diff --git a/cfg/gnu.cfg b/cfg/gnu.cfg
index 64be9d9d7..99c11f827 100644
--- a/cfg/gnu.cfg
+++ b/cfg/gnu.cfg
@@ -42,6 +42,7 @@
     </arg>
     <arg nr="2">
       <not-uninit/>
+      <valid>0:</valid>
     </arg>
   </function>
   <!-- char *strdupa(const char *s); -->
@@ -157,7 +158,10 @@
     <arg nr="5">
       <not-null/>
     </arg>
-    <arg nr="6"/>
+    <arg nr="6">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
   </function>
   <!-- int fcvt_r (double value, int ndigit, int *decpt, int *neg, char *buf, size_t len); -->
   <function name="fcvt_r">
@@ -178,7 +182,10 @@
     <arg nr="5">
       <not-null/>
     </arg>
-    <arg nr="6"/>
+    <arg nr="6">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
   </function>
   <!-- int qecvt_r (long double value, int ndigit, int *decpt, int *neg, char *buf, size_t len); -->
   <function name="qecvt_r">
@@ -199,7 +206,10 @@
     <arg nr="5">
       <not-null/>
     </arg>
-    <arg nr="6"/>
+    <arg nr="6">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
   </function>
   <!-- int qfcvt_r (long double value, int ndigit, int *decpt, int *neg, char *buf, size_t len); -->
   <function name="qfcvt_r">
@@ -220,7 +230,10 @@
     <arg nr="5">
       <not-null/>
     </arg>
-    <arg nr="6"/>
+    <arg nr="6">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
   </function>
   <!-- https://www.gnu.org/software/gnulib/manual/html_node/c_002dstrcasestr.html -->
   <!-- size_t strcasestr(const char *s1, const char *s2); -->
@@ -343,9 +356,13 @@
     <noreturn>false</noreturn>
     <arg nr="1">
       <not-uninit/>
+      <valid>0:4294967295</valid>
+      <!-- 0:UINT32_MAX-->
     </arg>
     <arg nr="2">
       <not-uninit/>
+      <valid>0:4294967295</valid>
+      <!-- 0:UINT32_MAX-->
     </arg>
     <leak-ignore/>
   </function>