debug: Fix clang mq_open fortify wrapper (BZ 31917)

The mqueue.h fortify wrapper for clang added by c23107effbfe5300
is not fully correct, where correct 4 argument usage are not
being correctly handled.  For instance, while building socat 1.8
with a yocto clang based system shows:

  ./socat-1.8.0.0/xio-posixmq.c:119:8: error: 'mq_open' is unavailable: mq_open can be called either with 2 or 4 arguments
    119 |         mqd = mq_open(name, oflag, opt_mode, NULL);
        |               ^
  [...] /usr/include/bits/mqueue2.h:66:8: note: 'mq_open' has been explicitly marked unavailable here
     66 | __NTH (mq_open (const char *__name, int __oflag, mode_t mode,
        |        ^
  1 error generated.

The correct way to define the wrapper is to set invalid usage
with __fortify_clang_unavailable (for the case with 5 or more
arguments), followed by the expected ones.  This fix make mq_open
similar to current open wrappers.

[1] http://www.dest-unreach.org/socat/

Reported-by: Khem Raj <raj.khem@gmail.com>
Acked-by: Khem Raj <raj.khem@gmail.com>

diff --git a/rt/bits/mqueue2.h b/rt/bits/mqueue2.h
index d6d2d9012d970a90f77734e688d8c727e457e488..386404c0c8cf24684ea706c509d2ca311b063660 100644 (file)
--- a/rt/bits/mqueue2.h
+++ b/rt/bits/mqueue2.h
@@ -59,13 +59,16 @@ __NTH (mq_open (const char *__name, int __oflag, ...))
 }
 #elif __fortify_use_clang
 __fortify_function_error_function __attribute_overloadable__ mqd_t
-__NTH (mq_open (const char *__name, int __oflag, mode_t mode))
+__NTH (mq_open (__fortify_clang_overload_arg (const char *, , __name),
+               int __oflag, mode_t __mode, ...))
      __fortify_clang_unavailable ("mq_open can be called either with 2 or 4 arguments");
 
-__fortify_function_error_function __attribute_overloadable__ mqd_t
-__NTH (mq_open (const char *__name, int __oflag, mode_t mode,
-               struct mq_attr *attr, ...))
-     __fortify_clang_unavailable ("mq_open can be called either with 2 or 4 arguments");
+__fortify_function __attribute_overloadable__ mqd_t
+__NTH (mq_open (__fortify_clang_overload_arg (const char *, ,__name),
+               int __oflag, mode_t __mode, struct mq_attr *__attr))
+{
+  return __mq_open_alias (__name, __oflag, __mode, __attr);
+}
 
 __fortify_function __attribute_overloadable__ mqd_t
 __NTH (mq_open (__fortify_clang_overload_arg (const char *, ,__name),
@@ -76,11 +79,4 @@ __NTH (mq_open (__fortify_clang_overload_arg (const char *, ,__name),
 {
   return __mq_open_alias (__name, __oflag);
 }
-
-__fortify_function __attribute_overloadable__ mqd_t
-__NTH (mq_open (__fortify_clang_overload_arg (const char *, ,__name),
-               int __oflag, int __mode, struct mq_attr *__attr))
-{
-  return __mq_open_alias (__name, __oflag, __mode, __attr);
-}
 #endif