From 72aa81732b3aff00e5bf1f69bb794513b3b37464 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Wed, 5 Jan 2022 19:21:45 -0800 Subject: ld: Add glibc dependency for DT_RELR When DT_RELR is enabled, to avoid random run-time crash with older glibc binaries without DT_RELR support, add a GLIBC_ABI_DT_RELR symbol version, which is provided by glibc with DT_RELR support, dependency on the shared C library if it provides a GLIBC_2.XX symbol version. bfd/ * elflink.c (elf_link_add_dt_relr_dependency): New function. (bfd_elf_size_dynamic_sections): Call elf_link_add_dt_relr_dependency if DT_RELR is enabled. ld/ * ld.texi: Mention GLIBC_ABI_DT_RELR in -z pack-relative-relocs entry. * testsuite/ld-elf/dt-relr-glibc-1.c: New file. * testsuite/ld-elf/dt-relr-glibc-1a.rd: Likewise. * testsuite/ld-elf/dt-relr-glibc-1b.rd: Likewise. * testsuite/ld-elf/dt-relr.exp: Likewise. --- ld/ld.texi | 4 ++- ld/testsuite/ld-elf/dt-relr-glibc-1.c | 11 +++++++++ ld/testsuite/ld-elf/dt-relr-glibc-1a.rd | 4 +++ ld/testsuite/ld-elf/dt-relr-glibc-1b.rd | 7 ++++++ ld/testsuite/ld-elf/dt-relr.exp | 44 +++++++++++++++++++++++++++++++++ 5 files changed, 69 insertions(+), 1 deletion(-) create mode 100644 ld/testsuite/ld-elf/dt-relr-glibc-1.c create mode 100644 ld/testsuite/ld-elf/dt-relr-glibc-1a.rd create mode 100644 ld/testsuite/ld-elf/dt-relr-glibc-1b.rd create mode 100644 ld/testsuite/ld-elf/dt-relr.exp (limited to 'ld') diff --git a/ld/ld.texi b/ld/ld.texi index 1b42c6b..fc75e9b 100644 --- a/ld/ld.texi +++ b/ld/ld.texi @@ -1437,7 +1437,9 @@ and shared library. It adds @code{DT_RELR}, @code{DT_RELRSZ} and @code{DT_RELRENT} entries to the dynamic section. It is ignored when building position-dependent executable and relocatable output. @option{nopack-relative-relocs} is the default, which disables compact -relative relocation. Supported for i386 and x86-64. +relative relocation. When linked against the GNU C Library, a +GLIBC_ABI_DT_RELR symbol version dependency on the shared C Library is +added to the output. Supported for i386 and x86-64. @item relro @itemx norelro diff --git a/ld/testsuite/ld-elf/dt-relr-glibc-1.c b/ld/testsuite/ld-elf/dt-relr-glibc-1.c new file mode 100644 index 0000000..beacffe --- /dev/null +++ b/ld/testsuite/ld-elf/dt-relr-glibc-1.c @@ -0,0 +1,11 @@ +#define REL(n) \ + static int data##n; \ + void *p##n = &data##n; + +REL(1) +REL(2) +REL(3) +REL(4) +REL(5) +REL(6) +REL(7) diff --git a/ld/testsuite/ld-elf/dt-relr-glibc-1a.rd b/ld/testsuite/ld-elf/dt-relr-glibc-1a.rd new file mode 100644 index 0000000..51bda5d --- /dev/null +++ b/ld/testsuite/ld-elf/dt-relr-glibc-1a.rd @@ -0,0 +1,4 @@ +#failif +#... + 0x[a-f0-9]+: Name: GLIBC_ABI_DT_RELR Flags: none Version: [0-9]+ +#... diff --git a/ld/testsuite/ld-elf/dt-relr-glibc-1b.rd b/ld/testsuite/ld-elf/dt-relr-glibc-1b.rd new file mode 100644 index 0000000..6556a6d --- /dev/null +++ b/ld/testsuite/ld-elf/dt-relr-glibc-1b.rd @@ -0,0 +1,7 @@ +#... +Version needs section '.gnu.version_r' contains 1 entry: + Addr: 0x[0-9a-f]+ +Offset: 0x[0-9a-f]+ +Link: +[0-9]+ +\(.dynstr\) + +0+: Version: 1 +File: libc\.so\.6(|\.1) +Cnt: +[0-9]+ +#... + 0x[a-f0-9]+: Name: GLIBC_ABI_DT_RELR Flags: none Version: [0-9]+ +#pass diff --git a/ld/testsuite/ld-elf/dt-relr.exp b/ld/testsuite/ld-elf/dt-relr.exp new file mode 100644 index 0000000..51d21e4 --- /dev/null +++ b/ld/testsuite/ld-elf/dt-relr.exp @@ -0,0 +1,44 @@ +# Expect script for DT_RELR. +# Copyright (C) 2022 Free Software Foundation, Inc. +# +# This file is part of the GNU Binutils. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, +# MA 02110-1301, USA. +# + +# Linux tests. +if { ![istarget "*-*-linux*"] } { + return +} + +run_cc_link_tests [list \ + [list \ + "Build dt-relr-glibc-1a.so" \ + "-shared $NO_DT_RELR_CC_LDFLAGS" \ + "-fPIC" \ + { dt-relr-glibc-1.c } \ + {{readelf {--version-info} dt-relr-glibc-1a.rd}} \ + "glibc-relr-1a.so" \ + ] \ + [list \ + "Build dt-relr-glibc-1b.so" \ + "-shared $DT_RELR_CC_LDFLAGS" \ + "-fPIC" \ + { dt-relr-glibc-1.c } \ + {{readelf {-W --version-info} dt-relr-glibc-1b.rd}} \ + "dt-relr-glibc-1b.so" \ + ] \ +] -- cgit v1.1