[glibc] aarch64: Fix the extension header write in getcontext and swapcontext

[glibc] aarch64: Fix the extension header write in getcontext and swapcontext

[Szabolcs Nagy]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=09c6c6073c925235b385af1d8edf6bc853eeaf60

commit 09c6c6073c925235b385af1d8edf6bc853eeaf60
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date:   Fri Jul 29 08:00:06 2022 +0100

    aarch64: Fix the extension header write in getcontext and swapcontext
    
    The extension header is two 32bit words and in the last header both
    should be 0. There is plenty space in the __reserved area, but it's
    better not to write more than we mean to.

Diff:
---
 sysdeps/unix/sysv/linux/aarch64/getcontext.S  | 4 ++--
 sysdeps/unix/sysv/linux/aarch64/swapcontext.S | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/aarch64/getcontext.S b/sysdeps/unix/sysv/linux/aarch64/getcontext.S
index 15fbd2d1a0..3109cbd99a 100644
--- a/sysdeps/unix/sysv/linux/aarch64/getcontext.S
+++ b/sysdeps/unix/sysv/linux/aarch64/getcontext.S
@@ -86,8 +86,8 @@ ENTRY(__getcontext)
 	/* Write the termination context extension header.  */
 	add	x2, x2, #FPSIMD_CONTEXT_SIZE
 
-	str	xzr, [x2, #oHEAD + oMAGIC]
-	str	xzr, [x2, #oHEAD + oSIZE]
+	str	wzr, [x2, #oHEAD + oMAGIC]
+	str	wzr, [x2, #oHEAD + oSIZE]
 
 	/* Grab the signal mask */
 	/* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */
diff --git a/sysdeps/unix/sysv/linux/aarch64/swapcontext.S b/sysdeps/unix/sysv/linux/aarch64/swapcontext.S
index 1ee2e40272..e3ec9da35d 100644
--- a/sysdeps/unix/sysv/linux/aarch64/swapcontext.S
+++ b/sysdeps/unix/sysv/linux/aarch64/swapcontext.S
@@ -75,8 +75,8 @@ ENTRY(__swapcontext)
 	/* Write the termination context extension header.  */
 	add	x2, x2, #FPSIMD_CONTEXT_SIZE
 
-	str	xzr, [x2, #oHEAD + oMAGIC]
-	str	xzr, [x2, #oHEAD + oSIZE]
+	str	wzr, [x2, #oHEAD + oMAGIC]
+	str	wzr, [x2, #oHEAD + oSIZE]
 
 	/* Preserve ucp.  */
 	mov	x21, x1