From 90f487dfe075092afbd0be376bd3c1cd5cfb8276 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Sun, 6 Feb 2005 18:11:30 +0000 Subject: [PATCH] 2005-02-06 H.J. Lu * elf32-i386.c (elf_i386_relocate_section): Disallow R_386_GOTOFF against protected function when building shared library. PR 584 * elf64-x86-64.c (is_32bit_relative_branch): New. (elf64_x86_64_relocate_section): Alllow R_X86_64_PC32 on a protected function symbol when building shared library for 32bit relative branch instruction. --- bfd/ChangeLog | 11 +++++++++++ bfd/elf32-i386.c | 16 ++++++++++++++++ bfd/elf64-x86-64.c | 43 +++++++++++++++++++++++++++++++++++++------ 3 files changed, 64 insertions(+), 6 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 32eb9cd7db..461b27c5c4 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,14 @@ +2005-02-06 H.J. Lu + + * elf32-i386.c (elf_i386_relocate_section): Disallow R_386_GOTOFF + against protected function when building shared library. + + PR 584 + * elf64-x86-64.c (is_32bit_relative_branch): New. + (elf64_x86_64_relocate_section): Alllow R_X86_64_PC32 on a + protected function symbol when building shared library for + 32bit relative branch instruction. + 2005-02-06 Alan Modra * elf64-ppc.c (add_symbol_adjust): Don't create fake descriptor diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index 4785552187..9bab9be124 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -2274,6 +2274,22 @@ elf_i386_relocate_section (bfd *output_bfd, /* Relocation is relative to the start of the global offset table. */ + /* Check to make sure it isn't a protected function symbol + for shared library since it may not be local when used + as function address. */ + if (info->shared + && h + && h->def_regular + && h->type == STT_FUNC + && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED) + { + (*_bfd_error_handler) + (_("%B: relocation R_386_GOTOFF against protected function `%s' can not be used when making a shared object"), + input_bfd, h->root.root.string); + bfd_set_error (bfd_error_bad_value); + return FALSE; + } + /* Note that sgot is not involved in this calculation. We always want the start of .got.plt. If we defined _GLOBAL_OFFSET_TABLE_ in a different way, as is diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index d5b38d830b..08e610b1db 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -1745,6 +1745,24 @@ tpoff (struct bfd_link_info *info, bfd_vma address) return address - htab->tls_size - htab->tls_sec->vma; } +/* Is the instruction before OFFSET in CONTENTS a 32bit relative + branch? */ + +static bfd_boolean +is_32bit_relative_branch (bfd_byte *contents, bfd_vma offset) +{ + /* Opcode Instruction + 0xe8 call + 0xe9 jump + 0x0f 0x8x conditional jump */ + return ((offset > 0 + && (contents [offset - 1] == 0xe8 + || contents [offset - 1] == 0xe9)) + || (offset > 1 + && contents [offset - 2] == 0x0f + && (contents [offset - 1] & 0xf0) == 0x80)); +} + /* Relocate an x86_64 ELF section. */ static bfd_boolean @@ -1950,13 +1968,26 @@ elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info, if (info->shared && !SYMBOL_REFERENCES_LOCAL (info, h) && (input_section->flags & SEC_ALLOC) != 0 - && (input_section->flags & SEC_READONLY) != 0) + && (input_section->flags & SEC_READONLY) != 0 + && (!h->def_regular + || r_type != R_X86_64_PC32 + || h->type != STT_FUNC + || ELF_ST_VISIBILITY (h->other) != STV_PROTECTED + || !is_32bit_relative_branch (contents, + rel->r_offset))) { - (*_bfd_error_handler) - (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"), - input_bfd, - x86_64_elf_howto_table[r_type].name, - (h) ? h->root.root.string : "a local symbol"); + if (h->def_regular + && r_type == R_X86_64_PC32 + && h->type == STT_FUNC + && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED) + (*_bfd_error_handler) + (_("%B: relocation R_X86_64_PC32 against protected function `%s' can not be used when making a shared object"), + input_bfd, h->root.root.string); + else + (*_bfd_error_handler) + (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"), + input_bfd, x86_64_elf_howto_table[r_type].name, + h->root.root.string); bfd_set_error (bfd_error_bad_value); return FALSE; }