diff options
Diffstat (limited to 'bfd')
| -rw-r--r-- | bfd/ChangeLog | 18 | ||||
| -rw-r--r-- | bfd/elf64-ppc.c | 77 | ||||
| -rw-r--r-- | bfd/elf64-ppc.h | 3 |
3 files changed, 85 insertions, 13 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 11a474e..cb4afa9 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,21 @@ +2017-06-01 Alan Modra <amodra@gmail.com> + + * elf64-ppc.c (struct ppc_link_hash_table): Add has_plt_localentry0. + (ppc64_elf_merge_symbol_attribute): Merge localentry bits from + dynamic objects. + (is_elfv2_localentry0): New function. + (ppc64_elf_tls_setup): Default params->plt_localentry0. + (plt_stub_size): Adjust size for tls_get_addr_opt stub. + (build_tls_get_addr_stub): Use a simpler stub when r2 is not saved. + (ppc64_elf_size_stubs): Leave stub_type as ppc_stub_plt_call for + optimized localentry:0 stubs. + (ppc64_elf_build_stubs): Save r2 in ELFv2 __glink_PLTresolve. + (ppc64_elf_relocate_section): Leave nop unchanged for optimized + localentry:0 stubs. + (ppc64_elf_finish_dynamic_sections): Set PPC64_OPT_LOCALENTRY in + DT_PPC64_OPT. + * elf64-ppc.h (struct ppc64_elf_params): Add plt_localentry0. + 2017-05-30 Casey Smith <clegg89@gmail.com> PR ld/21523 diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c index 948de12..42abb96 100644 --- a/bfd/elf64-ppc.c +++ b/bfd/elf64-ppc.c @@ -4118,6 +4118,9 @@ struct ppc_link_hash_table unsigned int local_ifunc_resolver:1; unsigned int maybe_local_ifunc_resolver:1; + /* Whether plt calls for ELFv2 localentry:0 funcs have been optimized. */ + unsigned int has_plt_localentry0:1; + /* Incremented every time we size stubs. */ unsigned int stub_iteration; @@ -5005,7 +5008,7 @@ ppc64_elf_merge_symbol_attribute (struct elf_link_hash_entry *h, bfd_boolean definition, bfd_boolean dynamic) { - if (definition && !dynamic) + if (definition && (!dynamic || !h->def_regular)) h->other = ((isym->st_other & ~ELF_ST_VISIBILITY (-1)) | ELF_ST_VISIBILITY (h->other)); } @@ -6318,6 +6321,21 @@ ppc64_elf_maybe_function_sym (const asymbol *sym, asection *sec, return size; } +/* Return true if symbol is a strong function defined in an ELFv2 + object with st_other localentry bits of zero, ie. its local entry + point coincides with its global entry point. */ + +static bfd_boolean +is_elfv2_localentry0 (struct elf_link_hash_entry *h) +{ + return (h != NULL + && h->type == STT_FUNC + && h->root.type == bfd_link_hash_defined + && (STO_PPC64_LOCAL_MASK & h->other) == 0 + && is_ppc64_elf (h->root.u.def.section->owner) + && abiversion (h->root.u.def.section->owner) >= 2); +} + /* Return true if symbol is defined in a regular object file. */ static bfd_boolean @@ -8328,6 +8346,11 @@ ppc64_elf_tls_setup (struct bfd_link_info *info) else if (!htab->do_multi_toc) htab->params->no_multi_toc = 1; + if (htab->params->plt_localentry0 < 0) + htab->params->plt_localentry0 + = elf_link_hash_lookup (&htab->elf, "GLIBC_2.26", + FALSE, FALSE, FALSE) != NULL; + htab->tls_get_addr = ((struct ppc_link_hash_entry *) elf_link_hash_lookup (&htab->elf, ".__tls_get_addr", FALSE, FALSE, TRUE)); @@ -10548,7 +10571,12 @@ plt_stub_size (struct ppc_link_hash_table *htab, && (stub_entry->h == htab->tls_get_addr_fd || stub_entry->h == htab->tls_get_addr) && htab->params->tls_get_addr_opt) - size += 13 * 4; + { + size += 7 * 4; + if (ALWAYS_EMIT_R2SAVE + || stub_entry->stub_type == ppc_stub_plt_call_r2save) + size += 6 * 4; + } return size; } @@ -10775,11 +10803,17 @@ build_tls_get_addr_stub (struct ppc_link_hash_table *htab, bfd_put_32 (obfd, ADD_R3_R12_R13, p), p += 4; bfd_put_32 (obfd, BEQLR, p), p += 4; bfd_put_32 (obfd, MR_R3_R0, p), p += 4; + if (r != NULL) + r[0].r_offset += 7 * 4; + if (!ALWAYS_EMIT_R2SAVE + && stub_entry->stub_type != ppc_stub_plt_call_r2save) + return build_plt_stub (htab, stub_entry, p, offset, r); + bfd_put_32 (obfd, MFLR_R11, p), p += 4; bfd_put_32 (obfd, STD_R11_0R1 + STK_LINKER (htab), p), p += 4; if (r != NULL) - r[0].r_offset += 9 * 4; + r[0].r_offset += 2 * 4; p = build_plt_stub (htab, stub_entry, p, offset, r); bfd_put_32 (obfd, BCTRL, p - 4); @@ -12598,17 +12632,23 @@ ppc64_elf_size_stubs (struct bfd_link_info *info) continue; } - if (stub_type == ppc_stub_plt_call - && irela + 1 < irelaend - && irela[1].r_offset == irela->r_offset + 4 - && ELF64_R_TYPE (irela[1].r_info) == R_PPC64_TOCSAVE) + if (stub_type == ppc_stub_plt_call) { - if (!tocsave_find (htab, INSERT, - &local_syms, irela + 1, input_bfd)) - goto error_ret_free_internal; + if (irela + 1 < irelaend + && irela[1].r_offset == irela->r_offset + 4 + && ELF64_R_TYPE (irela[1].r_info) == R_PPC64_TOCSAVE) + { + if (!tocsave_find (htab, INSERT, + &local_syms, irela + 1, input_bfd)) + goto error_ret_free_internal; + } + else if (!htab->opd_abi + && htab->params->plt_localentry0 != 0 + && is_elfv2_localentry0 (&hash->elf)) + htab->has_plt_localentry0 = 1; + else + stub_type = ppc_stub_plt_call_r2save; } - else if (stub_type == ppc_stub_plt_call) - stub_type = ppc_stub_plt_call_r2save; /* Support for grouping stub sections. */ id_sec = htab->sec_info[section->id].u.group->link_sec; @@ -13160,6 +13200,8 @@ ppc64_elf_build_stubs (struct bfd_link_info *info, p += 4; bfd_put_32 (htab->glink->owner, MFLR_R11, p); p += 4; + bfd_put_32 (htab->glink->owner, STD_R2_0R1 + 24, p); + p += 4; bfd_put_32 (htab->glink->owner, LD_R2_0R11 | (-16 & 0xfffc), p); p += 4; bfd_put_32 (htab->glink->owner, MTLR_R0, p); @@ -14170,7 +14212,7 @@ ppc64_elf_relocate_section (bfd *output_bfd, { bfd_boolean can_plt_call = FALSE; - /* All of these stubs will modify r2, so there must be a + /* All of these stubs may modify r2, so there must be a branch and link followed by a nop. The nop is replaced by an insn to restore r2. */ if (rel->r_offset + 8 <= input_section->size) @@ -14195,6 +14237,13 @@ ppc64_elf_relocate_section (bfd *output_bfd, { /* Special stub used, leave nop alone. */ } + else if (stub_entry->stub_type == ppc_stub_plt_call + && !htab->opd_abi + && htab->params->plt_localentry0 != 0 + && is_elfv2_localentry0 (&h->elf)) + { + /* The function doesn't use or change r2. */ + } else bfd_put_32 (input_bfd, LD_R2_0R1 + STK_TOC (htab), @@ -15636,6 +15685,8 @@ ppc64_elf_finish_dynamic_sections (bfd *output_bfd, case DT_PPC64_OPT: if (htab->do_multi_toc && htab->multi_toc_needed) dyn.d_un.d_val |= PPC64_OPT_MULTI_TOC; + if (htab->has_plt_localentry0) + dyn.d_un.d_val |= PPC64_OPT_LOCALENTRY; break; case DT_PPC64_OPDSZ: diff --git a/bfd/elf64-ppc.h b/bfd/elf64-ppc.h index 4609679..ca20fe4 100644 --- a/bfd/elf64-ppc.h +++ b/bfd/elf64-ppc.h @@ -48,6 +48,9 @@ struct ppc64_elf_params /* Set if individual PLT call stubs should be aligned. */ int plt_stub_align; + /* Set if PLT call stubs for localentry:0 functions should omit r2 save. */ + int plt_localentry0; + /* Whether to canonicalize .opd so that there are no overlapping .opd entries. */ int non_overlapping_opd; |