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-rw-r--r--sysdeps/generic/dl-prop.h54
-rw-r--r--sysdeps/i386/dl-cet.c67
-rw-r--r--sysdeps/i386/dl-trampoline.S72
-rw-r--r--sysdeps/unix/sysv/linux/x86/cpu-features.c38
-rw-r--r--sysdeps/unix/sysv/linux/x86/dl-cet.h37
-rw-r--r--sysdeps/x86/Makefile42
-rw-r--r--sysdeps/x86/cet-tunables.h29
-rw-r--r--sysdeps/x86/check-cet.awk53
-rw-r--r--sysdeps/x86/configure69
-rw-r--r--sysdeps/x86/configure.ac46
-rw-r--r--sysdeps/x86/cpu-features.c60
-rw-r--r--sysdeps/x86/cpu-tunables.c48
-rw-r--r--sysdeps/x86/dl-cet.c346
-rw-r--r--sysdeps/x86/dl-procruntime.c68
-rw-r--r--sysdeps/x86/dl-prop.h153
-rw-r--r--sysdeps/x86/dl-tunables.list6
-rw-r--r--sysdeps/x86/libc-start.h25
-rw-r--r--sysdeps/x86/link_map.h26
-rw-r--r--sysdeps/x86/sysdep.h8
-rw-r--r--sysdeps/x86_64/dl-trampoline.h2
20 files changed, 1249 insertions, 0 deletions
diff --git a/sysdeps/generic/dl-prop.h b/sysdeps/generic/dl-prop.h
new file mode 100644
index 0000000000..a2b1d38c79
--- /dev/null
+++ b/sysdeps/generic/dl-prop.h
@@ -0,0 +1,54 @@
+/* Support for GNU properties. Generic version.
+ Copyright (C) 2018 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/>. */
+
+#ifndef _DL_PROP_H
+#define _DL_PROP_H
+
+/* The following functions are used by the dynamic loader and the
+ dlopen machinery to process PT_NOTE entries in the binary or
+ shared object. The notes can be used to change the behaviour of
+ the loader, and as such offer a flexible mechanism for hooking in
+ various checks related to ABI tags or implementing "flag day" ABI
+ transitions. */
+
+static inline void __attribute__ ((always_inline))
+_rtld_main_check (struct link_map *m, const char *program)
+{
+}
+
+static inline void __attribute__ ((always_inline))
+_dl_open_check (struct link_map *m)
+{
+}
+
+#ifdef FILEBUF_SIZE
+static inline int __attribute__ ((always_inline))
+_dl_process_pt_note (struct link_map *l, const ElfW(Phdr) *ph,
+ int fd, struct filebuf *fbp)
+{
+ return 0;
+}
+#endif
+
+static inline int __attribute__ ((always_inline))
+_rtld_process_pt_note (struct link_map *l, const ElfW(Phdr) *ph)
+{
+ return 0;
+}
+
+#endif /* _DL_PROP_H */
diff --git a/sysdeps/i386/dl-cet.c b/sysdeps/i386/dl-cet.c
new file mode 100644
index 0000000000..5d9a4e8d51
--- /dev/null
+++ b/sysdeps/i386/dl-cet.c
@@ -0,0 +1,67 @@
+/* Linux/i386 CET initializers function.
+ Copyright (C) 2018 Free Software Foundation, Inc.
+
+ 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/>. */
+
+
+#define LINKAGE static inline
+#define _dl_cet_check cet_check
+#include <sysdeps/x86/dl-cet.c>
+#undef _dl_cet_check
+
+#ifdef SHARED
+void
+_dl_cet_check (struct link_map *main_map, const char *program)
+{
+ cet_check (main_map, program);
+
+ if ((GL(dl_x86_feature_1)[0] & GNU_PROPERTY_X86_FEATURE_1_SHSTK))
+ {
+ /* Replace _dl_runtime_resolve and _dl_runtime_profile with
+ _dl_runtime_resolve_shstk and _dl_runtime_profile_shstk,
+ respectively if SHSTK is enabled. */
+ extern void _dl_runtime_resolve (Elf32_Word) attribute_hidden;
+ extern void _dl_runtime_resolve_shstk (Elf32_Word) attribute_hidden;
+ extern void _dl_runtime_profile (Elf32_Word) attribute_hidden;
+ extern void _dl_runtime_profile_shstk (Elf32_Word) attribute_hidden;
+ unsigned int i;
+ struct link_map *l;
+ Elf32_Addr *got;
+
+ if (main_map->l_info[DT_JMPREL])
+ {
+ got = (Elf32_Addr *) D_PTR (main_map, l_info[DT_PLTGOT]);
+ if (got[2] == (Elf32_Addr) &_dl_runtime_resolve)
+ got[2] = (Elf32_Addr) &_dl_runtime_resolve_shstk;
+ else if (got[2] == (Elf32_Addr) &_dl_runtime_profile)
+ got[2] = (Elf32_Addr) &_dl_runtime_profile_shstk;
+ }
+
+ i = main_map->l_searchlist.r_nlist;
+ while (i-- > 0)
+ {
+ l = main_map->l_initfini[i];
+ if (l->l_info[DT_JMPREL])
+ {
+ got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
+ if (got[2] == (Elf32_Addr) &_dl_runtime_resolve)
+ got[2] = (Elf32_Addr) &_dl_runtime_resolve_shstk;
+ else if (got[2] == (Elf32_Addr) &_dl_runtime_profile)
+ got[2] = (Elf32_Addr) &_dl_runtime_profile_shstk;
+ }
+ }
+ }
+}
+#endif
diff --git a/sysdeps/i386/dl-trampoline.S b/sysdeps/i386/dl-trampoline.S
index 8bf86f8fd9..6dc0319216 100644
--- a/sysdeps/i386/dl-trampoline.S
+++ b/sysdeps/i386/dl-trampoline.S
@@ -32,6 +32,7 @@
.align 16
_dl_runtime_resolve:
cfi_adjust_cfa_offset (8)
+ _CET_ENDBR
pushl %eax # Preserve registers otherwise clobbered.
cfi_adjust_cfa_offset (4)
pushl %ecx
@@ -50,14 +51,85 @@ _dl_runtime_resolve:
cfi_endproc
.size _dl_runtime_resolve, .-_dl_runtime_resolve
+# The SHSTK compatible version.
+ .text
+ .globl _dl_runtime_resolve_shstk
+ .type _dl_runtime_resolve_shstk, @function
+ cfi_startproc
+ .align 16
+_dl_runtime_resolve_shstk:
+ cfi_adjust_cfa_offset (8)
+ _CET_ENDBR
+ pushl %eax # Preserve registers otherwise clobbered.
+ cfi_adjust_cfa_offset (4)
+ pushl %edx
+ cfi_adjust_cfa_offset (4)
+ movl 12(%esp), %edx # Copy args pushed by PLT in register. Note
+ movl 8(%esp), %eax # that `fixup' takes its parameters in regs.
+ call _dl_fixup # Call resolver.
+ movl (%esp), %edx # Get register content back.
+ movl %eax, %ecx # Store the function address.
+ movl 4(%esp), %eax # Get register content back.
+ addl $16, %esp # Adjust stack: PLT1 + PLT2 + %eax + %edx
+ cfi_adjust_cfa_offset (-16)
+ jmp *%ecx # Jump to function address.
+ cfi_endproc
+ .size _dl_runtime_resolve_shstk, .-_dl_runtime_resolve_shstk
#ifndef PROF
+# The SHSTK compatible version.
+ .globl _dl_runtime_profile_shstk
+ .type _dl_runtime_profile_shstk, @function
+ cfi_startproc
+ .align 16
+_dl_runtime_profile_shstk:
+ cfi_adjust_cfa_offset (8)
+ _CET_ENDBR
+ pushl %esp
+ cfi_adjust_cfa_offset (4)
+ addl $8, (%esp) # Account for the pushed PLT data
+ pushl %ebp
+ cfi_adjust_cfa_offset (4)
+ pushl %eax # Preserve registers otherwise clobbered.
+ cfi_adjust_cfa_offset (4)
+ pushl %ecx
+ cfi_adjust_cfa_offset (4)
+ pushl %edx
+ cfi_adjust_cfa_offset (4)
+ movl %esp, %ecx
+ subl $8, %esp
+ cfi_adjust_cfa_offset (8)
+ movl $-1, 4(%esp)
+ leal 4(%esp), %edx
+ movl %edx, (%esp)
+ pushl %ecx # Address of the register structure
+ cfi_adjust_cfa_offset (4)
+ movl 40(%esp), %ecx # Load return address
+ movl 36(%esp), %edx # Copy args pushed by PLT in register. Note
+ movl 32(%esp), %eax # that `fixup' takes its parameters in regs.
+ call _dl_profile_fixup # Call resolver.
+ cfi_adjust_cfa_offset (-8)
+ movl (%esp), %edx
+ testl %edx, %edx
+ jns 1f
+ movl 4(%esp), %edx # Get register content back.
+ movl %eax, %ecx # Store the function address.
+ movl 12(%esp), %eax # Get register content back.
+ # Adjust stack: PLT1 + PLT2 + %esp + %ebp + %eax + %ecx + %edx
+ # + free.
+ addl $32, %esp
+ cfi_adjust_cfa_offset (-32)
+ jmp *%ecx # Jump to function address.
+ cfi_endproc
+ .size _dl_runtime_profile_shstk, .-_dl_runtime_profile_shstk
+
.globl _dl_runtime_profile
.type _dl_runtime_profile, @function
cfi_startproc
.align 16
_dl_runtime_profile:
cfi_adjust_cfa_offset (8)
+ _CET_ENDBR
pushl %esp
cfi_adjust_cfa_offset (4)
addl $8, (%esp) # Account for the pushed PLT data
diff --git a/sysdeps/unix/sysv/linux/x86/cpu-features.c b/sysdeps/unix/sysv/linux/x86/cpu-features.c
new file mode 100644
index 0000000000..7c9df9b794
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/cpu-features.c
@@ -0,0 +1,38 @@
+/* Initialize CPU feature data for Linux/x86.
+ This file is part of the GNU C Library.
+ Copyright (C) 2018 Free Software Foundation, Inc.
+
+ 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 CET_ENABLED
+static inline int __attribute__ ((always_inline))
+get_cet_status (void)
+{
+ return 0;
+}
+
+# ifndef SHARED
+static inline void
+x86_setup_tls (void)
+{
+ __libc_setup_tls ();
+ THREAD_SETMEM (THREAD_SELF, header.feature_1, GL(dl_x86_feature_1)[0]);
+}
+
+# define ARCH_SETUP_TLS() x86_setup_tls ()
+# endif
+#endif
+
+#include <sysdeps/x86/cpu-features.c>
diff --git a/sysdeps/unix/sysv/linux/x86/dl-cet.h b/sysdeps/unix/sysv/linux/x86/dl-cet.h
new file mode 100644
index 0000000000..ae81e2f2ca
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/dl-cet.h
@@ -0,0 +1,37 @@
+/* Linux/x86 CET initializers function.
+ Copyright (C) 2018 Free Software Foundation, Inc.
+
+ 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/>. */
+
+static inline int __attribute__ ((always_inline))
+dl_cet_allocate_legacy_bitmap (unsigned long *legacy_bitmap)
+{
+ /* FIXME: Need syscall support. */
+ return -1;
+}
+
+static inline int __attribute__ ((always_inline))
+dl_cet_disable_cet (unsigned int cet_feature)
+{
+ /* FIXME: Need syscall support. */
+ return -1;
+}
+
+static inline int __attribute__ ((always_inline))
+dl_cet_lock_cet (void)
+{
+ /* FIXME: Need syscall support. */
+ return -1;
+}
diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
index 65292f4032..e9b2d0b35d 100644
--- a/sysdeps/x86/Makefile
+++ b/sysdeps/x86/Makefile
@@ -13,3 +13,45 @@ ifeq ($(subdir),setjmp)
gen-as-const-headers += jmp_buf-ssp.sym
sysdep_routines += __longjmp_cancel
endif
+
+ifeq ($(enable-cet),yes)
+ifeq ($(subdir),elf)
+sysdep-dl-routines += dl-cet
+endif
+
+# Add -fcf-protection to CFLAGS when CET is enabled.
+CFLAGS-.o += -fcf-protection
+CFLAGS-.os += -fcf-protection
+CFLAGS-.op += -fcf-protection
+CFLAGS-.oS += -fcf-protection
+
+# Compile assembly codes with <cet.h> when CET is enabled.
+asm-CPPFLAGS += -fcf-protection -include cet.h
+
+ifeq ($(subdir),elf)
+ifeq (yes,$(build-shared))
+tests-special += $(objpfx)check-cet.out
+endif
+
+# FIXME: Can't use all-built-dso in elf/Makefile since this file is
+# processed before elf/Makefile. Duplicate it here.
+cet-built-dso := $(common-objpfx)elf/ld.so $(common-objpfx)libc.so \
+ $(filter-out $(common-objpfx)linkobj/libc.so, \
+ $(sort $(wildcard $(addprefix $(common-objpfx), \
+ */lib*.so \
+ iconvdata/*.so))))
+
+$(cet-built-dso:=.note): %.note: %
+ @rm -f $@T
+ LC_ALL=C $(READELF) -n $< > $@T
+ test -s $@T
+ mv -f $@T $@
+common-generated += $(cet-built-dso:$(common-objpfx)%=%.note)
+
+$(objpfx)check-cet.out: $(..)sysdeps/x86/check-cet.awk \
+ $(cet-built-dso:=.note)
+ LC_ALL=C $(AWK) -f $^ > $@; \
+ $(evaluate-test)
+generated += check-cet.out
+endif
+endif
diff --git a/sysdeps/x86/cet-tunables.h b/sysdeps/x86/cet-tunables.h
new file mode 100644
index 0000000000..ca023053ee
--- /dev/null
+++ b/sysdeps/x86/cet-tunables.h
@@ -0,0 +1,29 @@
+/* x86 CET tuning.
+ This file is part of the GNU C Library.
+ Copyright (C) 2018 Free Software Foundation, Inc.
+
+ 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/>. */
+
+/* Valid control values:
+ 0: Enable CET features based on ELF property note.
+ 1: Always disable CET features.
+ 2: Always enable CET features.
+ 3: Enable CET features permissively.
+ */
+#define CET_ELF_PROPERTY 0
+#define CET_ALWAYS_OFF 1
+#define CET_ALWAYS_ON 2
+#define CET_PERMISSIVE 3
+#define CET_MAX CET_PERMISSIVE
diff --git a/sysdeps/x86/check-cet.awk b/sysdeps/x86/check-cet.awk
new file mode 100644
index 0000000000..380d998caf
--- /dev/null
+++ b/sysdeps/x86/check-cet.awk
@@ -0,0 +1,53 @@
+# Verify that all shared objects contain the CET property.
+# Copyright (C) 2018 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/>.
+
+# This awk script expects to get command-line files that are each
+# the output of 'readelf -n' on a single shared object.
+# It exits successfully (0) if all of them contained the CET property.
+# It fails (1) if any didn't contain the CET property
+# It fails (2) if the input did not take the expected form.
+
+BEGIN { result = cet = sanity = 0 }
+
+function check_one(name) {
+ if (!sanity) {
+ print name ": *** input did not look like readelf -n output";
+ result = 2;
+ } else if (cet) {
+ print name ": OK";
+ } else {
+ print name ": *** no CET property found";
+ result = result ? result : 1;
+ }
+
+ cet = sanity = 0;
+}
+
+FILENAME != lastfile {
+ if (lastfile)
+ check_one(lastfile);
+ lastfile = FILENAME;
+}
+
+index ($0, "Displaying notes") != 0 { sanity = 1 }
+index ($0, "IBT") != 0 && index ($0, "SHSTK") != 0 { cet = 1 }
+
+END {
+ check_one(lastfile);
+ exit(result);
+}
diff --git a/sysdeps/x86/configure b/sysdeps/x86/configure
new file mode 100644
index 0000000000..b1ff281249
--- /dev/null
+++ b/sysdeps/x86/configure
@@ -0,0 +1,69 @@
+# This file is generated from configure.ac by Autoconf. DO NOT EDIT!
+ # Local configure fragment for sysdeps/x86.
+
+if test x"$enable_cet" = xyes; then
+ # Check if CET can be enabled.
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether CET can be enabled" >&5
+$as_echo_n "checking whether CET can be enabled... " >&6; }
+if ${libc_cv_x86_cet_available+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ cat > conftest.c <<EOF
+#if !defined __CET__ || __CET__ != 3
+# error CET isn't available.
+#endif
+EOF
+ if { ac_try='${CC-cc} -c $CFLAGS -fcf-protection -include cet.h conftest.c 1>&5'
+ { { eval echo "\"\$as_me\":${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_cv_x86_cet_available=yes
+ else
+ libc_cv_x86_cet_available=no
+ fi
+ rm -rf conftest*
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_x86_cet_available" >&5
+$as_echo "$libc_cv_x86_cet_available" >&6; }
+ if test $libc_cv_x86_cet_available = yes; then
+ enable_cet=yes
+ else
+ if test x"$enable_cet" = xdefault; then
+ enable_cet=no
+ else
+ as_fn_error $? "$CC doesn't support CET" "$LINENO" 5
+ fi
+ fi
+fi
+if test $enable_cet = yes; then
+ # Check if assembler supports CET.
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $AS supports CET" >&5
+$as_echo_n "checking whether $AS supports CET... " >&6; }
+if ${libc_cv_x86_cet_as+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ cat > conftest.s <<EOF
+ incsspd %ecx
+EOF
+ if { ac_try='${CC-cc} -c $CFLAGS conftest.s -o conftest.o 1>&5'
+ { { eval echo "\"\$as_me\":${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_x86_cet_as=yes
+ else
+ libc_cv_x86_cet_as=no
+ fi
+ rm -rf conftest*
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_x86_cet_as" >&5
+$as_echo "$libc_cv_x86_cet_as" >&6; }
+ if test $libc_cv_x86_cet_as = no; then
+ as_fn_error $? "$AS doesn't support CET" "$LINENO" 5
+ fi
+fi
+config_vars="$config_vars
+enable-cet = $enable_cet"
diff --git a/sysdeps/x86/configure.ac b/sysdeps/x86/configure.ac
new file mode 100644
index 0000000000..a909b073af
--- /dev/null
+++ b/sysdeps/x86/configure.ac
@@ -0,0 +1,46 @@
+GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
+# Local configure fragment for sysdeps/x86.
+
+if test x"$enable_cet" = xyes; then
+ # Check if CET can be enabled.
+ AC_CACHE_CHECK(whether CET can be enabled,
+ libc_cv_x86_cet_available, [dnl
+cat > conftest.c <<EOF
+#if !defined __CET__ || __CET__ != 3
+# error CET isn't available.
+#endif
+EOF
+ if AC_TRY_COMMAND(${CC-cc} -c $CFLAGS -fcf-protection -include cet.h conftest.c 1>&AS_MESSAGE_LOG_FD); then
+ libc_cv_x86_cet_available=yes
+ else
+ libc_cv_x86_cet_available=no
+ fi
+ rm -rf conftest*])
+ if test $libc_cv_x86_cet_available = yes; then
+ enable_cet=yes
+ else
+ if test x"$enable_cet" = xdefault; then
+ enable_cet=no
+ else
+ AC_MSG_ERROR([$CC doesn't support CET])
+ fi
+ fi
+fi
+if test $enable_cet = yes; then
+ # Check if assembler supports CET.
+ AC_CACHE_CHECK(whether $AS supports CET,
+ libc_cv_x86_cet_as, [dnl
+cat > conftest.s <<EOF
+ incsspd %ecx
+EOF
+ if AC_TRY_COMMAND(${CC-cc} -c $CFLAGS conftest.s -o conftest.o 1>&AS_MESSAGE_LOG_FD); then
+ libc_cv_x86_cet_as=yes
+ else
+ libc_cv_x86_cet_as=no
+ fi
+ rm -rf conftest*])
+ if test $libc_cv_x86_cet_as = no; then
+ AC_MSG_ERROR([$AS doesn't support CET])
+ fi
+fi
+LIBC_CONFIG_VAR([enable-cet], [$enable_cet])
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index d41ebde823..0627f145e0 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -28,6 +28,15 @@
extern void TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *)
attribute_hidden;
+
+# if CET_ENABLED
+# include <dl-cet.h>
+# include <cet-tunables.h>
+extern void TUNABLE_CALLBACK (set_x86_ibt) (tunable_val_t *)
+ attribute_hidden;
+extern void TUNABLE_CALLBACK (set_x86_shstk) (tunable_val_t *)
+ attribute_hidden;
+# endif
#endif
static void
@@ -449,4 +458,55 @@ no_cpuid:
else if (CPU_FEATURES_ARCH_P (cpu_features, I586))
GLRO(dl_platform) = "i586";
#endif
+
+#if CET_ENABLED
+# if HAVE_TUNABLES
+ TUNABLE_GET (x86_ibt, tunable_val_t *,
+ TUNABLE_CALLBACK (set_x86_ibt));
+ TUNABLE_GET (x86_shstk, tunable_val_t *,
+ TUNABLE_CALLBACK (set_x86_shstk));
+# endif
+
+ /* Check CET status. */
+ unsigned int cet_status = get_cet_status ();
+
+ if (cet_status)
+ {
+ GL(dl_x86_feature_1)[0] = cet_status;
+
+# ifndef SHARED
+ /* Check if IBT and SHSTK are enabled by kernel. */
+ if ((cet_status & GNU_PROPERTY_X86_FEATURE_1_IBT)
+ || (cet_status & GNU_PROPERTY_X86_FEATURE_1_SHSTK))
+ {
+ /* Disable IBT and/or SHSTK if they are enabled by kernel, but
+ disabled by environment variable:
+
+ GLIBC_TUNABLES=glibc.tune.hwcaps=-IBT,-SHSTK
+ */
+ unsigned int cet_feature = 0;
+ if (!HAS_CPU_FEATURE (IBT))
+ cet_feature |= GNU_PROPERTY_X86_FEATURE_1_IBT;
+ if (!HAS_CPU_FEATURE (SHSTK))
+ cet_feature |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
+
+ if (cet_feature)
+ {
+ int res = dl_cet_disable_cet (cet_feature);
+
+ /* Clear the disabled bits in dl_x86_feature_1. */
+ if (res == 0)
+ GL(dl_x86_feature_1)[0] &= ~cet_feature;
+ }
+
+ /* Lock CET if IBT or SHSTK is enabled in executable. Don't
+ lock CET if SHSTK is enabled permissively. */
+ if (((GL(dl_x86_feature_1)[1] >> CET_MAX)
+ & ((1 << CET_MAX) - 1))
+ != CET_PERMISSIVE)
+ dl_cet_lock_cet ();
+ }
+# endif
+ }
+#endif
}
diff --git a/sysdeps/x86/cpu-tunables.c b/sysdeps/x86/cpu-tunables.c
index af761dcbbc..69155a8f44 100644
--- a/sysdeps/x86/cpu-tunables.c
+++ b/sysdeps/x86/cpu-tunables.c
@@ -334,4 +334,52 @@ TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *valp)
}
while (*p != '\0');
}
+
+# if CET_ENABLED
+# include <cet-tunables.h>
+
+attribute_hidden
+void
+TUNABLE_CALLBACK (set_x86_ibt) (tunable_val_t *valp)
+{
+ if (DEFAULT_MEMCMP (valp->strval, "on", sizeof ("on")) == 0)
+ {
+ GL(dl_x86_feature_1)[1] &= ~((1 << CET_MAX) - 1);
+ GL(dl_x86_feature_1)[1] |= CET_ALWAYS_ON;
+ }
+ else if (DEFAULT_MEMCMP (valp->strval, "off", sizeof ("off")) == 0)
+ {
+ GL(dl_x86_feature_1)[1] &= ~((1 << CET_MAX) - 1);
+ GL(dl_x86_feature_1)[1] |= CET_ALWAYS_OFF;
+ }
+ else if (DEFAULT_MEMCMP (valp->strval, "permissive",
+ sizeof ("permissive")) == 0)
+ {
+ GL(dl_x86_feature_1)[1] &= ~((1 << CET_MAX) - 1);
+ GL(dl_x86_feature_1)[1] |= CET_PERMISSIVE;
+ }
+}
+
+attribute_hidden
+void
+TUNABLE_CALLBACK (set_x86_shstk) (tunable_val_t *valp)
+{
+ if (DEFAULT_MEMCMP (valp->strval, "on", sizeof ("on")) == 0)
+ {
+ GL(dl_x86_feature_1)[1] &= ~(((1 << CET_MAX) - 1) << CET_MAX);
+ GL(dl_x86_feature_1)[1] |= (CET_ALWAYS_ON << CET_MAX);
+ }
+ else if (DEFAULT_MEMCMP (valp->strval, "off", sizeof ("off")) == 0)
+ {
+ GL(dl_x86_feature_1)[1] &= ~(((1 << CET_MAX) - 1) << CET_MAX);
+ GL(dl_x86_feature_1)[1] |= (CET_ALWAYS_OFF << CET_MAX);
+ }
+ else if (DEFAULT_MEMCMP (valp->strval, "permissive",
+ sizeof ("permissive")) == 0)
+ {
+ GL(dl_x86_feature_1)[1] &= ~(((1 << CET_MAX) - 1) << CET_MAX);
+ GL(dl_x86_feature_1)[1] |= (CET_PERMISSIVE << CET_MAX);
+ }
+}
+# endif
#endif
diff --git a/sysdeps/x86/dl-cet.c b/sysdeps/x86/dl-cet.c
new file mode 100644
index 0000000000..b82ba14e75
--- /dev/null
+++ b/sysdeps/x86/dl-cet.c
@@ -0,0 +1,346 @@
+/* x86 CET initializers function.
+ Copyright (C) 2018 Free Software Foundation, Inc.
+
+ 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/>. */
+
+#include <unistd.h>
+#include <errno.h>
+#include <libintl.h>
+#include <ldsodefs.h>
+#include <dl-cet.h>
+#include <cet-tunables.h>
+
+/* GNU_PROPERTY_X86_FEATURE_1_IBT and GNU_PROPERTY_X86_FEATURE_1_SHSTK
+ are defined in <elf.h>, which are only available for C sources.
+ X86_FEATURE_1_IBT and X86_FEATURE_1_SHSTK are defined in <sysdep.h>
+ which are available for both C and asm sources. They must match. */
+#if GNU_PROPERTY_X86_FEATURE_1_IBT != X86_FEATURE_1_IBT
+# error GNU_PROPERTY_X86_FEATURE_1_IBT != X86_FEATURE_1_IBT
+#endif
+#if GNU_PROPERTY_X86_FEATURE_1_SHSTK != X86_FEATURE_1_SHSTK
+# error GNU_PROPERTY_X86_FEATURE_1_SHSTK != X86_FEATURE_1_SHSTK
+#endif
+
+static int
+dl_cet_mark_legacy_region (struct link_map *l)
+{
+ /* Mark PT_LOAD segments with PF_X in legacy code page bitmap. */
+ size_t i, phnum = l->l_phnum;
+ const ElfW(Phdr) *phdr = l->l_phdr;
+#ifdef __x86_64__
+ typedef unsigned long long word_t;
+#else
+ typedef unsigned long word_t;
+#endif
+ unsigned int bits_to_set;
+ word_t mask_to_set;
+#define BITS_PER_WORD (sizeof (word_t) * 8)
+#define BITMAP_FIRST_WORD_MASK(start) \
+ (~((word_t) 0) << ((start) & (BITS_PER_WORD - 1)))
+#define BITMAP_LAST_WORD_MASK(nbits) \
+ (~((word_t) 0) >> (-(nbits) & (BITS_PER_WORD - 1)))
+
+ word_t *bitmap = (word_t *) GL(dl_x86_legacy_bitmap)[0];
+ word_t bitmap_size = GL(dl_x86_legacy_bitmap)[1];
+ word_t *p;
+ size_t page_size = GLRO(dl_pagesize);
+
+ for (i = 0; i < phnum; i++)
+ if (phdr[i].p_type == PT_LOAD && (phdr[i].p_flags & PF_X))
+ {
+ /* One bit in legacy bitmap represents a page. */
+ ElfW(Addr) start = (phdr[i].p_vaddr + l->l_addr) / page_size;
+ ElfW(Addr) len = (phdr[i].p_memsz + page_size - 1) / page_size;
+ ElfW(Addr) end = start + len;
+
+ if ((end / 8) > bitmap_size)
+ return -EINVAL;
+
+ p = bitmap + (start / BITS_PER_WORD);
+ bits_to_set = BITS_PER_WORD - (start % BITS_PER_WORD);
+ mask_to_set = BITMAP_FIRST_WORD_MASK (start);
+
+ while (len >= bits_to_set)
+ {
+ *p |= mask_to_set;
+ len -= bits_to_set;
+ bits_to_set = BITS_PER_WORD;
+ mask_to_set = ~((word_t) 0);
+ p++;
+ }
+ if (len)
+ {
+ mask_to_set &= BITMAP_LAST_WORD_MASK (end);
+ *p |= mask_to_set;
+ }
+ }
+
+ return 0;
+}
+
+/* Check if object M is compatible with CET. */
+
+static void
+dl_cet_check (struct link_map *m, const char *program)
+{
+ /* Check how IBT should be enabled. */
+ unsigned int enable_ibt_type
+ = GL(dl_x86_feature_1)[1] & ((1 << CET_MAX) - 1);
+ /* Check how SHSTK should be enabled. */
+ unsigned int enable_shstk_type
+ = ((GL(dl_x86_feature_1)[1] >> CET_MAX) & ((1 << CET_MAX) - 1));
+
+ /* No legacy object check if both IBT and SHSTK are always on. */
+ if (enable_ibt_type == CET_ALWAYS_ON
+ && enable_shstk_type == CET_ALWAYS_ON)
+ return;
+
+ /* Check if IBT is enabled by kernel. */
+ bool ibt_enabled
+ = (GL(dl_x86_feature_1)[0] & GNU_PROPERTY_X86_FEATURE_1_IBT) != 0;
+ /* Check if SHSTK is enabled by kernel. */
+ bool shstk_enabled
+ = (GL(dl_x86_feature_1)[0] & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0;
+
+ if (ibt_enabled || shstk_enabled)
+ {
+ struct link_map *l = NULL;
+
+ /* Check if IBT and SHSTK are enabled in object. */
+ bool enable_ibt = (ibt_enabled
+ && enable_ibt_type != CET_ALWAYS_OFF);
+ bool enable_shstk = (shstk_enabled
+ && enable_shstk_type != CET_ALWAYS_OFF);
+ if (program)
+ {
+ /* Enable IBT and SHSTK only if they are enabled in executable.
+ NB: IBT and SHSTK may be disabled by environment variable:
+
+ GLIBC_TUNABLES=glibc.tune.hwcaps=-IBT,-SHSTK
+ */
+ enable_ibt &= (HAS_CPU_FEATURE (IBT)
+ && (enable_ibt_type == CET_ALWAYS_ON
+ || (m->l_cet & lc_ibt) != 0));
+ enable_shstk &= (HAS_CPU_FEATURE (SHSTK)
+ && (enable_shstk_type == CET_ALWAYS_ON
+ || (m->l_cet & lc_shstk) != 0));
+ }
+
+ /* ld.so is CET-enabled by kernel. But shared objects may not
+ support IBT nor SHSTK. */
+ if (enable_ibt || enable_shstk)
+ {
+ int res;
+ unsigned int i;
+ unsigned int first_legacy, last_legacy;
+ bool need_legacy_bitmap = false;
+
+ i = m->l_searchlist.r_nlist;
+ while (i-- > 0)
+ {
+ /* Check each shared object to see if IBT and SHSTK are
+ enabled. */
+ l = m->l_initfini[i];
+
+ if (l->l_init_called)
+ continue;
+
+#ifdef SHARED
+ /* Skip CET check for ld.so since ld.so is CET-enabled.
+ CET will be disabled later if CET isn't enabled in
+ executable. */
+ if (l == &GL(dl_rtld_map)
+ || l->l_real == &GL(dl_rtld_map)
+ || (program && l == m))
+ continue;
+#endif
+
+ if (enable_ibt
+ && enable_ibt_type != CET_ALWAYS_ON
+ && !(l->l_cet & lc_ibt))
+ {
+ /* Remember the first and last legacy objects. */
+ if (!need_legacy_bitmap)
+ last_legacy = i;
+ first_legacy = i;
+ need_legacy_bitmap = true;
+ }
+
+ /* SHSTK is enabled only if it is enabled in executable as
+ well as all shared objects. */
+ enable_shstk &= (enable_shstk_type == CET_ALWAYS_ON
+ || (l->l_cet & lc_shstk) != 0);
+ }
+
+ if (need_legacy_bitmap)
+ {
+ if (GL(dl_x86_legacy_bitmap)[0])
+ {
+ /* Change legacy bitmap to writable. */
+ if (__mprotect ((void *) GL(dl_x86_legacy_bitmap)[0],
+ GL(dl_x86_legacy_bitmap)[1],
+ PROT_READ | PROT_WRITE) < 0)
+ {
+mprotect_failure:
+ if (program)
+ _dl_fatal_printf ("%s: mprotect legacy bitmap failed\n",
+ l->l_name);
+ else
+ _dl_signal_error (EINVAL, l->l_name, "dlopen",
+ N_("mprotect legacy bitmap failed"));
+ }
+ }
+ else
+ {
+ /* Allocate legacy bitmap. */
+ int res = dl_cet_allocate_legacy_bitmap
+ (GL(dl_x86_legacy_bitmap));
+ if (res != 0)
+ {
+ if (program)
+ _dl_fatal_printf ("%s: legacy bitmap isn't available\n",
+ l->l_name);
+ else
+ _dl_signal_error (EINVAL, l->l_name, "dlopen",
+ N_("legacy bitmap isn't available"));
+ }
+ }
+
+ /* Put legacy shared objects in legacy bitmap. */
+ for (i = first_legacy; i <= last_legacy; i++)
+ {
+ l = m->l_initfini[i];
+
+ if (l->l_init_called || (l->l_cet & lc_ibt))
+ continue;
+
+#ifdef SHARED
+ if (l == &GL(dl_rtld_map)
+ || l->l_real == &GL(dl_rtld_map)
+ || (program && l == m))
+ continue;
+#endif
+
+ /* If IBT is enabled in executable and IBT isn't enabled
+ in this shard object, mark PT_LOAD segments with PF_X
+ in legacy code page bitmap. */
+ res = dl_cet_mark_legacy_region (l);
+ if (res != 0)
+ {
+ if (program)
+ _dl_fatal_printf ("%s: failed to mark legacy code region\n",
+ l->l_name);
+ else
+ _dl_signal_error (-res, l->l_name, "dlopen",
+ N_("failed to mark legacy code region"));
+ }
+ }
+
+ /* Change legacy bitmap to read-only. */
+ if (__mprotect ((void *) GL(dl_x86_legacy_bitmap)[0],
+ GL(dl_x86_legacy_bitmap)[1], PROT_READ) < 0)
+ goto mprotect_failure;
+ }
+ }
+
+ bool cet_feature_changed = false;
+
+ if (enable_ibt != ibt_enabled || enable_shstk != shstk_enabled)
+ {
+ if (!program
+ && enable_shstk_type != CET_PERMISSIVE)
+ {
+ /* When SHSTK is enabled, we can't dlopening a shared
+ object without SHSTK. */
+ if (enable_shstk != shstk_enabled)
+ _dl_signal_error (EINVAL, l->l_name, "dlopen",
+ N_("shadow stack isn't enabled"));
+ return;
+ }
+
+ /* Disable IBT and/or SHSTK if they are enabled by kernel, but
+ disabled in executable or shared objects. */
+ unsigned int cet_feature = 0;
+
+ /* Disable IBT only during program startup. */
+ if (program && !enable_ibt)
+ cet_feature |= GNU_PROPERTY_X86_FEATURE_1_IBT;
+ if (!enable_shstk)
+ cet_feature |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
+
+ int res = dl_cet_disable_cet (cet_feature);
+ if (res != 0)
+ {
+ if (program)
+ _dl_fatal_printf ("%s: can't disable CET\n", program);
+ else
+ _dl_signal_error (-res, l->l_name, "dlopen",
+ N_("can't disable CET"));
+ }
+
+ /* Clear the disabled bits in dl_x86_feature_1. */
+ GL(dl_x86_feature_1)[0] &= ~cet_feature;
+
+ cet_feature_changed = true;
+ }
+
+#ifdef SHARED
+ if (program
+ && (!shstk_enabled
+ || enable_shstk_type != CET_PERMISSIVE)
+ && (ibt_enabled || shstk_enabled))
+ {
+ /* Lock CET if IBT or SHSTK is enabled in executable. Don't
+ lock CET if SHSTK is enabled permissively. */
+ int res = dl_cet_lock_cet ();
+ if (res != 0)
+ _dl_fatal_printf ("%s: can't lock CET\n", program);
+
+ cet_feature_changed = true;
+ }
+#endif
+
+ if (cet_feature_changed)
+ {
+ unsigned int feature_1 = 0;
+ if (enable_ibt)
+ feature_1 |= GNU_PROPERTY_X86_FEATURE_1_IBT;
+ if (enable_shstk)
+ feature_1 |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
+ struct pthread *self = THREAD_SELF;
+ THREAD_SETMEM (self, header.feature_1, feature_1);
+ }
+ }
+}
+
+void
+_dl_cet_open_check (struct link_map *l)
+{
+ dl_cet_check (l, NULL);
+}
+
+#ifdef SHARED
+
+# ifndef LINKAGE
+# define LINKAGE
+# endif
+
+LINKAGE
+void
+_dl_cet_check (struct link_map *main_map, const char *program)
+{
+ dl_cet_check (main_map, program);
+}
+#endif /* SHARED */
diff --git a/sysdeps/x86/dl-procruntime.c b/sysdeps/x86/dl-procruntime.c
new file mode 100644
index 0000000000..eddbde6a31
--- /dev/null
+++ b/sysdeps/x86/dl-procruntime.c
@@ -0,0 +1,68 @@
+/* Data for processor runtime information. x86 version.
+ Copyright (C) 2018 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/>. */
+
+/* This information must be kept in sync with the _DL_HWCAP_COUNT,
+ HWCAP_PLATFORMS_START and HWCAP_PLATFORMS_COUNT definitions in
+ dl-hwcap.h.
+
+ If anything should be added here check whether the size of each string
+ is still ok with the given array size.
+
+ All the #ifdefs in the definitions are quite irritating but
+ necessary if we want to avoid duplicating the information. There
+ are three different modes:
+
+ - PROCINFO_DECL is defined. This means we are only interested in
+ declarations.
+
+ - PROCINFO_DECL is not defined:
+
+ + if SHARED is defined the file is included in an array
+ initializer. The .element = { ... } syntax is needed.
+
+ + if SHARED is not defined a normal array initialization is
+ needed.
+ */
+
+#ifndef PROCINFO_CLASS
+# define PROCINFO_CLASS
+#endif
+
+#if !IS_IN (ldconfig)
+# if !defined PROCINFO_DECL && defined SHARED
+ ._dl_x86_feature_1
+# else
+PROCINFO_CLASS unsigned int _dl_x86_feature_1[2]
+# endif
+# if !defined SHARED || defined PROCINFO_DECL
+;
+# else
+,
+# endif
+
+# if !defined PROCINFO_DECL && defined SHARED
+ ._dl_x86_legacy_bitmap
+# else
+PROCINFO_CLASS unsigned long _dl_x86_legacy_bitmap[2]
+# endif
+# if !defined SHARED || defined PROCINFO_DECL
+;
+# else
+,
+# endif
+#endif
diff --git a/sysdeps/x86/dl-prop.h b/sysdeps/x86/dl-prop.h
new file mode 100644
index 0000000000..d56e20a6dc
--- /dev/null
+++ b/sysdeps/x86/dl-prop.h
@@ -0,0 +1,153 @@
+/* Support for GNU properties. x86 version.
+ Copyright (C) 2018 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/>. */
+
+#ifndef _DL_PROP_H
+#define _DL_PROP_H
+
+#include <not-cancel.h>
+
+extern void _dl_cet_check (struct link_map *, const char *)
+ attribute_hidden;
+extern void _dl_cet_open_check (struct link_map *)
+ attribute_hidden;
+
+static inline void __attribute__ ((always_inline))
+_rtld_main_check (struct link_map *m, const char *program)
+{
+#if CET_ENABLED
+ _dl_cet_check (m, program);
+#endif
+}
+
+static inline void __attribute__ ((always_inline))
+_dl_open_check (struct link_map *m)
+{
+#if CET_ENABLED
+ _dl_cet_open_check (m);
+#endif
+}
+
+static inline void __attribute__ ((unused))
+_dl_process_cet_property_note (struct link_map *l,
+ const ElfW(Nhdr) *note,
+ const ElfW(Addr) size,
+ const ElfW(Addr) align)
+{
+#if CET_ENABLED
+ /* The NT_GNU_PROPERTY_TYPE_0 note must be aliged to 4 bytes in
+ 32-bit objects and to 8 bytes in 64-bit objects. Skip notes
+ with incorrect alignment. */
+ if (align != (__ELF_NATIVE_CLASS / 8))
+ return;
+
+ const ElfW(Addr) start = (ElfW(Addr)) note;
+
+ while ((ElfW(Addr)) (note + 1) - start < size)
+ {
+ /* Find the NT_GNU_PROPERTY_TYPE_0 note. */
+ if (note->n_namesz == 4
+ && note->n_type == NT_GNU_PROPERTY_TYPE_0
+ && memcmp (note + 1, "GNU", 4) == 0)
+ {
+ /* Check for invalid property. */
+ if (note->n_descsz < 8
+ || (note->n_descsz % sizeof (ElfW(Addr))) != 0)
+ break;
+
+ /* Start and end of property array. */
+ unsigned char *ptr = (unsigned char *) (note + 1) + 4;
+ unsigned char *ptr_end = ptr + note->n_descsz;
+
+ while (1)
+ {
+ unsigned int type = *(unsigned int *) ptr;
+ unsigned int datasz = *(unsigned int *) (ptr + 4);
+
+ ptr += 8;
+ if ((ptr + datasz) > ptr_end)
+ break;
+
+ if (type == GNU_PROPERTY_X86_FEATURE_1_AND
+ && datasz == 4)
+ {
+ unsigned int feature_1 = *(unsigned int *) ptr;
+ if ((feature_1 & GNU_PROPERTY_X86_FEATURE_1_IBT))
+ l->l_cet |= lc_ibt;
+ if ((feature_1 & GNU_PROPERTY_X86_FEATURE_1_SHSTK))
+ l->l_cet |= lc_shstk;
+ break;
+ }
+ }
+ }
+
+ /* NB: Note sections like .note.ABI-tag and .note.gnu.build-id are
+ aligned to 4 bytes in 64-bit ELF objects. */
+ note = ((const void *) note
+ + ELF_NOTE_NEXT_OFFSET (note->n_namesz, note->n_descsz,
+ align));
+ }
+#endif
+}
+
+#ifdef FILEBUF_SIZE
+static inline int __attribute__ ((unused))
+_dl_process_pt_note (struct link_map *l, const ElfW(Phdr) *ph,
+ int fd, struct filebuf *fbp)
+{
+# if CET_ENABLED
+ const ElfW(Nhdr) *note;
+ ElfW(Nhdr) *note_malloced = NULL;
+ ElfW(Addr) size = ph->p_filesz;
+
+ if (ph->p_offset + size <= (size_t) fbp->len)
+ note = (const void *) (fbp->buf + ph->p_offset);
+ else
+ {
+ if (size < __MAX_ALLOCA_CUTOFF)
+ note = alloca (size);
+ else
+ {
+ note_malloced = malloc (size);
+ note = note_malloced;
+ }
+ __lseek (fd, ph->p_offset, SEEK_SET);
+ if (__read_nocancel (fd, (void *) note, size) != size)
+ {
+ if (note_malloced)
+ free (note_malloced);
+ return -1;
+ }
+ }
+
+ _dl_process_cet_property_note (l, note, size, ph->p_align);
+ if (note_malloced)
+ free (note_malloced);
+# endif
+ return 0;
+}
+#endif
+
+static inline int __attribute__ ((unused))
+_rtld_process_pt_note (struct link_map *l, const ElfW(Phdr) *ph)
+{
+ const ElfW(Nhdr) *note = (const void *) (ph->p_vaddr + l->l_addr);
+ _dl_process_cet_property_note (l, note, ph->p_memsz, ph->p_align);
+ return 0;
+}
+
+#endif /* _DL_PROP_H */
diff --git a/sysdeps/x86/dl-tunables.list b/sysdeps/x86/dl-tunables.list
index 7c3236a68f..73886b1352 100644
--- a/sysdeps/x86/dl-tunables.list
+++ b/sysdeps/x86/dl-tunables.list
@@ -21,6 +21,12 @@ glibc {
hwcaps {
type: STRING
}
+ x86_ibt {
+ type: STRING
+ }
+ x86_shstk {
+ type: STRING
+ }
x86_non_temporal_threshold {
type: SIZE_T
}
diff --git a/sysdeps/x86/libc-start.h b/sysdeps/x86/libc-start.h
new file mode 100644
index 0000000000..6f44262bf4
--- /dev/null
+++ b/sysdeps/x86/libc-start.h
@@ -0,0 +1,25 @@
+/* X86 definitions for libc main startup.
+ Copyright (C) 2018 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/>. */
+
+#ifndef SHARED
+# define ARCH_SETUP_IREL() apply_irel ()
+# define ARCH_APPLY_IREL()
+# ifndef ARCH_SETUP_TLS
+# define ARCH_SETUP_TLS() __libc_setup_tls ()
+# endif
+#endif /* !SHARED */
diff --git a/sysdeps/x86/link_map.h b/sysdeps/x86/link_map.h
new file mode 100644
index 0000000000..ef1206a9d2
--- /dev/null
+++ b/sysdeps/x86/link_map.h
@@ -0,0 +1,26 @@
+/* Additional fields in struct link_map. Linux/x86 version.
+ Copyright (C) 2018 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 this object is enabled with CET. */
+enum
+ {
+ lc_none = 0, /* Not enabled with CET. */
+ lc_ibt = 1 << 0, /* Enabled with IBT. */
+ lc_shstk = 1 << 1, /* Enabled with STSHK. */
+ lc_ibt_and_shstk = lc_ibt | lc_shstk /* Enabled with both. */
+ } l_cet:2;
diff --git a/sysdeps/x86/sysdep.h b/sysdeps/x86/sysdep.h
index 976566aa37..8776ad8374 100644
--- a/sysdeps/x86/sysdep.h
+++ b/sysdeps/x86/sysdep.h
@@ -52,6 +52,13 @@ enum cf_protection_level
/* Syntactic details of assembler. */
+#ifdef _CET_ENDBR
+# define _CET_NOTRACK notrack
+#else
+# define _CET_ENDBR
+# define _CET_NOTRACK
+#endif
+
/* ELF uses byte-counts for .align, most others use log2 of count of bytes. */
#define ALIGNARG(log2) 1<<log2
#define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
@@ -63,6 +70,7 @@ enum cf_protection_level
.align ALIGNARG(4); \
C_LABEL(name) \
cfi_startproc; \
+ _CET_ENDBR; \
CALL_MCOUNT
#undef END
diff --git a/sysdeps/x86_64/dl-trampoline.h b/sysdeps/x86_64/dl-trampoline.h
index 298cfb3d99..a28b1e73a4 100644
--- a/sysdeps/x86_64/dl-trampoline.h
+++ b/sysdeps/x86_64/dl-trampoline.h
@@ -64,6 +64,7 @@
cfi_startproc
_dl_runtime_resolve:
cfi_adjust_cfa_offset(16) # Incorporate PLT
+ _CET_ENDBR
# if DL_RUNTIME_RESOLVE_REALIGN_STACK
# if LOCAL_STORAGE_AREA != 8
# error LOCAL_STORAGE_AREA must be 8
@@ -168,6 +169,7 @@ _dl_runtime_resolve:
_dl_runtime_profile:
cfi_startproc
cfi_adjust_cfa_offset(16) # Incorporate PLT
+ _CET_ENDBR
/* The La_x86_64_regs data structure pointed to by the
fourth paramater must be VEC_SIZE-byte aligned. This must
be explicitly enforced. We have the set up a dynamically