diff options
Diffstat (limited to 'bfd')
| -rw-r--r-- | bfd/ChangeLog | 9 | ||||
| -rw-r--r-- | bfd/elf64-ppc.c | 111 |
2 files changed, 77 insertions, 43 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 71d6148..7511c6c 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,5 +1,14 @@ 2013-07-03 Alan Modra <amodra@gmail.com> + * elf64-ppc.c (struct ppc_stub_hash_entry): Delete "addend". + (ppc64_elf_size_stubs): Don't set "addend". + (ppc64_elf_relocate_section): Don't allow calls via + toc-adjusting stubs without a following nop even in an + executable, except for self-calls and both libc_start_main + and .libc_start_main. + +2013-07-03 Alan Modra <amodra@gmail.com> + * elf64-ppc.c (ppc64_elf_func_desc_adjust): Hide ".TOC.". 2013-07-02 Tristan Gingold <gingold@adacore.com> diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c index 5a4bcfd..21d8263 100644 --- a/bfd/elf64-ppc.c +++ b/bfd/elf64-ppc.c @@ -3618,9 +3618,6 @@ struct ppc_stub_hash_entry { struct ppc_link_hash_entry *h; struct plt_entry *plt_ent; - /* And the reloc addend that this was derived from. */ - bfd_vma addend; - /* Where this stub is being called from, or, in the case of combined stub sections, the first input section in the group. */ asection *id_sec; @@ -11752,7 +11749,6 @@ ppc64_elf_size_stubs (struct bfd_link_info *info, bfd_signed_vma group_size, } stub_entry->h = hash; stub_entry->plt_ent = plt_ent; - stub_entry->addend = irela->r_addend; if (stub_entry->h != NULL) htab->stub_globals += 1; @@ -13015,60 +13011,89 @@ 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 + 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) { - unsigned long nop; - nop = bfd_get_32 (input_bfd, contents + rel->r_offset + 4); - if (nop == NOP - || nop == CROR_151515 || nop == CROR_313131) + unsigned long br; + + br = bfd_get_32 (input_bfd, + contents + rel->r_offset); + if ((br & 1) != 0) { - if (h != NULL - && (h == htab->tls_get_addr_fd - || h == htab->tls_get_addr) - && !htab->no_tls_get_addr_opt) + unsigned long nop; + + nop = bfd_get_32 (input_bfd, + contents + rel->r_offset + 4); + if (nop == NOP + || nop == CROR_151515 || nop == CROR_313131) { - /* Special stub used, leave nop alone. */ + if (h != NULL + && (h == htab->tls_get_addr_fd + || h == htab->tls_get_addr) + && !htab->no_tls_get_addr_opt) + { + /* Special stub used, leave nop alone. */ + } + else + bfd_put_32 (input_bfd, LD_R2_40R1, + contents + rel->r_offset + 4); + can_plt_call = TRUE; } - else - bfd_put_32 (input_bfd, LD_R2_40R1, - contents + rel->r_offset + 4); - can_plt_call = TRUE; } } - if (!can_plt_call) + if (!can_plt_call && h != NULL) { - if (stub_entry->stub_type == ppc_stub_plt_call - || stub_entry->stub_type == ppc_stub_plt_call_r2save) - { - /* If this is a plain branch rather than a branch - and link, don't require a nop. However, don't - allow tail calls in a shared library as they - will result in r2 being corrupted. */ - unsigned long br; - br = bfd_get_32 (input_bfd, contents + rel->r_offset); - if (info->executable && (br & 1) == 0) - can_plt_call = TRUE; - else - stub_entry = NULL; - } - else if (h != NULL - && strcmp (h->elf.root.root.string, - ".__libc_start_main") == 0) + const char *name = h->elf.root.root.string; + + if (*name == '.') + ++name; + + if (strncmp (name, "__libc_start_main", 17) == 0 + && (name[17] == 0 || name[17] == '@')) { - /* Allow crt1 branch to go via a toc adjusting stub. */ + /* Allow crt1 branch to go via a toc adjusting + stub. Other calls that never return could do + the same, if we could detect such. */ can_plt_call = TRUE; } - else + } + + if (!can_plt_call) + { + /* g++ as of 20130507 emits self-calls without a + following nop. This is arguably wrong since we + have conflicting information. On the one hand a + global symbol and on the other a local call + sequence, but don't error for this special case. + It isn't possible to cheaply verify we have + exactly such a call. Allow all calls to the same + section. */ + asection *code_sec = sec; + + if (get_opd_info (sec) != NULL) { - info->callbacks->einfo - (_("%P: %H: call to `%T' lacks nop, can't restore toc; " - "recompile with -fPIC"), - input_bfd, input_section, rel->r_offset, sym_name); + bfd_vma off = (relocation + addend + - sec->output_section->vma + - sec->output_offset); - bfd_set_error (bfd_error_bad_value); - ret = FALSE; + opd_entry_value (sec, off, &code_sec, NULL, FALSE); } + if (code_sec == input_section) + can_plt_call = TRUE; + } + + if (!can_plt_call) + { + info->callbacks->einfo + (_("%P: %H: call to `%T' lacks nop, can't restore toc; " + "recompile with -fPIC"), + input_bfd, input_section, rel->r_offset, sym_name); + + bfd_set_error (bfd_error_bad_value); + ret = FALSE; } if (can_plt_call |