From ecf99cc09236316db27fd8ffaedca864f81ea081 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Fri, 8 Jun 2018 12:41:31 -0700 Subject: [PATCH] ld/x86: Remove hidden _edata, __bss_start, and _end There is no need to put hidden _edata, __bss_start, and _end in dynamic symbol table in shared libraries. bfd/ PR ld/23161 * elfxx-x86.c (elf_x86_hide_linker_defined): New function. (_bfd_x86_elf_link_check_relocs): Use it to hide hidden __bss_start, _end and _edata in shared libraries. ld/ PR ld/23161 * testsuite/ld-elf/pr23161d.rd: Remove local _edata, __bss_start, and _end from dynamic symbol table. --- bfd/ChangeLog | 7 +++++++ bfd/elfxx-x86.c | 29 +++++++++++++++++++++++++++++ ld/ChangeLog | 6 ++++++ ld/testsuite/ld-elf/pr23161c.rd | 8 +------- 4 files changed, 43 insertions(+), 7 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index c7e28b8..a0ea93e 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,10 @@ +2018-06-08 H.J. Lu + + PR ld/23161 + * elfxx-x86.c (elf_x86_hide_linker_defined): New function. + (_bfd_x86_elf_link_check_relocs): Use it to hide hidden + __bss_start, _end and _edata in shared libraries. + 2018-06-07 Alan Modra * elf32-tic6x.c (elf32_tic6x_check_relocs): Reference diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c index 3a7573f..827bb6c 100644 --- a/bfd/elfxx-x86.c +++ b/bfd/elfxx-x86.c @@ -876,6 +876,27 @@ elf_x86_linker_defined (struct bfd_link_info *info, const char *name) } } +/* Hide a linker-defined symbol, NAME, with hidden visibility. */ + +static void +elf_x86_hide_linker_defined (struct bfd_link_info *info, + const char *name) +{ + struct elf_link_hash_entry *h; + + h = elf_link_hash_lookup (elf_hash_table (info), name, + FALSE, FALSE, FALSE); + if (h == NULL) + return; + + while (h->root.type == bfd_link_hash_indirect) + h = (struct elf_link_hash_entry *) h->root.u.i.link; + + if (ELF_ST_VISIBILITY (h->other) == STV_INTERNAL + || ELF_ST_VISIBILITY (h->other) == STV_HIDDEN) + _bfd_elf_link_hash_hide_symbol (info, h, TRUE); +} + bfd_boolean _bfd_x86_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info) { @@ -916,6 +937,14 @@ _bfd_x86_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info) elf_x86_linker_defined (info, "_end"); elf_x86_linker_defined (info, "_edata"); } + else + { + /* Hide hidden __bss_start, _end and _edata in shared + libraries. */ + elf_x86_hide_linker_defined (info, "__bss_start"); + elf_x86_hide_linker_defined (info, "_end"); + elf_x86_hide_linker_defined (info, "_edata"); + } } } diff --git a/ld/ChangeLog b/ld/ChangeLog index 0dcfcbb..efdd6d7 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,4 +1,10 @@ 2018-06-08 H.J. Lu + + PR ld/23161 + * testsuite/ld-elf/pr23161d.rd: Remove local _edata, __bss_start, + and _end from dynamic symbol table. + +2018-06-08 H.J. Lu Alan Modra PR ld/23161 diff --git a/ld/testsuite/ld-elf/pr23161c.rd b/ld/testsuite/ld-elf/pr23161c.rd index 904f126..be99655 100644 --- a/ld/testsuite/ld-elf/pr23161c.rd +++ b/ld/testsuite/ld-elf/pr23161c.rd @@ -3,10 +3,4 @@ There are no relocations in this file. Symbol table '\.dynsym' contains [0-9]+ entries: +Num: +Value +Size Type +Bind +Vis +Ndx Name +0: 0+ +0 +NOTYPE +LOCAL +DEFAULT +UND + -#... - +[0-9]+: +[a-f0-9]+ +0 +NOTYPE +LOCAL +DEFAULT +[0-9]+ +__bss_start -#... - +[0-9]+: +[a-f0-9]+ +0 +NOTYPE +LOCAL +DEFAULT +[0-9]+ +_edata -#... - +[0-9]+: +[a-f0-9]+ +0 +NOTYPE +LOCAL +DEFAULT +[0-9]+ +_end -#... + +1: +[a-f0-9]+ +[0-9]+ +FUNC +GLOBAL +DEFAULT +[0-9]+ +foo -- 2.7.4