From 92a57534619a4058544ce8f9c0beae3e054f342b Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Tue, 4 Jul 2023 10:12:28 +0200 Subject: [PATCH] target/s390x: Fix MVCRL with a large value in R0 Using a large R0 causes an assertion error: qemu-s390x: target/s390x/tcg/mem_helper.c:183: access_prepare_nf: Assertion `size > 0 && size <= 4096' failed. Even though PoP explicitly advises against using more than 8 bits for the size, an emulator crash is never a good thing. Fix by truncating the size to 8 bits. Fixes: ea0a1053e276 ("s390x/tcg: Implement Miscellaneous-Instruction-Extensions Facility 3 for the s390x") Signed-off-by: Ilya Leoshkevich Reviewed-by: David Hildenbrand Cc: qemu-stable@nongnu.org Message-Id: <20230704081506.276055-5-iii@linux.ibm.com> Signed-off-by: Thomas Huth --- target/s390x/tcg/mem_helper.c | 1 + 1 file changed, 1 insertion(+) diff --git a/target/s390x/tcg/mem_helper.c b/target/s390x/tcg/mem_helper.c index d02ec861d8..84ad85212c 100644 --- a/target/s390x/tcg/mem_helper.c +++ b/target/s390x/tcg/mem_helper.c @@ -514,6 +514,7 @@ void HELPER(mvcrl)(CPUS390XState *env, uint64_t l, uint64_t dest, uint64_t src) int32_t i; /* MVCRL always copies one more byte than specified - maximum is 256 */ + l &= 0xff; l++; access_prepare(&srca, env, src, l, MMU_DATA_LOAD, mmu_idx, ra); -- 2.39.2