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| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2022-01-12 17:50:14 +0100 |
|---|---|---|
| committer | Thomas Huth <thuth@redhat.com> | 2022-01-17 08:36:33 +0100 |
| commit | df103c09bc2f549d36ba6313a69c18fc003ef1ee (patch) | |
| tree | 2df4706ba21bf1d8b7117a62be6d1c7e1aad30ef /target/s390x | |
| parent | 57556b28afde4b039bb12bfc274bd8df9022d946 (diff) | |
| download | qemu-df103c09bc2f549d36ba6313a69c18fc003ef1ee.zip qemu-df103c09bc2f549d36ba6313a69c18fc003ef1ee.tar.gz qemu-df103c09bc2f549d36ba6313a69c18fc003ef1ee.tar.bz2 | |
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 <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>
Diffstat (limited to 'target/s390x')
| -rw-r--r-- | target/s390x/tcg/cc_helper.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/target/s390x/tcg/cc_helper.c b/target/s390x/tcg/cc_helper.c index c2c96c3..c9b7b0e 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; |