posix.cfg: Add minsize to readlink[at] function configurations (#1216)

cfg/posix.cfg

@@ -2443,6 +2443,7 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
     </arg>
     <arg nr="2">
       <not-null/>
+      <minsize type="argvalue" arg="3"/>
     </arg>
     <arg nr="3">
       <not-uninit/>
@@ -2464,6 +2465,7 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
     </arg>
     <arg nr="3">
       <not-null/>
+      <minsize type="argvalue" arg="4"/>
     </arg>
     <arg nr="4">
       <not-uninit/>

test/cfg/posix.c

@@ -42,6 +42,12 @@ void bufferAccessOutOfBounds(int fd)
     sendto(fd,a,6,0,0x0,0x0);
     // cppcheck-suppress constStatement
     0;
+    readlink("path", a, 5);
+    // cppcheck-suppress bufferAccessOutOfBounds
+    readlink("path", a, 6);
+    readlinkat(1, "path", a, 5);
+    // cppcheck-suppress bufferAccessOutOfBounds
+    readlinkat(1, "path", a, 6);
 }
 
 void nullPointer(char *p, int fd)