From 300a84c83fc6f112bed7e488f0e64eb6c07d47bf Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Date: Tue, 23 May 2023 12:34:33 +0200 Subject: [PATCH 05/22] target/s390x: Fix cc_calc_sla_64() missing overflows MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Cédric Le Goater RH-MergeRequest: 279: Backport latest s390x-related fixes from upstream QEMU for qemu-kvm in RHEL 8.9 RH-Bugzilla: 2169308 2209605 RH-Acked-by: Thomas Huth RH-Acked-by: David Hildenbrand RH-Acked-by: Cornelia Huck RH-Commit: [4/21] 2f91de2ac980d6ffa4da0ec41bb30562624a2396 Bugzilla: https://bugzilla.redhat.com/2169308 commit df103c09bc2f549d36ba6313a69c18fc003ef1ee Author: Ilya Leoshkevich Date: Wed Jan 12 17:50:14 2022 +0100 target/s390x: Fix cc_calc_sla_64() missing overflows An overflow occurs for SLAG when at least one shifted bit is not equal to sign bit. Therefore, we need to check that `shift + 1` bits are neither all 0s nor all 1s. The current code checks only `shift` bits, missing some overflows. Fixes: cbe24bfa91d2 ("target-s390: Convert SHIFT, ROTATE SINGLE") Co-developed-by: David Hildenbrand Signed-off-by: Ilya Leoshkevich Reviewed-by: David Hildenbrand Message-Id: <20220112165016.226996-4-iii@linux.ibm.com> Signed-off-by: Thomas Huth Signed-off-by: Cédric Le Goater --- target/s390x/tcg/cc_helper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/target/s390x/tcg/cc_helper.c b/target/s390x/tcg/cc_helper.c index c2c96c3a3c..c9b7b0e8c6 100644 --- a/target/s390x/tcg/cc_helper.c +++ b/target/s390x/tcg/cc_helper.c @@ -297,7 +297,7 @@ static uint32_t cc_calc_sla_32(uint32_t src, int shift) static uint32_t cc_calc_sla_64(uint64_t src, int shift) { - uint64_t mask = ((1ULL << shift) - 1ULL) << (64 - shift); + uint64_t mask = -1ULL << (63 - shift); uint64_t sign = 1ULL << 63; uint64_t match; int64_t r; -- 2.37.3