Standalone MIRI - `read` FFI

3 files changed, 47 insertions, 3 deletions

diff --git a/tools/standalone_miri/miri.cpp b/tools/standalone_miri/miri.cpp
index f6ea1125..8d9f31ed 100644
--- a/tools/standalone_miri/miri.cpp
+++ b/tools/standalone_miri/miri.cpp
@@ -20,6 +20,7 @@
 #endif
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <unistd.h>
 #undef DEBUG
 
 unsigned ThreadState::s_next_tls_key = 1;
@@ -1915,6 +1916,30 @@ bool InterpreterThread::call_extern(Value& rv, const ::std::string& link_name, c
 
         rv = Value::new_isize(val);
     }
+    else if( link_name == "read" )
+    {
+        auto fd = args.at(0).read_i32(0);
+        auto count = args.at(2).read_isize(0);
+        auto buf_vr = args.at(1).read_pointer_valref_mut(0, count);
+
+        LOG_DEBUG("read(" << fd << ", " << buf_vr.data_ptr_mut() << ", " << count << ")");
+        ssize_t val = read(fd, buf_vr.data_ptr_mut(), count);
+        LOG_DEBUG("= " << val);
+
+        if( val > 0 )
+        {
+            buf_vr.mark_bytes_valid(0, val);
+        }
+
+        rv = Value::new_isize(val);
+    }
+    else if( link_name == "close" )
+    {
+        auto fd = args.at(0).read_i32(0);
+        LOG_DEBUG("close(" << fd << ")");
+        // TODO: Ensure that this FD is from the set known by the FFI layer
+        close(fd);
+    }
     else if( link_name == "sysconf" )
     {
         auto name = args.at(0).read_i32(0);
@@ -2224,7 +2249,7 @@ bool InterpreterThread::call_intrinsic(Value& rv, const RcString& name, const ::
     {
         rv = Value();
     }
-    else if( name == "atomic_store" )
+    else if( name == "atomic_store" || name == "atomic_store_relaxed" )
     {
         auto& ptr_val = args.at(0);
         auto& data_val = args.at(1);
diff --git a/tools/standalone_miri/value.cpp b/tools/standalone_miri/value.cpp
index 363d980b..01f0fbbc 100644
--- a/tools/standalone_miri/value.cpp
+++ b/tools/standalone_miri/value.cpp
@@ -962,6 +962,23 @@ extern ::std::ostream& operator<<(::std::ostream& os, const ValueRef& v)
     return os;
 }
 
+void ValueRef::mark_bytes_valid(size_t ofs, size_t size)
+{
+    if( m_alloc ) {
+        switch(m_alloc.get_ty())
+        {
+        case RelocationPtr::Ty::Allocation:
+            m_alloc.alloc().mark_bytes_valid(m_offset + ofs, size);
+            break;
+        default:
+            LOG_TODO("mark_valid in " << m_alloc);
+        }
+    }
+    else {
+        m_value->mark_bytes_valid(m_offset + ofs, size);
+    }
+}
+
 Value ValueRef::read_value(size_t ofs, size_t size) const
 {
     if( size == 0 )
diff --git a/tools/standalone_miri/value.hpp b/tools/standalone_miri/value.hpp
index 5e5ccc4f..ebae2699 100644
--- a/tools/standalone_miri/value.hpp
+++ b/tools/standalone_miri/value.hpp
@@ -365,7 +365,7 @@ struct ValueRef:
     {
         struct H {
             static bool in_bounds(size_t ofs, size_t size, size_t max_size) {
-                if( !(ofs < max_size) )
+                if( ofs > 0 && !(ofs < max_size) )
                     return false;
                 if( !(size <= max_size) )
                     return false;
@@ -448,6 +448,8 @@ struct ValueRef:
             return nullptr;
         }
     }
+
+    // TODO: Remove these two (move to a helper?)
     uint8_t* data_ptr_mut() {
         if( m_alloc ) {
             switch(m_alloc.get_ty())
@@ -466,7 +468,7 @@ struct ValueRef:
             return nullptr;
         }
     }
-    void mark_valid(size_t ofs, size_t size);
+    void mark_bytes_valid(size_t ofs, size_t size);
 
     void read_bytes(size_t ofs, void* dst, size_t size) const {
         if( size == 0 )