decode_open: print the mode argument when O_TMPFILE flag is set

O_TMPFILE reqires the mode argument (just like O_CREAT), so print it.

* open.c (STRACE_O_TMPFILE): New macro.
(decode_open): Print the mode argument when O_TMPFILE flag is set.
* tests/open.c (main): Check it.
Fixes RH#1377846.

open.c

@@ -115,14 +115,21 @@ tprint_open_modes(unsigned int flags)
 	tprints(sprint_open_modes(flags) + sizeof("flags"));
 }
 
+#ifdef O_TMPFILE
+/* The kernel & C libraries often inline O_DIRECTORY. */
+# define STRACE_O_TMPFILE (O_TMPFILE & ~O_DIRECTORY)
+#else /* !O_TMPFILE */
+# define STRACE_O_TMPFILE 0
+#endif
+
 static int
 decode_open(struct tcb *tcp, int offset)
 {
 	printpath(tcp, tcp->u_arg[offset]);
 	tprints(", ");
 	/* flags */
 	tprint_open_modes(tcp->u_arg[offset + 1]);
-	if (tcp->u_arg[offset + 1] & O_CREAT) {
+	if (tcp->u_arg[offset + 1] & (O_CREAT | STRACE_O_TMPFILE)) {
 		/* mode */
 		tprints(", ");
 		print_numeric_umode_t(tcp->u_arg[offset + 2]);

tests/open.c

@@ -56,6 +56,17 @@ main(void)
 		       sample, sprintrc(fd));
 	}
 
+#ifdef O_TMPFILE
+# if O_TMPFILE == (O_TMPFILE & ~O_DIRECTORY)
+#  define STR_O_TMPFILE "O_TMPFILE"
+# else
+#  define STR_O_TMPFILE "O_DIRECTORY|O_TMPFILE"
+# endif
+	fd = syscall(__NR_open, sample, O_WRONLY|O_TMPFILE, 0600);
+	printf("open(\"%s\", O_WRONLY|%s, 0600) = %s\n",
+	       sample, STR_O_TMPFILE, sprintrc(fd));
+#endif /* O_TMPFILE */
+
 	puts("+++ exited with 0 +++");
 	return 0;
 }