[PATCH] target/s390x/tcg: SPX: check validity of new prefix

[Janis Schoetterl-Glausch <scgl@linux.ibm.com>]

According to the architecture, SET PREFIX must try to access the new
prefix area and recognize an addressing exception if the area is not
accessible.
For qemu this check prevents a crash in cpu_map_lowcore after an
inaccessible prefix area has been set.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
---


Is there a stricter check to see if the memory is accessible?


 target/s390x/tcg/misc_helper.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/target/s390x/tcg/misc_helper.c b/target/s390x/tcg/misc_helper.c
index aab9c47747..c8447b36fc 100644
--- a/target/s390x/tcg/misc_helper.c
+++ b/target/s390x/tcg/misc_helper.c
@@ -158,6 +158,10 @@ void HELPER(spx)(CPUS390XState *env, uint64_t a1)
     if (prefix == old_prefix) {
         return;
     }
+    if (!mmu_absolute_addr_valid(prefix, true) ||
+        !mmu_absolute_addr_valid(prefix + TARGET_PAGE_SIZE, true)) {
+        tcg_s390_program_interrupt(env, PGM_ADDRESSING, GETPC());
+    }
 
     env->psa = prefix;
     HELPER_LOG("prefix: %#x\n", prefix);

base-commit: 3a821c52e1a30ecd9a436f2c67cc66b5628c829f
-- 
2.36.1