Re: [PATCH v7 2/4] tests: replace system by xsystem

[Siddhesh Poyarekar <siddhesh@gotplt.org>]

On 2023-06-13 10:13, Adhemerval Zanella Netto wrote:
> 
> 
> On 12/06/23 12:18, Frédéric Bérat via Libc-alpha wrote:
>> With fortification enabled, system calls return result needs to be checked,
>> has it gets the __wur macro enabled.
>> ---
>> Changes since v6:
>>   - Fixed support/Makefile ordering
>>
>>   elf/tst-stackguard1.c     |  5 ++++-
>>   libio/bug-mmap-fflush.c   |  7 +++++--
>>   nptl/tst-cancel7.c        |  3 ++-
>>   nptl/tst-stackguard1.c    |  4 +++-
>>   nss/tst-nss-db-endpwent.c |  3 ++-
>>   support/Makefile          |  1 +
>>   support/xstdlib.h         | 31 +++++++++++++++++++++++++++++++
>>   support/xsystem.c         | 37 +++++++++++++++++++++++++++++++++++++
>>   8 files changed, 85 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..e03b242e7e 100644
>> --- a/elf/tst-stackguard1.c
>> +++ b/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);
>>   	}
>>   
>> 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;
>>   }
> 
> Joseph's comments for tests that area actually checking for the interface
> [1] also applies here.  I think we should keep using 'system' rather than
> any wrapper here.
> 
> 
> [1] https://sourceware.org/pipermail/libc-alpha/2023-June/148978.html

Ahh yes, thanks, I missed that.

Sid

> 
>> diff --git a/nptl/tst-stackguard1.c b/nptl/tst-stackguard1.c
>> index 4ac57157e9..7308b9d37a 100644
>> --- a/nptl/tst-stackguard1.c
>> +++ b/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);
>>   	}
>>   
>> 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 5b14abdd28..8ee3344c9a 100644
>> --- a/support/Makefile
>> +++ b/support/Makefile
>> @@ -210,6 +210,7 @@ libsupport-routines = \
>>     xstrndup \
>>     xsymlink \
>>     xsysconf \
>> +  xsystem \
>>     xunlink \
>>     xuselocale \
>>     xwaitpid \
>> diff --git a/support/xstdlib.h b/support/xstdlib.h
>> new file mode 100644
>> index 0000000000..db5a5b9d4f
>> --- /dev/null
>> +++ b/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 */
>> diff --git a/support/xsystem.c b/support/xsystem.c
>> new file mode 100644
>> index 0000000000..1f558953bc
>> --- /dev/null
>> +++ b/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);
>> +}
>