From bb1cb422aef79013990a3331f837a8dd24d71165 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Tue, 13 Jul 2010 16:59:14 +0000 Subject: [PATCH] Support garbage collection against STT_GNU_IFUNC symbols. bfd/ 2010-07-13 H.J. Lu PR ld/11791 * elf-ifunc.c (_bfd_elf_allocate_ifunc_dyn_relocs): Support garbage collection against STT_GNU_IFUNC symbols. * elf32-i386.c (elf_i386_get_local_sym_hash): Don't set elf.plt.offset/elf.got.offset to -1. (elf_i386_tls_transition): Skip TLS transition for functions. (elf_i386_gc_sweep_hook): Support STT_GNU_IFUNC symbols. * elf64-x86-64.c (elf64_x86_64_get_local_sym_hash): Don't set elf.plt.offset/elf.got.offset to -1. (elf64_x86_64_tls_transition): Skip TLS transition for functions. (elf64_x86_64_gc_sweep_hook): Support STT_GNU_IFUNC symbols. ld/testsuite/ 2010-07-13 H.J. Lu PR ld/11791 * ld-ifunc/ifunc-10-i386.d: New. * ld-ifunc/ifunc-10-i386.s: Likewise. * ld-ifunc/ifunc-10-x86-64.d: Likewise. * ld-ifunc/ifunc-10-x86-64.s: Likewise. * ld-ifunc/ifunc-11-i386.d: Likewise. * ld-ifunc/ifunc-11-i386.s: Likewise. * ld-ifunc/ifunc-11-x86-64.d: Likewise. * ld-ifunc/ifunc-11-x86-64.s: Likewise. --- bfd/ChangeLog | 16 ++++++++++ bfd/elf-ifunc.c | 9 ++++++ bfd/elf32-i386.c | 40 +++++++++++++++++++++++-- bfd/elf64-x86-64.c | 31 +++++++++++++++++-- ld/testsuite/ChangeLog | 12 ++++++++ ld/testsuite/ld-ifunc/ifunc-10-i386.d | 6 ++++ ld/testsuite/ld-ifunc/ifunc-10-i386.s | 20 +++++++++++++ ld/testsuite/ld-ifunc/ifunc-10-x86-64.d | 6 ++++ ld/testsuite/ld-ifunc/ifunc-10-x86-64.s | 20 +++++++++++++ ld/testsuite/ld-ifunc/ifunc-11-i386.d | 6 ++++ ld/testsuite/ld-ifunc/ifunc-11-i386.s | 21 +++++++++++++ ld/testsuite/ld-ifunc/ifunc-11-x86-64.d | 6 ++++ ld/testsuite/ld-ifunc/ifunc-11-x86-64.s | 21 +++++++++++++ 13 files changed, 210 insertions(+), 4 deletions(-) create mode 100644 ld/testsuite/ld-ifunc/ifunc-10-i386.d create mode 100644 ld/testsuite/ld-ifunc/ifunc-10-i386.s create mode 100644 ld/testsuite/ld-ifunc/ifunc-10-x86-64.d create mode 100644 ld/testsuite/ld-ifunc/ifunc-10-x86-64.s create mode 100644 ld/testsuite/ld-ifunc/ifunc-11-i386.d create mode 100644 ld/testsuite/ld-ifunc/ifunc-11-i386.s create mode 100644 ld/testsuite/ld-ifunc/ifunc-11-x86-64.d create mode 100644 ld/testsuite/ld-ifunc/ifunc-11-x86-64.s diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 32c44a934a4..e12771ae94c 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,19 @@ +2010-07-13 H.J. Lu + + PR ld/11791 + * elf-ifunc.c (_bfd_elf_allocate_ifunc_dyn_relocs): Support + garbage collection against STT_GNU_IFUNC symbols. + + * elf32-i386.c (elf_i386_get_local_sym_hash): Don't set + elf.plt.offset/elf.got.offset to -1. + (elf_i386_tls_transition): Skip TLS transition for functions. + (elf_i386_gc_sweep_hook): Support STT_GNU_IFUNC symbols. + + * elf64-x86-64.c (elf64_x86_64_get_local_sym_hash): Don't set + elf.plt.offset/elf.got.offset to -1. + (elf64_x86_64_tls_transition): Skip TLS transition for functions. + (elf64_x86_64_gc_sweep_hook): Support STT_GNU_IFUNC symbols. + 2010-07-12 H.J. Lu * elf32-i386.c (elf_i386_check_relocs): Re-indent. diff --git a/bfd/elf-ifunc.c b/bfd/elf-ifunc.c index 0de236f8c27..760fc26c1a1 100644 --- a/bfd/elf-ifunc.c +++ b/bfd/elf-ifunc.c @@ -187,6 +187,15 @@ _bfd_elf_allocate_ifunc_dyn_relocs (struct bfd_link_info *info, htab = elf_hash_table (info); + /* Support garbage collection against STT_GNU_IFUNC symbols. */ + if (h->plt.refcount <= 0 && h->got.refcount <= 0) + { + 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) diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index e85a7e5d896..ac9bdb63eb3 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -789,8 +789,6 @@ elf_i386_get_local_sym_hash (struct elf_i386_link_hash_table *htab, ret->elf.indx = sec->id; ret->elf.dynstr_index = ELF32_R_SYM (rel->r_info); ret->elf.dynindx = -1; - ret->elf.plt.offset = (bfd_vma) -1; - ret->elf.got.offset = (bfd_vma) -1; *slot = ret; } return &ret->elf; @@ -1162,6 +1160,12 @@ elf_i386_tls_transition (struct bfd_link_info *info, bfd *abfd, unsigned int to_type = from_type; bfd_boolean check = TRUE; + /* Skip TLS transition for functions. */ + if (h != NULL + && (h->type == STT_FUNC + || h->type == STT_GNU_IFUNC)) + return TRUE; + switch (from_type) { case R_386_TLS_GD: @@ -1819,6 +1823,23 @@ elf_i386_gc_sweep_hook (bfd *abfd, break; } } + else + { + /* A local symbol. */ + Elf_Internal_Sym *isym; + + isym = bfd_sym_from_r_symndx (&htab->sym_cache, + abfd, r_symndx); + + /* Check relocation against local STT_GNU_IFUNC symbol. */ + if (isym != NULL + && ELF32_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) + { + h = elf_i386_get_local_sym_hash (htab, abfd, rel, FALSE); + if (h == NULL) + abort (); + } + } r_type = ELF32_R_TYPE (rel->r_info); if (! elf_i386_tls_transition (info, abfd, sec, NULL, @@ -1845,6 +1866,11 @@ elf_i386_gc_sweep_hook (bfd *abfd, { if (h->got.refcount > 0) h->got.refcount -= 1; + if (h->type == STT_GNU_IFUNC) + { + if (h->plt.refcount > 0) + h->plt.refcount -= 1; + } } else if (local_got_refcounts != NULL) { @@ -1867,6 +1893,16 @@ elf_i386_gc_sweep_hook (bfd *abfd, } break; + case R_386_GOTOFF: + if (h != NULL && h->type == STT_GNU_IFUNC) + { + if (h->got.refcount > 0) + h->got.refcount -= 1; + if (h->plt.refcount > 0) + h->plt.refcount -= 1; + } + break; + default: break; } diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index 21524fa7495..108f2578fd6 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -603,8 +603,6 @@ elf64_x86_64_get_local_sym_hash (struct elf64_x86_64_link_hash_table *htab, ret->elf.indx = sec->id; ret->elf.dynstr_index = ELF64_R_SYM (rel->r_info); ret->elf.dynindx = -1; - ret->elf.plt.offset = (bfd_vma) -1; - ret->elf.got.offset = (bfd_vma) -1; *slot = ret; } return &ret->elf; @@ -951,6 +949,12 @@ elf64_x86_64_tls_transition (struct bfd_link_info *info, bfd *abfd, unsigned int to_type = from_type; bfd_boolean check = TRUE; + /* Skip TLS transition for functions. */ + if (h != NULL + && (h->type == STT_FUNC + || h->type == STT_GNU_IFUNC)) + return TRUE; + switch (from_type) { case R_X86_64_TLSGD: @@ -1657,6 +1661,24 @@ elf64_x86_64_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info, break; } } + else + { + /* A local symbol. */ + Elf_Internal_Sym *isym; + + isym = bfd_sym_from_r_symndx (&htab->sym_cache, + abfd, r_symndx); + + /* Check relocation against local STT_GNU_IFUNC symbol. */ + if (isym != NULL + && ELF64_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) + { + h = elf64_x86_64_get_local_sym_hash (htab, abfd, rel, + FALSE); + if (h == NULL) + abort (); + } + } r_type = ELF64_R_TYPE (rel->r_info); if (! elf64_x86_64_tls_transition (info, abfd, sec, NULL, @@ -1687,6 +1709,11 @@ elf64_x86_64_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info, h->plt.refcount -= 1; if (h->got.refcount > 0) h->got.refcount -= 1; + if (h->type == STT_GNU_IFUNC) + { + if (h->plt.refcount > 0) + h->plt.refcount -= 1; + } } else if (local_got_refcounts != NULL) { diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog index 463a14c5fe2..67555235841 100644 --- a/ld/testsuite/ChangeLog +++ b/ld/testsuite/ChangeLog @@ -1,3 +1,15 @@ +2010-07-13 H.J. Lu + + PR ld/11791 + * ld-ifunc/ifunc-10-i386.d: New. + * ld-ifunc/ifunc-10-i386.s: Likewise. + * ld-ifunc/ifunc-10-x86-64.d: Likewise. + * ld-ifunc/ifunc-10-x86-64.s: Likewise. + * ld-ifunc/ifunc-11-i386.d: Likewise. + * ld-ifunc/ifunc-11-i386.s: Likewise. + * ld-ifunc/ifunc-11-x86-64.d: Likewise. + * ld-ifunc/ifunc-11-x86-64.s: Likewise. + 2010-07-06 Alan Modra * ld-powerpc/relax.s: Add branch back to _start. diff --git a/ld/testsuite/ld-ifunc/ifunc-10-i386.d b/ld/testsuite/ld-ifunc/ifunc-10-i386.d new file mode 100644 index 00000000000..5f56b24425a --- /dev/null +++ b/ld/testsuite/ld-ifunc/ifunc-10-i386.d @@ -0,0 +1,6 @@ +#ld: -m elf_i386 -e bar --gc-sections +#as: --32 +#readelf: -r --wide +#target: x86_64-*-* i?86-*-* + +There are no relocations in this file. diff --git a/ld/testsuite/ld-ifunc/ifunc-10-i386.s b/ld/testsuite/ld-ifunc/ifunc-10-i386.s new file mode 100644 index 00000000000..8411e815eb6 --- /dev/null +++ b/ld/testsuite/ld-ifunc/ifunc-10-i386.s @@ -0,0 +1,20 @@ + .section .text.foo,"ax",@progbits + .type foo, @function +foo: + .global foo + movl ifunc@GOT(%ecx), %eax + movl ifunc@GOTOFF(%ecx), %eax + call ifunc@PLT + call ifunc + ret + + .section .text.bar,"ax",@progbits + .type bar, @function +bar: + .global bar + ret + + .section .text.ifunc,"ax",@progbits + .type ifunc, @gnu_indirect_function +ifunc: + ret diff --git a/ld/testsuite/ld-ifunc/ifunc-10-x86-64.d b/ld/testsuite/ld-ifunc/ifunc-10-x86-64.d new file mode 100644 index 00000000000..8ece379efbc --- /dev/null +++ b/ld/testsuite/ld-ifunc/ifunc-10-x86-64.d @@ -0,0 +1,6 @@ +#ld: -m elf_x86_64 -e bar --gc-sections +#as: --64 +#readelf: -r --wide +#target: x86_64-*-* + +There are no relocations in this file. diff --git a/ld/testsuite/ld-ifunc/ifunc-10-x86-64.s b/ld/testsuite/ld-ifunc/ifunc-10-x86-64.s new file mode 100644 index 00000000000..ea6f8c2d16e --- /dev/null +++ b/ld/testsuite/ld-ifunc/ifunc-10-x86-64.s @@ -0,0 +1,20 @@ + .section .text.foo,"ax",@progbits + .type foo, @function +foo: + .global foo + movl ifunc@GOTPCREL(%rip), %eax + movl ifunc(%rip), %eax + call ifunc@PLT + call ifunc + ret + + .section .text.bar,"ax",@progbits + .type bar, @function +bar: + .global bar + ret + + .section .text.ifunc,"ax",@progbits + .type ifunc, @gnu_indirect_function +ifunc: + ret diff --git a/ld/testsuite/ld-ifunc/ifunc-11-i386.d b/ld/testsuite/ld-ifunc/ifunc-11-i386.d new file mode 100644 index 00000000000..5f56b24425a --- /dev/null +++ b/ld/testsuite/ld-ifunc/ifunc-11-i386.d @@ -0,0 +1,6 @@ +#ld: -m elf_i386 -e bar --gc-sections +#as: --32 +#readelf: -r --wide +#target: x86_64-*-* i?86-*-* + +There are no relocations in this file. diff --git a/ld/testsuite/ld-ifunc/ifunc-11-i386.s b/ld/testsuite/ld-ifunc/ifunc-11-i386.s new file mode 100644 index 00000000000..06f592400e8 --- /dev/null +++ b/ld/testsuite/ld-ifunc/ifunc-11-i386.s @@ -0,0 +1,21 @@ + .section .text.foo,"ax",@progbits + .type foo, @function +foo: + .global foo + movl ifunc@GOT(%ecx), %eax + movl ifunc@GOTOFF(%ecx), %eax + call ifunc@PLT + call ifunc + ret + + .section .text.bar,"ax",@progbits + .type bar, @function +bar: + .global bar + ret + + .section .text.ifunc,"ax",@progbits + .type ifunc, @gnu_indirect_function + .global ifunc +ifunc: + ret diff --git a/ld/testsuite/ld-ifunc/ifunc-11-x86-64.d b/ld/testsuite/ld-ifunc/ifunc-11-x86-64.d new file mode 100644 index 00000000000..8ece379efbc --- /dev/null +++ b/ld/testsuite/ld-ifunc/ifunc-11-x86-64.d @@ -0,0 +1,6 @@ +#ld: -m elf_x86_64 -e bar --gc-sections +#as: --64 +#readelf: -r --wide +#target: x86_64-*-* + +There are no relocations in this file. diff --git a/ld/testsuite/ld-ifunc/ifunc-11-x86-64.s b/ld/testsuite/ld-ifunc/ifunc-11-x86-64.s new file mode 100644 index 00000000000..70d4fbfdb16 --- /dev/null +++ b/ld/testsuite/ld-ifunc/ifunc-11-x86-64.s @@ -0,0 +1,21 @@ + .section .text.foo,"ax",@progbits + .type foo, @function +foo: + .global foo + movl ifunc@GOTPCREL(%rip), %eax + movl ifunc(%rip), %eax + call ifunc@PLT + call ifunc + ret + + .section .text.bar,"ax",@progbits + .type bar, @function +bar: + .global bar + ret + + .section .text.ifunc,"ax",@progbits + .type ifunc, @gnu_indirect_function + .global ifunc +ifunc: + ret -- 2.30.2