From bc696fd5af08fa199750abfca092894ab54206c7 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Sat, 13 Dec 2014 23:37:22 -0800 Subject: [PATCH] Handle weak alias for PIE with copy reloc When there is a weak symbol with a real definition, the processor independent code will have arranged for us to see the real definition first. We need to copy the needs_copy bit from the real definition and check it when allowing copy reloc in PIE. bfd/ PR ld/17689 * elf64-x86-64.c (elf_x86_64_link_hash_entry): Add needs_copy. Change has_bnd_reloc to bit field. (elf_x86_64_link_hash_newfunc): Initialize needs_copy and has_bnd_reloc to 0. (elf_x86_64_check_relocs): Set has_bnd_reloc to 1 instead of TRUE. (elf_x86_64_adjust_dynamic_symbol): Copy needs_copy from the real definition to a weak symbol. (elf_x86_64_allocate_dynrelocs): Also check needs_copy of a weak symbol for PIE when discarding space for relocs against symbols which turn out to need copy relocs. (elf_x86_64_relocate_section): Also check needs_copy of a weak symbol for PIE with copy reloc. ld/testsuite/ PR ld/17689 * ld-x86-64/pr17689.out: New file. * ld-x86-64/pr17689.rd: Likewise. * ld-x86-64/pr17689a.c: Likewise. * ld-x86-64/pr17689b.S: Likewise. * ld-x86-64/x86-64.exp: Run PR ld/17689 tests. --- bfd/ChangeLog | 17 +++++++++++++++++ bfd/elf64-x86-64.c | 27 ++++++++++++++++++++------- ld/testsuite/ChangeLog | 10 ++++++++++ ld/testsuite/ld-x86-64/pr17689.out | 1 + ld/testsuite/ld-x86-64/pr17689.rd | 3 +++ ld/testsuite/ld-x86-64/pr17689a.c | 10 ++++++++++ ld/testsuite/ld-x86-64/pr17689b.S | 12 ++++++++++++ ld/testsuite/ld-x86-64/x86-64.exp | 24 ++++++++++++++++++++++++ 8 files changed, 97 insertions(+), 7 deletions(-) create mode 100644 ld/testsuite/ld-x86-64/pr17689.out create mode 100644 ld/testsuite/ld-x86-64/pr17689.rd create mode 100644 ld/testsuite/ld-x86-64/pr17689a.c create mode 100644 ld/testsuite/ld-x86-64/pr17689b.S diff --git a/bfd/ChangeLog b/bfd/ChangeLog index d783e3ebae8..23e4ba5d44b 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,20 @@ +2014-12-13 H.J. Lu + + PR ld/17689 + * elf64-x86-64.c (elf_x86_64_link_hash_entry): Add needs_copy. + Change has_bnd_reloc to bit field. + (elf_x86_64_link_hash_newfunc): Initialize needs_copy and + has_bnd_reloc to 0. + (elf_x86_64_check_relocs): Set has_bnd_reloc to 1 instead + of TRUE. + (elf_x86_64_adjust_dynamic_symbol): Copy needs_copy from the + real definition to a weak symbol. + (elf_x86_64_allocate_dynrelocs): Also check needs_copy of a + weak symbol for PIE when discarding space for relocs against + symbols which turn out to need copy relocs. + (elf_x86_64_relocate_section): Also check needs_copy of a + weak symbol for PIE with copy reloc. + 2014-12-12 Alan Modra PR 15228 diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index 40a2a8767b6..4aff9b0ac65 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -757,8 +757,15 @@ struct elf_x86_64_link_hash_entry (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type)) unsigned char tls_type; + /* TRUE if a weak symbol with a real definition needs a copy reloc. + When there is a weak symbol with a real definition, the processor + independent code will have arranged for us to see the real + definition first. We need to copy the needs_copy bit from the + real definition and check it when allowing copy reloc in PIE. */ + unsigned int needs_copy : 1; + /* TRUE if symbol has at least one BND relocation. */ - bfd_boolean has_bnd_reloc; + unsigned int has_bnd_reloc : 1; /* Information about the GOT PLT entry. Filled when there are both GOT and PLT relocations against the same function. */ @@ -897,7 +904,8 @@ elf_x86_64_link_hash_newfunc (struct bfd_hash_entry *entry, eh = (struct elf_x86_64_link_hash_entry *) entry; eh->dyn_relocs = NULL; eh->tls_type = GOT_UNKNOWN; - eh->has_bnd_reloc = FALSE; + eh->needs_copy = 0; + eh->has_bnd_reloc = 0; eh->plt_bnd.offset = (bfd_vma) -1; eh->plt_got.offset = (bfd_vma) -1; eh->tlsdesc_got = (bfd_vma) -1; @@ -1665,7 +1673,7 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, && (get_elf_x86_64_backend_data (abfd) == &elf_x86_64_arch_bed)) { - elf_x86_64_hash_entry (h)->has_bnd_reloc = TRUE; + elf_x86_64_hash_entry (h)->has_bnd_reloc = 1; /* Create the second PLT for Intel MPX support. */ if (htab->plt_bnd == NULL) @@ -2373,7 +2381,11 @@ elf_x86_64_adjust_dynamic_symbol (struct bfd_link_info *info, h->root.u.def.section = h->u.weakdef->root.u.def.section; h->root.u.def.value = h->u.weakdef->root.u.def.value; if (ELIMINATE_COPY_RELOCS || info->nocopyreloc) - h->non_got_ref = h->u.weakdef->non_got_ref; + { + eh = (struct elf_x86_64_link_hash_entry *) h; + h->non_got_ref = h->u.weakdef->non_got_ref; + eh->needs_copy = h->u.weakdef->needs_copy; + } return TRUE; } @@ -2733,7 +2745,7 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) /* For PIE, discard space for relocs against symbols which turn out to need copy relocs. */ else if (info->executable - && h->needs_copy + && (h->needs_copy || eh->needs_copy) && h->def_dynamic && !h->def_regular) eh->dyn_relocs = NULL; @@ -4058,7 +4070,8 @@ elf_x86_64_relocate_section (bfd *output_bfd, defined locally or for a branch. */ fail = !h->def_regular && !branch; } - else if (!(info->executable && h->needs_copy)) + else if (!(info->executable + && (h->needs_copy || eh->needs_copy))) { /* Symbol doesn't need copy reloc and isn't referenced locally. We only allow branch to symbol with @@ -4121,7 +4134,7 @@ direct: if ((info->shared && !(info->executable && h != NULL - && h->needs_copy + && (h->needs_copy || eh->needs_copy) && IS_X86_64_PCREL_TYPE (r_type)) && (h == NULL || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog index b27177e0c3a..bcdcf0b1461 100644 --- a/ld/testsuite/ChangeLog +++ b/ld/testsuite/ChangeLog @@ -1,3 +1,13 @@ +2014-12-13 H.J. Lu + + PR ld/17689 + * ld-x86-64/pr17689.out: New file. + * ld-x86-64/pr17689.rd: Likewise. + * ld-x86-64/pr17689a.c: Likewise. + * ld-x86-64/pr17689b.S: Likewise. + + * ld-x86-64/x86-64.exp: Run PR ld/17689 tests. + 2014-12-06 Eric Botcazou * lib/ld-lib.exp (check_shared_lib_support): Return 0 for Visium. diff --git a/ld/testsuite/ld-x86-64/pr17689.out b/ld/testsuite/ld-x86-64/pr17689.out new file mode 100644 index 00000000000..7ef22e9a431 --- /dev/null +++ b/ld/testsuite/ld-x86-64/pr17689.out @@ -0,0 +1 @@ +PASS diff --git a/ld/testsuite/ld-x86-64/pr17689.rd b/ld/testsuite/ld-x86-64/pr17689.rd new file mode 100644 index 00000000000..d720a9b058f --- /dev/null +++ b/ld/testsuite/ld-x86-64/pr17689.rd @@ -0,0 +1,3 @@ +#... +[0-9a-f ]+R_X86_64_COPY+[0-9a-f ]+ +bar \+ 0 +#... diff --git a/ld/testsuite/ld-x86-64/pr17689a.c b/ld/testsuite/ld-x86-64/pr17689a.c new file mode 100644 index 00000000000..5317668876e --- /dev/null +++ b/ld/testsuite/ld-x86-64/pr17689a.c @@ -0,0 +1,10 @@ +#include + +char *bar = "PASS"; +extern char *bar_alias __attribute__ ((weak, alias ("bar"))); + +void +foo (char *x) +{ + printf ("%s\n", x); +} diff --git a/ld/testsuite/ld-x86-64/pr17689b.S b/ld/testsuite/ld-x86-64/pr17689b.S new file mode 100644 index 00000000000..c95f891057a --- /dev/null +++ b/ld/testsuite/ld-x86-64/pr17689b.S @@ -0,0 +1,12 @@ + .text + .globl main + .type main, @function +main: + subq $8, %rsp + movq bar_alias(%rip), %rdi + call foo@PLT + xorl %eax, %eax + addq $8, %rsp + ret + .size main, .-main + .section .note.GNU-stack,"",@progbits diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp index 253f0c609cf..443d1016677 100644 --- a/ld/testsuite/ld-x86-64/x86-64.exp +++ b/ld/testsuite/ld-x86-64/x86-64.exp @@ -416,6 +416,22 @@ if { [isnative] && [which $CC] != 0 } { {{readelf {-Wr} copyreloc-main2.rd}} \ "copyreloc-main" \ ] \ + [list \ + "Build pr17689.so" \ + "-shared" \ + "-fPIC" \ + { pr17689a.c } \ + {} \ + "pr17689.so" \ + ] \ + [list \ + "Build pr17689 with PIE without -fPIE" \ + "tmpdir/pr17689.so -pie" \ + "" \ + { pr17689b.S } \ + {{readelf {-Wr} pr17689.rd}} \ + "pr17689" \ + ] \ ] run_ld_link_exec_tests [] [list \ @@ -446,6 +462,14 @@ if { [isnative] && [which $CC] != 0 } { "copyreloc-main" \ "copyreloc-main.out" \ ] \ + [list \ + "Run pr17689 with PIE without -fPIE" \ + "tmpdir/pr17689.so -pie" \ + "" \ + { pr17689b.S } \ + "pr17689" \ + "pr17689.out" \ + ] \ ] if { [istarget "x86_64-*-linux*"] \ -- 2.30.2