protect/map shenanigans with macOS

src/common/host_memory.cpp

@@ -629,8 +629,9 @@ public:
         u8* addr = virtual_base + virtual_offset;
 #ifdef __APPLE__
         // The way Steve Jobs intended
-        addr = (void*)trunc_page(u64(addr));
+        addr = (u8*)trunc_page(u64(addr) + host_offset);
         length = round_page(length);
+        host_offset = 0;
 #endif
         void* ret = mmap(addr, length, prot_flags, flags, fd, host_offset);
         ASSERT_MSG(ret != MAP_FAILED, "mmap: {}", strerror(errno));
@@ -665,7 +666,13 @@ public:
         if (execute)
             flags |= PROT_EXEC;
 #endif
-        int ret = mprotect(virtual_base + virtual_offset, length, flags);
+        u8* addr = virtual_base + virtual_offset;
+#ifdef __APPLE__
+        // The way Steve Jobs intended
+        addr = (u8*)trunc_page(u64(addr));
+        length = round_page(length);
+#endif
+        int ret = mprotect(addr, length, flags);
         ASSERT_MSG(ret == 0, "mprotect failed: {}", strerror(errno));
     }