From 766bc6567a42d77ac24103c5f7b9e14aaab81bba Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Mon, 25 Jan 2010 06:47:16 +0000 Subject: [PATCH] PR ld/11217 * elf64-ppc.c (ppc64_elf_tls_optimize): Optimize tls sequences with relocations against undefined weak symbols. (ppc64_elf_relocate_section): Don't optimize calls to undefined weak functions if the symbol is dynamic. (ppc64_elf_relocate_section): Edit tprel tls sequences. * elf32-ppc.c (ppc_elf_relocate_section): Likewise. (_bfd_elf_ppc_at_tprel_transform): New function. * bfd-in.h (_bfd_elf_ppc_at_tprel_transform): Declare. * bfd-in2.h: Regenerate. --- bfd/ChangeLog | 13 +++++++++++ bfd/bfd-in.h | 5 +++- bfd/bfd-in2.h | 5 +++- bfd/elf32-ppc.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++- bfd/elf64-ppc.c | 42 ++++++++++++++++++++++++++------- 5 files changed, 116 insertions(+), 11 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 714f03fe7d..c9c2d3acad 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,16 @@ +2010-01-25 Alan Modra + + PR ld/11217 + * elf64-ppc.c (ppc64_elf_tls_optimize): Optimize tls sequences + with relocations against undefined weak symbols. + (ppc64_elf_relocate_section): Don't optimize calls to undefined + weak functions if the symbol is dynamic. + (ppc64_elf_relocate_section): Edit tprel tls sequences. + * elf32-ppc.c (ppc_elf_relocate_section): Likewise. + (_bfd_elf_ppc_at_tprel_transform): New function. + * bfd-in.h (_bfd_elf_ppc_at_tprel_transform): Declare. + * bfd-in2.h: Regenerate. + 2010-01-23 Richard Sandiford * coff-rs6000.c (xcoff_howto_table): Change size to 0 and bitsize to 1. diff --git a/bfd/bfd-in.h b/bfd/bfd-in.h index 82bf043354..c775a0b5ee 100644 --- a/bfd/bfd-in.h +++ b/bfd/bfd-in.h @@ -1,7 +1,7 @@ /* Main header file for the bfd library -- portable access to object files. Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, - 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 + 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. Contributed by Cygnus Support. @@ -911,6 +911,9 @@ extern bfd_boolean elf32_arm_fix_exidx_coverage /* PowerPC @tls opcode transform/validate. */ extern unsigned int _bfd_elf_ppc_at_tls_transform (unsigned int, unsigned int); +/* PowerPC @tprel opcode transform/validate. */ +extern unsigned int _bfd_elf_ppc_at_tprel_transform + (unsigned int, unsigned int); /* TI COFF load page support. */ extern void bfd_ticoff_set_section_load_page diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h index b17f2e196d..df9b6e0431 100644 --- a/bfd/bfd-in2.h +++ b/bfd/bfd-in2.h @@ -8,7 +8,7 @@ /* Main header file for the bfd library -- portable access to object files. Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, - 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 + 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. Contributed by Cygnus Support. @@ -918,6 +918,9 @@ extern bfd_boolean elf32_arm_fix_exidx_coverage /* PowerPC @tls opcode transform/validate. */ extern unsigned int _bfd_elf_ppc_at_tls_transform (unsigned int, unsigned int); +/* PowerPC @tprel opcode transform/validate. */ +extern unsigned int _bfd_elf_ppc_at_tprel_transform + (unsigned int, unsigned int); /* TI COFF load page support. */ extern void bfd_ticoff_set_section_load_page diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c index 0c372f00a4..fc4347e444 100644 --- a/bfd/elf32-ppc.c +++ b/bfd/elf32-ppc.c @@ -1,6 +1,6 @@ /* PowerPC-specific support for 32-bit ELF Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, - 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc. + 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. Written by Ian Lance Taylor, Cygnus Support. This file is part of BFD, the Binary File Descriptor library. @@ -6669,6 +6669,51 @@ _bfd_elf_ppc_at_tls_transform (unsigned int insn, unsigned int reg) return insn; } +/* If INSN is an opcode that may be used with an @tprel operand, return + the transformed insn for an undefined weak symbol, ie. with the + thread pointer REG operand removed. Otherwise return 0. */ + +unsigned int +_bfd_elf_ppc_at_tprel_transform (unsigned int insn, unsigned int reg) +{ + if ((insn & (0x1f << 16)) == reg << 16 + && ((insn & (0x3f << 26)) == 14u << 26 /* addi */ + || (insn & (0x3f << 26)) == 15u << 26 /* addis */ + || (insn & (0x3f << 26)) == 32u << 26 /* lwz */ + || (insn & (0x3f << 26)) == 34u << 26 /* lbz */ + || (insn & (0x3f << 26)) == 36u << 26 /* stw */ + || (insn & (0x3f << 26)) == 38u << 26 /* stb */ + || (insn & (0x3f << 26)) == 40u << 26 /* lhz */ + || (insn & (0x3f << 26)) == 42u << 26 /* lha */ + || (insn & (0x3f << 26)) == 44u << 26 /* sth */ + || (insn & (0x3f << 26)) == 46u << 26 /* lmw */ + || (insn & (0x3f << 26)) == 47u << 26 /* stmw */ + || (insn & (0x3f << 26)) == 48u << 26 /* lfs */ + || (insn & (0x3f << 26)) == 50u << 26 /* lfd */ + || (insn & (0x3f << 26)) == 52u << 26 /* stfs */ + || (insn & (0x3f << 26)) == 54u << 26 /* stfd */ + || ((insn & (0x3f << 26)) == 58u << 26 /* lwa,ld,lmd */ + && (insn & 3) != 1) + || ((insn & (0x3f << 26)) == 62u << 26 /* std, stmd */ + && ((insn & 3) == 0 || (insn & 3) == 3)))) + { + insn &= ~(0x1f << 16); + } + else if ((insn & (0x1f << 21)) == reg << 21 + && ((insn & (0x3e << 26)) == 24u << 26 /* ori, oris */ + || (insn & (0x3e << 26)) == 26u << 26 /* xori,xoris */ + || (insn & (0x3e << 26)) == 28u << 26 /* andi,andis */)) + { + insn &= ~(0x1f << 21); + insn |= (insn & (0x1f << 16)) << 5; + if ((insn & (0x3e << 26)) == 26 << 26 /* xori,xoris */) + insn -= 2 >> 26; /* convert to ori,oris */ + } + else + insn = 0; + return insn; +} + /* The RELOCATE_SECTION function is called by the ELF backend linker to handle the relocations for a section. @@ -7471,6 +7516,21 @@ ppc_elf_relocate_section (bfd *output_bfd, case R_PPC_TPREL16_LO: case R_PPC_TPREL16_HI: case R_PPC_TPREL16_HA: + if (h != NULL + && h->root.type == bfd_link_hash_undefweak + && h->dynindx == -1) + { + /* Make this relocation against an undefined weak symbol + resolve to zero. This is really just a tweak, since + code using weak externs ought to check that they are + defined before using them. */ + bfd_byte *p = contents + rel->r_offset - d_offset; + unsigned int insn = bfd_get_32 (output_bfd, p); + insn = _bfd_elf_ppc_at_tprel_transform (insn, 2); + if (insn != 0) + bfd_put_32 (output_bfd, insn, p); + break; + } addend -= htab->elf.tls_sec->vma + TP_OFFSET; /* The TPREL16 relocs shouldn't really be used in shared libs as they will result in DT_TEXTREL being set, but diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c index 6648ddca51..4a468812a5 100644 --- a/bfd/elf64-ppc.c +++ b/bfd/elf64-ppc.c @@ -7409,10 +7409,13 @@ ppc64_elf_tls_optimize (bfd *obfd ATTRIBUTE_UNUSED, struct bfd_link_info *info) if (h != NULL) { - if (h->root.type != bfd_link_hash_defined - && h->root.type != bfd_link_hash_defweak) + if (h->root.type == bfd_link_hash_defined + || h->root.type == bfd_link_hash_defweak) + value = h->root.u.def.value; + else if (h->root.type == bfd_link_hash_undefweak) + value = 0; + else continue; - value = h->root.u.def.value; } else /* Symbols referenced by TLS relocs must be of type @@ -7425,11 +7428,17 @@ ppc64_elf_tls_optimize (bfd *obfd ATTRIBUTE_UNUSED, struct bfd_link_info *info) || !h->def_dynamic) { is_local = TRUE; - value += sym_sec->output_offset; - value += sym_sec->output_section->vma; - value -= htab->elf.tls_sec->vma; - ok_tprel = (value + TP_OFFSET + ((bfd_vma) 1 << 31) - < (bfd_vma) 1 << 32); + if (h != NULL + && h->root.type == bfd_link_hash_undefweak) + ok_tprel = TRUE; + else + { + value += sym_sec->output_offset; + value += sym_sec->output_section->vma; + value -= htab->elf.tls_sec->vma; + ok_tprel = (value + TP_OFFSET + ((bfd_vma) 1 << 31) + < (bfd_vma) 1 << 32); + } } r_type = ELF64_R_TYPE (rel->r_info); @@ -11498,6 +11507,7 @@ ppc64_elf_relocate_section (bfd *output_bfd, checking whether the function is defined. */ else if (h != NULL && h->elf.root.type == bfd_link_hash_undefweak + && h->elf.dynindx == -1 && r_type == R_PPC64_REL24 && relocation == 0 && addend == 0) @@ -11833,6 +11843,22 @@ ppc64_elf_relocate_section (bfd *output_bfd, case R_PPC64_TPREL16_HIGHERA: case R_PPC64_TPREL16_HIGHEST: case R_PPC64_TPREL16_HIGHESTA: + if (h != NULL + && h->elf.root.type == bfd_link_hash_undefweak + && h->elf.dynindx == -1) + { + /* Make this relocation against an undefined weak symbol + resolve to zero. This is really just a tweak, since + code using weak externs ought to check that they are + defined before using them. */ + bfd_byte *p = contents + rel->r_offset - d_offset; + + insn = bfd_get_32 (output_bfd, p); + insn = _bfd_elf_ppc_at_tprel_transform (insn, 13); + if (insn != 0) + bfd_put_32 (output_bfd, insn, p); + break; + } addend -= htab->elf.tls_sec->vma + TP_OFFSET; if (info->shared) /* The TPREL16 relocs shouldn't really be used in shared -- 2.34.1