tests: extend test coverage of setgid syscall

* tests/setgid.c: New file.
* tests/setgid.test: New test.
* tests/.gitignore: Add setgid.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(DECODER_TESTS): Add setgid.test.

tests/.gitignore

@@ -142,6 +142,7 @@ semop
 sendfile
 sendfile64
 set_ptracer_any
+setgid
 sethostname
 setuid
 setuid32

tests/Makefile.am

@@ -192,6 +192,7 @@ check_PROGRAMS = \
 	sendfile \
 	sendfile64 \
 	set_ptracer_any \
+	setgid \
 	sethostname \
 	setuid \
 	setuid32 \
@@ -401,6 +402,7 @@ DECODER_TESTS = \
 	semop.test \
 	sendfile.test \
 	sendfile64.test \
+	setgid.test \
 	sethostname.test \
 	setuid.test \
 	setuid32.test \

tests/setgid.c

@@ -0,0 +1,25 @@
+#include "tests.h"
+#include <sys/syscall.h>
+
+#ifdef __NR_setgid
+
+# define SYSCALL_NR	__NR_setgid
+# define SYSCALL_NAME	"setgid"
+
+# if defined __NR_setgid32 && __NR_setgid != __NR_setgid32
+#  define UGID_TYPE	short
+#  define GETUGID	syscall(__NR_getegid)
+#  define CHECK_OVERFLOWUGID(arg)	check_overflowgid(arg)
+# else
+#  define UGID_TYPE	int
+#  define GETUGID	getegid()
+#  define CHECK_OVERFLOWUGID(arg)
+# endif
+
+# include "setugid.c"
+
+#else
+
+SKIP_MAIN_UNDEFINED("__NR_setgid")
+
+#endif

tests/setgid.test

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+# Check setgid syscall decoding.
+
+. "${srcdir=.}/init.sh"
+run_strace_match_diff -a10