diff options
| author | Andreas Krebbel <Andreas.Krebbel@de.ibm.com> | 2012-07-13 15:47:27 +0000 |
|---|---|---|
| committer | Andreas Krebbel <Andreas.Krebbel@de.ibm.com> | 2012-07-13 15:47:27 +0000 |
| commit | 470b557aaf678bdadcd05a04e8fd312ba6d2f098 (patch) | |
| tree | e5cd03984d101b6c5a8d4c774cd7c73c4ca14b0a /bfd | |
| parent | 2c3fc38946973ec305b63248abdd170eda059f80 (diff) | |
| download | binutils-gdb-470b557aaf678bdadcd05a04e8fd312ba6d2f098.tar.gz | |
2012-07-13 Andreas Krebbel <Andreas.Krebbel@de.ibm.com>
* elf64-s390.c: Include elf-s390-common.c.
(R_390_IRELATIVE): New reloc.
(elf_s390_reloc_type_lookup): Support R_390_IRELATIVE.
(RELA_ENTRY_SIZE): New macro.
(elf_s390_link_hash_entry): New fields ifunc_resolver_address and
*ifunc_resolver_section.
(struct plt_entry): New struct.
(struct elf_s390_obj_tdata): New field local_plt.
(elf_s390_local_plt): New macro.
(struct elf_s390_link_hash_table): New field irelifunc.
(ELF64): New macro.
(link_hash_newfunc): Initialize new fields.
(elf_s390_check_relocs): Handle IFUNC symbols.
(elf_s390_adjust_dynamic_symbol): Don't do anything for IFUNC
symbols.
(allocate_dynrelocs): Call s390_elf_allocate_ifunc_dyn_relocs for
IFUNC symbols.
(elf_s390_size_dynamic_sections): Handle IFUNC symbols.
(elf_s390_relocate_section): Likewise.
(elf_s390_finish_dynamic_symbol): Likewise.
(elf_s390_finish_dynamic_sections): Handle local IFUNC symbols.
(elf_s390_finish_ifunc_symbol): New function.
(elf_s390_gc_sweep_hook): Handle local plt entries.
(elf_backend_add_symbol_hook): Define.
* elf32-s390.c: See elf64-s390.c changes.
* elf-s390-common.c: New file.
* bfd-in2.h (BFD_RELOC_390_IRELATIVE): New enum field.
* libbfd.h (BFD_RELOC_390_IRELATIVE): New entry for
BFD_RELOC_390_IRELATIVE.
* reloc.c (BFD_RELOC_390_IRELATIVE): Document new relocation.
2012-07-13 Andreas Krebbel <Andreas.Krebbel@de.ibm.com>
* elf/s390.h (START_RELOC_NUMBERS): Define R_390_IRELATIVE reloc.
2012-07-13 Andreas Krebbel <Andreas.Krebbel@de.ibm.com>
* emulparams/elf_s390.sh (IREL_IN_PLT): Define.
* emulparams/elf64_s390.sh (IREL_IN_PLT): Define.
Diffstat (limited to 'bfd')
| -rw-r--r-- | bfd/ChangeLog | 33 | ||||
| -rw-r--r-- | bfd/bfd-in2.h | 1 | ||||
| -rw-r--r-- | bfd/elf-s390-common.c | 243 | ||||
| -rw-r--r-- | bfd/elf32-s390.c | 827 | ||||
| -rw-r--r-- | bfd/elf64-s390.c | 671 | ||||
| -rw-r--r-- | bfd/libbfd.h | 1 | ||||
| -rw-r--r-- | bfd/reloc.c | 5 |
7 files changed, 1503 insertions, 278 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 81da9442696..da9e6a2e86e 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,36 @@ +2012-07-13 Andreas Krebbel <Andreas.Krebbel@de.ibm.com> + + * elf64-s390.c: Include elf-s390-common.c. + (R_390_IRELATIVE): New reloc. + (elf_s390_reloc_type_lookup): Support R_390_IRELATIVE. + (RELA_ENTRY_SIZE): New macro. + (elf_s390_link_hash_entry): New fields ifunc_resolver_address and + *ifunc_resolver_section. + (struct plt_entry): New struct. + (struct elf_s390_obj_tdata): New field local_plt. + (elf_s390_local_plt): New macro. + (struct elf_s390_link_hash_table): New field irelifunc. + (ELF64): New macro. + (link_hash_newfunc): Initialize new fields. + (elf_s390_check_relocs): Handle IFUNC symbols. + (elf_s390_adjust_dynamic_symbol): Don't do anything for IFUNC + symbols. + (allocate_dynrelocs): Call s390_elf_allocate_ifunc_dyn_relocs for + IFUNC symbols. + (elf_s390_size_dynamic_sections): Handle IFUNC symbols. + (elf_s390_relocate_section): Likewise. + (elf_s390_finish_dynamic_symbol): Likewise. + (elf_s390_finish_dynamic_sections): Handle local IFUNC symbols. + (elf_s390_finish_ifunc_symbol): New function. + (elf_s390_gc_sweep_hook): Handle local plt entries. + (elf_backend_add_symbol_hook): Define. + * elf32-s390.c: See elf64-s390.c changes. + * elf-s390-common.c: New file. + * bfd-in2.h (BFD_RELOC_390_IRELATIVE): New enum field. + * libbfd.h (BFD_RELOC_390_IRELATIVE): New entry for + BFD_RELOC_390_IRELATIVE. + * reloc.c (BFD_RELOC_390_IRELATIVE): Document new relocation. + 2012-07-13 Nick Clifton <nickc@redhat.com> * aix386-core.c: Remove use of PTR and PARAMS macros. diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h index 11f3e497811..c1c5e90a37b 100644 --- a/bfd/bfd-in2.h +++ b/bfd/bfd-in2.h @@ -4293,6 +4293,7 @@ in .byte hlo8(symbol) */ BFD_RELOC_390_GOT20, BFD_RELOC_390_GOTPLT20, BFD_RELOC_390_TLS_GOTIE20, + BFD_RELOC_390_IRELATIVE, /* Score relocations Low 16 bit for load/store */ diff --git a/bfd/elf-s390-common.c b/bfd/elf-s390-common.c new file mode 100644 index 00000000000..691f7511df3 --- /dev/null +++ b/bfd/elf-s390-common.c @@ -0,0 +1,243 @@ +/* IBM S/390-specific support for ELF 32 and 64 bit functions + Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, + 2011, 2012 Free Software Foundation, Inc. + Contributed by Andreas Krebbel. + + 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; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA + 02110-1301, USA. */ + + +/* Return TRUE if H is an IFUNC symbol. Simply checking for the + symbol type might not be enough since it might get changed to + STT_FUNC for pointer equality reasons. */ +static inline bfd_boolean +s390_is_ifunc_symbol_p (struct elf_link_hash_entry *h) +{ + struct elf_s390_link_hash_entry *eh = (struct elf_s390_link_hash_entry*)h; + return h->type == STT_GNU_IFUNC || eh->ifunc_resolver_address != 0; +} + +/* Create sections needed by STT_GNU_IFUNC symbol. */ + +static bfd_boolean +s390_elf_create_ifunc_sections (bfd *abfd, struct bfd_link_info *info) +{ + flagword flags; + asection *s; + const struct elf_backend_data *bed = get_elf_backend_data (abfd); + struct elf_link_hash_table *htab = elf_hash_table (info); + + if (htab->iplt != NULL) + return TRUE; + + flags = bed->dynamic_sec_flags; + + if (info->shared) + { + s = bfd_make_section_with_flags (abfd, ".rela.ifunc", + flags | SEC_READONLY); + if (s == NULL + || ! bfd_set_section_alignment (abfd, s, + bed->s->log_file_align)) + return FALSE; + htab->irelifunc = s; + } + + /* Create .iplt, .rel[a].iplt, and .igot.plt. */ + s = bfd_make_section_with_flags (abfd, ".iplt", + flags | SEC_CODE | SEC_READONLY); + if (s == NULL + || ! bfd_set_section_alignment (abfd, s, bed->plt_alignment)) + return FALSE; + htab->iplt = s; + + s = bfd_make_section_with_flags (abfd, ".rela.iplt", flags | SEC_READONLY); + if (s == NULL + || ! bfd_set_section_alignment (abfd, s, + bed->s->log_file_align)) + return FALSE; + htab->irelplt = s; + + s = bfd_make_section_with_flags (abfd, ".igot.plt", flags); + if (s == NULL + || !bfd_set_section_alignment (abfd, s, + bed->s->log_file_align)) + return FALSE; + htab->igotplt = s; + + return TRUE; +} + + +/* Allocate space in .plt, .got and associated reloc sections for + dynamic relocs against a STT_GNU_IFUNC symbol definition. */ + +static bfd_boolean +s390_elf_allocate_ifunc_dyn_relocs (struct bfd_link_info *info, + struct elf_link_hash_entry *h, + struct elf_dyn_relocs **head) +{ + struct elf_dyn_relocs *p; + struct elf_link_hash_table *htab; + struct elf_s390_link_hash_entry *eh = (struct elf_s390_link_hash_entry*)h; + + htab = elf_hash_table (info); + eh->ifunc_resolver_address = h->root.u.def.value; + eh->ifunc_resolver_section = h->root.u.def.section; + + /* Support garbage collection against STT_GNU_IFUNC symbols. */ + if (h->plt.refcount <= 0 && h->got.refcount <= 0) + { + /* When building shared library, we need to handle the case + where it is marked with regular reference, but not non-GOT + reference. It may happen if we didn't see STT_GNU_IFUNC + symbol at the time when checking relocations. */ + if (info->shared + && !h->non_got_ref + && h->ref_regular) + for (p = *head; p != NULL; p = p->next) + if (p->count) + { + h->non_got_ref = 1; + goto keep; + } + + h->got = htab->init_got_offset; + h->plt = htab->init_plt_offset; + *head = NULL; + return TRUE; + } + + /* Return and discard space for dynamic relocations against it if + it is never referenced in a non-shared object. */ + if (!h->ref_regular) + { + if (h->plt.refcount > 0 + || h->got.refcount > 0) + abort (); + h->got = htab->init_got_offset; + h->plt = htab->init_plt_offset; + *head = NULL; + return TRUE; + } + +keep: + /* Without checking h->plt.refcount here we allocate a PLT slot. + When setting plt.refcount in check_relocs it might not have been + known that this will be an IFUNC symol. */ + h->plt.offset = htab->iplt->size; + h->needs_plt = 1; + htab->iplt->size += PLT_ENTRY_SIZE; + htab->igotplt->size += GOT_ENTRY_SIZE; + htab->irelplt->size += RELA_ENTRY_SIZE; + htab->irelplt->reloc_count++; + + /* In order to make pointer equality work with IFUNC symbols defined + in a non-PIE executable and referenced in a shared lib, we turn + the symbol into a STT_FUNC symbol and make the symbol value to + point to the IPLT slot. That way the referencing shared lib will + always get the PLT slot address when resolving the respective + R_390_GLOB_DAT/R_390_64 relocs on that symbol. */ + if (info->executable && !info->shared && h->def_regular && h->ref_dynamic) + { + h->root.u.def.section = htab->iplt; + h->root.u.def.value = h->plt.offset; + h->size = PLT_ENTRY_SIZE; + h->type = STT_FUNC; + } + + /* We need dynamic relocation for STT_GNU_IFUNC symbol only when + there is a non-GOT reference in a shared object. */ + if (!info->shared || !h->non_got_ref) + *head = NULL; + + /* Finally, allocate space. */ + p = *head; + if (p != NULL) + { + bfd_size_type count = 0; + do + { + count += p->count; + p = p->next; + } + while (p != NULL); + htab->irelifunc->size += count * RELA_ENTRY_SIZE; + } + + /* Decide whether the got.iplt slot can be used. This has to be + avoided if the values in the GOT slots could differ for pointer + equality reasons. */ + if (h->got.refcount <= 0 + || (info->shared + && (h->dynindx == -1 || h->forced_local)) + || (info->executable && info->shared) + || htab->sgot == NULL) + { + /* Use .got.iplt. */ + h->got.offset = (bfd_vma) -1; + } + else + { + h->got.offset = htab->sgot->size; + htab->sgot->size += GOT_ENTRY_SIZE; + if (info->shared) + htab->srelgot->size += RELA_ENTRY_SIZE; + } + + return TRUE; +} + +static bfd_boolean +elf_s390_allocate_local_syminfo (bfd *abfd, Elf_Internal_Shdr *symtab_hdr) +{ + bfd_size_type size; + + size = symtab_hdr->sh_info; + size *= (sizeof (bfd_signed_vma) /* local got */ + + sizeof (struct plt_entry) /* local plt */ + + sizeof(char)); /* local tls type */ + elf_local_got_refcounts (abfd) = ((bfd_signed_vma *) + bfd_zalloc (abfd, size)); + if (elf_local_got_refcounts (abfd) == NULL) + return FALSE; + elf_s390_local_plt (abfd) + = (struct plt_entry*)(elf_local_got_refcounts (abfd) + + symtab_hdr->sh_info); + elf_s390_local_got_tls_type (abfd) + = (char *) (elf_s390_local_plt (abfd) + symtab_hdr->sh_info); + + return TRUE; +} + +/* Pick ELFOSABI_GNU if IFUNC symbols are used. */ + +static bfd_boolean +elf_s390_add_symbol_hook (bfd *abfd, + struct bfd_link_info *info, + Elf_Internal_Sym *sym, + const char **namep ATTRIBUTE_UNUSED, + flagword *flagsp ATTRIBUTE_UNUSED, + asection **secp ATTRIBUTE_UNUSED, + bfd_vma *valp ATTRIBUTE_UNUSED) +{ + if ((abfd->flags & DYNAMIC) == 0 + && ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC) + elf_tdata (info->output_bfd)->has_gnu_symbols = TRUE; + + return TRUE; +} diff --git a/bfd/elf32-s390.c b/bfd/elf32-s390.c index cbf768df421..8d654d54867 100644 --- a/bfd/elf32-s390.c +++ b/bfd/elf32-s390.c @@ -159,6 +159,8 @@ static reloc_howto_type elf_howto_table[] = s390_elf_ldisp_reloc, "R_390_GOTPLT20", FALSE, 0,0x0fffff00, FALSE), HOWTO(R_390_TLS_GOTIE20, 0, 2, 20, FALSE, 8, complain_overflow_dont, s390_elf_ldisp_reloc, "R_390_TLS_GOTIE20", FALSE, 0,0x0fffff00, FALSE), + HOWTO(R_390_IRELATIVE, 0, 2, 32, TRUE, 0, complain_overflow_bitfield, + bfd_elf_generic_reloc, "R_390_IRELATIVE", FALSE, 0, 0xffffffff, FALSE), }; /* GNU extension to record C++ vtable hierarchy. */ @@ -271,6 +273,8 @@ elf_s390_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED, return &elf_howto_table[(int) R_390_GOTPLT20]; case BFD_RELOC_390_TLS_GOTIE20: return &elf_howto_table[(int) R_390_TLS_GOTIE20]; + case BFD_RELOC_390_IRELATIVE: + return &elf_howto_table[(int) R_390_IRELATIVE]; case BFD_RELOC_VTABLE_INHERIT: return &elf32_s390_vtinherit_howto; case BFD_RELOC_VTABLE_ENTRY: @@ -425,6 +429,8 @@ elf_s390_is_local_label_name (bfd *abfd, const char *name) #define GOT_ENTRY_SIZE 4 +#define RELA_ENTRY_SIZE sizeof (Elf32_External_Rela) + /* The first three entries in a procedure linkage table are reserved, and the initial contents are unimportant (we zero them out). Subsequent entries look like this. See the SVR4 ABI 386 @@ -639,17 +645,43 @@ struct elf_s390_link_hash_entry #define GOT_TLS_IE 3 #define GOT_TLS_IE_NLT 4 unsigned char tls_type; + + /* For pointer equality reasons we might need to change the symbol + type from STT_GNU_IFUNC to STT_FUNC together with its value and + section entry. So after alloc_dynrelocs only these values should + be used. In order to check whether a symbol is IFUNC use + s390_is_ifunc_symbol_p. */ + bfd_vma ifunc_resolver_address; + asection *ifunc_resolver_section; }; #define elf_s390_hash_entry(ent) \ ((struct elf_s390_link_hash_entry *)(ent)) +/* This structure represents an entry in the local PLT list needed for + local IFUNC symbols. */ +struct plt_entry +{ + /* The section of the local symbol. + Set in relocate_section and used in finish_dynamic_sections. */ + asection *sec; + + union + { + bfd_signed_vma refcount; + bfd_vma offset; + } plt; +}; + /* NOTE: Keep this structure in sync with the one declared in elf64-s390.c. */ struct elf_s390_obj_tdata { struct elf_obj_tdata root; + /* A local PLT is needed for ifunc symbols. */ + struct plt_entry *local_plt; + /* TLS type for each local got entry. */ char *local_got_tls_type; }; @@ -657,6 +689,9 @@ struct elf_s390_obj_tdata #define elf_s390_tdata(abfd) \ ((struct elf_s390_obj_tdata *) (abfd)->tdata.any) +#define elf_s390_local_plt(abfd) \ + (elf_s390_tdata (abfd)->local_plt) + #define elf_s390_local_got_tls_type(abfd) \ (elf_s390_tdata (abfd)->local_got_tls_type) @@ -688,6 +723,7 @@ struct elf_s390_link_hash_table /* Short-cuts to get to dynamic linker sections. */ asection *sdynbss; asection *srelbss; + asection *irelifunc; union { @@ -705,6 +741,9 @@ struct elf_s390_link_hash_table (elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \ == S390_ELF_DATA ? ((struct elf_s390_link_hash_table *) ((p)->hash)) : NULL) +#undef ELF64 +#include "elf-s390-common.c" + /* Create an entry in an s390 ELF linker hash table. */ static struct bfd_hash_entry * @@ -732,6 +771,8 @@ link_hash_newfunc (struct bfd_hash_entry *entry, eh->dyn_relocs = NULL; eh->gotplt_refcount = 0; eh->tls_type = GOT_UNKNOWN; + eh->ifunc_resolver_address = 0; + eh->ifunc_resolver_section = NULL; } return entry; @@ -930,6 +971,7 @@ elf_s390_check_relocs (bfd *abfd, asection *sreloc; bfd_signed_vma *local_got_refcounts; int tls_type, old_tls_type; + Elf_Internal_Sym *isym; if (info->relocatable) return TRUE; @@ -960,7 +1002,31 @@ elf_s390_check_relocs (bfd *abfd, } if (r_symndx < symtab_hdr->sh_info) - h = NULL; + { + /* A local symbol. */ + isym = bfd_sym_from_r_symndx (&htab->sym_cache, + abfd, r_symndx); + if (isym == NULL) + return FALSE; + + if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) + { + struct plt_entry *plt; + + if (!s390_elf_create_ifunc_sections (htab->elf.dynobj, info)) + return FALSE; + + if (local_got_refcounts == NULL) + { + if (!elf_s390_allocate_local_syminfo (abfd, symtab_hdr)) + return FALSE; + local_got_refcounts = elf_local_got_refcounts (abfd); + } + plt = elf_s390_local_plt (abfd); + plt[r_symndx].plt.refcount++; + } + h = NULL; + } else { h = sym_hashes[r_symndx - symtab_hdr->sh_info]; @@ -996,17 +1062,9 @@ elf_s390_check_relocs (bfd *abfd, if (h == NULL && local_got_refcounts == NULL) { - bfd_size_type size; - - size = symtab_hdr->sh_info; - size *= (sizeof (bfd_signed_vma) + sizeof(char)); - local_got_refcounts = ((bfd_signed_vma *) - bfd_zalloc (abfd, size)); - if (local_got_refcounts == NULL) + if (!elf_s390_allocate_local_syminfo (abfd, symtab_hdr)) return FALSE; - elf_local_got_refcounts (abfd) = local_got_refcounts; - elf_s390_local_got_tls_type (abfd) - = (char *) (local_got_refcounts + symtab_hdr->sh_info); + local_got_refcounts = elf_local_got_refcounts (abfd); } /* Fall through. */ case R_390_GOTOFF16: @@ -1022,13 +1080,34 @@ elf_s390_check_relocs (bfd *abfd, } } + if (h != NULL) + { + if (htab->elf.dynobj == NULL) + htab->elf.dynobj = abfd; + if (!s390_elf_create_ifunc_sections (htab->elf.dynobj, info)) + return FALSE; + + /* Make sure an IFUNC symbol defined in a non-shared object + always gets a PLT slot. */ + if (s390_is_ifunc_symbol_p (h) && h->def_regular) + { + /* The symbol is called by the dynamic loader in order + to resolve the relocation. So it is in fact also + referenced. */ + h->ref_regular = 1; + h->needs_plt = 1; + } + } switch (r_type) { case R_390_GOTOFF16: case R_390_GOTOFF32: case R_390_GOTPC: case R_390_GOTPCDBL: - /* Got is created, nothing to be done. */ + /* These relocs do not need a GOT slot. They just load the + GOT pointer itself or address something else relative to + the GOT. Since the GOT pointer has been set up above we + are done. */ break; case R_390_PLT16DBL: @@ -1169,7 +1248,7 @@ elf_s390_check_relocs (bfd *abfd, case R_390_PC16DBL: case R_390_PC32DBL: case R_390_PC32: - if (h != NULL && !info->shared) + if (h != NULL) { /* If this reloc is in a read-only section, we might need a copy reloc. We can't check reliably at this @@ -1179,9 +1258,12 @@ elf_s390_check_relocs (bfd *abfd, adjust_dynamic_symbol. */ h->non_got_ref = 1; - /* We may need a .plt entry if the function this reloc - refers to is in a shared lib. */ - h->plt.refcount += 1; + if (!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 @@ -1253,7 +1335,6 @@ elf_s390_check_relocs (bfd *abfd, easily. Oh well. */ asection *s; void *vpp; - Elf_Internal_Sym *isym; isym = bfd_sym_from_r_symndx (&htab->sym_cache, abfd, r_symndx); @@ -1346,6 +1427,7 @@ elf_s390_gc_sweep_hook (bfd *abfd, asection *sec, const Elf_Internal_Rela *relocs) { + struct elf_s390_link_hash_table *htab; Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; bfd_signed_vma *local_got_refcounts; @@ -1354,6 +1436,10 @@ elf_s390_gc_sweep_hook (bfd *abfd, if (info->relocatable) return TRUE; + htab = elf_s390_hash_table (info); + if (htab == NULL) + return FALSE; + elf_section_data (sec)->local_dynrel = NULL; symtab_hdr = &elf_symtab_hdr (abfd); @@ -1388,6 +1474,23 @@ elf_s390_gc_sweep_hook (bfd *abfd, break; } } + else + { + Elf_Internal_Sym *isym; + + /* A local symbol. */ + isym = bfd_sym_from_r_symndx (&htab->sym_cache, + abfd, r_symndx); + if (isym == NULL) + return FALSE; + + if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) + { + struct plt_entry *plt = elf_s390_local_plt (abfd); + if (plt[r_symndx].plt.refcount > 0) + plt[r_symndx].plt.refcount--; + } + } r_type = ELF32_R_TYPE (rel->r_info); r_type = elf_s390_tls_transition (info, r_type, h != NULL); @@ -1513,6 +1616,10 @@ elf_s390_adjust_dynamic_symbol (struct bfd_link_info *info, struct elf_s390_link_hash_table *htab; asection *s; + /* STT_GNU_IFUNC symbol must go through PLT. */ + if (s390_is_ifunc_symbol_p (h)) + return TRUE; + /* 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). */ @@ -1636,7 +1743,7 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) { struct bfd_link_info *info; struct elf_s390_link_hash_table *htab; - struct elf_s390_link_hash_entry *eh; + struct elf_s390_link_hash_entry *eh = (struct elf_s390_link_hash_entry *)h; struct elf_dyn_relocs *p; if (h->root.type == bfd_link_hash_indirect) @@ -1645,8 +1752,13 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) info = (struct bfd_link_info *) inf; htab = elf_s390_hash_table (info); - if (htab->elf.dynamic_sections_created - && h->plt.refcount > 0) + /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it + here if it is defined and referenced in a non-shared object. */ + if (s390_is_ifunc_symbol_p (h) && h->def_regular) + return s390_elf_allocate_ifunc_dyn_relocs (info, h, + &eh->dyn_relocs); + else if (htab->elf.dynamic_sections_created + && h->plt.refcount > 0) { /* Make sure this symbol is output as a dynamic symbol. Undefined weak syms won't yet be marked as dynamic. */ @@ -1763,7 +1875,6 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) else h->got.offset = (bfd_vma) -1; - eh = (struct elf_s390_link_hash_entry *) h; if (eh->dyn_relocs == NULL) return TRUE; @@ -1918,6 +2029,8 @@ elf_s390_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, bfd_size_type locsymcount; Elf_Internal_Shdr *symtab_hdr; asection *srela; + struct plt_entry *local_plt; + unsigned int i; if (! is_s390_elf (ibfd)) continue; @@ -1970,6 +2083,19 @@ elf_s390_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, else *local_got = (bfd_vma) -1; } + local_plt = elf_s390_local_plt (ibfd); + for (i = 0; i < symtab_hdr->sh_info; i++) + { + if (local_plt[i].plt.refcount > 0) + { + local_plt[i].plt.offset = htab->elf.iplt->size; + htab->elf.iplt->size += PLT_ENTRY_SIZE; + htab->elf.igotplt->size += GOT_ENTRY_SIZE; + htab->elf.irelplt->size += RELA_ENTRY_SIZE; + } + else + local_plt[i].plt.offset = (bfd_vma) -1; + } } if (htab->tls_ldm_got.refcount > 0) @@ -1998,7 +2124,10 @@ elf_s390_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, if (s == htab->elf.splt || s == htab->elf.sgot || s == htab->elf.sgotplt - || s == htab->sdynbss) + || s == htab->sdynbss + || s == htab->elf.iplt + || s == htab->elf.igotplt + || s == htab->irelifunc) { /* Strip this section if we don't need it; see the comment below. */ @@ -2184,6 +2313,7 @@ elf_s390_relocate_section (bfd *output_bfd, bfd_boolean unresolved_reloc; bfd_reloc_status_type r; int tls_type; + asection *base_got = htab->elf.sgot; r_type = ELF32_R_TYPE (rel->r_info); if (r_type == (int) R_390_GNU_VTINHERIT @@ -2206,7 +2336,52 @@ elf_s390_relocate_section (bfd *output_bfd, { sym = local_syms + r_symndx; sec = local_sections[r_symndx]; - relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel); + if (ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC) + { + struct plt_entry *local_plt = elf_s390_local_plt (input_bfd); + if (local_plt == NULL) + return FALSE; + + /* Address of the PLT slot. */ + relocation = (htab->elf.iplt->output_section->vma + + htab->elf.iplt->output_offset + + local_plt[r_symndx].plt.offset); + + switch (r_type) + { + case R_390_GOTPLT12: + case R_390_GOTPLT16: + case R_390_GOTPLT20: + case R_390_GOTPLT32: + case R_390_GOTPLTENT: + case R_390_GOT12: + case R_390_GOT16: + case R_390_GOT20: + case R_390_GOT32: + case R_390_GOTENT: + { + /* Write the PLT slot address into the GOT slot. */ + bfd_put_32 (output_bfd, relocation, + htab->elf.sgot->contents + + local_got_offsets[r_symndx]); + relocation = (local_got_offsets[r_symndx] + + htab->elf.sgot->output_offset); + + if (r_type == R_390_GOTENT || r_type == R_390_GOTPLTENT) + relocation += htab->elf.sgot->output_section->vma; + break; + } + default: + break; + } + /* The output section is needed later in + finish_dynamic_section when creating the dynamic + relocation. */ + local_plt[r_symndx].sec = sec; + goto do_relocation; + } + else + relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel); } else { @@ -2245,19 +2420,29 @@ elf_s390_relocate_section (bfd *output_bfd, { bfd_vma plt_index; - /* Calc. index no. - Current offset - size first entry / entry size. */ - plt_index = (h->plt.offset - PLT_FIRST_ENTRY_SIZE) / - PLT_ENTRY_SIZE; - - /* Offset in GOT is PLT index plus GOT headers(3) times 4, - addr & GOT addr. */ - relocation = (plt_index + 3) * GOT_ENTRY_SIZE; + if (s390_is_ifunc_symbol_p (h)) + { + plt_index = h->plt.offset / PLT_ENTRY_SIZE; + relocation = (plt_index * GOT_ENTRY_SIZE + + htab->elf.igotplt->output_offset); + if (r_type == R_390_GOTPLTENT) + relocation += htab->elf.igotplt->output_section->vma; + } + else + { + /* Calc. index no. + Current offset - size first entry / entry size. */ + plt_index = (h->plt.offset - PLT_FIRST_ENTRY_SIZE) / + PLT_ENTRY_SIZE; + + /* Offset in GOT is PLT index plus GOT headers(3) + times 4, addr & GOT addr. */ + relocation = (plt_index + 3) * GOT_ENTRY_SIZE; + if (r_type == R_390_GOTPLTENT) + relocation += htab->elf.sgot->output_section->vma; + } unresolved_reloc = FALSE; - if (r_type == R_390_GOTPLTENT) - relocation += htab->elf.sgot->output_section->vma; - break; } /* Fall through. */ @@ -2268,7 +2453,7 @@ elf_s390_relocate_section (bfd *output_bfd, case R_390_GOTENT: /* Relocation is to the entry for this symbol in the global offset table. */ - if (htab->elf.sgot == NULL) + if (base_got == NULL) abort (); if (h != NULL) @@ -2277,11 +2462,30 @@ elf_s390_relocate_section (bfd *output_bfd, off = h->got.offset; dyn = htab->elf.dynamic_sections_created; - if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h) - || (info->shared - && SYMBOL_REFERENCES_LOCAL (info, h)) - || (ELF_ST_VISIBILITY (h->other) - && h->root.type == bfd_link_hash_undefweak)) + + if (s390_is_ifunc_symbol_p (h)) + { + BFD_ASSERT (h->plt.offset != (bfd_vma) -1); + if (off == (bfd_vma)-1) + { + /* No explicit GOT usage so redirect to the + got.iplt slot. */ + base_got = htab->elf.igotplt; + off = h->plt.offset / PLT_ENTRY_SIZE * GOT_ENTRY_SIZE; + } + else + { + /* Explicit GOT slots must contain the address + of the PLT slot. This will be handled in + finish_dynamic_symbol. */ + } + } + else if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h) + || (info->shared + && SYMBOL_REFERENCES_LOCAL (info, h)) + || (ELF_ST_VISIBILITY (h->other) + && h->root.type == bfd_link_hash_undefweak)) + { /* This is actually a static link, or it is a -Bsymbolic link and the symbol is defined @@ -2300,7 +2504,7 @@ elf_s390_relocate_section (bfd *output_bfd, else { bfd_put_32 (output_bfd, relocation, - htab->elf.sgot->contents + off); + base_got->contents + off); h->got.offset |= 1; } } @@ -2351,7 +2555,7 @@ elf_s390_relocate_section (bfd *output_bfd, if (off >= (bfd_vma) -2) abort (); - relocation = htab->elf.sgot->output_offset + off; + relocation = base_got->output_offset + off; /* For @GOTENT the relocation is against the offset between the instruction and the symbols entry in the GOT and not @@ -2359,7 +2563,7 @@ elf_s390_relocate_section (bfd *output_bfd, add the vma of the GOT to get the correct value. */ if ( r_type == R_390_GOTENT || r_type == R_390_GOTPLTENT) - relocation += htab->elf.sgot->output_section->vma; + relocation += base_got->output_section->vma; break; @@ -2395,7 +2599,7 @@ elf_s390_relocate_section (bfd *output_bfd, break; if (h->plt.offset == (bfd_vma) -1 - || htab->elf.splt == NULL) + || (htab->elf.splt == NULL && htab->elf.iplt == NULL)) { /* We didn't make a PLT entry for this symbol. This happens when statically linking PIC code, or when @@ -2403,9 +2607,14 @@ elf_s390_relocate_section (bfd *output_bfd, break; } - relocation = (htab->elf.splt->output_section->vma - + htab->elf.splt->output_offset - + h->plt.offset); + if (s390_is_ifunc_symbol_p (h)) + relocation = (htab->elf.iplt->output_section->vma + + htab->elf.iplt->output_offset + + h->plt.offset); + else + relocation = (htab->elf.splt->output_section->vma + + htab->elf.splt->output_offset + + h->plt.offset); unresolved_reloc = FALSE; break; @@ -2424,10 +2633,16 @@ elf_s390_relocate_section (bfd *output_bfd, break; } - relocation = (htab->elf.splt->output_section->vma - + htab->elf.splt->output_offset - + h->plt.offset - - htab->elf.sgot->output_section->vma); + if (s390_is_ifunc_symbol_p (h)) + relocation = (htab->elf.iplt->output_section->vma + + htab->elf.iplt->output_offset + + h->plt.offset + - htab->elf.sgot->output_section->vma); + else + relocation = (htab->elf.splt->output_section->vma + + htab->elf.splt->output_offset + + h->plt.offset + - htab->elf.sgot->output_section->vma); unresolved_reloc = FALSE; break; @@ -2438,6 +2653,67 @@ elf_s390_relocate_section (bfd *output_bfd, case R_390_PC16DBL: case R_390_PC32DBL: case R_390_PC32: + if (h != NULL + && s390_is_ifunc_symbol_p (h) + && h->def_regular) + { + if (!info->shared || !h->non_got_ref) + { + /* For a non-shared object STT_GNU_IFUNC symbol must + go through PLT. */ + relocation = (htab->elf.iplt->output_section->vma + + htab->elf.iplt->output_offset + + h ->plt.offset); + goto do_relocation; + } + else + { + /* For shared objects a runtime relocation is needed. */ + + Elf_Internal_Rela outrel; + asection *sreloc; + + /* Need a dynamic relocation to get the real function + address. */ + outrel.r_offset = _bfd_elf_section_offset (output_bfd, + info, + input_section, + rel->r_offset); + if (outrel.r_offset == (bfd_vma) -1 + || outrel.r_offset == (bfd_vma) -2) + abort (); + + outrel.r_offset += (input_section->output_section->vma + + input_section->output_offset); + + if (h->dynindx == -1 + || h->forced_local + || info->executable) + { + /* This symbol is resolved locally. */ + outrel.r_info = ELF32_R_INFO (0, R_390_IRELATIVE); + outrel.r_addend = (h->root.u.def.value + + h->root.u.def.section->output_section->vma + + h->root.u.def.section->output_offset); + } + else + { + outrel.r_info = ELF32_R_INFO (h->dynindx, r_type); + outrel.r_addend = 0; + } + + sreloc = htab->elf.irelifunc; + elf_append_rela (output_bfd, sreloc, &outrel); + + /* If this reloc is against an external symbol, we + do not want to fiddle with the addend. Otherwise, + we need to include the symbol value so that it + becomes an addend for the dynamic reloc. For an + internal symbol, we have updated addend. */ + continue; + } + } + if ((input_section->flags & SEC_ALLOC) == 0) break; @@ -2963,6 +3239,8 @@ elf_s390_relocate_section (bfd *output_bfd, howto->name, h->root.root.string); + do_relocation: + if (r_type == R_390_20 || r_type == R_390_GOT20 || r_type == R_390_GOTPLT20 @@ -3019,6 +3297,152 @@ elf_s390_relocate_section (bfd *output_bfd, return TRUE; } +/* Generate the PLT slots together with the dynamic relocations needed + for IFUNC symbols. */ + +static void +elf_s390_finish_ifunc_symbol (bfd *output_bfd, + struct bfd_link_info *info, + struct elf_link_hash_entry *h, + struct elf_s390_link_hash_table *htab, + bfd_vma iplt_offset, + bfd_vma resolver_address) +{ + bfd_vma iplt_index; + bfd_vma got_offset; + bfd_vma igotiplt_offset; + Elf_Internal_Rela rela; + bfd_byte *loc; + asection *plt, *gotplt, *relplt; + bfd_vma relative_offset; + + if (htab->elf.iplt == NULL + || htab->elf.igotplt == NULL + || htab->elf.irelplt == NULL) + abort (); + + gotplt = htab->elf.igotplt; + relplt = htab->elf.irelplt; + + /* Index of the PLT slot within iplt section. */ + iplt_index = iplt_offset / PLT_ENTRY_SIZE; + plt = htab->elf.iplt; + /* Offset into the igot.plt section. */ + igotiplt_offset = iplt_index * GOT_ENTRY_SIZE; + /* Offset into the got section. */ + got_offset = igotiplt_offset + gotplt->output_offset; + + /* S390 uses halfwords for relative branch calc! */ + relative_offset = - (plt->output_offset + + (PLT_ENTRY_SIZE * iplt_index) + 18) / 2; +/* If offset is > 32768, branch to a previous branch + 390 can only handle +-64 K jumps. */ + if ( -32768 > (int) relative_offset ) + relative_offset + = -(unsigned) (((65536 / PLT_ENTRY_SIZE - 1) * PLT_ENTRY_SIZE) / 2); + + /* Fill in the entry in the procedure linkage table. */ + if (!info->shared) + { + memcpy (plt->contents + iplt_offset, elf_s390_plt_entry, + PLT_ENTRY_SIZE); + + /* Adjust jump to the first plt entry. */ + bfd_put_32 (output_bfd, (bfd_vma) 0+(relative_offset << 16), + plt->contents + iplt_offset + 20); + + /* Push the GOT offset field. */ + bfd_put_32 (output_bfd, + (gotplt->output_section->vma + + got_offset), + plt->contents + iplt_offset + 24); + } + else if (got_offset < 4096) + { + /* The GOT offset is small enough to be used directly as + displacement. */ + memcpy (plt->contents + iplt_offset, + elf_s390_plt_pic12_entry, + PLT_ENTRY_SIZE); + + /* Put in the GOT offset as displacement value. The 0xc000 + value comes from the first word of the plt entry. Look + at the elf_s390_plt_pic16_entry content. */ + bfd_put_16 (output_bfd, (bfd_vma)0xc000 | got_offset, + plt->contents + iplt_offset + 2); + + /* Adjust the jump to the first plt entry. */ + bfd_put_32 (output_bfd, (bfd_vma) 0+(relative_offset << 16), + plt->contents + iplt_offset + 20); + } + else if (got_offset < 32768) + { + /* The GOT offset is too big for a displacement but small + enough to be a signed 16 bit immediate value as it can be + used in an lhi instruction. */ + memcpy (plt->contents + iplt_offset, + elf_s390_plt_pic16_entry, + PLT_ENTRY_SIZE); + + /* Put in the GOT offset for the lhi instruction. */ + bfd_put_16 (output_bfd, (bfd_vma)got_offset, + plt->contents + iplt_offset + 2); + + /* Adjust the jump to the first plt entry. */ + bfd_put_32 (output_bfd, (bfd_vma) 0+(relative_offset << 16), + plt->contents + iplt_offset + 20); + } + else + { + memcpy (plt->contents + iplt_offset, + elf_s390_plt_pic_entry, + PLT_ENTRY_SIZE); + + /* Adjust the jump to the first plt entry. */ + bfd_put_32 (output_bfd, (bfd_vma) 0+(relative_offset << 16), + plt->contents + iplt_offset + 20); + + /* Push the GOT offset field. */ + bfd_put_32 (output_bfd, got_offset, + plt->contents + iplt_offset + 24); + } + /* Insert offset into reloc. table here. */ + bfd_put_32 (output_bfd, relplt->output_offset + + iplt_index * RELA_ENTRY_SIZE, + plt->contents + iplt_offset + 28); + + /* Fill in the entry in the global offset table. + Points to instruction after GOT offset. */ + bfd_put_32 (output_bfd, + (plt->output_section->vma + + plt->output_offset + + iplt_offset + + 12), + gotplt->contents + igotiplt_offset); + + /* Fill in the entry in the .rela.plt section. */ + rela.r_offset = gotplt->output_section->vma + got_offset; + + if (!h + || h->dynindx == -1 + || ((info->executable + || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT) + && h->def_regular)) + { + /* The symbol can be locally resolved. */ + rela.r_info = ELF32_R_INFO (0, R_390_IRELATIVE); + rela.r_addend = resolver_address; + } + else + { + rela.r_info = ELF32_R_INFO (h->dynindx, R_390_JMP_SLOT); + rela.r_addend = 0; + } + + loc = relplt->contents + iplt_index * RELA_ENTRY_SIZE; + bfd_elf32_swap_reloca_out (output_bfd, &rela, loc); +} + /* Finish up dynamic symbol handling. We set the contents of various dynamic sections here. */ @@ -3029,6 +3453,7 @@ elf_s390_finish_dynamic_symbol (bfd *output_bfd, Elf_Internal_Sym *sym) { struct elf_s390_link_hash_table *htab; + struct elf_s390_link_hash_entry *eh = (struct elf_s390_link_hash_entry*)h; htab = elf_s390_hash_table (info); @@ -3042,125 +3467,139 @@ elf_s390_finish_dynamic_symbol (bfd *output_bfd, /* This symbol has an entry in the procedure linkage table. Set it up. */ - if (h->dynindx == -1 - || htab->elf.splt == NULL - || htab->elf.sgotplt == NULL - || htab->elf.srelplt == NULL) - abort (); - - /* Calc. index no. - Current offset - size first entry / entry size. */ - plt_index = (h->plt.offset - PLT_FIRST_ENTRY_SIZE) / PLT_ENTRY_SIZE; - - /* Offset in GOT is PLT index plus GOT headers(3) times 4, - addr & GOT addr. */ - got_offset = (plt_index + 3) * GOT_ENTRY_SIZE; - - /* S390 uses halfwords for relative branch calc! */ - relative_offset = - ((PLT_FIRST_ENTRY_SIZE + - (PLT_ENTRY_SIZE * plt_index) + 18) / 2); - /* If offset is > 32768, branch to a previous branch - 390 can only handle +-64 K jumps. */ - if ( -32768 > (int) relative_offset ) - relative_offset - = -(unsigned) (((65536 / PLT_ENTRY_SIZE - 1) * PLT_ENTRY_SIZE) / 2); - - /* Fill in the entry in the procedure linkage table. */ - if (!info->shared) + if (s390_is_ifunc_symbol_p (h)) { - memcpy (htab->elf.splt->contents + h->plt.offset, elf_s390_plt_entry, - PLT_ENTRY_SIZE); - - /* Adjust jump to the first plt entry. */ - bfd_put_32 (output_bfd, (bfd_vma) 0+(relative_offset << 16), - htab->elf.splt->contents + h->plt.offset + 20); - - /* Push the GOT offset field. */ - bfd_put_32 (output_bfd, - (htab->elf.sgotplt->output_section->vma - + htab->elf.sgotplt->output_offset - + got_offset), - htab->elf.splt->contents + h->plt.offset + 24); - } - else if (got_offset < 4096) - { - /* The GOT offset is small enough to be used directly as - displacement. */ - memcpy (htab->elf.splt->contents + h->plt.offset, - elf_s390_plt_pic12_entry, - PLT_ENTRY_SIZE); - - /* Put in the GOT offset as displacement value. The 0xc000 - value comes from the first word of the plt entry. Look - at the elf_s390_plt_pic16_entry content. */ - bfd_put_16 (output_bfd, (bfd_vma)0xc000 | got_offset, - htab->elf.splt->contents + h->plt.offset + 2); - - /* Adjust the jump to the first plt entry. */ - bfd_put_32 (output_bfd, (bfd_vma) 0+(relative_offset << 16), - htab->elf.splt->contents + h->plt.offset + 20); - } - else if (got_offset < 32768) - { - /* The GOT offset is too big for a displacement but small - enough to be a signed 16 bit immediate value as it can be - used in an lhi instruction. */ - memcpy (htab->elf.splt->contents + h->plt.offset, - elf_s390_plt_pic16_entry, - PLT_ENTRY_SIZE); - - /* Put in the GOT offset for the lhi instruction. */ - bfd_put_16 (output_bfd, (bfd_vma)got_offset, - htab->elf.splt->contents + h->plt.offset + 2); - - /* Adjust the jump to the first plt entry. */ - bfd_put_32 (output_bfd, (bfd_vma) 0+(relative_offset << 16), - htab->elf.splt->contents + h->plt.offset + 20); + /* If we can resolve the IFUNC symbol locally we generate an + IRELATIVE reloc. */ + elf_s390_finish_ifunc_symbol (output_bfd, info, h, htab, h->plt.offset, + eh->ifunc_resolver_address + + eh->ifunc_resolver_section->output_offset + + eh->ifunc_resolver_section->output_section->vma); + /* Fallthrough. Handling of explicit GOT slots of IFUNC + symbols is below. */ } else { - memcpy (htab->elf.splt->contents + h->plt.offset, - elf_s390_plt_pic_entry, - PLT_ENTRY_SIZE); + if (h->dynindx == -1 + || htab->elf.splt == NULL + || htab->elf.sgotplt == NULL + || htab->elf.srelplt == NULL) + abort (); - /* Adjust the jump to the first plt entry. */ - bfd_put_32 (output_bfd, (bfd_vma) 0+(relative_offset << 16), - htab->elf.splt->contents + h->plt.offset + 20); + /* Calc. index no. + Current offset - size first entry / entry size. */ + plt_index = (h->plt.offset - PLT_FIRST_ENTRY_SIZE) / PLT_ENTRY_SIZE; - /* Push the GOT offset field. */ - bfd_put_32 (output_bfd, got_offset, - htab->elf.splt->contents + h->plt.offset + 24); - } - /* Insert offset into reloc. table here. */ - bfd_put_32 (output_bfd, plt_index * sizeof (Elf32_External_Rela), - htab->elf.splt->contents + h->plt.offset + 28); + /* Offset in GOT is PLT index plus GOT headers(3) times 4, + addr & GOT addr. */ + got_offset = (plt_index + 3) * GOT_ENTRY_SIZE; - /* Fill in the entry in the global offset table. - Points to instruction after GOT offset. */ - bfd_put_32 (output_bfd, - (htab->elf.splt->output_section->vma - + htab->elf.splt->output_offset - + h->plt.offset - + 12), - htab->elf.sgotplt->contents + got_offset); - - /* Fill in the entry in the .rela.plt section. */ - rela.r_offset = (htab->elf.sgotplt->output_section->vma - + htab->elf.sgotplt->output_offset - + got_offset); - rela.r_info = ELF32_R_INFO (h->dynindx, R_390_JMP_SLOT); - rela.r_addend = 0; - loc = htab->elf.srelplt->contents + plt_index * sizeof (Elf32_External_Rela); - bfd_elf32_swap_reloca_out (output_bfd, &rela, loc); + /* S390 uses halfwords for relative branch calc! */ + relative_offset = - ((PLT_FIRST_ENTRY_SIZE + + (PLT_ENTRY_SIZE * plt_index) + 18) / 2); + /* If offset is > 32768, branch to a previous branch + 390 can only handle +-64 K jumps. */ + if ( -32768 > (int) relative_offset ) + relative_offset + = -(unsigned) (((65536 / PLT_ENTRY_SIZE - 1) * PLT_ENTRY_SIZE) / 2); - if (!h->def_regular) - { - /* Mark the symbol as undefined, rather than as defined in - the .plt section. Leave the value alone. This is a clue - for the dynamic linker, to make function pointer - comparisons work between an application and shared - library. */ - sym->st_shndx = SHN_UNDEF; + /* Fill in the entry in the procedure linkage table. */ + if (!info->shared) + { + memcpy (htab->elf.splt->contents + h->plt.offset, elf_s390_plt_entry, + PLT_ENTRY_SIZE); + + /* Adjust jump to the first plt entry. */ + bfd_put_32 (output_bfd, (bfd_vma) 0+(relative_offset << 16), + htab->elf.splt->contents + h->plt.offset + 20); + + /* Push the GOT offset field. */ + bfd_put_32 (output_bfd, + (htab->elf.sgotplt->output_section->vma + + htab->elf.sgotplt->output_offset + + got_offset), + htab->elf.splt->contents + h->plt.offset + 24); + } + else if (got_offset < 4096) + { + /* The GOT offset is small enough to be used directly as + displacement. */ + memcpy (htab->elf.splt->contents + h->plt.offset, + elf_s390_plt_pic12_entry, + PLT_ENTRY_SIZE); + + /* Put in the GOT offset as displacement value. The 0xc000 + value comes from the first word of the plt entry. Look + at the elf_s390_plt_pic16_entry content. */ + bfd_put_16 (output_bfd, (bfd_vma)0xc000 | got_offset, + htab->elf.splt->contents + h->plt.offset + 2); + + /* Adjust the jump to the first plt entry. */ + bfd_put_32 (output_bfd, (bfd_vma) 0+(relative_offset << 16), + htab->elf.splt->contents + h->plt.offset + 20); + } + else if (got_offset < 32768) + { + /* The GOT offset is too big for a displacement but small + enough to be a signed 16 bit immediate value as it can be + used in an lhi instruction. */ + memcpy (htab->elf.splt->contents + h->plt.offset, + elf_s390_plt_pic16_entry, + PLT_ENTRY_SIZE); + + /* Put in the GOT offset for the lhi instruction. */ + bfd_put_16 (output_bfd, (bfd_vma)got_offset, + htab->elf.splt->contents + h->plt.offset + 2); + + /* Adjust the jump to the first plt entry. */ + bfd_put_32 (output_bfd, (bfd_vma) 0+(relative_offset << 16), + htab->elf.splt->contents + h->plt.offset + 20); + } + else + { + memcpy (htab->elf.splt->contents + h->plt.offset, + elf_s390_plt_pic_entry, + PLT_ENTRY_SIZE); + + /* Adjust the jump to the first plt entry. */ + bfd_put_32 (output_bfd, (bfd_vma) 0+(relative_offset << 16), + htab->elf.splt->contents + h->plt.offset + 20); + + /* Push the GOT offset field. */ + bfd_put_32 (output_bfd, got_offset, + htab->elf.splt->contents + h->plt.offset + 24); + } + /* Insert offset into reloc. table here. */ + bfd_put_32 (output_bfd, plt_index * sizeof (Elf32_External_Rela), + htab->elf.splt->contents + h->plt.offset + 28); + + /* Fill in the entry in the global offset table. + Points to instruction after GOT offset. */ + bfd_put_32 (output_bfd, + (htab->elf.splt->output_section->vma + + htab->elf.splt->output_offset + + h->plt.offset + + 12), + htab->elf.sgotplt->contents + got_offset); + + /* Fill in the entry in the .rela.plt section. */ + rela.r_offset = (htab->elf.sgotplt->output_section->vma + + htab->elf.sgotplt->output_offset + + got_offset); + rela.r_info = ELF32_R_INFO (h->dynindx, R_390_JMP_SLOT); + rela.r_addend = 0; + loc = htab->elf.srelplt->contents + plt_index * sizeof (Elf32_External_Rela); + bfd_elf32_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. This is a clue + for the dynamic linker, to make function pointer + comparisons work between an application and shared + library. */ + sym->st_shndx = SHN_UNDEF; + } } } @@ -3187,9 +3626,37 @@ elf_s390_finish_dynamic_symbol (bfd *output_bfd, of a version file, we just want to emit a RELATIVE reloc. The entry in the global offset table will already have been initialized in the relocate_section function. */ - if (info->shared + if (h->def_regular && s390_is_ifunc_symbol_p (h)) + { + if (info->shared) + { + /* An explicit GOT slot usage needs GLOB_DAT. If the + symbol references local the implicit got.iplt slot + will be used and the IRELATIVE reloc has been created + above. */ + goto do_glob_dat; + } + else + { + /* For non-shared objects explicit GOT slots must be + filled with the PLT slot address for pointer + equality reasons. */ + bfd_put_32 (output_bfd, (htab->elf.iplt->output_section->vma + + htab->elf.iplt->output_offset + + h->plt.offset), + htab->elf.sgot->contents + h->got.offset); + return TRUE; + } + } + else if (info->shared && SYMBOL_REFERENCES_LOCAL (info, h)) { + /* If this is a static link, or it is a -Bsymbolic link and + the symbol is defined locally or was forced to be local + because of a version file, we just want to emit a + RELATIVE reloc. The entry in the global offset table + will already have been initialized in the + relocate_section function. */ if (!h->def_regular) return FALSE; BFD_ASSERT((h->got.offset & 1) != 0); @@ -3201,6 +3668,7 @@ elf_s390_finish_dynamic_symbol (bfd *output_bfd, else { BFD_ASSERT((h->got.offset & 1) == 0); + do_glob_dat: bfd_put_32 (output_bfd, (bfd_vma) 0, htab->elf.sgot->contents + h->got.offset); rela.r_info = ELF32_R_INFO (h->dynindx, R_390_GLOB_DAT); rela.r_addend = 0; @@ -3271,6 +3739,8 @@ elf_s390_finish_dynamic_sections (bfd *output_bfd, struct elf_s390_link_hash_table *htab; bfd *dynobj; asection *sdyn; + bfd *ibfd; + unsigned int i; htab = elf_s390_hash_table (info); dynobj = htab->elf.dynobj; @@ -3356,6 +3826,36 @@ elf_s390_finish_dynamic_sections (bfd *output_bfd, elf_section_data (htab->elf.sgotplt->output_section) ->this_hdr.sh_entsize = 4; } + /* Finish dynamic symbol for local IFUNC symbols. */ + for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next) + { + struct plt_entry *local_plt; + Elf_Internal_Sym *isym; + Elf_Internal_Shdr *symtab_hdr; + + symtab_hdr = &elf_symtab_hdr (ibfd); + + local_plt = elf_s390_local_plt (ibfd); + if (local_plt != NULL) + for (i = 0; i < symtab_hdr->sh_info; i++) + { + if (local_plt[i].plt.offset != (bfd_vma) -1) + { + asection *sec = local_plt[i].sec; + isym = bfd_sym_from_r_symndx (&htab->sym_cache, ibfd, i); + if (isym == NULL) + return FALSE; + + if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) + elf_s390_finish_ifunc_symbol (output_bfd, info, NULL, htab, + local_plt[i].plt.offset, + isym->st_value + + sec->output_section->vma + + sec->output_offset); + + } + } + } return TRUE; } @@ -3446,6 +3946,7 @@ elf32_s390_merge_private_bfd_data (bfd *ibfd, bfd *obfd) #define elf_backend_reloc_type_class elf_s390_reloc_type_class #define elf_backend_grok_prstatus elf_s390_grok_prstatus #define elf_backend_plt_sym_val elf_s390_plt_sym_val +#define elf_backend_add_symbol_hook elf_s390_add_symbol_hook #define bfd_elf32_mkobject elf_s390_mkobject #define elf_backend_object_p elf_s390_object_p diff --git a/bfd/elf64-s390.c b/bfd/elf64-s390.c index 7cf4706d9c6..8512fc0700b 100644 --- a/bfd/elf64-s390.c +++ b/bfd/elf64-s390.c @@ -169,6 +169,9 @@ static reloc_howto_type elf_howto_table[] = s390_elf_ldisp_reloc, "R_390_GOTPLT20", FALSE, 0,0x0fffff00, FALSE), HOWTO(R_390_TLS_GOTIE20, 0, 2, 20, FALSE, 8, complain_overflow_dont, s390_elf_ldisp_reloc, "R_390_TLS_GOTIE20", FALSE, 0,0x0fffff00, FALSE), + HOWTO(R_390_IRELATIVE, 0, 4, 64, FALSE, 0, complain_overflow_bitfield, + bfd_elf_generic_reloc, "R_390_IRELATIVE", FALSE, 0, MINUS_ONE, FALSE), + }; /* GNU extension to record C++ vtable hierarchy. */ @@ -295,6 +298,8 @@ elf_s390_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED, return &elf_howto_table[(int) R_390_GOTPLT20]; case BFD_RELOC_390_TLS_GOTIE20: return &elf_howto_table[(int) R_390_TLS_GOTIE20]; + case BFD_RELOC_390_IRELATIVE: + return &elf_howto_table[(int) R_390_IRELATIVE]; case BFD_RELOC_VTABLE_INHERIT: return &elf64_s390_vtinherit_howto; case BFD_RELOC_VTABLE_ENTRY: @@ -450,6 +455,8 @@ elf_s390_is_local_label_name (bfd *abfd, const char *name) #define GOT_ENTRY_SIZE 8 +#define RELA_ENTRY_SIZE sizeof (Elf64_External_Rela) + /* The first three entries in a procedure linkage table are reserved, and the initial contents are unimportant (we zero them out). Subsequent entries look like this. See the SVR4 ABI 386 @@ -552,17 +559,43 @@ struct elf_s390_link_hash_entry #define GOT_TLS_IE 3 #define GOT_TLS_IE_NLT 3 unsigned char tls_type; + + /* For pointer equality reasons we might need to change the symbol + type from STT_GNU_IFUNC to STT_FUNC together with its value and + section entry. So after alloc_dynrelocs only these values should + be used. In order to check whether a symbol is IFUNC use + s390_is_ifunc_symbol_p. */ + bfd_vma ifunc_resolver_address; + asection *ifunc_resolver_section; }; #define elf_s390_hash_entry(ent) \ ((struct elf_s390_link_hash_entry *)(ent)) +/* This structure represents an entry in the local PLT list needed for + local IFUNC symbols. */ +struct plt_entry +{ + /* The section of the local symbol. + Set in relocate_section and used in finish_dynamic_sections. */ + asection *sec; + + union + { + bfd_signed_vma refcount; + bfd_vma offset; + } plt; +}; + /* NOTE: Keep this structure in sync with the one declared in elf32-s390.c. */ struct elf_s390_obj_tdata { struct elf_obj_tdata root; + /* A local PLT is needed for ifunc symbols. */ + struct plt_entry *local_plt; + /* TLS type for each local got entry. */ char *local_got_tls_type; }; @@ -570,6 +603,9 @@ struct elf_s390_obj_tdata #define elf_s390_tdata(abfd) \ ((struct elf_s390_obj_tdata *) (abfd)->tdata.any) +#define elf_s390_local_plt(abfd) \ + (elf_s390_tdata (abfd)->local_plt) + #define elf_s390_local_got_tls_type(abfd) \ (elf_s390_tdata (abfd)->local_got_tls_type) @@ -601,6 +637,7 @@ struct elf_s390_link_hash_table /* Short-cuts to get to dynamic linker sections. */ asection *sdynbss; asection *srelbss; + asection *irelifunc; union { bfd_signed_vma refcount; @@ -617,6 +654,9 @@ struct elf_s390_link_hash_table (elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \ == S390_ELF_DATA ? ((struct elf_s390_link_hash_table *) ((p)->hash)) : NULL) +#define ELF64 1 +#include "elf-s390-common.c" + /* Create an entry in an s390 ELF linker hash table. */ static struct bfd_hash_entry * @@ -644,6 +684,8 @@ link_hash_newfunc (struct bfd_hash_entry *entry, eh->dyn_relocs = NULL; eh->gotplt_refcount = 0; eh->tls_type = GOT_UNKNOWN; + eh->ifunc_resolver_address = 0; + eh->ifunc_resolver_section = NULL; } return entry; @@ -871,6 +913,7 @@ elf_s390_check_relocs (bfd *abfd, unsigned int r_type; unsigned long r_symndx; struct elf_link_hash_entry *h; + Elf_Internal_Sym *isym; r_symndx = ELF64_R_SYM (rel->r_info); @@ -883,7 +926,31 @@ elf_s390_check_relocs (bfd *abfd, } if (r_symndx < symtab_hdr->sh_info) - h = NULL; + { + /* A local symbol. */ + isym = bfd_sym_from_r_symndx (&htab->sym_cache, + abfd, r_symndx); + if (isym == NULL) + return FALSE; + + if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) + { + struct plt_entry *plt; + + if (!s390_elf_create_ifunc_sections (htab->elf.dynobj, info)) + return FALSE; + + if (local_got_refcounts == NULL) + { + if (!elf_s390_allocate_local_syminfo (abfd, symtab_hdr)) + return FALSE; + local_got_refcounts = elf_local_got_refcounts (abfd); + } + plt = elf_s390_local_plt (abfd); + plt[r_symndx].plt.refcount++; + } + h = NULL; + } else { h = sym_hashes[r_symndx - symtab_hdr->sh_info]; @@ -921,18 +988,11 @@ elf_s390_check_relocs (bfd *abfd, if (h == NULL && local_got_refcounts == NULL) { - bfd_size_type size; - - size = symtab_hdr->sh_info; - size *= (sizeof (bfd_signed_vma) + sizeof(char)); - local_got_refcounts = ((bfd_signed_vma *) - bfd_zalloc (abfd, size)); - if (local_got_refcounts == NULL) + if (!elf_s390_allocate_local_syminfo (abfd, symtab_hdr)) return FALSE; - elf_local_got_refcounts (abfd) = local_got_refcounts; - elf_s390_local_got_tls_type (abfd) - = (char *) (local_got_refcounts + symtab_hdr->sh_info); + local_got_refcounts = elf_local_got_refcounts (abfd); } + /* Fall through. */ case R_390_GOTOFF16: case R_390_GOTOFF32: @@ -948,6 +1008,25 @@ elf_s390_check_relocs (bfd *abfd, } } + if (h != NULL) + { + if (htab->elf.dynobj == NULL) + htab->elf.dynobj = abfd; + if (!s390_elf_create_ifunc_sections (htab->elf.dynobj, info)) + return FALSE; + + /* Make sure an IFUNC symbol defined in a non-shared object + always gets a PLT slot. */ + if (s390_is_ifunc_symbol_p (h) && h->def_regular) + { + /* The symbol is called by the dynamic loader in order + to resolve the relocation. So it is in fact also + referenced. */ + h->ref_regular = 1; + h->needs_plt = 1; + } + } + switch (r_type) { case R_390_GOTOFF16: @@ -955,7 +1034,10 @@ elf_s390_check_relocs (bfd *abfd, case R_390_GOTOFF64: case R_390_GOTPC: case R_390_GOTPCDBL: - /* Got is created, nothing to be done. */ + /* These relocs do not need a GOT slot. They just load the + GOT pointer itself or address something else relative to + the GOT. Since the GOT pointer has been set up above we + are done. */ break; case R_390_PLT16DBL: @@ -1102,7 +1184,7 @@ elf_s390_check_relocs (bfd *abfd, case R_390_PC32: case R_390_PC32DBL: case R_390_PC64: - if (h != NULL && !info->shared) + if (h != NULL) { /* If this reloc is in a read-only section, we might need a copy reloc. We can't check reliably at this @@ -1112,9 +1194,12 @@ elf_s390_check_relocs (bfd *abfd, adjust_dynamic_symbol. */ h->non_got_ref = 1; - /* We may need a .plt entry if the function this reloc - refers to is in a shared lib. */ - h->plt.refcount += 1; + if (!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 @@ -1187,7 +1272,6 @@ elf_s390_check_relocs (bfd *abfd, easily. Oh well. */ asection *s; void *vpp; - Elf_Internal_Sym *isym; isym = bfd_sym_from_r_symndx (&htab->sym_cache, abfd, r_symndx); @@ -1327,6 +1411,23 @@ elf_s390_gc_sweep_hook (bfd *abfd, break; } } + else + { + Elf_Internal_Sym *isym; + + /* A local symbol. */ + isym = bfd_sym_from_r_symndx (&htab->sym_cache, + abfd, r_symndx); + if (isym == NULL) + return FALSE; + + if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) + { + struct plt_entry *plt = elf_s390_local_plt (abfd); + if (plt[r_symndx].plt.refcount > 0) + plt[r_symndx].plt.refcount--; + } + } r_type = ELF64_R_TYPE (rel->r_info); r_type = elf_s390_tls_transition (info, r_type, h != NULL); @@ -1459,6 +1560,10 @@ elf_s390_adjust_dynamic_symbol (struct bfd_link_info *info, struct elf_s390_link_hash_table *htab; asection *s; + /* STT_GNU_IFUNC symbol must go through PLT. */ + if (s390_is_ifunc_symbol_p (h)) + return TRUE; + /* 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). */ @@ -1585,7 +1690,7 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, { struct bfd_link_info *info; struct elf_s390_link_hash_table *htab; - struct elf_s390_link_hash_entry *eh; + struct elf_s390_link_hash_entry *eh = (struct elf_s390_link_hash_entry *)h; struct elf_dyn_relocs *p; if (h->root.type == bfd_link_hash_indirect) @@ -1596,8 +1701,13 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, if (htab == NULL) return FALSE; - if (htab->elf.dynamic_sections_created - && h->plt.refcount > 0) + /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it + here if it is defined and referenced in a non-shared object. */ + if (s390_is_ifunc_symbol_p (h) && h->def_regular) + return s390_elf_allocate_ifunc_dyn_relocs (info, h, + &eh->dyn_relocs); + else if (htab->elf.dynamic_sections_created + && h->plt.refcount > 0) { /* Make sure this symbol is output as a dynamic symbol. Undefined weak syms won't yet be marked as dynamic. */ @@ -1714,7 +1824,6 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, else h->got.offset = (bfd_vma) -1; - eh = (struct elf_s390_link_hash_entry *) h; if (eh->dyn_relocs == NULL) return TRUE; @@ -1871,6 +1980,8 @@ elf_s390_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, bfd_size_type locsymcount; Elf_Internal_Shdr *symtab_hdr; asection *srela; + struct plt_entry *local_plt; + unsigned int i; if (! is_s390_elf (ibfd)) continue; @@ -1923,6 +2034,20 @@ elf_s390_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, else *local_got = (bfd_vma) -1; } + + local_plt = elf_s390_local_plt (ibfd); + for (i = 0; i < symtab_hdr->sh_info; i++) + { + if (local_plt[i].plt.refcount > 0) + { + local_plt[i].plt.offset = htab->elf.iplt->size; + htab->elf.iplt->size += PLT_ENTRY_SIZE; + htab->elf.igotplt->size += GOT_ENTRY_SIZE; + htab->elf.irelplt->size += sizeof (Elf64_External_Rela); + } + else + local_plt[i].plt.offset = (bfd_vma) -1; + } } if (htab->tls_ldm_got.refcount > 0) @@ -1951,7 +2076,10 @@ elf_s390_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, if (s == htab->elf.splt || s == htab->elf.sgot || s == htab->elf.sgotplt - || s == htab->sdynbss) + || s == htab->sdynbss + || s == htab->elf.iplt + || s == htab->elf.igotplt + || s == htab->irelifunc) { /* Strip this section if we don't need it; see the comment below. */ @@ -2141,6 +2269,7 @@ elf_s390_relocate_section (bfd *output_bfd, bfd_boolean unresolved_reloc; bfd_reloc_status_type r; int tls_type; + asection *base_got = htab->elf.sgot; r_type = ELF64_R_TYPE (rel->r_info); if (r_type == (int) R_390_GNU_VTINHERIT @@ -2163,7 +2292,55 @@ elf_s390_relocate_section (bfd *output_bfd, { sym = local_syms + r_symndx; sec = local_sections[r_symndx]; - relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel); + + if (ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC) + { + struct plt_entry *local_plt = elf_s390_local_plt (input_bfd); + if (local_plt == NULL) + return FALSE; + + /* Address of the PLT slot. */ + relocation = (htab->elf.iplt->output_section->vma + + htab->elf.iplt->output_offset + + local_plt[r_symndx].plt.offset); + + switch (r_type) + { + case R_390_GOTPLT12: + case R_390_GOTPLT16: + case R_390_GOTPLT20: + case R_390_GOTPLT32: + case R_390_GOTPLT64: + case R_390_GOTPLTENT: + case R_390_GOT12: + case R_390_GOT16: + case R_390_GOT20: + case R_390_GOT32: + case R_390_GOT64: + case R_390_GOTENT: + { + /* Write the PLT slot address into the GOT slot. */ + bfd_put_64 (output_bfd, relocation, + htab->elf.sgot->contents + + local_got_offsets[r_symndx]); + relocation = (local_got_offsets[r_symndx] + + htab->elf.sgot->output_offset); + + if (r_type == R_390_GOTENT || r_type == R_390_GOTPLTENT) + relocation += htab->elf.sgot->output_section->vma; + break; + } + default: + break; + } + /* The output section is needed later in + finish_dynamic_section when creating the dynamic + relocation. */ + local_plt[r_symndx].sec = sec; + goto do_relocation; + } + else + relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel); } else { @@ -2203,18 +2380,28 @@ elf_s390_relocate_section (bfd *output_bfd, { bfd_vma plt_index; - /* Calc. index no. - Current offset - size first entry / entry size. */ - plt_index = (h->plt.offset - PLT_FIRST_ENTRY_SIZE) / - PLT_ENTRY_SIZE; - - /* Offset in GOT is PLT index plus GOT headers(3) times 4, - addr & GOT addr. */ - relocation = (plt_index + 3) * GOT_ENTRY_SIZE; + if (s390_is_ifunc_symbol_p (h)) + { + plt_index = h->plt.offset / PLT_ENTRY_SIZE; + relocation = (plt_index * GOT_ENTRY_SIZE + + htab->elf.igotplt->output_offset); + if (r_type == R_390_GOTPLTENT) + relocation += htab->elf.igotplt->output_section->vma; + } + else + { + /* Calc. index no. + Current offset - size first entry / entry size. */ + plt_index = (h->plt.offset - PLT_FIRST_ENTRY_SIZE) / + PLT_ENTRY_SIZE; + + /* Offset in GOT is PLT index plus GOT headers(3) + times 4, addr & GOT addr. */ + relocation = (plt_index + 3) * GOT_ENTRY_SIZE; + if (r_type == R_390_GOTPLTENT) + relocation += htab->elf.sgot->output_section->vma; + } unresolved_reloc = FALSE; - - if (r_type == R_390_GOTPLTENT) - relocation += htab->elf.sgot->output_section->vma; break; } /* Fall through. */ @@ -2227,7 +2414,7 @@ elf_s390_relocate_section (bfd *output_bfd, case R_390_GOTENT: /* Relocation is to the entry for this symbol in the global offset table. */ - if (htab->elf.sgot == NULL) + if (base_got == NULL) abort (); if (h != NULL) @@ -2236,11 +2423,29 @@ elf_s390_relocate_section (bfd *output_bfd, off = h->got.offset; dyn = htab->elf.dynamic_sections_created; - if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h) - || (info->shared - && SYMBOL_REFERENCES_LOCAL (info, h)) - || (ELF_ST_VISIBILITY (h->other) - && h->root.type == bfd_link_hash_undefweak)) + + if (s390_is_ifunc_symbol_p (h)) + { + BFD_ASSERT (h->plt.offset != (bfd_vma) -1); + if (off == (bfd_vma)-1) + { + /* No explicit GOT usage so redirect to the + got.iplt slot. */ + base_got = htab->elf.igotplt; + off = h->plt.offset / PLT_ENTRY_SIZE * GOT_ENTRY_SIZE; + } + else + { + /* Explicit GOT slots must contain the address + of the PLT slot. This will be handled in + finish_dynamic_symbol. */ + } + } + else if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h) + || (info->shared + && SYMBOL_REFERENCES_LOCAL (info, h)) + || (ELF_ST_VISIBILITY (h->other) + && h->root.type == bfd_link_hash_undefweak)) { /* This is actually a static link, or it is a -Bsymbolic link and the symbol is defined @@ -2259,7 +2464,7 @@ elf_s390_relocate_section (bfd *output_bfd, else { bfd_put_64 (output_bfd, relocation, - htab->elf.sgot->contents + off); + base_got->contents + off); h->got.offset |= 1; } } @@ -2310,7 +2515,7 @@ elf_s390_relocate_section (bfd *output_bfd, if (off >= (bfd_vma) -2) abort (); - relocation = htab->elf.sgot->output_offset + off; + relocation = base_got->output_offset + off; /* For @GOTENT the relocation is against the offset between the instruction and the symbols entry in the GOT and not @@ -2318,7 +2523,7 @@ elf_s390_relocate_section (bfd *output_bfd, add the vma of the GOT to get the correct value. */ if ( r_type == R_390_GOTENT || r_type == R_390_GOTPLTENT) - relocation += htab->elf.sgot->output_section->vma; + relocation += base_got->output_section->vma; break; @@ -2356,17 +2561,21 @@ elf_s390_relocate_section (bfd *output_bfd, break; if (h->plt.offset == (bfd_vma) -1 - || htab->elf.splt == NULL) + || (htab->elf.splt == NULL && htab->elf.iplt == NULL)) { /* We didn't make a PLT entry for this symbol. This happens when statically linking PIC code, or when using -Bsymbolic. */ break; } - - relocation = (htab->elf.splt->output_section->vma - + htab->elf.splt->output_offset - + h->plt.offset); + if (s390_is_ifunc_symbol_p (h)) + relocation = (htab->elf.iplt->output_section->vma + + htab->elf.iplt->output_offset + + h->plt.offset); + else + relocation = (htab->elf.splt->output_section->vma + + htab->elf.splt->output_offset + + h->plt.offset); unresolved_reloc = FALSE; break; @@ -2386,10 +2595,16 @@ elf_s390_relocate_section (bfd *output_bfd, break; } - relocation = (htab->elf.splt->output_section->vma - + htab->elf.splt->output_offset - + h->plt.offset - - htab->elf.sgot->output_section->vma); + if (s390_is_ifunc_symbol_p (h)) + relocation = (htab->elf.iplt->output_section->vma + + htab->elf.iplt->output_offset + + h->plt.offset + - htab->elf.sgot->output_section->vma); + else + relocation = (htab->elf.splt->output_section->vma + + htab->elf.splt->output_offset + + h->plt.offset + - htab->elf.sgot->output_section->vma); unresolved_reloc = FALSE; break; @@ -2402,6 +2617,68 @@ elf_s390_relocate_section (bfd *output_bfd, case R_390_PC32: case R_390_PC32DBL: case R_390_PC64: + + if (h != NULL + && s390_is_ifunc_symbol_p (h) + && h->def_regular) + { + if (!info->shared || !h->non_got_ref) + { + /* For a non-shared object STT_GNU_IFUNC symbol must + go through PLT. */ + relocation = (htab->elf.iplt->output_section->vma + + htab->elf.iplt->output_offset + + h ->plt.offset); + goto do_relocation; + } + else + { + /* For shared objects a runtime relocation is needed. */ + + Elf_Internal_Rela outrel; + asection *sreloc; + + /* Need a dynamic relocation to get the real function + address. */ + outrel.r_offset = _bfd_elf_section_offset (output_bfd, + info, + input_section, + rel->r_offset); + if (outrel.r_offset == (bfd_vma) -1 + || outrel.r_offset == (bfd_vma) -2) + abort (); + + outrel.r_offset += (input_section->output_section->vma + + input_section->output_offset); + + if (h->dynindx == -1 + || h->forced_local + || info->executable) + { + /* This symbol is resolved locally. */ + outrel.r_info = ELF64_R_INFO (0, R_390_IRELATIVE); + outrel.r_addend = (h->root.u.def.value + + h->root.u.def.section->output_section->vma + + h->root.u.def.section->output_offset); + } + else + { + outrel.r_info = ELF64_R_INFO (h->dynindx, r_type); + outrel.r_addend = 0; + } + + sreloc = htab->elf.irelifunc; + elf_append_rela (output_bfd, sreloc, &outrel); + + /* If this reloc is against an external symbol, we + do not want to fiddle with the addend. Otherwise, + we need to include the symbol value so that it + becomes an addend for the dynamic reloc. For an + internal symbol, we have updated addend. */ + continue; + } + } + if ((input_section->flags & SEC_ALLOC) == 0) break; @@ -2887,6 +3164,8 @@ elf_s390_relocate_section (bfd *output_bfd, howto->name, h->root.root.string); + do_relocation: + if (r_type == R_390_20 || r_type == R_390_GOT20 || r_type == R_390_GOTPLT20 @@ -2943,6 +3222,92 @@ elf_s390_relocate_section (bfd *output_bfd, return TRUE; } +/* Generate the PLT slots together with the dynamic relocations needed + for IFUNC symbols. */ + +static void +elf_s390_finish_ifunc_symbol (bfd *output_bfd, + struct bfd_link_info *info, + struct elf_link_hash_entry *h, + struct elf_s390_link_hash_table *htab, + bfd_vma plt_offset, + bfd_vma resolver_address) +{ + bfd_vma plt_index; + bfd_vma got_offset; + Elf_Internal_Rela rela; + bfd_byte *loc; + asection *plt, *gotplt, *relplt; + + if (htab->elf.iplt == NULL + || htab->elf.igotplt == NULL + || htab->elf.irelplt == NULL) + abort (); + + /* Index of the PLT slot within iplt section. */ + plt_index = plt_offset / PLT_ENTRY_SIZE; + plt = htab->elf.iplt; + /* Offset into the igot.plt section. */ + got_offset = plt_index * GOT_ENTRY_SIZE; + gotplt = htab->elf.igotplt; + relplt = htab->elf.irelplt; + + /* Fill in the blueprint of a PLT. */ + memcpy (plt->contents + plt_offset, elf_s390x_plt_entry, + PLT_ENTRY_SIZE); + + /* Fixup the relative address to the GOT entry */ + bfd_put_32 (output_bfd, + (gotplt->output_section->vma + + gotplt->output_offset + got_offset + - (plt->output_section->vma + + plt->output_offset + + plt_offset))/2, + plt->contents + plt_offset + 2); + /* Fixup the relative branch to PLT 0 */ + bfd_put_32 (output_bfd, - (plt->output_offset + + (PLT_ENTRY_SIZE * plt_index) + 22)/2, + plt->contents + plt_offset + 24); + /* Fixup offset into .rela.plt section. */ + bfd_put_32 (output_bfd, relplt->output_offset + + plt_index * sizeof (Elf64_External_Rela), + plt->contents + plt_offset + 28); + + /* Fill in the entry in the global offset table. + Points to instruction after GOT offset. */ + bfd_put_64 (output_bfd, + (plt->output_section->vma + + plt->output_offset + + plt_offset + + 14), + gotplt->contents + got_offset); + + /* Fill in the entry in the .rela.plt section. */ + rela.r_offset = (gotplt->output_section->vma + + gotplt->output_offset + + got_offset); + + if (!h + || h->dynindx == -1 + || ((info->executable + || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT) + && h->def_regular)) + { + /* The symbol can be locally resolved. */ + rela.r_info = ELF64_R_INFO (0, R_390_IRELATIVE); + rela.r_addend = resolver_address; + } + else + { + rela.r_info = ELF64_R_INFO (h->dynindx, R_390_JMP_SLOT); + rela.r_addend = 0; + } + + loc = relplt->contents + plt_index * sizeof (Elf64_External_Rela); + bfd_elf64_swap_reloca_out (output_bfd, &rela, loc); +} + + /* Finish up dynamic symbol handling. We set the contents of various dynamic sections here. */ @@ -2953,6 +3318,7 @@ elf_s390_finish_dynamic_symbol (bfd *output_bfd, Elf_Internal_Sym *sym) { struct elf_s390_link_hash_table *htab; + struct elf_s390_link_hash_entry *eh = (struct elf_s390_link_hash_entry*)h; htab = elf_s390_hash_table (info); if (htab == NULL) @@ -2967,65 +3333,82 @@ elf_s390_finish_dynamic_symbol (bfd *output_bfd, /* This symbol has an entry in the procedure linkage table. Set it up. */ + if (s390_is_ifunc_symbol_p (h)) + { + /* If we can resolve the IFUNC symbol locally we generate an + IRELATIVE reloc. */ + elf_s390_finish_ifunc_symbol (output_bfd, info, h, htab, h->plt.offset, + eh->ifunc_resolver_address + + eh->ifunc_resolver_section->output_offset + + eh->ifunc_resolver_section->output_section->vma); + ; + /* Fallthrough. Handling of explicit GOT slots of IFUNC + symbols is below. */ + } + else + { + if (h->dynindx == -1 + || htab->elf.splt == NULL + || htab->elf.sgotplt == NULL + || htab->elf.srelplt == NULL) + abort (); - if (h->dynindx == -1 - || htab->elf.splt == NULL - || htab->elf.sgotplt == NULL - || htab->elf.srelplt == NULL) - abort (); + /* Calc. index no. + Current offset - size first entry / entry size. */ + plt_index = (h->plt.offset - PLT_FIRST_ENTRY_SIZE) / PLT_ENTRY_SIZE; - /* Calc. index no. - Current offset - size first entry / entry size. */ - plt_index = (h->plt.offset - PLT_FIRST_ENTRY_SIZE) / PLT_ENTRY_SIZE; - - /* Offset in GOT is PLT index plus GOT headers(3) times 8, - addr & GOT addr. */ - got_offset = (plt_index + 3) * GOT_ENTRY_SIZE; - - /* Fill in the blueprint of a PLT. */ - memcpy (htab->elf.splt->contents + h->plt.offset, elf_s390x_plt_entry, - PLT_ENTRY_SIZE); - - /* Fixup the relative address to the GOT entry */ - bfd_put_32 (output_bfd, - (htab->elf.sgotplt->output_section->vma + - htab->elf.sgotplt->output_offset + got_offset - - (htab->elf.splt->output_section->vma + h->plt.offset))/2, - htab->elf.splt->contents + h->plt.offset + 2); - /* Fixup the relative branch to PLT 0 */ - bfd_put_32 (output_bfd, - (PLT_FIRST_ENTRY_SIZE + - (PLT_ENTRY_SIZE * plt_index) + 22)/2, - htab->elf.splt->contents + h->plt.offset + 24); - /* Fixup offset into .rela.plt section. */ - bfd_put_32 (output_bfd, plt_index * sizeof (Elf64_External_Rela), - htab->elf.splt->contents + h->plt.offset + 28); - - /* Fill in the entry in the global offset table. - Points to instruction after GOT offset. */ - bfd_put_64 (output_bfd, - (htab->elf.splt->output_section->vma - + htab->elf.splt->output_offset - + h->plt.offset - + 14), - htab->elf.sgotplt->contents + got_offset); - - /* Fill in the entry in the .rela.plt section. */ - rela.r_offset = (htab->elf.sgotplt->output_section->vma - + htab->elf.sgotplt->output_offset - + got_offset); - rela.r_info = ELF64_R_INFO (h->dynindx, R_390_JMP_SLOT); - rela.r_addend = 0; - loc = htab->elf.srelplt->contents + plt_index * sizeof (Elf64_External_Rela); - bfd_elf64_swap_reloca_out (output_bfd, &rela, loc); + /* Offset in GOT is PLT index plus GOT headers(3) times 8, + addr & GOT addr. */ + got_offset = (plt_index + 3) * GOT_ENTRY_SIZE; - if (!h->def_regular) - { - /* Mark the symbol as undefined, rather than as defined in - the .plt section. Leave the value alone. This is a clue - for the dynamic linker, to make function pointer - comparisons work between an application and shared - library. */ - sym->st_shndx = SHN_UNDEF; + /* Fill in the blueprint of a PLT. */ + memcpy (htab->elf.splt->contents + h->plt.offset, elf_s390x_plt_entry, + PLT_ENTRY_SIZE); + + /* Fixup the relative address to the GOT entry */ + bfd_put_32 (output_bfd, + (htab->elf.sgotplt->output_section->vma + + htab->elf.sgotplt->output_offset + got_offset + - (htab->elf.splt->output_section->vma + + htab->elf.splt->output_offset + + h->plt.offset))/2, + htab->elf.splt->contents + h->plt.offset + 2); + /* Fixup the relative branch to PLT 0 */ + bfd_put_32 (output_bfd, - (PLT_FIRST_ENTRY_SIZE + + (PLT_ENTRY_SIZE * plt_index) + 22)/2, + htab->elf.splt->contents + h->plt.offset + 24); + /* Fixup offset into .rela.plt section. */ + bfd_put_32 (output_bfd, plt_index * sizeof (Elf64_External_Rela), + htab->elf.splt->contents + h->plt.offset + 28); + + /* Fill in the entry in the global offset table. + Points to instruction after GOT offset. */ + bfd_put_64 (output_bfd, + (htab->elf.splt->output_section->vma + + htab->elf.splt->output_offset + + h->plt.offset + + 14), + htab->elf.sgotplt->contents + got_offset); + + /* Fill in the entry in the .rela.plt section. */ + rela.r_offset = (htab->elf.sgotplt->output_section->vma + + htab->elf.sgotplt->output_offset + + got_offset); + rela.r_info = ELF64_R_INFO (h->dynindx, R_390_JMP_SLOT); + rela.r_addend = 0; + loc = htab->elf.srelplt->contents + plt_index * + sizeof (Elf64_External_Rela); + bfd_elf64_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. This is a clue + for the dynamic linker, to make function pointer + comparisons work between an application and shared + library. */ + sym->st_shndx = SHN_UNDEF; + } } } @@ -3046,14 +3429,37 @@ elf_s390_finish_dynamic_symbol (bfd *output_bfd, + htab->elf.sgot->output_offset + (h->got.offset &~ (bfd_vma) 1)); - /* If this is a static link, or it is a -Bsymbolic link and the - symbol is defined locally or was forced to be local because - of a version file, we just want to emit a RELATIVE reloc. - The entry in the global offset table will already have been - initialized in the relocate_section function. */ - if (info->shared + if (h->def_regular && s390_is_ifunc_symbol_p (h)) + { + if (info->shared) + { + /* An explicit GOT slot usage needs GLOB_DAT. If the + symbol references local the implicit got.iplt slot + will be used and the IRELATIVE reloc has been created + above. */ + goto do_glob_dat; + } + else + { + /* For non-shared objects explicit GOT slots must be + filled with the PLT slot address for pointer + equality reasons. */ + bfd_put_64 (output_bfd, (htab->elf.iplt->output_section->vma + + htab->elf.iplt->output_offset + + h->plt.offset), + htab->elf.sgot->contents + h->got.offset); + return TRUE; + } + } + else if (info->shared && SYMBOL_REFERENCES_LOCAL (info, h)) { + /* If this is a static link, or it is a -Bsymbolic link and + the symbol is defined locally or was forced to be local + because of a version file, we just want to emit a + RELATIVE reloc. The entry in the global offset table + will already have been initialized in the + relocate_section function. */ if (!h->def_regular) return FALSE; BFD_ASSERT((h->got.offset & 1) != 0); @@ -3065,6 +3471,7 @@ elf_s390_finish_dynamic_symbol (bfd *output_bfd, else { BFD_ASSERT((h->got.offset & 1) == 0); +do_glob_dat: bfd_put_64 (output_bfd, (bfd_vma) 0, htab->elf.sgot->contents + h->got.offset); rela.r_info = ELF64_R_INFO (h->dynindx, R_390_GLOB_DAT); rela.r_addend = 0; @@ -3135,6 +3542,8 @@ elf_s390_finish_dynamic_sections (bfd *output_bfd, struct elf_s390_link_hash_table *htab; bfd *dynobj; asection *sdyn; + bfd *ibfd; + unsigned int i; htab = elf_s390_hash_table (info); if (htab == NULL) @@ -3228,6 +3637,38 @@ elf_s390_finish_dynamic_sections (bfd *output_bfd, elf_section_data (htab->elf.sgot->output_section) ->this_hdr.sh_entsize = 8; } + + /* Finish dynamic symbol for local IFUNC symbols. */ + for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next) + { + struct plt_entry *local_plt; + Elf_Internal_Sym *isym; + Elf_Internal_Shdr *symtab_hdr; + + symtab_hdr = &elf_symtab_hdr (ibfd); + + local_plt = elf_s390_local_plt (ibfd); + if (local_plt != NULL) + for (i = 0; i < symtab_hdr->sh_info; i++) + { + if (local_plt[i].plt.offset != (bfd_vma) -1) + { + asection *sec = local_plt[i].sec; + isym = bfd_sym_from_r_symndx (&htab->sym_cache, ibfd, i); + if (isym == NULL) + return FALSE; + + if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) + elf_s390_finish_ifunc_symbol (output_bfd, info, NULL, htab, + local_plt[i].plt.offset, + isym->st_value + + sec->output_section->vma + + sec->output_offset); + + } + } + } + return TRUE; } @@ -3241,7 +3682,6 @@ elf_s390_plt_sym_val (bfd_vma i, const asection *plt, return plt->vma + PLT_FIRST_ENTRY_SIZE + i * PLT_ENTRY_SIZE; } - /* Why was the hash table entry size definition changed from ARCH_SIZE/8 to 4? This breaks the 64 bit dynamic linker and this is the only reason for the s390_elf64_size_info structure. */ @@ -3316,6 +3756,7 @@ const struct elf_size_info s390_elf64_size_info = #define elf_backend_init_index_section _bfd_elf_init_1_index_section #define elf_backend_reloc_type_class elf_s390_reloc_type_class #define elf_backend_plt_sym_val elf_s390_plt_sym_val +#define elf_backend_add_symbol_hook elf_s390_add_symbol_hook #define bfd_elf64_mkobject elf_s390_mkobject #define elf_backend_object_p elf_s390_object_p diff --git a/bfd/libbfd.h b/bfd/libbfd.h index 0bd5dd2abf8..1d95fd8352f 100644 --- a/bfd/libbfd.h +++ b/bfd/libbfd.h @@ -1996,6 +1996,7 @@ static const char *const bfd_reloc_code_real_names[] = { "@@uninitialized@@", "BFD_RELOC_390_GOT20", "BFD_RELOC_390_GOTPLT20", "BFD_RELOC_390_TLS_GOTIE20", + "BFD_RELOC_390_IRELATIVE", "BFD_RELOC_SCORE_GPREL15", "BFD_RELOC_SCORE_DUMMY2", "BFD_RELOC_SCORE_JMP", diff --git a/bfd/reloc.c b/bfd/reloc.c index cc4a5db59a2..19c1f96a275 100644 --- a/bfd/reloc.c +++ b/bfd/reloc.c @@ -4694,6 +4694,11 @@ ENUMDOC Long displacement extension. ENUM + BFD_RELOC_390_IRELATIVE +ENUMDOC + STT_GNU_IFUNC relocation. + +ENUM BFD_RELOC_SCORE_GPREL15 ENUMDOC Score relocations |