diff --git a/packages/cultmath/tools/device/gen.py b/packages/cultmath/tools/device/gen.py
index 4dfd70ca..62632beb 100644
--- a/packages/cultmath/tools/device/gen.py
+++ b/packages/cultmath/tools/device/gen.py
@@ -67,6 +67,13 @@ def write(kind, glsl, value):
     return {'f': 'asuint(%s)', 'i': 'asuint(%s)', 'u': '%s'}[kind] % value
 
 
+def hlsl_type(t):
+    m = GLSL_VEC.match(t)
+    if m:
+        return {'': 'float', 'i': 'int', 'u': 'uint'}[m.group(1)] + m.group(2)
+    return 'float3x3' if t == 'mat3' else t
+
+
 def body(sig, n, win, wout, defs, glsl):
     m = re.fullmatch(r'(\w+)\s+(\w+)\((.*)\)', sig)
     ret, name, params = m.group(1), m.group(2), [p.strip() for p in m.group(3).split(',') if p.strip()]
diff --git a/packages/cultmath/tools/device/vkrun.c b/packages/cultmath/tools/device/vkrun.c
index 6ba6a336..0df21d8d 100644
--- a/packages/cultmath/tools/device/vkrun.c
+++ b/packages/cultmath/tools/device/vkrun.c
@@ -10,7 +10,7 @@
 static void *slurp(const char *p, size_t *n) {
   FILE *f = fopen(p, "rb"); if (!f) { perror(p); exit(2); }
   fseek(f, 0, SEEK_END); *n = ftell(f); fseek(f, 0, SEEK_SET);
-  void *b = malloc(*n ? *n : 4); fread(b, 1, *n, f); fclose(f); return b;
+  void *b = malloc(*n ? *n : 4); if (fread(b, 1, *n, f) != *n) exit(2); fclose(f); return b;
 }
 
 int main(int argc, char **argv) {