[PATCH v2 0/4] i386: Remove remaining CET bits

[PATCH v2 0/4] i386: Remove remaining CET bits

[H.J. Lu]

Changes in v2:

1. Remove sysdeps/i386/libc-start.h.
2. Replace x86 to x86-64 in comments in sysdeps/x86_64/dl-cet.c and
sysdeps/x86_64/feature-control.h.
3. Replace _CET_CONTROL_H with _X86_64_FEATURE_CONTROL_H in
sysdeps/x86_64/feature-control.h.

1. Move sysdeps/x86/libc-start.h to sysdeps/x86_64/libc-start.h .
2. Move dl-cet.[ch] to x86_64 directories.
3. Move check-cet.awk to x86_64.
4. i386: Remove CET support bits.


H.J. Lu (4):
  x86: Move x86-64 shadow stack startup codes
  x86-64/cet: Move dl-cet.[ch] to x86_64 directories
  x86-64/cet: Move check-cet.awk to x86_64
  i386: Remove CET support bits

 sysdeps/i386/dl-machine.h                     | 11 +--
 sysdeps/i386/dl-trampoline.S                  | 69 -------------------
 sysdeps/unix/sysv/linux/x86/dl-cet.h          | 63 -----------------
 sysdeps/unix/sysv/linux/x86_64/dl-cet.h       | 49 ++++++++++++-
 sysdeps/x86/cpu-features-offsets.sym          |  2 -
 sysdeps/x86/cpu-features.c                    |  4 +-
 sysdeps/x86/ldsodefs.h                        |  1 -
 sysdeps/x86_64/Makefile                       |  4 +-
 sysdeps/{x86 => x86_64}/check-cet.awk         |  0
 sysdeps/{x86 => x86_64}/dl-cet.c              |  2 +-
 sysdeps/{x86 => x86_64}/dl-procruntime.c      |  2 +-
 sysdeps/x86_64/dl-trampoline.S                |  1 +
 .../feature-control.h}                        |  8 +--
 sysdeps/x86_64/features-offsets.sym           |  6 ++
 sysdeps/x86_64/ldsodefs.h                     | 26 +++++++
 sysdeps/{x86 => x86_64}/libc-start.h          |  2 +-
 16 files changed, 94 insertions(+), 156 deletions(-)
 delete mode 100644 sysdeps/unix/sysv/linux/x86/dl-cet.h
 rename sysdeps/{x86 => x86_64}/check-cet.awk (100%)
 rename sysdeps/{x86 => x86_64}/dl-cet.c (99%)
 rename sysdeps/{x86 => x86_64}/dl-procruntime.c (97%)
 rename sysdeps/{x86/cet-control.h => x86_64/feature-control.h} (92%)
 create mode 100644 sysdeps/x86_64/features-offsets.sym
 create mode 100644 sysdeps/x86_64/ldsodefs.h
 rename sysdeps/{x86 => x86_64}/libc-start.h (98%)

-- 
2.43.0

[PATCH v2 1/4] x86: Move x86-64 shadow stack startup codes

[H.J. Lu]

Move sysdeps/x86/libc-start.h to sysdeps/x86_64/libc-start.h and use
sysdeps/generic/libc-start.h for i386.
---
 sysdeps/{x86 => x86_64}/libc-start.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
 rename sysdeps/{x86 => x86_64}/libc-start.h (98%)

diff --git a/sysdeps/x86/libc-start.h b/sysdeps/x86_64/libc-start.h
similarity index 98%
rename from sysdeps/x86/libc-start.h
rename to sysdeps/x86_64/libc-start.h
index c3cc05888d..63fef17029 100644
--- a/sysdeps/x86/libc-start.h
+++ b/sysdeps/x86_64/libc-start.h
@@ -1,4 +1,4 @@
-/* X86 definitions for libc main startup.
+/* x86-64 definitions for libc main startup.
    Copyright (C) 2018-2024 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
-- 
2.43.0

[PATCH v2 2/4] x86-64/cet: Move dl-cet.[ch] to x86_64 directories

[H.J. Lu]

Since CET is only enabled for x86-64, move dl-cet.[ch] to x86_64
directories.
---
 sysdeps/unix/sysv/linux/x86/dl-cet.h    | 63 -------------------------
 sysdeps/unix/sysv/linux/x86_64/dl-cet.h | 47 +++++++++++++++++-
 sysdeps/{x86 => x86_64}/dl-cet.c        |  2 +-
 3 files changed, 47 insertions(+), 65 deletions(-)
 delete mode 100644 sysdeps/unix/sysv/linux/x86/dl-cet.h
 rename sysdeps/{x86 => x86_64}/dl-cet.c (99%)

diff --git a/sysdeps/unix/sysv/linux/x86/dl-cet.h b/sysdeps/unix/sysv/linux/x86/dl-cet.h
deleted file mode 100644
index c10773ab0e..0000000000
--- a/sysdeps/unix/sysv/linux/x86/dl-cet.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/* Linux/x86 CET initializers function.
-   Copyright (C) 2018-2024 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
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sys/prctl.h>
-#include <asm/prctl.h>
-
-static __always_inline int
-dl_cet_disable_cet (unsigned int cet_feature)
-{
-  if (cet_feature != GNU_PROPERTY_X86_FEATURE_1_SHSTK)
-    return -1;
-  long long int kernel_feature = ARCH_SHSTK_SHSTK;
-  return (int) INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_DISABLE,
-				      kernel_feature);
-}
-
-static __always_inline int
-dl_cet_lock_cet (unsigned int cet_feature)
-{
-  if (cet_feature != GNU_PROPERTY_X86_FEATURE_1_SHSTK)
-    return -1;
-  /* Lock all SHSTK features.  */
-  long long int kernel_feature = -1;
-  return (int) INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_LOCK,
-				      kernel_feature);
-}
-
-static __always_inline unsigned int
-dl_cet_get_cet_status (void)
-{
-  unsigned long long kernel_feature;
-  unsigned int status = 0;
-  if (INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_STATUS,
-			     &kernel_feature) == 0)
-    {
-      if ((kernel_feature & ARCH_SHSTK_SHSTK) != 0)
-	status = GNU_PROPERTY_X86_FEATURE_1_SHSTK;
-    }
-  return status;
-}
-
-/* Enable shadow stack with a macro to avoid shadow stack underflow.  */
-#define ENABLE_X86_CET(cet_feature)				\
-  if ((cet_feature & GNU_PROPERTY_X86_FEATURE_1_SHSTK))		\
-    {								\
-      long long int kernel_feature = ARCH_SHSTK_SHSTK;		\
-      INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_ENABLE,	\
-			     kernel_feature);			\
-    }
diff --git a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
index c89dd6bd42..94e9b9aa86 100644
--- a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
+++ b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
@@ -15,8 +15,53 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <sys/prctl.h>
+#include <asm/prctl.h>
 #include <cpu-features-offsets.h>
-#include_next <dl-cet.h>
+
+static __always_inline int
+dl_cet_disable_cet (unsigned int cet_feature)
+{
+  if (cet_feature != GNU_PROPERTY_X86_FEATURE_1_SHSTK)
+    return -1;
+  long long int kernel_feature = ARCH_SHSTK_SHSTK;
+  return (int) INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_DISABLE,
+				      kernel_feature);
+}
+
+static __always_inline int
+dl_cet_lock_cet (unsigned int cet_feature)
+{
+  if (cet_feature != GNU_PROPERTY_X86_FEATURE_1_SHSTK)
+    return -1;
+  /* Lock all SHSTK features.  */
+  long long int kernel_feature = -1;
+  return (int) INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_LOCK,
+				      kernel_feature);
+}
+
+static __always_inline unsigned int
+dl_cet_get_cet_status (void)
+{
+  unsigned long long kernel_feature;
+  unsigned int status = 0;
+  if (INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_STATUS,
+			     &kernel_feature) == 0)
+    {
+      if ((kernel_feature & ARCH_SHSTK_SHSTK) != 0)
+	status = GNU_PROPERTY_X86_FEATURE_1_SHSTK;
+    }
+  return status;
+}
+
+/* Enable shadow stack with a macro to avoid shadow stack underflow.  */
+#define ENABLE_X86_CET(cet_feature)				\
+  if ((cet_feature & GNU_PROPERTY_X86_FEATURE_1_SHSTK))		\
+    {								\
+      long long int kernel_feature = ARCH_SHSTK_SHSTK;		\
+      INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_ENABLE,	\
+			     kernel_feature);			\
+    }
 
 #define X86_STRINGIFY_1(x)	#x
 #define X86_STRINGIFY(x)	X86_STRINGIFY_1 (x)
diff --git a/sysdeps/x86/dl-cet.c b/sysdeps/x86_64/dl-cet.c
similarity index 99%
rename from sysdeps/x86/dl-cet.c
rename to sysdeps/x86_64/dl-cet.c
index d1d42ab002..1297c09f84 100644
--- a/sysdeps/x86/dl-cet.c
+++ b/sysdeps/x86_64/dl-cet.c
@@ -1,4 +1,4 @@
-/* x86 CET initializers function.
+/* x86-64 CET initializers function.
    Copyright (C) 2018-2024 Free Software Foundation, Inc.
 
    The GNU C Library is free software; you can redistribute it and/or
-- 
2.43.0

[PATCH v2 3/4] x86-64/cet: Move check-cet.awk to x86_64

[H.J. Lu]

---
 sysdeps/x86_64/Makefile               | 2 +-
 sysdeps/{x86 => x86_64}/check-cet.awk | 0
 2 files changed, 1 insertion(+), 1 deletion(-)
 rename sysdeps/{x86 => x86_64}/check-cet.awk (100%)

diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile
index 98f0e04f90..abb8b354af 100644
--- a/sysdeps/x86_64/Makefile
+++ b/sysdeps/x86_64/Makefile
@@ -468,7 +468,7 @@ $(cet-built-dso:=.note): %.note: %
 	mv -f $@T $@
 common-generated += $(cet-built-dso:$(common-objpfx)%=%.note)
 
-$(objpfx)check-cet.out: $(..)sysdeps/x86/check-cet.awk \
+$(objpfx)check-cet.out: $(..)/sysdeps/x86_64/check-cet.awk \
 			$(cet-built-dso:=.note)
 	LC_ALL=C $(AWK) -f $^ > $@; \
 	$(evaluate-test)
diff --git a/sysdeps/x86/check-cet.awk b/sysdeps/x86_64/check-cet.awk
similarity index 100%
rename from sysdeps/x86/check-cet.awk
rename to sysdeps/x86_64/check-cet.awk
-- 
2.43.0

[PATCH v2 4/4] i386: Remove CET support bits

[H.J. Lu]

1. Remove _dl_runtime_resolve_shstk and _dl_runtime_profile_shstk.
2. Move CET offsets from x86 cpu-features-offsets.sym to x86-64
features-offsets.sym.
3. Rename x86 cet-control.h to x86-64 feature-control.h since it is only
for x86-64 and also used for PLT rewrite.
4. Add x86-64 ldsodefs.h to include feature-control.h.
5. Change TUNABLE_CALLBACK (set_plt_rewrite) to x86-64 only.
6. Move x86 dl-procruntime.c to x86-64.
---
 sysdeps/i386/dl-machine.h                     | 11 +--
 sysdeps/i386/dl-trampoline.S                  | 69 -------------------
 sysdeps/unix/sysv/linux/x86_64/dl-cet.h       |  2 +-
 sysdeps/x86/cpu-features-offsets.sym          |  2 -
 sysdeps/x86/cpu-features.c                    |  4 +-
 sysdeps/x86/ldsodefs.h                        |  1 -
 sysdeps/x86_64/Makefile                       |  2 +-
 sysdeps/{x86 => x86_64}/dl-procruntime.c      |  2 +-
 sysdeps/x86_64/dl-trampoline.S                |  1 +
 .../feature-control.h}                        |  8 +--
 sysdeps/x86_64/features-offsets.sym           |  6 ++
 sysdeps/x86_64/ldsodefs.h                     | 26 +++++++
 12 files changed, 45 insertions(+), 89 deletions(-)
 rename sysdeps/{x86 => x86_64}/dl-procruntime.c (97%)
 rename sysdeps/{x86/cet-control.h => x86_64/feature-control.h} (92%)
 create mode 100644 sysdeps/x86_64/features-offsets.sym
 create mode 100644 sysdeps/x86_64/ldsodefs.h

diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h
index c69ae165ac..fc1ef96587 100644
--- a/sysdeps/i386/dl-machine.h
+++ b/sysdeps/i386/dl-machine.h
@@ -65,9 +65,6 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
   extern void _dl_runtime_profile (Elf32_Word) attribute_hidden;
   extern void _dl_runtime_resolve_shstk (Elf32_Word) attribute_hidden;
   extern void _dl_runtime_profile_shstk (Elf32_Word) attribute_hidden;
-  /* Check if SHSTK is enabled by kernel.  */
-  bool shstk_enabled
-    = (GL(dl_x86_feature_1) & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0;
 
   if (l->l_info[DT_JMPREL] && lazy)
     {
@@ -95,9 +92,7 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
 #ifdef SHARED
       if (__glibc_unlikely (profile))
 	{
-	  got[2] = (shstk_enabled
-		    ? (Elf32_Addr) &_dl_runtime_profile_shstk
-		    : (Elf32_Addr) &_dl_runtime_profile);
+	  got[2] = (Elf32_Addr) &_dl_runtime_profile;
 
 	  if (GLRO(dl_profile) != NULL
 	      && _dl_name_match_p (GLRO(dl_profile), l))
@@ -109,9 +104,7 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
 #endif
 	/* This function will get called to fix up the GOT entry indicated by
 	   the offset on the stack, and then jump to the resolved address.  */
-	got[2] = (shstk_enabled
-		  ? (Elf32_Addr) &_dl_runtime_resolve_shstk
-		  : (Elf32_Addr) &_dl_runtime_resolve);
+	got[2] = (Elf32_Addr) &_dl_runtime_resolve;
     }
 
   return lazy;
diff --git a/sysdeps/i386/dl-trampoline.S b/sysdeps/i386/dl-trampoline.S
index 2632020145..6c14d463b6 100644
--- a/sysdeps/i386/dl-trampoline.S
+++ b/sysdeps/i386/dl-trampoline.S
@@ -44,76 +44,7 @@ _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)
-	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
-
 #if !defined PROF && defined SHARED
-# 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)
-	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
diff --git a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
index 94e9b9aa86..a00c7ee662 100644
--- a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
+++ b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
@@ -17,7 +17,7 @@
 
 #include <sys/prctl.h>
 #include <asm/prctl.h>
-#include <cpu-features-offsets.h>
+#include <features-offsets.h>
 
 static __always_inline int
 dl_cet_disable_cet (unsigned int cet_feature)
diff --git a/sysdeps/x86/cpu-features-offsets.sym b/sysdeps/x86/cpu-features-offsets.sym
index 5429f60632..6a8fd29813 100644
--- a/sysdeps/x86/cpu-features-offsets.sym
+++ b/sysdeps/x86/cpu-features-offsets.sym
@@ -2,6 +2,4 @@
 
 #include <ldsodefs.h>
 
-RTLD_GLOBAL_RO_DL_X86_CPU_FEATURES_OFFSET offsetof (struct rtld_global_ro, _dl_x86_cpu_features)
 XSAVE_STATE_SIZE_OFFSET	offsetof (struct cpu_features, xsave_state_size)
-RTLD_GLOBAL_DL_X86_FEATURE_1_OFFSET offsetof (struct rtld_global, _dl_x86_feature_1)
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index 9ca307f521..46bdaffbc2 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -27,7 +27,7 @@
 extern void TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *)
   attribute_hidden;
 
-#ifdef SHARED
+#if defined SHARED && defined __x86_64__
 static void
 TUNABLE_CALLBACK (set_plt_rewrite) (tunable_val_t *valp)
 {
@@ -1125,8 +1125,10 @@ no_cpuid:
 #endif
 
 #ifdef SHARED
+# ifdef __x86_64__
   TUNABLE_GET (plt_rewrite, tunable_val_t *,
 	       TUNABLE_CALLBACK (set_plt_rewrite));
+# endif
 #else
   /* NB: In libc.a, call init_cacheinfo.  */
   init_cacheinfo ();
diff --git a/sysdeps/x86/ldsodefs.h b/sysdeps/x86/ldsodefs.h
index b2a6d71513..50dc81c022 100644
--- a/sysdeps/x86/ldsodefs.h
+++ b/sysdeps/x86/ldsodefs.h
@@ -61,7 +61,6 @@ struct La_x32_retval;
 				     struct La_x86_64_retval *,		\
 				     const char *)
 
-#include <cet-control.h>
 #include_next <ldsodefs.h>
 
 #endif
diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile
index abb8b354af..10a253e4f1 100644
--- a/sysdeps/x86_64/Makefile
+++ b/sysdeps/x86_64/Makefile
@@ -10,7 +10,7 @@ LDFLAGS-rtld += -Wl,-z,nomark-plt
 endif
 
 ifeq ($(subdir),csu)
-gen-as-const-headers += link-defines.sym
+gen-as-const-headers += features-offsets.sym link-defines.sym
 endif
 
 ifeq ($(subdir),gmon)
diff --git a/sysdeps/x86/dl-procruntime.c b/sysdeps/x86_64/dl-procruntime.c
similarity index 97%
rename from sysdeps/x86/dl-procruntime.c
rename to sysdeps/x86_64/dl-procruntime.c
index 15b3d0d878..7078581778 100644
--- a/sysdeps/x86/dl-procruntime.c
+++ b/sysdeps/x86_64/dl-procruntime.c
@@ -1,4 +1,4 @@
-/* Data for processor runtime information.  x86 version.
+/* Data for processor runtime information.  x86-64 version.
    Copyright (C) 2018-2024 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
diff --git a/sysdeps/x86_64/dl-trampoline.S b/sysdeps/x86_64/dl-trampoline.S
index 4c1ba5c9af..b2e7e0f69b 100644
--- a/sysdeps/x86_64/dl-trampoline.S
+++ b/sysdeps/x86_64/dl-trampoline.S
@@ -19,6 +19,7 @@
 #include <config.h>
 #include <sysdep.h>
 #include <cpu-features-offsets.h>
+#include <features-offsets.h>
 #include <link-defines.h>
 #include <isa-level.h>
 
diff --git a/sysdeps/x86/cet-control.h b/sysdeps/x86_64/feature-control.h
similarity index 92%
rename from sysdeps/x86/cet-control.h
rename to sysdeps/x86_64/feature-control.h
index f09f193e9b..4c8727e844 100644
--- a/sysdeps/x86/cet-control.h
+++ b/sysdeps/x86_64/feature-control.h
@@ -1,4 +1,4 @@
-/* x86 CET tuning.
+/* x86-64 feature tuning.
    This file is part of the GNU C Library.
    Copyright (C) 2018-2024 Free Software Foundation, Inc.
 
@@ -16,8 +16,8 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#ifndef _CET_CONTROL_H
-#define _CET_CONTROL_H
+#ifndef _X86_64_FEATURE_CONTROL_H
+#define _X86_64_FEATURE_CONTROL_H
 
 /* For each CET feature, IBT and SHSTK, valid control values.  */
 enum dl_x86_cet_control
@@ -50,4 +50,4 @@ struct dl_x86_feature_control
   enum dl_plt_rewrite_control plt_rewrite : 2;
 };
 
-#endif /* cet-control.h */
+#endif /* feature-control.h */
diff --git a/sysdeps/x86_64/features-offsets.sym b/sysdeps/x86_64/features-offsets.sym
new file mode 100644
index 0000000000..9e4be3393a
--- /dev/null
+++ b/sysdeps/x86_64/features-offsets.sym
@@ -0,0 +1,6 @@
+#define SHARED 1
+
+#include <ldsodefs.h>
+
+RTLD_GLOBAL_RO_DL_X86_CPU_FEATURES_OFFSET offsetof (struct rtld_global_ro, _dl_x86_cpu_features)
+RTLD_GLOBAL_DL_X86_FEATURE_1_OFFSET offsetof (struct rtld_global, _dl_x86_feature_1)
diff --git a/sysdeps/x86_64/ldsodefs.h b/sysdeps/x86_64/ldsodefs.h
new file mode 100644
index 0000000000..0f468ddf5b
--- /dev/null
+++ b/sysdeps/x86_64/ldsodefs.h
@@ -0,0 +1,26 @@
+/* Run-time dynamic linker data structures for loaded ELF shared objects.
+   x86-64 version.
+   Copyright (C) 2024 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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef	_X86_64_LDSODEFS_H
+#define	_X86_64_LDSODEFS_H	1
+
+#include <feature-control.h>
+#include_next <ldsodefs.h>
+
+#endif
-- 
2.43.0