Fix segfault when accessing bad memory addresses

1 files changed, 4 insertions, 7 deletions

diff --git a/riscv/devices.cc b/riscv/devices.cc
index af4dc7d..15115c8 100644
--- a/riscv/devices.cc
+++ b/riscv/devices.cc
@@ -21,13 +21,10 @@ bool bus_t::store(reg_t addr, size_t len, const uint8_t* bytes)
   return it->second->store(addr - -it->first, len, bytes);
 }
 
-bus_t::descriptor bus_t::find_device(reg_t addr)
+std::pair<reg_t, abstract_device_t*> bus_t::find_device(reg_t addr)
 {
   auto it = devices.lower_bound(-addr);
-  if (it == devices.end()) {
-    bus_t::descriptor desc = {0, 0};
-    return desc;
-  }
-  bus_t::descriptor desc = {-it->first, it->second};
-  return desc;
+  if (it == devices.end() || addr < -it->first)
+    return std::make_pair((reg_t)0, (abstract_device_t*)NULL);
+  return std::make_pair(-it->first, it->second);
 }