commit 4c92a1041257c0155c6aa7a182fe5f78e477b0e6
Author: Matheus Castanho <msc@linux.ibm.com>
Date:   Tue Jun 7 10:27:26 2022 -0300

    powerpc: Fix VSX register number on __strncpy_power9 [BZ #29197]
    
    __strncpy_power9 initializes VR 18 with zeroes to be used throughout the
    code, including when zero-padding the destination string. However, the
    v18 reference was mistakenly being used for stxv and stxvl, which take a
    VSX vector as operand. The code ended up using the uninitialized VSR 18
    register by mistake.
    
    Both occurrences have been changed to use the proper VSX number for VR 18
    (i.e. VSR 50).
    
    Tested on powerpc, powerpc64 and powerpc64le.
    
    Signed-off-by: Kewen Lin <linkw@gcc.gnu.org>
    (cherry picked from commit 0218463dd8265ed937622f88ac68c7d984fe0cfc)

diff --git a/sysdeps/powerpc/powerpc64/le/power9/strncpy.S b/sysdeps/powerpc/powerpc64/le/power9/strncpy.S
index 291941c1e5c0eb4b..5421525acee3ebfe 100644
--- a/sysdeps/powerpc/powerpc64/le/power9/strncpy.S
+++ b/sysdeps/powerpc/powerpc64/le/power9/strncpy.S
@@ -352,7 +352,7 @@ L(zero_padding_loop):
 	cmpldi	cr6,r5,16	/* Check if length was reached.  */
 	ble	cr6,L(zero_padding_end)
 
-	stxv	v18,0(r11)
+	stxv	32+v18,0(r11)
 	addi	r11,r11,16
 	addi	r5,r5,-16
 
@@ -360,7 +360,7 @@ L(zero_padding_loop):
 
 L(zero_padding_end):
 	sldi	r10,r5,56	/* stxvl wants size in top 8 bits  */
-	stxvl	v18,r11,r10	/* Partial store  */
+	stxvl	32+v18,r11,r10	/* Partial store  */
 	blr
 
 	.align	4