From patchwork Fri Sep 1 17:49:09 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Lu, Hongjiu" X-Patchwork-Id: 22505 Received: (qmail 24546 invoked by alias); 1 Sep 2017 17:49:17 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 24053 invoked by uid 89); 1 Sep 2017 17:49:16 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-24.5 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_LAZY_DOMAIN_SECURITY, NO_DNS_FOR_FROM, RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy=LD X-HELO: mga05.intel.com X-ExtLoop1: 1 Date: Fri, 1 Sep 2017 10:49:09 -0700 From: "H.J. Lu" To: GNU C Library Subject: [PATCH] Add --enable-static-pie to build static PIE Message-ID: <20170901174909.GA11261@gmail.com> Reply-To: "H.J. Lu" MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.8.3 (2017-05-23) --enable-static-pie configures glibc to compile libc.a as PIE and creates static executables as PIE. A static position independent executable (static PIE) is similar to static executable, but can be loaded at any address without help from a dynamic linker. All linker input files must be compiled with -fpie or -fPIE. "-z text" is also passed to linker to prevent dynamic relocations in read-only segments. It passes -static-pie to the GCC driver with the patch: https://gcc.gnu.org/ml/gcc-patches/2017-08/msg01455.html This patch requires: 1. Linker supports --no-dynamic-linker to remove PT_INTERP segment from static PIE. 2. Linker can create working static PIE. The x86-64 linker needs the fix for https://sourceware.org/bugzilla/show_bug.cgi?id=21782 Binutils 2.29 or above are OK. Tested on i686 and x86-64. OK for master? H.J. --- * Makeconfig (pic-default): Updated for --enable-static-pie. (pie-default): New for --enable-static-pie. (default-pie-ldflag): Likewise. (+link-static-before-libc): Add $(default-pie-ldflag). (+prectorT): Updated for --enable-static-pie. (+postctorT): Likewise. (CFLAGS-.o): Add $(pie-default). (CFLAGS-.op): Likewise. * config.h.in (ENABLE_STATIC_PIE): New. * configure.ac (--enable-static-pie): New configure option. (have-no-dynamic-linker): New LIBC_CONFIG_VAR. (have-static-pie): Likewise. Enable static PIE if linker supports --no-dynamic-linker. (ENABLE_STATIC_PIE): New AC_DEFINE. (enable-static-pie): New LIBC_CONFIG_VAR. * configure: Regenerated. * csu/libc-start.c (LIBC_START_MAIN): Call _dl_relocate_static_pie in libc.a. * csu/libc-tls.c (__libc_setup_tls): Add main_map->l_addr to initimage. * elf/dl-support.c: Include "dynamic-link.h" and don't include "get-dynamic-info.h" for --enable-static-pie. (_dl_relocate_static_pie): New function for --enable-static-pie. (STATIC_PIE_BOOTSTRAP): New for --enable-static-pie. (RESOLVE_MAP): Likewise. * elf/dynamic-link.h (ELF_DURING_STARTUP): Also check STATIC_PIE_BOOTSTRAP. * elf/get-dynamic-info.h (elf_get_dynamic_info): Likewise. * sysdeps/generic/ldsodefs.h (_dl_relocate_static_pie): New. * sysdeps/x86_64/configure.ac: Check if linker supports static PIE. * sysdeps/x86_64/configure: Regenerated. --- Makeconfig | 20 ++++++++++-- config.h.in | 3 ++ configure | 78 +++++++++++++++++++++++++++++++++++++++++++++ configure.ac | 29 +++++++++++++++++ csu/libc-start.c | 2 ++ csu/libc-tls.c | 6 ++-- elf/dl-support.c | 39 +++++++++++++++++++++-- elf/dynamic-link.h | 2 +- elf/get-dynamic-info.h | 6 ++-- sysdeps/generic/ldsodefs.h | 7 ++++ sysdeps/x86_64/configure | 33 +++++++++++++++++++ sysdeps/x86_64/configure.ac | 22 +++++++++++++ 12 files changed, 237 insertions(+), 10 deletions(-) diff --git a/Makeconfig b/Makeconfig index b51904b797..b45209fe5f 100644 --- a/Makeconfig +++ b/Makeconfig @@ -386,6 +386,16 @@ LDFLAGS.so += $(hashstyle-LDFLAGS) LDFLAGS-rtld += $(hashstyle-LDFLAGS) endif +ifeq (yes,$(enable-static-pie)) +pic-default = -DPIC +pie-default = $(pie-ccflag) +ifeq (yes,$(have-static-pie)) +default-pie-ldflag = -static-pie +else +default-pie-ldflag = -Wl,-pie,--no-dynamic-linker,--eh-frame-hdr,-z,text +endif +endif + # If lazy relocations are disabled, add the -z now flag. Use # LDFLAGS-lib.so instead of LDFLAGS.so, to avoid adding the flag to # test modules. @@ -435,6 +445,7 @@ endif # Command for statically linking programs with the C library. ifndef +link-static +link-static-before-libc = $(CC) -nostdlib -nostartfiles -static -o $@ \ + $(default-pie-ldflag) \ $(sysdep-LDFLAGS) $(LDFLAGS) $(LDFLAGS-$(@F)) \ $(addprefix $(csu-objpfx),$(static-start-installed-name)) \ $(+preinit) $(+prectorT) \ @@ -651,8 +662,13 @@ endif +prectorS = `$(CC) $(sysdep-LDFLAGS) --print-file-name=crtbeginS.o` +postctorS = `$(CC) $(sysdep-LDFLAGS) --print-file-name=crtendS.o` # Variants of the two previous definitions for statically linking programs. +ifeq (yes,$(enable-static-pie)) ++prectorT = $(+prectorS) ++postctorT = $(+postctorS) +else +prectorT = `$(CC) $(sysdep-LDFLAGS) --print-file-name=crtbeginT.o` +postctorT = `$(CC) $(sysdep-LDFLAGS) --print-file-name=crtend.o` +endif csu-objpfx = $(common-objpfx)csu/ elf-objpfx = $(common-objpfx)elf/ @@ -973,7 +989,7 @@ libtypes = $(foreach o,$(object-suffixes-for-libc),$(libtype$o)) all-object-suffixes := .o .os .oS object-suffixes := CPPFLAGS-.o = $(pic-default) -CFLAGS-.o = $(filter %frame-pointer,$(+cflags)) +CFLAGS-.o = $(filter %frame-pointer,$(+cflags)) $(pie-default) libtype.o := lib%.a object-suffixes += .o ifeq (yes,$(build-shared)) @@ -998,7 +1014,7 @@ ifeq (yes,$(build-profile)) all-object-suffixes += .op object-suffixes += .op CPPFLAGS-.op = -DPROF $(pic-default) -CFLAGS-.op = -pg +CFLAGS-.op = -pg $(pie-default) libtype.op = lib%_p.a endif diff --git a/config.h.in b/config.h.in index 014fb4ea0e..26ed7865ef 100644 --- a/config.h.in +++ b/config.h.in @@ -236,6 +236,9 @@ /* Build glibc with tunables support. */ #define HAVE_TUNABLES 0 +/* Define if static PIE is enabled. */ +#define ENABLE_STATIC_PIE 0 + /* Some compiler options may now allow to use ebp in __asm__ (used mainly in i386 6 argument syscall issue). */ #define CAN_USE_REGISTER_ASM_EBP 0 diff --git a/configure b/configure index 5cb5210107..a04c59bacd 100755 --- a/configure +++ b/configure @@ -767,6 +767,7 @@ with_default_link enable_sanity_checks enable_shared enable_profile +enable_static_pie enable_timezone_tools enable_hardcoded_path_in_tests enable_stackguard_randomization @@ -1424,6 +1425,7 @@ Optional Features: in special situations) [default=yes] --enable-shared build shared library [default=yes if GNU ld] --enable-profile build profiled library [default=no] + --enable-static-pie build static executables as PIE [default=no] --disable-timezone-tools do not install timezone tools [default=install] --enable-hardcoded-path-in-tests @@ -3372,6 +3374,13 @@ else profile=no fi +# Check whether --enable-static-pie was given. +if test "${enable_static_pie+set}" = set; then : + enableval=$enable_static_pie; static_pie=$enableval +else + static_pie=no +fi + # Check whether --enable-timezone-tools was given. if test "${enable_timezone_tools+set}" = set; then : enableval=$enable_timezone_tools; enable_timezone_tools=$enableval @@ -5994,6 +6003,62 @@ fi $as_echo "$libc_linker_feature" >&6; } +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for linker that supports --no-dynamic-linker" >&5 +$as_echo_n "checking for linker that supports --no-dynamic-linker... " >&6; } +libc_linker_feature=no +if test x"$gnu_ld" = x"yes"; then + libc_linker_check=`$LD -v --help 2>/dev/null | grep "\--no-dynamic-linker"` + if test -n "$libc_linker_check"; then + cat > conftest.c <&5 + (eval $ac_try) 2>&5 + ac_status=$? + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 + test $ac_status = 0; }; } + then + libc_linker_feature=yes + fi + rm -f conftest* + fi +fi +if test $libc_linker_feature = yes; then + libc_cv_no_dynamic_linker=yes +else + libc_cv_no_dynamic_linker=no +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_linker_feature" >&5 +$as_echo "$libc_linker_feature" >&6; } +config_vars="$config_vars +have-no-dynamic-linker = $libc_cv_no_dynamic_linker" + +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for -static-pie" >&5 +$as_echo_n "checking for -static-pie... " >&6; } +if ${libc_cv_static_pie+:} false; then : + $as_echo_n "(cached) " >&6 +else + if { ac_try='${CC-cc} -static-pie -xc /dev/null -S -o /dev/null' + { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 + (eval $ac_try) 2>&5 + ac_status=$? + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 + test $ac_status = 0; }; }; then : + libc_cv_static_pie=yes +else + libc_cv_static_pie=no +fi + +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_static_pie" >&5 +$as_echo "$libc_cv_static_pie" >&6; } +config_vars="$config_vars +have-static-pie = $libc_cv_static_pie" + { $as_echo "$as_me:${as_lineno-$LINENO}: checking for -fpie" >&5 $as_echo_n "checking for -fpie... " >&6; } if ${libc_cv_fpie+:} false; then : @@ -6888,6 +6953,19 @@ fi $as_echo "$libc_cv_pie_default" >&6; } +if test "$static_pie" = yes; then + # The linker must support --no-dynamic-linker. + if test "$libc_cv_no_dynamic_linker" != yes; then + as_fn_error $? "linker support for --no-dynamic-linker needed" "$LINENO" 5 + fi + # Default to PIE. + libc_cv_pie_default=yes + $as_echo "#define ENABLE_STATIC_PIE 1" >>confdefs.h + +fi +config_vars="$config_vars +enable-static-pie = $static_pie" + diff --git a/configure.ac b/configure.ac index 2c6308883c..96af835ce8 100644 --- a/configure.ac +++ b/configure.ac @@ -176,6 +176,11 @@ AC_ARG_ENABLE([profile], [build profiled library @<:@default=no@:>@]), [profile=$enableval], [profile=no]) +AC_ARG_ENABLE([static-pie], + AC_HELP_STRING([--enable-static-pie], + [build static executables as PIE @<:@default=no@:>@]), + [static_pie=$enableval], + [static_pie=no]) AC_ARG_ENABLE([timezone-tools], AC_HELP_STRING([--disable-timezone-tools], [do not install timezone tools @<:@default=install@:>@]), @@ -1460,6 +1465,19 @@ LIBC_LINKER_FEATURE([-z execstack], [-Wl,-z,execstack], [libc_cv_z_execstack=yes], [libc_cv_z_execstack=no]) AC_SUBST(libc_cv_z_execstack) +LIBC_LINKER_FEATURE([--no-dynamic-linker], + [-Wl,--no-dynamic-linker], + [libc_cv_no_dynamic_linker=yes], + [libc_cv_no_dynamic_linker=no]) +LIBC_CONFIG_VAR([have-no-dynamic-linker], [$libc_cv_no_dynamic_linker]) + +AC_CACHE_CHECK(for -static-pie, libc_cv_static_pie, [dnl +LIBC_TRY_CC_OPTION([-static-pie], + [libc_cv_static_pie=yes], + [libc_cv_static_pie=no]) +]) +LIBC_CONFIG_VAR([have-static-pie], [$libc_cv_static_pie]) + AC_CACHE_CHECK(for -fpie, libc_cv_fpie, [dnl LIBC_TRY_CC_OPTION([-fpie], [libc_cv_fpie=yes], [libc_cv_fpie=no]) ]) @@ -1962,6 +1980,17 @@ fi rm -f conftest.*]) AC_SUBST(libc_cv_pie_default) +if test "$static_pie" = yes; then + # The linker must support --no-dynamic-linker. + if test "$libc_cv_no_dynamic_linker" != yes; then + AC_MSG_ERROR([linker support for --no-dynamic-linker needed]) + fi + # Default to PIE. + libc_cv_pie_default=yes + AC_DEFINE(ENABLE_STATIC_PIE) +fi +LIBC_CONFIG_VAR([enable-static-pie], [$static_pie]) + AC_SUBST(profile) AC_SUBST(static_nss) diff --git a/csu/libc-start.c b/csu/libc-start.c index 24c63be02f..34dd125260 100644 --- a/csu/libc-start.c +++ b/csu/libc-start.c @@ -141,6 +141,8 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL), __libc_multiple_libcs = &_dl_starting_up && !_dl_starting_up; #ifndef SHARED + _dl_relocate_static_pie (); + char **ev = &argv[argc + 1]; __environ = ev; diff --git a/csu/libc-tls.c b/csu/libc-tls.c index 00138eb43a..1f8ddaf543 100644 --- a/csu/libc-tls.c +++ b/csu/libc-tls.c @@ -114,6 +114,8 @@ __libc_setup_tls (void) size_t tcb_offset; const ElfW(Phdr) *phdr; + struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded; + /* Look through the TLS segment if there is any. */ if (_dl_phdr != NULL) for (phdr = _dl_phdr; phdr < &_dl_phdr[_dl_phnum]; ++phdr) @@ -122,7 +124,7 @@ __libc_setup_tls (void) /* Remember the values we need. */ memsz = phdr->p_memsz; filesz = phdr->p_filesz; - initimage = (void *) phdr->p_vaddr; + initimage = (void *) phdr->p_vaddr + main_map->l_addr; align = phdr->p_align; if (phdr->p_align > max_align) max_align = phdr->p_align; @@ -163,8 +165,6 @@ __libc_setup_tls (void) _dl_static_dtv[0].counter = (sizeof (_dl_static_dtv) / sizeof (_dl_static_dtv[0])) - 2; // _dl_static_dtv[1].counter = 0; would be needed if not already done - struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded; - /* Initialize the TLS block. */ #if TLS_TCB_AT_TP _dl_static_dtv[2].pointer.val = ((char *) tlsblock + tcb_offset diff --git a/elf/dl-support.c b/elf/dl-support.c index 48340f7959..09b2229d48 100644 --- a/elf/dl-support.c +++ b/elf/dl-support.c @@ -26,7 +26,11 @@ #include #include #include -#include +#if ENABLE_STATIC_PIE +# include "dynamic-link.h" +#else +# include +#endif #include #include #include @@ -199,7 +203,9 @@ const ElfW(Ehdr) *_dl_sysinfo_dso; struct link_map *_dl_sysinfo_map; -# include "get-dynamic-info.h" +# if !ENABLE_STATIC_PIE +# include "get-dynamic-info.h" +# endif #endif #include "setup-vdso.h" @@ -303,6 +309,35 @@ _dl_aux_init (ElfW(auxv_t) *av) } #endif +#if ENABLE_STATIC_PIE +/* Relocate static executable with PIE. */ + +void +_dl_relocate_static_pie (void) +{ +# define STATIC_PIE_BOOTSTRAP +# define RESOLVE_MAP(sym, version, flags) (&_dl_main_map) +# include "dynamic-link.h" + + /* Figure out the run-time load addres of static PIE. */ + _dl_main_map.l_addr = elf_machine_load_address (); + + /* Read our own dynamic section and fill in the info array. */ + _dl_main_map.l_ld = ((void *) _dl_main_map.l_addr + + elf_machine_dynamic ()); + elf_get_dynamic_info (&_dl_main_map, NULL); + +# ifdef ELF_MACHINE_BEFORE_RTLD_RELOC + ELF_MACHINE_BEFORE_RTLD_RELOC (_dl_main_map.l_info); +# endif + + /* Relocate ourselves so we can do normal function calls and + data access using the global offset table. */ + ELF_DYNAMIC_RELOCATE (&_dl_main_map, 0, 0, 0); + _dl_main_map.l_relocated = 1; +} +#endif + void internal_function diff --git a/elf/dynamic-link.h b/elf/dynamic-link.h index 60f2d91151..d3935f7da7 100644 --- a/elf/dynamic-link.h +++ b/elf/dynamic-link.h @@ -95,7 +95,7 @@ elf_machine_lazy_rel (struct link_map *map, #ifdef RESOLVE_MAP -# ifdef RTLD_BOOTSTRAP +# if defined RTLD_BOOTSTRAP || defined STATIC_PIE_BOOTSTRAP # define ELF_DURING_STARTUP (1) # else # define ELF_DURING_STARTUP (0) diff --git a/elf/get-dynamic-info.h b/elf/get-dynamic-info.h index 7525c3a5b2..eb26d23649 100644 --- a/elf/get-dynamic-info.h +++ b/elf/get-dynamic-info.h @@ -38,7 +38,7 @@ elf_get_dynamic_info (struct link_map *l, ElfW(Dyn) *temp) typedef Elf64_Xword d_tag_utype; #endif -#ifndef RTLD_BOOTSTRAP +#if !defined RTLD_BOOTSTRAP && !defined STATIC_PIE_BOOTSTRAP if (dyn == NULL) return; #endif @@ -139,9 +139,11 @@ elf_get_dynamic_info (struct link_map *l, ElfW(Dyn) *temp) /* Only the bind now flags are allowed. */ assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0); + /* Flags must not be set for ld.so. */ assert (info[DT_FLAGS] == NULL || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0); - /* Flags must not be set for ld.so. */ +#endif +#if defined RTLD_BOOTSTRAP || defined STATIC_PIE_BOOTSTRAP assert (info[DT_RUNPATH] == NULL); assert (info[DT_RPATH] == NULL); #else diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h index 49e673dd24..83791103cf 100644 --- a/sysdeps/generic/ldsodefs.h +++ b/sysdeps/generic/ldsodefs.h @@ -1069,6 +1069,13 @@ extern void _dl_determine_tlsoffset (void) internal_function attribute_hidden; stack protector, among other things). */ void __libc_setup_tls (void); +# if ENABLE_STATIC_PIE +/* Relocate static executable with PIE. */ +void _dl_relocate_static_pie (void) attribute_hidden; +# else +# define _dl_relocate_static_pie() +# endif + /* Initialization of libpthread for statically linked applications. If libpthread is not linked in, this is an empty function. */ void __pthread_initialize_minimal (void) weak_function; diff --git a/sysdeps/x86_64/configure b/sysdeps/x86_64/configure index efef46b1b7..8ee15b8a25 100644 --- a/sysdeps/x86_64/configure +++ b/sysdeps/x86_64/configure @@ -85,6 +85,39 @@ if test x"$build_mathvec" = xnotset; then build_mathvec=yes fi +if test "$static_pie" = yes; then + { $as_echo "$as_me:${as_lineno-$LINENO}: checking for linker static PIE support" >&5 +$as_echo_n "checking for linker static PIE support... " >&6; } +if ${libc_cv_ld_static_pie+:} false; then : + $as_echo_n "(cached) " >&6 +else + cat > conftest.s <<\EOF + .text + .global _start + .weak foo +_start: + leaq foo(%rip), %rax +EOF + libc_cv_pie_option="-Wl,-pie" + if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -nostartfiles -nostdlib $no_ssp $libc_cv_pie_option conftest.s 1>&5' + { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 + (eval $ac_try) 2>&5 + ac_status=$? + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 + test $ac_status = 0; }; }; then + libc_cv_ld_static_pie=yes + else + libc_cv_ld_static_pie=no + fi +rm -f conftest* +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_ld_static_pie" >&5 +$as_echo "$libc_cv_ld_static_pie" >&6; } + if test "$libc_cv_ld_static_pie" != yes; then + as_fn_error $? "linker support for static PIE needed" "$LINENO" 5 + fi +fi + $as_echo "#define PI_STATIC_AND_HIDDEN 1" >>confdefs.h diff --git a/sysdeps/x86_64/configure.ac b/sysdeps/x86_64/configure.ac index fa86e953ee..c2d7cf3e61 100644 --- a/sysdeps/x86_64/configure.ac +++ b/sysdeps/x86_64/configure.ac @@ -44,6 +44,28 @@ if test x"$build_mathvec" = xnotset; then build_mathvec=yes fi +dnl Check if linker supports static PIE. +if test "$static_pie" = yes; then + AC_CACHE_CHECK(for linker static PIE support, libc_cv_ld_static_pie, [dnl +cat > conftest.s <<\EOF + .text + .global _start + .weak foo +_start: + leaq foo(%rip), %rax +EOF + libc_cv_pie_option="-Wl,-pie" + if AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -nostartfiles -nostdlib $no_ssp $libc_cv_pie_option conftest.s 1>&AS_MESSAGE_LOG_FD); then + libc_cv_ld_static_pie=yes + else + libc_cv_ld_static_pie=no + fi +rm -f conftest*]) + if test "$libc_cv_ld_static_pie" != yes; then + AC_MSG_ERROR([linker support for static PIE needed]) + fi +fi + dnl It is always possible to access static and hidden symbols in an dnl position independent way. AC_DEFINE(PI_STATIC_AND_HIDDEN)