tests: replace system by xsystem

With fortification enabled, system calls return result needs to be checked,
has it gets the __wur macro enabled.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

elf/tst-stackguard1.c

@@ -26,6 +26,8 @@
 #include <tls.h>
 #include <unistd.h>
 
+#include <support/xstdlib.h>
+
 static const char *command;
 static bool child;
 static uintptr_t stack_chk_guard_copy;
@@ -108,7 +110,8 @@ do_test (void)
 	  dup2 (fds[1], 2);
 	  close (fds[1]);
 
-	  system (command);
+	  xsystem (command);
+
 	  exit (0);
 	}
 

libio/bug-mmap-fflush.c

@@ -4,6 +4,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <support/xstdlib.h>
 
 static char *fname;
 
@@ -35,14 +36,16 @@ do_test (void)
   char buffer[1024];
 
   snprintf (buffer, sizeof (buffer), "echo 'From foo@bar.com' > %s", fname);
-  system (buffer);
+  xsystem (buffer);
+
   f = fopen (fname, "r");
   fseek (f, 0, SEEK_END);
   o = ftello (f);
   fseek (f, 0, SEEK_SET);
   fflush (f);
   snprintf (buffer, sizeof (buffer), "echo 'From bar@baz.edu' >> %s", fname);
-  system (buffer);
+  xsystem (buffer);
+
   fseek (f, o, SEEK_SET);
   if (fgets (buffer, 1024, f) == NULL)
     exit (1);

nptl/tst-cancel7.c

@@ -43,7 +43,8 @@ tf (void *arg)
 {
   char *cmd = xasprintf ("%s --direct --sem %s --pidfile %s",
 			 command, semfilename, pidfilename);
-  system (cmd);
+  if (system (cmd))
+    FAIL_EXIT1("system call unexpectedly returned");
   /* This call should never return.  */
   return NULL;
 }

nptl/tst-stackguard1.c

@@ -28,6 +28,7 @@
 #include <unistd.h>
 
 #include <support/xunistd.h>
+#include <support/xstdlib.h>
 
 static const char *command;
 static bool child;
@@ -140,7 +141,8 @@ do_test (void)
 	  dup2 (fds[1], 2);
 	  close (fds[1]);
 
-	  system (command);
+	  xsystem (command);
+
 	  exit (0);
 	}
 

nss/tst-nss-db-endpwent.c

@@ -23,6 +23,7 @@
 
 #include <support/support.h>
 #include <support/check.h>
+#include <support/xstdlib.h>
 
 /* It is entirely allowed to start with a getpwent call without
    resetting the state of the service via a call to setpwent.
@@ -55,7 +56,7 @@ do_test (void)
 
   cmd = xasprintf ("%s/makedb -o /var/db/passwd.db /var/db/passwd.in",
 		   support_bindir_prefix);
-  system (cmd);
+  xsystem (cmd);
   free (cmd);
 
   try_it ();

support/Makefile

@@ -212,6 +212,7 @@ libsupport-routines = \
   xstrndup \
   xsymlink \
   xsysconf \
+  xsystem \
   xunlink \
   xuselocale \
   xwaitpid \

support/xstdlib.h

@@ -0,0 +1,31 @@
+/* Error-checking wrappers for stdlib functions.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef SUPPORT_XSTDLIB_H
+#define SUPPORT_XSTDLIB_H
+
+#include <stdlib.h>
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+void xsystem (const char *cmd);
+
+__END_DECLS
+
+#endif /* SUPPORT_XSTDLIB_H */

support/xsystem.c

@@ -0,0 +1,37 @@
+/* Error-checking replacement for "system".
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <support/support.h>
+#include <support/check.h>
+
+#include <support/xstdlib.h>
+
+void
+xsystem (const char *cmd)
+{
+  int ret = system (cmd);
+
+  if (ret == 0 && cmd == NULL)
+    FAIL_EXIT1 ("Unable to spawn a shell for NULL command");
+
+  if (ret == 127)
+    FAIL_EXIT1 ("Child terminated with status 127");
+
+  if (ret < 0)
+    FAIL_EXIT1 ("system (\"%s\")", cmd);
+}