From 647e4d46495f2bfb0950fd1066c8a660173cca40 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Wed, 22 Jun 2016 05:37:24 -0700 Subject: [PATCH] ld: Add a linker configure option --enable-relro Add a configure option --enable-relro to decide whether -z relro should be enabled in ELF linker by default. Default to yes for all Linux targets, except FRV, HPPA, IA64 and MIPS, since many relro tests fail on these targets. PR ld/20283 * NEWS: Mention --enable-relro. * configure.ac: Add --enable-relro. (DEFAULT_LD_Z_RELRO): New. Set by --enable-relro. * configure.tgt (ac_default_ld_z_relro): Default it to 1 for some Linux targets. * config.in: Regenerated. * configure: Likewise. * emultempl/elf32.em (gld${EMULATION_NAME}_before_parse): Set link_info.relro to DEFAULT_LD_Z_RELRO. * testsuite/config/default.exp (ld_elf_shared_opt): New. * testsuite/lib/ld-lib.exp (run_dump_test): Pass $ld_elf_shared_opt to ld for ELF targets with shared object support. (run_ld_link_tests): Likewise. --- ld/ChangeLog | 18 ++++++++++++++++++ ld/NEWS | 4 ++++ ld/config.in | 3 +++ ld/configure | 26 ++++++++++++++++++++++++-- ld/configure.ac | 18 ++++++++++++++++++ ld/configure.tgt | 25 +++++++++++++++++++++++++ ld/emultempl/elf32.em | 1 + ld/testsuite/config/default.exp | 3 +++ ld/testsuite/lib/ld-lib.exp | 18 ++++++++++++++++-- 9 files changed, 112 insertions(+), 4 deletions(-) diff --git a/ld/ChangeLog b/ld/ChangeLog index 7a2d781fc7b..8c85993b605 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,21 @@ +2016-06-22 H.J. Lu + + PR ld/20283 + * NEWS: Mention --enable-relro. + * configure.ac: Add --enable-relro. + (DEFAULT_LD_Z_RELRO): New. Set by --enable-relro. + * configure.tgt (ac_default_ld_z_relro): Default it to 1 for + some Linux targets. + * config.in: Regenerated. + * configure: Likewise. + * emultempl/elf32.em (gld${EMULATION_NAME}_before_parse): Set + link_info.relro to DEFAULT_LD_Z_RELRO. + * testsuite/config/default.exp (ld_elf_shared_opt): New. + * testsuite/lib/ld-lib.exp (run_dump_test): Pass + $ld_elf_shared_opt to ld for ELF targets with shared object + support. + (run_ld_link_tests): Likewise. + 2016-06-21 Maciej W. Rozycki * testsuite/ld-mips-elf/mode-change-error-1a.s: Trigger an error diff --git a/ld/NEWS b/ld/NEWS index 228fddf7103..b373f7cc97d 100644 --- a/ld/NEWS +++ b/ld/NEWS @@ -1,5 +1,9 @@ -*- text -*- +* Add a configure option --enable-relro to decide whether -z relro should + be enabled in ELF linker by default. Default to yes for all Linux + targets except FRV, HPPA, IA64 and MIPS. + * Support for -z noreloc-overflow in the x86-64 ELF linker to disable relocation overflow check. diff --git a/ld/config.in b/ld/config.in index 276fb776da0..2c6d698b6ce 100644 --- a/ld/config.in +++ b/ld/config.in @@ -10,6 +10,9 @@ /* Define if you want compressed debug sections by default. */ #undef DEFAULT_FLAG_COMPRESS_DEBUG +/* Define to 1 if you want to enable -z relro in ELF linker by default. */ +#undef DEFAULT_LD_Z_RELRO + /* Define to 1 if translation of program messages to the user's native language is requested. */ #undef ENABLE_NLS diff --git a/ld/configure b/ld/configure index da93e0723a3..a469ad464a4 100755 --- a/ld/configure +++ b/ld/configure @@ -791,6 +791,7 @@ with_sysroot enable_gold enable_got enable_compressed_debug_sections +enable_relro enable_werror enable_build_warnings enable_nls @@ -1449,6 +1450,7 @@ Optional Features: multigot) --enable-compressed-debug-sections={all,ld,none} compress debug sections by default] + --enable-relro enable -z relro in ELF linker by default --enable-werror treat compile warnings as errors --enable-build-warnings enable build-time compiler warnings --disable-nls do not use Native Language Support @@ -11721,7 +11723,7 @@ else lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2 lt_status=$lt_dlunknown cat > conftest.$ac_ext <<_LT_EOF -#line 11724 "configure" +#line 11726 "configure" #include "confdefs.h" #if HAVE_DLFCN_H @@ -11827,7 +11829,7 @@ else lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2 lt_status=$lt_dlunknown cat > conftest.$ac_ext <<_LT_EOF -#line 11830 "configure" +#line 11832 "configure" #include "confdefs.h" #if HAVE_DLFCN_H @@ -15541,6 +15543,17 @@ if test "${enable_compressed_debug_sections+set}" = set; then : esac fi +# Decide if -z relro should be enabled in ELF linker by default. +ac_default_ld_z_relro=unset +# Provide a configure time option to override our default. +# Check whether --enable-relro was given. +if test "${enable_relro+set}" = set; then : + enableval=$enable_relro; case "${enableval}" in + yes) ac_default_ld_z_relro=1 ;; + no) ac_default_ld_z_relro=0 ;; +esac +fi + # Set the 'development' global. . $srcdir/../bfd/development.sh @@ -17147,6 +17160,15 @@ $as_echo "#define DEFAULT_FLAG_COMPRESS_DEBUG 1" >>confdefs.h fi +if test "${ac_default_ld_z_relro}" = unset; then + ac_default_ld_z_relro=0 +fi + +cat >>confdefs.h <<_ACEOF +#define DEFAULT_LD_Z_RELRO $ac_default_ld_z_relro +_ACEOF + + diff --git a/ld/configure.ac b/ld/configure.ac index 65425060c02..d17281f0a0c 100644 --- a/ld/configure.ac +++ b/ld/configure.ac @@ -155,6 +155,17 @@ AC_ARG_ENABLE(compressed_debug_sections, ,no, | ,none,) ac_default_compressed_debug_sections=no ;; esac])dnl +# Decide if -z relro should be enabled in ELF linker by default. +ac_default_ld_z_relro=unset +# Provide a configure time option to override our default. +AC_ARG_ENABLE(relro, + AS_HELP_STRING([--enable-relro], + [enable -z relro in ELF linker by default]), +[case "${enableval}" in + yes) ac_default_ld_z_relro=1 ;; + no) ac_default_ld_z_relro=0 ;; +esac])dnl + AM_BINUTILS_WARNINGS AM_LC_MESSAGES @@ -376,6 +387,13 @@ if test x$ac_default_compressed_debug_sections = xyes ; then AC_DEFINE(DEFAULT_FLAG_COMPRESS_DEBUG, 1, [Define if you want compressed debug sections by default.]) fi +if test "${ac_default_ld_z_relro}" = unset; then + ac_default_ld_z_relro=0 +fi +AC_DEFINE_UNQUOTED(DEFAULT_LD_Z_RELRO, + $ac_default_ld_z_relro, + [Define to 1 if you want to enable -z relro in ELF linker by default.]) + AC_SUBST(elf_list_options) AC_SUBST(elf_shlib_list_options) AC_SUBST(elf_plt_unwind_list_options) diff --git a/ld/configure.tgt b/ld/configure.tgt index 625194342e7..a3db9091243 100644 --- a/ld/configure.tgt +++ b/ld/configure.tgt @@ -882,3 +882,28 @@ alpha*-*-*) ;; esac + +case "${target}" in +frv-*-* | hppa*-*-* | ia64-*-* | mips*-*-*) + # Don't enable -z relro by default since many relro tests fail on these + # targets: + # FAIL: strip -z relro (relro1) + # FAIL: strip -z relro -shared (relro1) + # FAIL: objcopy -z relro (relro1) + # FAIL: objcopy -z relro -shared (relro1) + # FAIL: objcopy -z relro (tdata1) + # FAIL: objcopy -shared -z relro (tdata1) + # FAIL: objcopy -z relro (tdata2) + # FAIL: objcopy -shared -z relro (tdata2) + # FAIL: objcopy -z relro (tdata3) + # FAIL: objcopy -shared -z relro (tdata3) + # FAIL: objcopy -shared -z relro (tbss1) + # FAIL: objcopy -shared -z relro (tbss2) + # FAIL: objcopy -shared -z relro (tbss3) + ;; +*-*-linux*) + if test ${ac_default_ld_z_relro} = unset; then + ac_default_ld_z_relro=1 + fi + ;; +esac diff --git a/ld/emultempl/elf32.em b/ld/emultempl/elf32.em index c2ad2022cee..47fa549a9af 100644 --- a/ld/emultempl/elf32.em +++ b/ld/emultempl/elf32.em @@ -105,6 +105,7 @@ gld${EMULATION_NAME}_before_parse (void) config.separate_code = `if test "x${SEPARATE_CODE}" = xyes ; then echo TRUE ; else echo FALSE ; fi`; `if test -n "$CALL_NOP_BYTE" ; then echo link_info.call_nop_byte = $CALL_NOP_BYTE; fi`; link_info.check_relocs_after_open_input = `if test "x${CHECK_RELOCS_AFTER_OPEN_INPUT}" = xyes ; then echo TRUE ; else echo FALSE ; fi`; + link_info.relro = DEFAULT_LD_Z_RELRO; } EOF diff --git a/ld/testsuite/config/default.exp b/ld/testsuite/config/default.exp index 8ccad111b5f..208c0d3b03d 100644 --- a/ld/testsuite/config/default.exp +++ b/ld/testsuite/config/default.exp @@ -76,6 +76,9 @@ if {[file exists tmpdir/libpath.exp]} { } } +# Many ELF testcases expect that "-z relro" is off. +set ld_elf_shared_opt "-z norelro" + # The "make check" target in the Makefile passes in # "CC=$(CC_FOR_TARGET)". But, if the user invokes runtest directly # (as when testing an installed linker), these flags may not be set. diff --git a/ld/testsuite/lib/ld-lib.exp b/ld/testsuite/lib/ld-lib.exp index 29af846427a..62f97689ac5 100644 --- a/ld/testsuite/lib/ld-lib.exp +++ b/ld/testsuite/lib/ld-lib.exp @@ -589,6 +589,13 @@ proc run_dump_test { name {extra_options {}} } { global OBJDUMPFLAGS NMFLAGS ASFLAGS OBJCOPYFLAGS READELFFLAGS LDFLAGS global host_triplet runtests global env verbose + global ld_elf_shared_opt + + if { [is_elf_format] && [check_shared_lib_support] } { + set ld_extra_opt "$ld_elf_shared_opt" + } else { + set ld_extra_opt "" + } if [string match "*/*" $name] { set file $name @@ -912,7 +919,7 @@ proc run_dump_test { name {extra_options {}} } { # Add -L$srcdir/$subdir so that the linker command can use # linker scripts in the source directory. - set cmd "$LD $LDFLAGS -L$srcdir/$subdir \ + set cmd "$LD $ld_extra_opt $LDFLAGS -L$srcdir/$subdir \ $opts(ld) -o $objfile $objfiles $opts(ld_after_inputfiles)" # If needed then check for, or add a -Map option. @@ -1166,6 +1173,13 @@ proc run_ld_link_tests { ldtests } { global CFLAGS global runtests global exec_output + global ld_elf_shared_opt + + if { [is_elf_format] && [check_shared_lib_support] } { + set ld_extra_opt "$ld_elf_shared_opt" + } else { + set ld_extra_opt "" + } foreach testitem $ldtests { set testname [lindex $testitem 0] @@ -1228,7 +1242,7 @@ proc run_ld_link_tests { ldtests } { if { ![ar_simple_create $ar $ld_options $binfile "$objfiles $ld_after"] } { set failed 1 } - } elseif { ![ld_simple_link $ld $binfile "-L$srcdir/$subdir $ld_options $objfiles $ld_after"] } { + } elseif { ![ld_simple_link $ld $binfile "$ld_extra_opt -L$srcdir/$subdir $ld_options $objfiles $ld_after"] } { set maybe_failed 1 set ld_output "$exec_output" } -- 2.30.2