[v4,10/15] tests: replace system by xsystem

With fortification enabled, system calls return result needs to be checked,
has it gets the __wur macro enabled.
---
 elf/tst-stackguard1.c     |  2 +-
 libio/bug-mmap-fflush.c   |  7 +++++--
 nptl/tst-cancel7.c        |  3 ++-
 nptl/tst-stackguard1.c    |  2 +-
 nss/tst-nss-db-endpwent.c |  3 ++-
 support/Makefile          |  1 +
 support/xstdlib.h         | 31 +++++++++++++++++++++++++++++++
 support/xsystem.c         | 29 +++++++++++++++++++++++++++++
 8 files changed, 72 insertions(+), 6 deletions(-)
 create mode 100644 support/xstdlib.h
 create mode 100644 support/xsystem.c

On 2023-04-28 08:21, Frédéric Bérat wrote:
> With fortification enabled, system calls return result needs to be checked,
> has it gets the __wur macro enabled.
> ---
>   elf/tst-stackguard1.c     |  2 +-
>   libio/bug-mmap-fflush.c   |  7 +++++--
>   nptl/tst-cancel7.c        |  3 ++-
>   nptl/tst-stackguard1.c    |  2 +-
>   nss/tst-nss-db-endpwent.c |  3 ++-
>   support/Makefile          |  1 +
>   support/xstdlib.h         | 31 +++++++++++++++++++++++++++++++
>   support/xsystem.c         | 29 +++++++++++++++++++++++++++++
>   8 files changed, 72 insertions(+), 6 deletions(-)
>   create mode 100644 support/xstdlib.h
>   create mode 100644 support/xsystem.c
> 
> diff --git a/elf/tst-stackguard1.c b/elf/tst-stackguard1.c
> index 2e65e36078..7dbde6568c 100644
> --- a/elf/tst-stackguard1.c
> +++ b/elf/tst-stackguard1.c
> @@ -108,7 +108,7 @@ do_test (void)
>   	  dup2 (fds[1], 2);
>   	  close (fds[1]);
>   
> -	  system (command);
> +	  if (system (command)) {/* We aren't interested on the result */}
>   	  exit (0);
>   	}
>   
> diff --git a/libio/bug-mmap-fflush.c b/libio/bug-mmap-fflush.c
> index d8aa58985a..3f99222eef 100644
> --- a/libio/bug-mmap-fflush.c
> +++ b/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);
> diff --git a/nptl/tst-cancel7.c b/nptl/tst-cancel7.c
> index 2835613a9b..0ecb7d025f 100644
> --- a/nptl/tst-cancel7.c
> +++ b/nptl/tst-cancel7.c
> @@ -27,6 +27,7 @@
>   #include <support/support.h>
>   #include <support/temp_file.h>
>   #include <support/xstdio.h>
> +#include <support/xstdlib.h>
>   #include <support/xunistd.h>
>   #include <support/xthread.h>
>   
> @@ -43,7 +44,7 @@ tf (void *arg)
>   {
>     char *cmd = xasprintf ("%s --direct --sem %s --pidfile %s",
>   			 command, semfilename, pidfilename);
> -  system (cmd);
> +  xsystem (cmd);
>     /* This call should never return.  */
>     return NULL;
>   }
> diff --git a/nptl/tst-stackguard1.c b/nptl/tst-stackguard1.c
> index 4ac57157e9..9ec9e8f982 100644
> --- a/nptl/tst-stackguard1.c
> +++ b/nptl/tst-stackguard1.c
> @@ -140,7 +140,7 @@ do_test (void)
>   	  dup2 (fds[1], 2);
>   	  close (fds[1]);
>   
> -	  system (command);
> +	  if (system (command)) {/* We aren't interested in the result */}

Why not?

>   	  exit (0);
>   	}
>   
> diff --git a/nss/tst-nss-db-endpwent.c b/nss/tst-nss-db-endpwent.c
> index 2b0fc1b064..4dba3fada6 100644
> --- a/nss/tst-nss-db-endpwent.c
> +++ b/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 ();
> diff --git a/support/Makefile b/support/Makefile
> index a4ac86544c..4c8eb3dedd 100644
> --- a/support/Makefile
> +++ b/support/Makefile
> @@ -209,6 +209,7 @@ libsupport-routines = \
>     xstrdup \
>     xstrndup \
>     xsymlink \
> +  xsystem \
>     xsysconf \
>     xunlink \
>     xuselocale \
> diff --git a/support/xstdlib.h b/support/xstdlib.h
> new file mode 100644
> index 0000000000..58642e3542
> --- /dev/null
> +++ b/support/xstdlib.h
> @@ -0,0 +1,31 @@
> +/* Error-checking wrappers for stdlib functions.
> +   Copyright (C) 2016-2023 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 */
> diff --git a/support/xsystem.c b/support/xsystem.c
> new file mode 100644
> index 0000000000..8ceaad1531
> --- /dev/null
> +++ b/support/xsystem.c
> @@ -0,0 +1,29 @@
> +/* Error-checking replacement for "system".
> +   Copyright (C) 2018-2023 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)
> +{
> +  if (system (cmd) < 0)
> +    FAIL_EXIT1 ("system (\"%s\")", cmd);

This would succeed if system exits with status 127, when it's unable to 
spawn a child shell.  It will also not behave correctly with a NULL cmd, 
where I reckon we'd want to fail if no shell is available, i.e. return 
value of 0.

> +}