From 899623b29caa02f25e069acbcef581d19fe0a64e Mon Sep 17 00:00:00 2001 From: Holger Dengler Date: Wed, 20 Aug 2025 17:55:43 +0200 Subject: [PATCH] aes-s390x.pl: Initialize reserved and unused memory The reserved bytes in the parameter block (bytes 0-11) for the KMA instruction should be set to zero to be compatible in case of future architecture changes. While at it, also the following unused parts of the parameter block (bytes 48-63) are also cleared to avoid false positives with various memory checkers like valgrind. As it makes - performance wise - no difference to process 12, 48 or 64 bytes with one XC call, but two XC calls are slower than one call, the first 64 bytes of the parameter block will be cleared with a single XC call. This will also initialize the counter in the parameter block (bytes 12-15), although it is not strictly necessary. Co-developed-by: Juergen Christ Signed-off-by: Juergen Christ Signed-off-by: Holger Dengler Reviewed-by: Tomas Mraz Reviewed-by: Paul Dale Reviewed-by: Neil Horman (Merged from https://github.com/openssl/openssl/pull/28315) --- crypto/aes/asm/aes-s390x.pl | 3 +++ 1 file changed, 3 insertions(+) diff --git a/crypto/aes/asm/aes-s390x.pl b/crypto/aes/asm/aes-s390x.pl index 78aa6dacfc..891d33bb7d 100644 --- a/crypto/aes/asm/aes-s390x.pl +++ b/crypto/aes/asm/aes-s390x.pl @@ -1431,6 +1431,9 @@ $code.=<<___ if (!$softonly); st${g} $s3,0($sp) # backchain la %r1,$stdframe($sp) + xc $stdframe+0(64,$sp),$stdframe+0($sp) # clear reserved/unused + # in parameter block + lmg $s2,$s3,0($key) # copy key stg $s2,$stdframe+80($sp) stg $s3,$stdframe+88($sp) -- 2.50.1