linux-user: Clear translations on mprotect()

Currently it's possible to execute pages that do not have PAGE_EXEC
if there is an existing translation block. Fix by invalidating TBs
that touch the affected pages.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20220817150506.592862-2-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

linux-user/mmap.c

@@ -177,9 +177,11 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
             goto error;
         }
     }
+
     page_set_flags(start, start + len, page_flags);
-    mmap_unlock();
-    return 0;
+    tb_invalidate_phys_range(start, start + len);
+    ret = 0;
+
 error:
     mmap_unlock();
     return ret;