From: Wilco Dijkstra <wilco.dijkstra@arm.com>
Date: Wed, 14 May 2025 16:32:31 +0000 (+0000)
Subject: AArch64: Cleanup PAC and BTI
X-Git-Tag: glibc-2.42~232
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2c421fc4302ecb729823ca442f9dfab95afba752;p=thirdparty%2Fglibc.git

AArch64: Cleanup PAC and BTI

Now we finally support modern GCC and binutils, it's time for a cleanup.
Use PAC and BTI instructions unconditionally and use proper assembler syntax.
Remove the PR target/94791 strip_pac workarounds for buggy GCCs.  Remove the
PAC/BTI configure checks - always emit GNU property notes on assembly files.
Change cfi_window_save to the correct cfi_negate_ra_state unwind directive.

Reviewed-by: Matthieu Longo <matthieu.longo@arm.com>
---

diff --git a/config.h.in b/config.h.in
index d3575c9845..f8e7d1780d 100644
--- a/config.h.in
+++ b/config.h.in
@@ -113,12 +113,6 @@
 /* AArch64 big endian ABI */
 #undef HAVE_AARCH64_BE
 
-/* AArch64 BTI support enabled.  */
-#define HAVE_AARCH64_BTI 0
-
-/* AArch64 PAC-RET code generation is enabled.  */
-#define HAVE_AARCH64_PAC_RET 0
-
 /* Assembler support ARMv8.2-A SVE.
    This macro becomes obsolete when glibc increased the minimum
    required version of GNU 'binutils' to 2.28 or later. */
diff --git a/elf/tst-asm-helper.h b/elf/tst-asm-helper.h
index 6f91ac2ddc..ae2e3aae5c 100644
--- a/elf/tst-asm-helper.h
+++ b/elf/tst-asm-helper.h
@@ -20,6 +20,7 @@
 
 #include <config.h>
 
+#ifdef __aarch64__
 /* GNU_PROPERTY_AARCH64_* macros from elf.h for use in asm code.  */
 #define FEATURE_1_AND 0xc0000000
 #define FEATURE_1_BTI 1
@@ -42,8 +43,5 @@
 
 /* Add GNU property note with the supported features to all asm code
    where sysdep.h is included.  */
-#if HAVE_AARCH64_BTI && HAVE_AARCH64_PAC_RET
 GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI|FEATURE_1_PAC|FEATURE_1_GCS)
-#elif HAVE_AARCH64_BTI
-GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI|FEATURE_1_GCS)
 #endif
diff --git a/sysdeps/aarch64/__arm_za_disable.S b/sysdeps/aarch64/__arm_za_disable.S
index 629080372c..92f48145a3 100644
--- a/sysdeps/aarch64/__arm_za_disable.S
+++ b/sysdeps/aarch64/__arm_za_disable.S
@@ -88,10 +88,8 @@ L(save_loop):
 L(end):
 	ret
 L(fail):
-#if HAVE_AARCH64_PAC_RET
-	PACIASP
-	cfi_window_save
-#endif
+	paciasp
+	cfi_negate_ra_state
 	stp	x29, x30, [sp, -32]!
 	cfi_adjust_cfa_offset (32)
 	cfi_rel_offset (x29, 0)
diff --git a/sysdeps/aarch64/__longjmp.S b/sysdeps/aarch64/__longjmp.S
index d062e04862..ed5b6b1fba 100644
--- a/sysdeps/aarch64/__longjmp.S
+++ b/sysdeps/aarch64/__longjmp.S
@@ -27,10 +27,8 @@ ENTRY (__longjmp)
 
 #if IS_IN(libc)
 	/* Disable ZA state of SME in libc.a and libc.so, but not in ld.so.  */
-# if HAVE_AARCH64_PAC_RET
-	PACIASP
-	cfi_window_save
-# endif
+	paciasp
+	cfi_negate_ra_state
 	stp	x29, x30, [sp, -16]!
 	cfi_adjust_cfa_offset (16)
 	cfi_rel_offset (x29, 0)
@@ -41,10 +39,8 @@ ENTRY (__longjmp)
 	cfi_adjust_cfa_offset (-16)
 	cfi_restore (x29)
 	cfi_restore (x30)
-# if HAVE_AARCH64_PAC_RET
-	AUTIASP
-	cfi_window_save
-# endif
+	autiasp
+	cfi_negate_ra_state
 #endif
 
 	cfi_def_cfa (x0, 0)
diff --git a/sysdeps/aarch64/configure b/sysdeps/aarch64/configure
index 4bd5496a4a..7bddc99d7f 100755
--- a/sysdeps/aarch64/configure
+++ b/sysdeps/aarch64/configure
@@ -185,93 +185,6 @@ else
 default-abi = lp64"
 fi
 
-# Only consider BTI supported if -mbranch-protection=bti is
-# on by default in the compiler and the linker produces
-# binaries with GNU property notes in PT_GNU_PROPERTY segment.
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for BTI support" >&5
-printf %s "checking for BTI support... " >&6; }
-if test ${libc_cv_aarch64_bti+y}
-then :
-  printf %s "(cached) " >&6
-else case e in #(
-  e)   cat > conftest.c <<EOF
-void foo (void) { }
-EOF
-  libc_cv_aarch64_bti=no
-  if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -nostdlib -nostartfiles $no_ssp -shared -fPIC -o conftest.so conftest.c'
-  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; } \
-     && { ac_try='$READELF -lW conftest.so | grep -q GNU_PROPERTY'
-  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; } \
-     && { ac_try='$READELF -nW conftest.so | grep -q "NT_GNU_PROPERTY_TYPE_0.*AArch64 feature:.* BTI"'
-  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; }
-  then
-    libc_cv_aarch64_bti=yes
-  fi
-  rm -rf conftest.* ;;
-esac
-fi
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_aarch64_bti" >&5
-printf "%s\n" "$libc_cv_aarch64_bti" >&6; }
-config_vars="$config_vars
-aarch64-bti = $libc_cv_aarch64_bti"
-if test $libc_cv_aarch64_bti = yes; then
-  printf "%s\n" "#define HAVE_AARCH64_BTI 1" >>confdefs.h
-
-fi
-
-# Check if glibc is built with return address signing, i.e.
-# if -mbranch-protection=pac-ret is on. We need this because
-# pac-ret relies on unwinder support so it's not safe to use
-# it in assembly code unconditionally, but there is no
-# feature test macro for it in gcc.
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking if pac-ret is enabled" >&5
-printf %s "checking if pac-ret is enabled... " >&6; }
-if test ${libc_cv_aarch64_pac_ret+y}
-then :
-  printf %s "(cached) " >&6
-else case e in #(
-  e)   cat > conftest.c <<EOF
-int bar (void);
-int foo (void) { return bar () + 1; }
-EOF
-  libc_cv_aarch64_pac_ret=no
-  if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -S -o conftest.s conftest.c'
-  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; } \
-     && { ac_try='grep -q -E '\''(hint( |	)+25|paciasp)'\'' conftest.s'
-  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; }
-  then
-    libc_cv_aarch64_pac_ret=yes
-  fi
-  rm -rf conftest.* ;;
-esac
-fi
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_aarch64_pac_ret" >&5
-printf "%s\n" "$libc_cv_aarch64_pac_ret" >&6; }
-if test $libc_cv_aarch64_pac_ret = yes; then
-  printf "%s\n" "#define HAVE_AARCH64_PAC_RET 1" >>confdefs.h
-
-fi
-
 # Check if binutils supports variant PCS symbols.
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for variant PCS support" >&5
 printf %s "checking for variant PCS support... " >&6; }
diff --git a/sysdeps/aarch64/configure.ac b/sysdeps/aarch64/configure.ac
index 56d12d661d..633513374a 100644
--- a/sysdeps/aarch64/configure.ac
+++ b/sysdeps/aarch64/configure.ac
@@ -24,47 +24,6 @@ else
   LIBC_CONFIG_VAR([default-abi], [lp64])
 fi
 
-# Only consider BTI supported if -mbranch-protection=bti is
-# on by default in the compiler and the linker produces
-# binaries with GNU property notes in PT_GNU_PROPERTY segment.
-AC_CACHE_CHECK([for BTI support], [libc_cv_aarch64_bti], [dnl
-  cat > conftest.c <<EOF
-void foo (void) { }
-EOF
-  libc_cv_aarch64_bti=no
-  if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -nostdlib -nostartfiles $no_ssp -shared -fPIC -o conftest.so conftest.c]) \
-     && AC_TRY_COMMAND([$READELF -lW conftest.so | grep -q GNU_PROPERTY]) \
-     && AC_TRY_COMMAND([$READELF -nW conftest.so | grep -q "NT_GNU_PROPERTY_TYPE_0.*AArch64 feature:.* BTI"])
-  then
-    libc_cv_aarch64_bti=yes
-  fi
-  rm -rf conftest.*])
-LIBC_CONFIG_VAR([aarch64-bti], [$libc_cv_aarch64_bti])
-if test $libc_cv_aarch64_bti = yes; then
-  AC_DEFINE(HAVE_AARCH64_BTI)
-fi
-
-# Check if glibc is built with return address signing, i.e.
-# if -mbranch-protection=pac-ret is on. We need this because
-# pac-ret relies on unwinder support so it's not safe to use
-# it in assembly code unconditionally, but there is no
-# feature test macro for it in gcc.
-AC_CACHE_CHECK([if pac-ret is enabled], [libc_cv_aarch64_pac_ret], [dnl
-  cat > conftest.c <<EOF
-int bar (void);
-int foo (void) { return bar () + 1; }
-EOF
-  libc_cv_aarch64_pac_ret=no
-  if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -S -o conftest.s conftest.c]) \
-     && AC_TRY_COMMAND([grep -q -E '\''(hint( |	)+25|paciasp)'\'' conftest.s])
-  then
-    libc_cv_aarch64_pac_ret=yes
-  fi
-  rm -rf conftest.*])
-if test $libc_cv_aarch64_pac_ret = yes; then
-  AC_DEFINE(HAVE_AARCH64_PAC_RET)
-fi
-
 # Check if binutils supports variant PCS symbols.
 AC_CACHE_CHECK([for variant PCS support], [libc_cv_aarch64_variant_pcs], [dnl
   cat > conftest.S <<EOF
diff --git a/sysdeps/aarch64/crti.S b/sysdeps/aarch64/crti.S
index 0c3ee40400..e9e530c848 100644
--- a/sysdeps/aarch64/crti.S
+++ b/sysdeps/aarch64/crti.S
@@ -65,7 +65,7 @@ call_weak_fn:
 	cbz	x0, 1f
 	b	PREINIT_FUNCTION
 1:
-	RET
+	ret
 	.size	call_weak_fn, .-call_weak_fn
 #endif
 
@@ -75,11 +75,7 @@ call_weak_fn:
 	.hidden	_init
 	.type	_init, %function
 _init:
-#if HAVE_AARCH64_PAC_RET
-	PACIASP
-#else
-	BTI_C
-#endif
+	paciasp
 	stp	x29, x30, [sp, -16]!
 	mov	x29, sp
 #if PREINIT_FUNCTION_WEAK
@@ -94,10 +90,6 @@ _init:
 	.hidden	_fini
 	.type	_fini, %function
 _fini:
-#if HAVE_AARCH64_PAC_RET
-	PACIASP
-#else
-	BTI_C
-#endif
+	paciasp
 	stp	x29, x30, [sp, -16]!
 	mov	x29, sp
diff --git a/sysdeps/aarch64/crtn.S b/sysdeps/aarch64/crtn.S
index b52b10edec..653a548a5a 100644
--- a/sysdeps/aarch64/crtn.S
+++ b/sysdeps/aarch64/crtn.S
@@ -41,14 +41,10 @@
 
 	.section .init,"ax",%progbits
 	ldp	x29, x30, [sp], 16
-#if HAVE_AARCH64_PAC_RET
-	AUTIASP
-#endif
-	RET
+	autiasp
+	ret
 
 	.section .fini,"ax",%progbits
 	ldp	x29, x30, [sp], 16
-#if HAVE_AARCH64_PAC_RET
-	AUTIASP
-#endif
-	RET
+	autiasp
+	ret
diff --git a/sysdeps/aarch64/dl-tlsdesc.S b/sysdeps/aarch64/dl-tlsdesc.S
index fc40d66c07..2ff8d95eff 100644
--- a/sysdeps/aarch64/dl-tlsdesc.S
+++ b/sysdeps/aarch64/dl-tlsdesc.S
@@ -74,9 +74,9 @@
 	cfi_startproc
 	.align 2
 _dl_tlsdesc_return:
-	BTI_C
+	bti	c
 	ldr	x0, [x0, 8]
-	RET
+	ret
 	cfi_endproc
 	.size	_dl_tlsdesc_return, .-_dl_tlsdesc_return
 
@@ -95,7 +95,7 @@ _dl_tlsdesc_return:
 	cfi_startproc
 	.align  2
 _dl_tlsdesc_undefweak:
-	BTI_C
+	bti	c
 	str	x1, [sp, #-16]!
 	cfi_adjust_cfa_offset (16)
 	ldr	x0, [x0, 8]
@@ -103,7 +103,7 @@ _dl_tlsdesc_undefweak:
 	sub	x0, x0, x1
 	ldr	x1, [sp], #16
 	cfi_adjust_cfa_offset (-16)
-	RET
+	ret
 	cfi_endproc
 	.size	_dl_tlsdesc_undefweak, .-_dl_tlsdesc_undefweak
 
@@ -141,12 +141,8 @@ _dl_tlsdesc_undefweak:
 	cfi_startproc
 	.align 2
 _dl_tlsdesc_dynamic:
-# if HAVE_AARCH64_PAC_RET
-	PACIASP
-	cfi_window_save
-# else
-	BTI_C
-# endif
+	paciasp
+	cfi_negate_ra_state
 
 	/* Save just enough registers to support fast path, if we fall
 	   into slow path we will save additional registers.  */
@@ -177,12 +173,10 @@ _dl_tlsdesc_dynamic:
 1:
 	ldp	 x3,  x4, [sp, #16]
 	ldp	 x1,  x2, [sp], #32
-# if HAVE_AARCH64_PAC_RET
-	AUTIASP
-	cfi_window_save
-# endif
+	autiasp
+	cfi_negate_ra_state
 	cfi_adjust_cfa_offset (-32)
-	RET
+	ret
 2:
 	/* This is the slow path. We need to call __tls_get_addr() which
 	   means we need to save and restore all the register that the
diff --git a/sysdeps/aarch64/dl-trampoline.S b/sysdeps/aarch64/dl-trampoline.S
index d6bed96d61..d628b010b8 100644
--- a/sysdeps/aarch64/dl-trampoline.S
+++ b/sysdeps/aarch64/dl-trampoline.S
@@ -34,7 +34,7 @@
 	cfi_startproc
 	.align 2
 _dl_runtime_resolve:
-	BTI_C
+	bti	c
 	/* AArch64 we get called with:
 	   ip0		&PLTGOT[2]
 	   ip1		temp(dl resolver entry point)
@@ -127,12 +127,8 @@ _dl_runtime_resolve:
 	cfi_startproc
 	.align 2
 _dl_runtime_profile:
-# if HAVE_AARCH64_PAC_RET
-	PACIASP
-	cfi_window_save
-# else
-	BTI_C
-# endif
+	paciasp
+	cfi_negate_ra_state
 	/* AArch64 we get called with:
 	   ip0		&PLTGOT[2]
 	   ip1		temp(dl resolver entry point)
@@ -251,17 +247,12 @@ _dl_runtime_profile:
 	cfi_restore(x29)
 	cfi_restore(x30)
 
-# if HAVE_AARCH64_PAC_RET
 	add	sp, sp, SF_SIZE
 	cfi_adjust_cfa_offset (-SF_SIZE)
-	AUTIASP
-	cfi_window_save
+	autiasp
+	cfi_negate_ra_state
 	add	sp, sp, 16
 	cfi_adjust_cfa_offset (-16)
-# else
-	add	sp, sp, SF_SIZE + 16
-	cfi_adjust_cfa_offset (- SF_SIZE - 16)
-# endif
 
 	/* Jump to the newly found address.  */
 	br	ip0
@@ -321,10 +312,8 @@ _dl_runtime_profile:
 	/* LR from within La_aarch64_reg */
 	ldr	lr, [x29, #OFFSET_RG + DL_OFFSET_RG_LR]
 	cfi_restore(lr)
-# if HAVE_AARCH64_PAC_RET
 	/* Note: LR restored from La_aarch64_reg has no PAC.  */
-	cfi_window_save
-# endif
+	cfi_negate_ra_state
 	mov	sp, x29
 	cfi_def_cfa_register (sp)
 	ldr	x29, [x29, #0]
diff --git a/sysdeps/aarch64/machine-gmon.h b/sysdeps/aarch64/machine-gmon.h
index eba7c24197..05323c9d8f 100644
--- a/sysdeps/aarch64/machine-gmon.h
+++ b/sysdeps/aarch64/machine-gmon.h
@@ -27,9 +27,8 @@ static void mcount_internal (u_long frompc, u_long selfpc);
 #define _MCOUNT_DECL(frompc, selfpc) \
 static inline void mcount_internal (u_long frompc, u_long selfpc)
 
-/* Note: strip_pac is needed for frompc because of gcc PR target/94791.  */
 #define MCOUNT                                                    \
 void __mcount (void *frompc)                                      \
 {                                                                 \
-  mcount_internal ((u_long) strip_pac (frompc), (u_long) RETURN_ADDRESS (0)); \
+  mcount_internal ((u_long) frompc, (u_long) RETURN_ADDRESS (0)); \
 }
diff --git a/sysdeps/aarch64/multiarch/ifunc-impl-list.c b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
index 8dc314b67d..66b5cc02c4 100644
--- a/sysdeps/aarch64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
@@ -37,7 +37,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
   IFUNC_IMPL (i, name, memcpy,
 	      IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_oryon1)
 #if HAVE_AARCH64_SVE_ASM
-	      IFUNC_IMPL_ADD (array, i, memcpy, sve && !bti, __memcpy_a64fx)
+	      IFUNC_IMPL_ADD (array, i, memcpy, sve, __memcpy_a64fx)
 	      IFUNC_IMPL_ADD (array, i, memcpy, sve, __memcpy_sve)
 #endif
 	      IFUNC_IMPL_ADD (array, i, memcpy, mops, __memcpy_mops)
@@ -45,7 +45,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
   IFUNC_IMPL (i, name, memmove,
 	      IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_oryon1)
 #if HAVE_AARCH64_SVE_ASM
-	      IFUNC_IMPL_ADD (array, i, memmove, sve && !bti, __memmove_a64fx)
+	      IFUNC_IMPL_ADD (array, i, memmove, sve, __memmove_a64fx)
 	      IFUNC_IMPL_ADD (array, i, memmove, sve, __memmove_sve)
 #endif
 	      IFUNC_IMPL_ADD (array, i, memmove, mops, __memmove_mops)
@@ -56,7 +56,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 	      IFUNC_IMPL_ADD (array, i, memset, 1, __memset_emag)
 	      IFUNC_IMPL_ADD (array, i, memset, 1, __memset_kunpeng)
 #if HAVE_AARCH64_SVE_ASM
-	      IFUNC_IMPL_ADD (array, i, memset, sve && !bti && zva_size == 256, __memset_a64fx)
+	      IFUNC_IMPL_ADD (array, i, memset, sve && zva_size == 256, __memset_a64fx)
 	      IFUNC_IMPL_ADD (array, i, memset, sve && zva_size == 64, __memset_sve_zva64)
 #endif
 	      IFUNC_IMPL_ADD (array, i, memset, mops, __memset_mops)
diff --git a/sysdeps/aarch64/multiarch/init-arch.h b/sysdeps/aarch64/multiarch/init-arch.h
index 63c24e7f25..75b3e08303 100644
--- a/sysdeps/aarch64/multiarch/init-arch.h
+++ b/sysdeps/aarch64/multiarch/init-arch.h
@@ -31,7 +31,7 @@
   unsigned __attribute__((unused)) zva_size =				      \
     GLRO(dl_aarch64_cpu_features).zva_size;				      \
   bool __attribute__((unused)) bti =					      \
-    HAVE_AARCH64_BTI && GLRO(dl_aarch64_cpu_features).bti;		      \
+    GLRO(dl_aarch64_cpu_features).bti;					      \
   bool __attribute__((unused)) mte =					      \
     MTE_ENABLED ();							      \
   bool __attribute__((unused)) sve =					      \
diff --git a/sysdeps/aarch64/multiarch/memcpy_a64fx.S b/sysdeps/aarch64/multiarch/memcpy_a64fx.S
index ed18682700..bfadcd0317 100644
--- a/sysdeps/aarch64/multiarch/memcpy_a64fx.S
+++ b/sysdeps/aarch64/multiarch/memcpy_a64fx.S
@@ -19,9 +19,6 @@
 
 #include <sysdep.h>
 
-#undef BTI_C
-#define BTI_C
-
 /* Assumptions:
  *
  * ARMv8.2-a, AArch64, unaligned accesses, sve
@@ -91,9 +88,6 @@
 	st1b	z7.b, p0, [dst, 7, mul vl]
 	.endm
 
-#undef BTI_C
-#define BTI_C
-
 ENTRY (__memcpy_a64fx)
 
 	cntb	vlen
diff --git a/sysdeps/aarch64/multiarch/memset_a64fx.S b/sysdeps/aarch64/multiarch/memset_a64fx.S
index ea60b78e69..bebc191309 100644
--- a/sysdeps/aarch64/multiarch/memset_a64fx.S
+++ b/sysdeps/aarch64/multiarch/memset_a64fx.S
@@ -50,10 +50,6 @@
 	.endif
 	.endm
 
-
-#undef BTI_C
-#define BTI_C
-
 ENTRY (__memset_a64fx)
 
 	cntb	vector_length
diff --git a/sysdeps/aarch64/setjmp.S b/sysdeps/aarch64/setjmp.S
index 83d1e342bc..c8a2994f46 100644
--- a/sysdeps/aarch64/setjmp.S
+++ b/sysdeps/aarch64/setjmp.S
@@ -38,10 +38,8 @@ ENTRY_ALIGN (__sigsetjmp, 2)
 
 #if IS_IN(libc)
 	/* Disable ZA state of SME in libc.a and libc.so, but not in ld.so.  */
-# if HAVE_AARCH64_PAC_RET
-	PACIASP
-	cfi_window_save
-# endif
+	paciasp
+	cfi_negate_ra_state
 	stp	x29, x30, [sp, -16]!
 	cfi_adjust_cfa_offset (16)
 	cfi_rel_offset (x29, 0)
@@ -52,10 +50,8 @@ ENTRY_ALIGN (__sigsetjmp, 2)
 	cfi_adjust_cfa_offset (-16)
 	cfi_restore (x29)
 	cfi_restore (x30)
-# if HAVE_AARCH64_PAC_RET
-	AUTIASP
-	cfi_window_save
-# endif
+	autiasp
+	cfi_negate_ra_state
 #endif
 
 	stp	x19, x20, [x0, #JB_X19<<3]
@@ -96,7 +92,7 @@ L(gcs_done):
 #if IS_IN (rtld)
 	/* In ld.so we never save the signal mask */
 	mov	w0, #0
-	RET
+	ret
 #else
 	b	C_SYMBOL_NAME(__sigjmp_save)
 #endif
diff --git a/sysdeps/aarch64/start.S b/sysdeps/aarch64/start.S
index 544e397c50..694c338c8b 100644
--- a/sysdeps/aarch64/start.S
+++ b/sysdeps/aarch64/start.S
@@ -108,7 +108,7 @@ ENTRY(_start)
 	   because crt1.o and rcrt1.o share code and the later must avoid the
 	   use of GOT relocations before __libc_start_main is called.  */
 __wrap_main:
-	BTI_C
+	bti	c
 	b	main
 #endif
 END(_start)
diff --git a/sysdeps/aarch64/sysdep.h b/sysdeps/aarch64/sysdep.h
index 942411599d..f5e28cb242 100644
--- a/sysdeps/aarch64/sysdep.h
+++ b/sysdeps/aarch64/sysdep.h
@@ -21,43 +21,15 @@
 
 #include <sysdeps/generic/sysdep.h>
 
-#ifndef __ASSEMBLER__
-/* Strip pointer authentication code from pointer p.  */
-static inline void *
-strip_pac (void *p)
-{
-  register void *ra asm ("x30") = (p);
-  asm ("hint 7 // xpaclri" : "+r"(ra));
-  return ra;
-}
-
-/* This is needed when glibc is built with -mbranch-protection=pac-ret
-   with a gcc that is affected by PR target/94891.  */
-# if HAVE_AARCH64_PAC_RET
-#  undef RETURN_ADDRESS
-#  define RETURN_ADDRESS(n) strip_pac (__builtin_return_address (n))
-# endif
-#endif
-
 #ifdef	__ASSEMBLER__
 
+/* CFI directive for return address.  */
+#define cfi_negate_ra_state	.cfi_negate_ra_state
+
 /* Syntactic details of assembler.  */
 
 #define ASM_SIZE_DIRECTIVE(name) .size name,.-name
 
-/* Branch Target Identitication support.  */
-#if HAVE_AARCH64_BTI
-# define BTI_C		hint	34
-# define BTI_J		hint	36
-#else
-# define BTI_C		nop
-# define BTI_J		nop
-#endif
-
-/* Return address signing support (pac-ret).  */
-#define PACIASP		hint	25
-#define AUTIASP		hint	29
-
 /* Guarded Control Stack support.  */
 #define CHKFEAT_X16	hint	40
 #define MRS_GCSPR(x)	mrs	x, s3_3_c2_c5_1
@@ -87,11 +59,7 @@ strip_pac (void *p)
 
 /* Add GNU property note with the supported features to all asm code
    where sysdep.h is included.  */
-#if HAVE_AARCH64_BTI && HAVE_AARCH64_PAC_RET
 GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI|FEATURE_1_PAC|FEATURE_1_GCS)
-#elif HAVE_AARCH64_BTI
-GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI|FEATURE_1_GCS)
-#endif
 
 /* Define an entry point visible from C.  */
 #define ENTRY(name)						\
@@ -100,7 +68,7 @@ GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI|FEATURE_1_GCS)
   .p2align 6;							\
   C_LABEL(name)							\
   cfi_startproc;						\
-  BTI_C;							\
+  bti	c;							\
   CALL_MCOUNT
 
 /* Define an entry point visible from C.  */
@@ -110,7 +78,7 @@ GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI|FEATURE_1_GCS)
   .p2align align;						\
   C_LABEL(name)							\
   cfi_startproc;						\
-  BTI_C;							\
+  bti	c;							\
   CALL_MCOUNT
 
 /* Define an entry point visible from C with a specified alignment and
@@ -127,7 +95,7 @@ GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI|FEATURE_1_GCS)
   .endr;							\
   C_LABEL(name)							\
   cfi_startproc;						\
-  BTI_C;							\
+  bti	c;							\
   CALL_MCOUNT
 
 #undef	END
diff --git a/sysdeps/unix/sysv/linux/aarch64/setcontext.S b/sysdeps/unix/sysv/linux/aarch64/setcontext.S
index 022a263c47..18e4fb7f21 100644
--- a/sysdeps/unix/sysv/linux/aarch64/setcontext.S
+++ b/sysdeps/unix/sysv/linux/aarch64/setcontext.S
@@ -49,10 +49,8 @@ ENTRY (__setcontext)
 	b	C_SYMBOL_NAME (__syscall_error)
 1:
 	/* Disable ZA of SME.  */
-#if HAVE_AARCH64_PAC_RET
-	PACIASP
-	cfi_window_save
-#endif
+	paciasp
+	cfi_negate_ra_state
 	stp	x29, x30, [sp, -16]!
 	cfi_adjust_cfa_offset (16)
 	cfi_rel_offset (x29, 0)
@@ -63,10 +61,8 @@ ENTRY (__setcontext)
 	cfi_adjust_cfa_offset (-16)
 	cfi_restore (x29)
 	cfi_restore (x30)
-#if HAVE_AARCH64_PAC_RET
-	AUTIASP
-	cfi_window_save
-#endif
+	autiasp
+	cfi_negate_ra_state
 	/* Restore the general purpose registers.  */
 	mov	x0, x9
 	cfi_def_cfa (x0, 0)
diff --git a/sysdeps/unix/sysv/linux/aarch64/swapcontext.S b/sysdeps/unix/sysv/linux/aarch64/swapcontext.S
index cc41253a13..58ddb95591 100644
--- a/sysdeps/unix/sysv/linux/aarch64/swapcontext.S
+++ b/sysdeps/unix/sysv/linux/aarch64/swapcontext.S
@@ -119,7 +119,7 @@ L(gcs_done):
 2:
 	/* The oucp context is restored here via an indirect branch,
 	   x1 must be restored too which has the real return address.  */
-	BTI_J
+	bti	j
 	mov	x30, x1
 	RET
 PSEUDO_END (__swapcontext)