[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PULL 04/10] target/s390x: Fix cc_calc_sla_64() missing overflows
From: |
Thomas Huth |
Subject: |
[PULL 04/10] target/s390x: Fix cc_calc_sla_64() missing overflows |
Date: |
Wed, 19 Jan 2022 09:32:09 +0100 |
From: Ilya Leoshkevich <iii@linux.ibm.com>
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 <david@redhat.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20220112165016.226996-4-iii@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
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;
--
2.27.0
- [PULL 00/10] s390x patches (shift instructions, MAINTAINERS, ...), Thomas Huth, 2022/01/19
- [PULL 01/10] s390x/css: fix PMCW invalid mask, Thomas Huth, 2022/01/19
- [PULL 02/10] target/s390x: Fix SLDA sign bit index, Thomas Huth, 2022/01/19
- [PULL 03/10] target/s390x: Fix SRDA CC calculation, Thomas Huth, 2022/01/19
- [PULL 04/10] target/s390x: Fix cc_calc_sla_64() missing overflows,
Thomas Huth <=
- [PULL 06/10] tests/tcg/s390x: Test shift instructions, Thomas Huth, 2022/01/19
- [PULL 05/10] target/s390x: Fix shifting 32-bit values for more than 31 bits, Thomas Huth, 2022/01/19
- [PULL 07/10] MAINTAINERS: split out s390x sections, Thomas Huth, 2022/01/19
- [PULL 08/10] MAINTAINERS: Add myself to s390 I/O areas, Thomas Huth, 2022/01/19
- [PULL 09/10] s390x/ipl: support extended kernel command line size, Thomas Huth, 2022/01/19
- [PULL 10/10] s390x: sigp: Reorder the SIGP STOP code, Thomas Huth, 2022/01/19
- Re: [PULL 00/10] s390x patches (shift instructions, MAINTAINERS, ...), Peter Maydell, 2022/01/19