From c9972a39895ce2aeb19d0f783569aea750f1698f Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Mon, 17 Jul 2017 08:17:32 -0700
Subject: [PATCH 01/11] Add --enable-static-pie configure option to build
static PIE [BZ #19574]
Dynamic linker, ld.so, is a standalone program which can be loaded at
any address. This patch adds a configure option, --enable-static-pie,
to embed the part of ld.so in static executable to create static position
independent executable (static PIE). A static PIE is similar to static
executable, but can be loaded at any address without help from a dynamic
linker. When --enable-static-pie is used to configure glibc, libc.a is
built as PIE and all static executables, including tests, are built as
static PIE. The resulting libc.a can be used together with GCC 8 or
above to build static PIE with the compiler option, -static-pie. But
GCC 8 isn't required to build glibc with --enable-static-pie. When an
older GCC is used to build glibc with --enable-static-pie, proper input
files are passed to linker to create static executables as static PIE,
together with "-z text" to prevent dynamic relocations in read-only
segments, which are allowed in static PIE.
crt1.o, which is used to create dynamic and non-PIE static executables,
is updated to include a dummy _dl_relocate_static_pie. Pcrt1.o is added
to create static PIE, which will link in the real _dl_relocate_static_pie.
Static PIE can work on all architectures which support PIE, provided
1. Target must support accessing of local functions without dynamic
relocations, which is needed in start.S to call __libc_start_main with
function addresses of __libc_csu_init, __libc_csu_fini and main. All
functions in statice PIE are local functions. If PIE start.S can't
reach main () defined in a shared object, the code sequence:
pass addess of local_main to __libc_start_main
...
local_main:
tail call to main via PLT
can be used.
2. start.S is updated to check PIC instead SHARED for PIC code path and
avoid dynamic relocation, when PIC is defined and SHARED isn't defined,
to support static PIE. Patches are submitted for aarch64, hppa, m68k,
microblaze and sparc.
3. All assembly codes are updated check PIC instead SHARED for PIC code
path to avoid dynamic relocations in read-only sections.
4. All assembly codes are updated check SHARED instead PIC for static
symbol name. A patch is submitted for tile.
5. elf_machine_load_address in dl-machine.h are updated to support static
PIE. Patches are submitted for aarch64, m68k, s390 and sh.
NB: When glibc is built with GCC defaulted to PIE, libc.a is compiled
with -fPIE, regardless if --enable-static-pie is used to configure glibc.
When glibc is configured with --enable-static-pie, libc.a is compiled
with -fPIE, regardless wether GCC defaults to PIE or not. The same libc.a
can be used to build both static executable and static PIE. There is no
need for separate PIE copy of libc.a.
Linker requirements to build glibc with --enable-static-pie:
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
The i386 linker needs to be able to convert "movl main@GOT(%ebx), %eax"
to "leal main@GOTOFF(%ebx), %eax" if main is defined locally.
Binutils 2.29 or above are OK for i686 and x86-64. But linker status for
other targets need to be verified.
Tested on i686 and x86-64.
Build results of build-many-glibcs.py with --enable-static-pie with all
patches for static PIE applied are
PASS: glibcs-aarch64_be-linux-gnu build
PASS: glibcs-aarch64-linux-gnu build
PASS: glibcs-armeb-linux-gnueabi build
PASS: glibcs-armeb-linux-gnueabi-be8 build
PASS: glibcs-armeb-linux-gnueabihf build
PASS: glibcs-armeb-linux-gnueabihf-be8 build
PASS: glibcs-arm-linux-gnueabi build
PASS: glibcs-arm-linux-gnueabihf build
PASS: glibcs-hppa-linux-gnu build
PASS: glibcs-i486-linux-gnu build
PASS: glibcs-i586-linux-gnu build
PASS: glibcs-i686-linux-gnu build
PASS: glibcs-i686-linux-gnu-disable-multi-arch build
PASS: glibcs-m68k-linux-gnu build
PASS: glibcs-microblazeel-linux-gnu build
PASS: glibcs-microblaze-linux-gnu build
PASS: glibcs-mips64el-linux-gnu-n64 build
PASS: glibcs-mips64el-linux-gnu-n64-nan2008 build
PASS: glibcs-mips64el-linux-gnu-n64-nan2008-soft build
PASS: glibcs-mips64el-linux-gnu-n64-soft build
PASS: glibcs-mips64-linux-gnu-n64 build
PASS: glibcs-mips64-linux-gnu-n64-nan2008 build
PASS: glibcs-mips64-linux-gnu-n64-nan2008-soft build
PASS: glibcs-mips64-linux-gnu-n64-soft build
PASS: glibcs-nios2-linux-gnu build
PASS: glibcs-powerpc64le-linux-gnu build
PASS: glibcs-powerpc64-linux-gnu build
PASS: glibcs-s390x-linux-gnu build
PASS: glibcs-x86_64-linux-gnu build
PASS: glibcs-x86_64-linux-gnu-disable-multi-arch build
PASS: glibcs-x86_64-linux-gnu-x32 build
FAIL: glibcs-alpha-linux-gnu build
elf/sln is failed to link due to:
assertion fail bfd/elf64-alpha.c:4125
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-ia64-linux-gnu build
elf/sln is failed to link due to:
libc.a(sched_yield.o): non-pic code with imm relocation against dynamic symbol `_dl_sysinfo'
This is caused by non-PIC version of DO_CALL macro in ia64 sysdep.h. PIE
libc.a should use PIC version of DO_CALL, except during startup in static
PIE. An ia64 startup.h, similar to i386 startup.h, is needed to handle
this.
FAIL: glibcs-mips64el-linux-gnu-n32 build
FAIL: glibcs-mips64el-linux-gnu-n32-nan2008 build
FAIL: glibcs-mips64el-linux-gnu-n32-nan2008-soft build
FAIL: glibcs-mips64el-linux-gnu-n32-soft build
FAIL: glibcs-mips64-linux-gnu-n32 build
FAIL: glibcs-mips64-linux-gnu-n32-nan2008 build
FAIL: glibcs-mips64-linux-gnu-n32-nan2008-soft build
FAIL: glibcs-mips64-linux-gnu-n32-soft build
FAIL: glibcs-mipsel-linux-gnu build
FAIL: glibcs-mipsel-linux-gnu-nan2008 build
FAIL: glibcs-mipsel-linux-gnu-nan2008-soft build
FAIL: glibcs-mipsel-linux-gnu-soft build
FAIL: glibcs-mips-linux-gnu build
FAIL: glibcs-mips-linux-gnu-nan2008 build
FAIL: glibcs-mips-linux-gnu-nan2008-soft build
FAIL: glibcs-mips-linux-gnu-soft build
elf/sln is failed to link due to:
crt1.o: relocation R_MIPS_HI16 against `_gp' can not be used when making a shared object; recompile with -fPIC
This is caused by linker bug and/or non-PIC code in crt1.o.
FAIL: glibcs-powerpc-linux-gnu build
FAIL: glibcs-powerpc-linux-gnu-soft build
FAIL: glibcs-powerpc-linux-gnuspe build
FAIL: glibcs-powerpc-linux-gnuspe-e500v1 build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a. See:
https://sourceware.org/bugzilla/show_bug.cgi?id=22264
FAIL: glibcs-powerpc-linux-gnu-power4 build
elf/sln is failed to link due to:
findlocale.c:96:(.text+0x22c): @local call to ifunc memchr
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-s390-linux-gnu build
elf/sln is failed to link due to:
collect2: fatal error: ld terminated with signal 11 [Segmentation fault], core dumped
assertion fail bfd/elflink.c:14242
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-sh3eb-linux-gnu build
FAIL: glibcs-sh3-linux-gnu build
FAIL: glibcs-sh4eb-linux-gnu build
FAIL: glibcs-sh4eb-linux-gnu-soft build
FAIL: glibcs-sh4-linux-gnu build
FAIL: glibcs-sh4-linux-gnu-soft build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-sparc64-linux-gnu build
FAIL: glibcs-sparcv9-linux-gnu build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a. See:
https://sourceware.org/bugzilla/show_bug.cgi?id=20179
FAIL: glibcs-tilegxbe-linux-gnu build
FAIL: glibcs-tilegxbe-linux-gnu-32 build
FAIL: glibcs-tilegx-linux-gnu build
FAIL: glibcs-tilegx-linux-gnu-32 build
FAIL: glibcs-tilepro-linux-gnu build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a. See:
https://sourceware.org/bugzilla/show_bug.cgi?id=22263
[BZ #19574]
* INSTALL: Regenerated.
* Makeconfig (static-start-installed-name): Add the `P' prefix
for --enable-static-pie.
(pic-default): Updated for --enable-static-pie.
(pie-default): New for --enable-static-pie.
(default-pie-ldflag): Likewise.
(+link-static-before-libc): Use the first of $(DEFAULT-LDFLAGS-$(@F))
and $(default-pie-ldflag). Use the first of $(CRT-$(@F)) and
$(csu-objpfx)$(static-start-installed-name).
(+prectorT): Updated for --enable-static-pie.
(+postctorT): Likewise.
(CFLAGS-.o): Add $(pie-default).
(CFLAGS-.op): Likewise.
* NEWS: Mention --enable-static-pie.
* config.h.in (ENABLE_STATIC_PIE): New.
* configure.ac (--enable-static-pie): New configure option.
(have-no-dynamic-linker): New LIBC_CONFIG_VAR.
(have-static-pie): Likewise.
Enable static PIE if linker supports --no-dynamic-linker.
(ENABLE_STATIC_PIE): New AC_DEFINE.
(enable-static-pie): New LIBC_CONFIG_VAR.
* configure: Regenerated.
* csu/Makefile (omit-deps): Add P$(start-installed-name) for
--enable-static-pie.
(extra-objs): Likewise.
(install-lib): Likewise.
Don't add gPcrt1.o.
(extra-objs): Add static-reloc.o.
($(objpfx)$(start-installed-name)): Include $(objpfx)static-reloc.o.
($(objpfx)P$(start-installed-name)): New.
* 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.
* csu/static-reloc.c: New file.
* elf/Makefile (routines): Add dl-reloc-static-pie.
(elide-routines.os): Likewise.
* dl-reloc-static-pie.c: New file.
* elf/dl-support.c (_dl_main_map): Make it hidden global.
* elf/dynamic-link.h (ELF_DURING_STARTUP): Also check
STATIC_PIE_BOOTSTRAP.
* elf/get-dynamic-info.h (elf_get_dynamic_info): Likewise.
* manual/install.texi: Document --enable-static-pie.
* sysdeps/generic/ldsodefs.h (_dl_relocate_static_pie): New.
* sysdeps/i386/configure.ac: Check if linker supports static PIE.
* sysdeps/x86_64/configure.ac: Likewise.
* sysdeps/i386/configure: Regenerated.
* sysdeps/x86_64/configure: Likewise.
---
INSTALL | 8 +++++
Makeconfig | 27 +++++++++++++---
NEWS | 6 ++++
config.h.in | 3 ++
configure | 78 +++++++++++++++++++++++++++++++++++++++++++++
configure.ac | 29 +++++++++++++++++
csu/Makefile | 16 ++++++++--
csu/libc-start.c | 2 ++
csu/libc-tls.c | 6 ++--
csu/static-reloc.c | 26 +++++++++++++++
elf/Makefile | 5 +--
elf/dl-reloc-static-pie.c | 53 ++++++++++++++++++++++++++++++
elf/dl-support.c | 2 +-
elf/dynamic-link.h | 2 +-
elf/get-dynamic-info.h | 6 ++--
manual/install.texi | 8 +++++
sysdeps/generic/ldsodefs.h | 7 ++++
sysdeps/i386/configure | 33 +++++++++++++++++++
sysdeps/i386/configure.ac | 23 +++++++++++++
sysdeps/x86_64/configure | 33 +++++++++++++++++++
sysdeps/x86_64/configure.ac | 25 +++++++++++++++
21 files changed, 383 insertions(+), 15 deletions(-)
create mode 100644 csu/static-reloc.c
create mode 100644 elf/dl-reloc-static-pie.c
@@ -106,6 +106,14 @@ will be used, and CFLAGS sets optimization options for the compiler.
systems support shared libraries; you need ELF support and
(currently) the GNU linker.
+'--enable-static-pie'
+ Build static executables, including tests, as position independent
+ executable (static PIE) which is similar to static executable, but
+ can be loaded at any address without help from a dynamic linker.
+ The resulting libc.a can be used with the GCC option, -static-pie,
+ which is available with GCC 8 or above, to create static PIE. Only
+ i686, x86-64 and x32 targets are verified to work.
+
'--disable-profile'
Don't build libraries with profiling information. You may want to
use this option if you don't plan to do profiling.
@@ -367,6 +367,10 @@ ifndef static-start-installed-name
static-start-installed-name = $(start-installed-name)
endif
+ifeq (yes,$(enable-static-pie))
+static-start-installed-name := P$(static-start-installed-name)
+endif
+
ifeq (yesyes,$(build-shared)$(have-z-combreloc))
combreloc-LDFLAGS = -Wl,-z,combreloc
LDFLAGS.so += $(combreloc-LDFLAGS)
@@ -386,6 +390,16 @@ 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.
@@ -435,9 +449,9 @@ endif
# Command for statically linking programs with the C library.
ifndef +link-static
+link-static-before-libc = $(CC) -nostdlib -nostartfiles -static -o $@ \
- $(DEFAULT-LDFLAGS-$(@F)) \
+ $(firstword $(DEFAULT-LDFLAGS-$(@F)) $(default-pie-ldflag)) \
$(sysdep-LDFLAGS) $(LDFLAGS) $(LDFLAGS-$(@F)) \
- $(addprefix $(csu-objpfx),$(static-start-installed-name)) \
+ $(firstword $(CRT-$(@F)) $(csu-objpfx)$(static-start-installed-name)) \
$(+preinit) $(+prectorT) \
$(filter-out $(addprefix $(csu-objpfx),start.o \
$(start-installed-name))\
@@ -652,8 +666,13 @@ endif
+prectorS = `$(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/
@@ -974,7 +993,7 @@ 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))
@@ -999,7 +1018,7 @@ ifeq (yes,$(build-profile))
all-object-suffixes += .op
object-suffixes += .op
CPPFLAGS-.op = -DPROF $(pic-default)
-CFLAGS-.op = -pg
+CFLAGS-.op = -pg $(pie-default)
libtype.op = lib%_p.a
endif
@@ -9,6 +9,12 @@ Version 2.27
Major new features:
+* Add --enable-static-pie configure option to build static PIE. The
+ resulting libc.a can be used with the GCC option, -static-pie, which
+ is available with GCC 8 or above, to create static position independent
+ executable (static PIE). Only i686, x86-64 and x32 targets are verified
+ to work.
+
* Optimized x86-64 asin, atan2, exp, expf, log, pow, atan, sin and tan
with FMA, contributed by Arjan van de Ven and H.J. Lu from Intel.
@@ -244,6 +244,9 @@
/* Build glibc with tunables support. */
#define HAVE_TUNABLES 0
+/* Define if static PIE is enabled. */
+#define ENABLE_STATIC_PIE 0
+
/* Some compiler options may now allow to use ebp in __asm__ (used mainly
in i386 6 argument syscall issue). */
#define CAN_USE_REGISTER_ASM_EBP 0
@@ -767,6 +767,7 @@ with_default_link
enable_sanity_checks
enable_shared
enable_profile
+enable_static_pie
enable_timezone_tools
enable_hardcoded_path_in_tests
enable_stackguard_randomization
@@ -1424,6 +1425,7 @@ Optional Features:
in special situations) [default=yes]
--enable-shared build shared library [default=yes if GNU ld]
--enable-profile build profiled library [default=no]
+ --enable-static-pie build static executables as PIE [default=no]
--disable-timezone-tools
do not install timezone tools [default=install]
--enable-hardcoded-path-in-tests
@@ -3372,6 +3374,13 @@ else
profile=no
fi
+# Check whether --enable-static-pie was given.
+if test "${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
@@ -5998,6 +6007,62 @@ 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 <<EOF
+int _start (void) { return 42; }
+EOF
+ if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp
+ -Wl,--no-dynamic-linker -nostdlib -nostartfiles
+ -fPIC -shared -o conftest.so conftest.c
+ 1>&5'
+ { { eval echo "\"\$as_me\":${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_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 :
@@ -6892,6 +6957,19 @@ 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 = $static_pie"
+
@@ -176,6 +176,11 @@ AC_ARG_ENABLE([profile],
[build profiled library @<:@default=no@:>@]),
[profile=$enableval],
[profile=no])
+AC_ARG_ENABLE([static-pie],
+ AC_HELP_STRING([--enable-static-pie],
+ [build static executables as PIE @<:@default=no@:>@]),
+ [static_pie=$enableval],
+ [static_pie=no])
AC_ARG_ENABLE([timezone-tools],
AC_HELP_STRING([--disable-timezone-tools],
[do not install timezone tools @<:@default=install@:>@]),
@@ -1464,6 +1469,19 @@ LIBC_LINKER_FEATURE([-z execstack], [-Wl,-z,execstack],
[libc_cv_z_execstack=yes], [libc_cv_z_execstack=no])
AC_SUBST(libc_cv_z_execstack)
+LIBC_LINKER_FEATURE([--no-dynamic-linker],
+ [-Wl,--no-dynamic-linker],
+ [libc_cv_no_dynamic_linker=yes],
+ [libc_cv_no_dynamic_linker=no])
+LIBC_CONFIG_VAR([have-no-dynamic-linker], [$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], [$libc_cv_static_pie])
+
AC_CACHE_CHECK(for -fpie, libc_cv_fpie, [dnl
LIBC_TRY_CC_OPTION([-fpie], [libc_cv_fpie=yes], [libc_cv_fpie=no])
])
@@ -1966,6 +1984,17 @@ fi
rm -f conftest.*])
AC_SUBST(libc_cv_pie_default)
+if test "$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)
@@ -37,7 +37,8 @@ extra-objs = start.o \
S$(start-installed-name)
omit-deps = $(patsubst %.o,%,$(start-installed-name) g$(start-installed-name) \
b$(start-installed-name) $(csu-dummies) \
- S$(start-installed-name))
+ S$(start-installed-name) \
+ P$(start-installed-name))
install-lib = $(start-installed-name) g$(start-installed-name) $(csu-dummies)
# No tests are allowed in the csu/ subdirectory because the startup
@@ -55,16 +56,24 @@ extra-objs += gmon-start.o
endif
install-lib += S$(start-installed-name)
generated += start.os
+ifeq (yes,$(enable-static-pie))
+extra-objs += P$(start-installed-name)
+install-lib += P$(start-installed-name)
+endif
else
extra-objs += gmon-start.o
endif
ifneq ($(start-installed-name),$(static-start-installed-name))
+# FIXME: If we want to support profiling static PIE, we need to create
+# and install gPcrt1.o.
+ifneq (P$(start-installed-name),$(static-start-installed-name))
extra-objs += $(static-start-installed-name) g$(static-start-installed-name)
omit-deps += $(patsubst %.o,%,$(static-start-installed-name) \
g$(static-start-installed-name))
install-lib += $(static-start-installed-name) g$(static-start-installed-name)
endif
+endif
before-compile += $(objpfx)abi-tag.h
generated += abi-tag.h
@@ -77,7 +86,7 @@ crtstuff = crti crtn
install-lib += $(crtstuff:=.o)
extra-objs += $(crtstuff:=.o)
-extra-objs += abi-note.o init.o
+extra-objs += abi-note.o init.o static-reloc.o
asm-CPPFLAGS += -I$(objpfx).
# Enable unwinding so backtrace unwinds to __libc_start_main
@@ -96,6 +105,9 @@ ifndef start-installed-name-rule
# We link the ELF startfile along with a SHT_NOTE section indicating
# the kernel ABI the binaries linked with this library will require.
$(objpfx)$(start-installed-name): $(objpfx)start.o $(objpfx)abi-note.o \
+ $(objpfx)init.o $(objpfx)static-reloc.o
+ $(link-relocatable)
+$(objpfx)P$(start-installed-name): $(objpfx)start.o $(objpfx)abi-note.o \
$(objpfx)init.o
$(link-relocatable)
$(objpfx)S$(start-installed-name): $(objpfx)start.os $(objpfx)abi-note.o \
@@ -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;
@@ -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
new file mode 100644
@@ -0,0 +1,26 @@
+/* Special startup support for non-PIE static executables.
+ Copyright (C) 2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#if ENABLE_STATIC_PIE
+#include <ldsodefs.h>
+
+void
+_dl_relocate_static_pie (void)
+{
+}
+#endif
@@ -24,7 +24,8 @@ include ../Makeconfig
headers = elf.h bits/elfclass.h link.h bits/link.h
routines = $(all-dl-routines) dl-support dl-iteratephdr \
dl-addr dl-addr-obj enbl-secure dl-profstub \
- dl-origin dl-libc dl-sym dl-sysdep dl-error
+ dl-origin dl-libc dl-sym dl-sysdep dl-error \
+ dl-reloc-static-pie
# The core dynamic linking functions are in libc for the static and
# profiled libraries.
@@ -52,7 +53,7 @@ endif
all-dl-routines = $(dl-routines) $(sysdep-dl-routines)
# But they are absent from the shared libc, because that code is in ld.so.
elide-routines.os = $(all-dl-routines) dl-support enbl-secure dl-origin \
- dl-sysdep dl-exception
+ dl-sysdep dl-exception dl-reloc-static-pie
shared-only-routines += dl-caller
# ld.so uses those routines, plus some special stuff for being the program
new file mode 100644
@@ -0,0 +1,53 @@
+/* Support for relocating static PIE.
+ Copyright (C) 2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#if ENABLE_STATIC_PIE
+#include <unistd.h>
+#include <ldsodefs.h>
+#include "dynamic-link.h"
+
+/* Relocate static executable with PIE. */
+
+extern struct link_map _dl_main_map __attribute__((visibility ("hidden")));
+
+void
+_dl_relocate_static_pie (void)
+{
+# define STATIC_PIE_BOOTSTRAP
+# define BOOTSTRAP_MAP (&_dl_main_map)
+# define RESOLVE_MAP(sym, version, flags) BOOTSTRAP_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
@@ -72,7 +72,7 @@ int _dl_bind_not;
/* A dummy link map for the executable, used by dlopen to access the global
scope. We don't export any symbols ourselves, so this can be minimal. */
-static struct link_map _dl_main_map =
+struct link_map _dl_main_map __attribute__((visibility ("hidden"))) =
{
.l_name = (char *) "",
.l_real = &_dl_main_map,
@@ -94,7 +94,7 @@ 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)
@@ -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
@@ -136,6 +136,14 @@ Don't build shared libraries even if it is possible. Not all systems
support shared libraries; you need ELF support and (currently) the GNU
linker.
+@item --enable-static-pie
+Build static executables, including tests, as position independent
+executable (static PIE) which is similar to static executable, but can
+be loaded at any address without help from a dynamic linker. The
+resulting libc.a can be used with the GCC option, -static-pie, which
+is available with GCC 8 or above, to create static PIE. Only i686, x86-64
+and x32 targets are verified to work.
+
@item --disable-profile
Don't build libraries with profiling information. You may want to use
this option if you don't plan to do profiling.
@@ -1048,6 +1048,13 @@ extern void _dl_determine_tlsoffset (void) 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;
@@ -50,6 +50,39 @@ fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_compiler_builtin_inlined" >&5
$as_echo "$libc_compiler_builtin_inlined" >&6; }
+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 :
+ $as_echo_n "(cached) " >&6
+else
+ cat > conftest.s <<\EOF
+ .text
+ .global _start
+_start:
+ movl _start@GOT(%ebx), %eax
+EOF
+ libc_cv_pie_option="-Wl,-pie"
+ libc_cv_ld_static_pie=no
+ if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -nostartfiles -nostdlib $no_ssp $libc_cv_pie_option -o conftest conftest.s 1>&5'
+ { { eval echo "\"\$as_me\":${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
+ if $READELF -r conftest | grep 'There are no relocations in this file.' > /dev/null; then
+ libc_cv_ld_static_pie=yes
+ fi
+ 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
+
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for Intel MPX support" >&5
$as_echo_n "checking for Intel MPX support... " >&6; }
if ${libc_cv_asm_mpx+:} false; then :
@@ -30,6 +30,29 @@ LIBC_COMPILER_BUILTIN_INLINED(
*** Please use host i786, i686, i586, or i486.
*** For example: /source/glibc/configure CFLAGS='-O2 -march=i686' ...])])
+dnl Check if linker can convert "movl main@GOT(%ebx), %eax" to
+dnl "leal main@GOTOFF(%ebx), %eax" for static PIE.
+if test "$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
+_start:
+ movl _start@GOT(%ebx), %eax
+EOF
+ libc_cv_pie_option="-Wl,-pie"
+ libc_cv_ld_static_pie=no
+ if AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -nostartfiles -nostdlib $no_ssp $libc_cv_pie_option -o conftest conftest.s 1>&AS_MESSAGE_LOG_FD); then
+ if $READELF -r conftest | grep 'There are no relocations in this file.' > /dev/null; then
+ libc_cv_ld_static_pie=yes
+ fi
+ fi
+rm -f conftest*])
+ if test "$libc_cv_ld_static_pie" != yes; then
+ AC_MSG_ERROR([linker support for static PIE needed])
+ fi
+fi
+
dnl Check whether asm supports Intel MPX
AC_CACHE_CHECK(for Intel MPX support, libc_cv_asm_mpx, [dnl
cat > conftest.s <<\EOF
@@ -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 $libc_cv_pie_option -o conftest conftest.s 1>&5'
+ { { eval echo "\"\$as_me\":${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
+
$as_echo "#define PI_STATIC_AND_HIDDEN 1" >>confdefs.h
@@ -44,6 +44,31 @@ if test x"$build_mathvec" = xnotset; then
build_mathvec=yes
fi
+dnl Check if linker supports static PIE with the fix for
+dnl
+dnl https://sourceware.org/bugzilla/show_bug.cgi?id=21782
+dnl
+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 $libc_cv_pie_option -o conftest conftest.s 1>&AS_MESSAGE_LOG_FD); then
+ libc_cv_ld_static_pie=yes
+ else
+ libc_cv_ld_static_pie=no
+ fi
+rm -f conftest*])
+ if test "$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)
--
2.13.6