULL); + if (isymbuf == NULL) + goto relax_return; + } + + isym = isymbuf + r_symndx; + if (isym->st_shndx == SHN_UNDEF) + continue; + else if (isym->st_shndx == SHN_ABS) + sym_sec = bfd_abs_section_ptr; + else if (isym->st_shndx == SHN_COMMON) + sym_sec = bfd_com_section_ptr; + else + sym_sec + = bfd_section_from_elf_index (abfd, isym->st_shndx); + symval = isym->st_value + + sym_sec->output_section->vma + + sym_sec->output_offset; + } + + /* Compute branch offset, from delay slot of the jump to the + branch target. */ + sym_offset = (symval + irel->r_addend) + - (sec_start + irel->r_offset + 4); + + /* Branch offset must be properly aligned. */ + if ((sym_offset & 3) != 0) + continue; + + sym_offset >>= 2; + + /* Check that it's in range. */ + if (sym_offset < -0x8000 || sym_offset >= 0x8000) + continue; + + /* Get the section contents if we haven't done so already. */ + if (contents == NULL) + { + /* Get cached copy if it exists. */ + if (elf_section_data (sec)->this_hdr.contents != NULL) + contents = elf_section_data (sec)->this_hdr.contents; + else + { + contents = (bfd_byte *) bfd_malloc (sec->_raw_size); + if (contents == NULL) + goto relax_return; + + free_contents = contents; + if (! bfd_get_section_contents (abfd, sec, contents, + (file_ptr) 0, sec->_raw_size)) + goto relax_return; + } + } + + instruction = bfd_get_32 (abfd, contents + irel->r_offset); + + /* If it was jalr <reg>, turn it into bgezal $zero, <target>. */ + if ((instruction & 0xfc1fffff) == 0x0000f809) + instruction = 0x04110000; + /* If it was jr <reg>, turn it into b <target>. */ + else if ((instruction & 0xfc1fffff) == 0x00000008) + instruction = 0x10000000; + else + continue; + + instruction |= (sym_offset & 0xffff); + bfd_put_32 (abfd, instruction, contents + irel->r_offset); + changed_contents = TRUE; + } + + if (contents != NULL + && elf_section_data (sec)->this_hdr.contents != contents) + { + if (!changed_contents && !link_info->keep_memory) + free (contents); + else + { + /* Cache the section contents for elf_link_input_bfd. */ + elf_section_data (sec)->this_hdr.contents = contents; + } + } + return TRUE; + + relax_return: + if (free_contents != NULL) + free (free_contents); + return FALSE; +} + /* 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 @@ -7518,55 +7803,58 @@ _bfd_mips_elf_hide_symbol (info, entry, force_local) h->forced_local = TRUE; dynobj = elf_hash_table (info)->dynobj; - got = mips_elf_got_section (dynobj, FALSE); - g = mips_elf_section_data (got)->u.got_info; - - if (g->next) + if (dynobj != NULL) { - struct mips_got_entry e; - struct mips_got_info *gg = g; + got = mips_elf_got_section (dynobj, FALSE); + g = mips_elf_section_data (got)->u.got_info; - /* Since we're turning what used to be a global symbol into a - local one, bump up the number of local entries of each GOT - that had an entry for it. This will automatically decrease - the number of global entries, since global_gotno is actually - the upper limit of global entries. */ - e.abfd = dynobj; - e.symndx = -1; - e.d.h = h; + if (g->next) + { + struct mips_got_entry e; + struct mips_got_info *gg = g; + + /* Since we're turning what used to be a global symbol into a + local one, bump up the number of local entries of each GOT + that had an entry for it. This will automatically decrease + the number of global entries, since global_gotno is actually + the upper limit of global entries. */ + e.abfd = dynobj; + e.symndx = -1; + e.d.h = h; - for (g = g->next; g != gg; g = g->next) - if (htab_find (g->got_entries, &e)) - { - BFD_ASSERT (g->global_gotno > 0); - g->local_gotno++; - g->global_gotno--; - } + for (g = g->next; g != gg; g = g->next) + if (htab_find (g->got_entries, &e)) + { + BFD_ASSERT (g->global_gotno > 0); + g->local_gotno++; + g->global_gotno--; + } - /* If this was a global symbol forced into the primary GOT, we - no longer need an entry for it. We can't release the entry - at this point, but we must at least stop counting it as one - of the symbols that required a forced got entry. */ - if (h->root.got.offset == 2) + /* If this was a global symbol forced into the primary GOT, we + no longer need an entry for it. We can't release the entry + at this point, but we must at least stop counting it as one + of the symbols that required a forced got entry. */ + if (h->root.got.offset == 2) + { + BFD_ASSERT (gg->assigned_gotno > 0); + gg->assigned_gotno--; + } + } + else if (g->global_gotno == 0 && g->global_gotsym == NULL) + /* If we haven't got through GOT allocation yet, just bump up the + number of local entries, as this symbol won't be counted as + global. */ + g->local_gotno++; + else if (h->root.got.offset == 1) { - BFD_ASSERT (gg->assigned_gotno > 0); - gg->assigned_gotno--; + /* If we're past non-multi-GOT allocation and this symbol had + been marked for a global got entry, give it a local entry + instead. */ + BFD_ASSERT (g->global_gotno > 0); + g->local_gotno++; + g->global_gotno--; } } - else if (g->global_gotno == 0 && g->global_gotsym == NULL) - /* If we haven't got through GOT allocation yet, just bump up the - number of local entries, as this symbol won't be counted as - global. */ - g->local_gotno++; - else if (h->root.got.offset == 1) - { - /* If we're past non-multi-GOT allocation and this symbol had - been marked for a global got entry, give it a local entry - instead. */ - BFD_ASSERT (g->global_gotno > 0); - g->local_gotno++; - g->global_gotno--; - } _bfd_elf_link_hash_hide_symbol (info, &h->root, force_local); } |