sysconf: Fix missing definition of UIO_MAXIOV on Linux [BZ #22321]

Message ID 20171019183228.4BD2A428666AA@oldenburg.str.redhat.com
State Committed
Headers

Commit Message

Florian Weimer Oct. 19, 2017, 6:32 p.m. UTC
  2017-10-19  Florian Weimer  <fweimer@redhat.com>

	[BZ #22321]
	sysconf: Fix missing definition of UIO_MAXIOV on Linux.
	* sysdeps/posix/sysconf.c: Include <sys/uio.h>.
	* sysdeps/unix/sysv/linux/Makefile (tests): Add tst-sysconf-iov_max.
	(tst-sysconf-iov_max): Link with tst-sysconf-iov_max-uapi.o.
	* sysdeps/unix/sysv/linux/tst-sysconf-iov_max.c: New file.
	* sysdeps/unix/sysv/linux/tst-sysconf-iov_max-uapi.c: Likewise.
  

Comments

Carlos O'Donell Oct. 19, 2017, 7:13 p.m. UTC | #1
On 10/19/2017 11:32 AM, Florian Weimer wrote:
> 2017-10-19  Florian Weimer  <fweimer@redhat.com>
> 
> 	[BZ #22321]
> 	sysconf: Fix missing definition of UIO_MAXIOV on Linux.
> 	* sysdeps/posix/sysconf.c: Include <sys/uio.h>.
> 	* sysdeps/unix/sysv/linux/Makefile (tests): Add tst-sysconf-iov_max.
> 	(tst-sysconf-iov_max): Link with tst-sysconf-iov_max-uapi.o.
> 	* sysdeps/unix/sysv/linux/tst-sysconf-iov_max.c: New file.
> 	* sysdeps/unix/sysv/linux/tst-sysconf-iov_max-uapi.c: Likewise.

Looks good to me. I had some questions though, see below.

OK to commit if the answer to the questions is "Yes." and we
add additional tests.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

> diff --git a/sysdeps/posix/sysconf.c b/sysdeps/posix/sysconf.c
> index a95e1b3f05..254f87c437 100644
> --- a/sysdeps/posix/sysconf.c
> +++ b/sysdeps/posix/sysconf.c
> @@ -29,6 +29,7 @@
>  #include <sys/stat.h>
>  #include <sys/sysinfo.h>
>  #include <sys/types.h>
> +#include <sys/uio.h>

OK. Inclusion of define enables returned result.

>  #include <regex.h>
>  
>  #define NEED_SPEC_ARRAY 0
> diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
> index 30bd167bae..0c8a009b5e 100644
> --- a/sysdeps/unix/sysv/linux/Makefile
> +++ b/sysdeps/unix/sysv/linux/Makefile
> @@ -50,7 +50,7 @@ sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
>  		  bits/siginfo-arch.h bits/siginfo-consts-arch.h
>  
>  tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
> -	 tst-quota tst-sync_file_range test-errno-linux
> +	 tst-quota tst-sync_file_range test-errno-linux tst-sysconf-iov_max

OK.

Thanks for the new test.

>  
>  # Generate the list of SYS_* macros for the system calls (__NR_*
>  # macros).  The file syscall-names.list contains all possible system
> @@ -95,6 +95,9 @@ $(objpfx)tst-syscall-list.out: \
>    $(objpfx)tst-syscall-list-sys.list
>  	$(BASH) $^ $(AWK) > $@; $(evaluate-test)
>  
> +# Separate object file for access to the constant from the UAPI header.
> +$(objpfx)tst-sysconf-iov_max: $(objpfx)tst-sysconf-iov_max-uapi.o
> +
>  endif # $(subdir) == misc
>  
>  ifeq ($(subdir),time)
> diff --git a/sysdeps/unix/sysv/linux/tst-sysconf-iov_max-uapi.c b/sysdeps/unix/sysv/linux/tst-sysconf-iov_max-uapi.c
> new file mode 100644
> index 0000000000..1240b846e6
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tst-sysconf-iov_max-uapi.c
> @@ -0,0 +1,27 @@
> +/* Check IOV_MAX definition: Helper function to capture UAPI header value.
> +   Copyright (C) 2017 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
> +   <http://www.gnu.org/licenses/>.  */
> +
> +/* Use a separate function to avoid header compatibility issues.  */

OK. Clever use of the distinct object file.

> +
> +#include <linux/uio.h>
> +
> +long
> +uio_maxiov_value (void)
> +{
> +  return UIO_MAXIOV;
> +}
> diff --git a/sysdeps/unix/sysv/linux/tst-sysconf-iov_max.c b/sysdeps/unix/sysv/linux/tst-sysconf-iov_max.c
> new file mode 100644
> index 0000000000..e85bd59550
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tst-sysconf-iov_max.c
> @@ -0,0 +1,38 @@
> +/* Check IOV_MAX definition for consistency (bug 22321).
> +   Copyright (C) 2017 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
> +   <http://www.gnu.org/licenses/>.  */
> +
> +/* Defined in tst-sysconf-iov_max-uapi.c.  */
> +long uio_maxiov_value (void);
> +
> +
> +#include <limits.h>
> +#include <support/check.h>
> +#include <sys/uio.h>
> +#include <unistd.h>
> +
> +static int
> +do_test (void)
> +{
> +  TEST_VERIFY (IOV_MAX == uio_maxiov_value ());
> +  TEST_VERIFY (UIO_MAXIOV == uio_maxiov_value ());
> +  TEST_VERIFY (sysconf (_SC_UIO_MAXIOV) == uio_maxiov_value ());
> +  TEST_VERIFY (sysconf (_SC_IOV_MAX) == uio_maxiov_value ());

Is there an expectation that the value, although consistent,
should not be -1?

e.g.
TEST_VERIFY (IOV_MAX != -1);
TEST_VERIFY (UIOV_MAX != -1);

Do we need to verify it is >= _XOPEN_IOV_MAX?

e.g.
TEST_VERIFY (IOV_MAX >= _XOPEN_IOV_MAX);
TEST_VERIFY (UIOV_MAX >= _XOPEN_IOV_MAX);


> +  return 0;
> +}
> +
> +#include <support/test-driver.c>
>
  
Florian Weimer Oct. 19, 2017, 7:21 p.m. UTC | #2
On 10/19/2017 09:13 PM, Carlos O'Donell wrote:
>> +  TEST_VERIFY (IOV_MAX == uio_maxiov_value ());
>> +  TEST_VERIFY (UIO_MAXIOV == uio_maxiov_value ());
>> +  TEST_VERIFY (sysconf (_SC_UIO_MAXIOV) == uio_maxiov_value ());
>> +  TEST_VERIFY (sysconf (_SC_IOV_MAX) == uio_maxiov_value ());

> Is there an expectation that the value, although consistent,
> should not be -1?
> 
> e.g.
> TEST_VERIFY (IOV_MAX != -1);
> TEST_VERIFY (UIOV_MAX != -1);
> 
> Do we need to verify it is >= _XOPEN_IOV_MAX?
> 
> e.g.
> TEST_VERIFY (IOV_MAX >= _XOPEN_IOV_MAX);
> TEST_VERIFY (UIOV_MAX >= _XOPEN_IOV_MAX);

Should I add

   TEST_VERIFY (uio_maxiov_value () >= _XOPEN_IOV_MAX);

?

That would indirectly cover all the additional tests you suggest.

Thanks,
Florian
  
Carlos O'Donell Oct. 19, 2017, 7:53 p.m. UTC | #3
On 10/19/2017 12:21 PM, Florian Weimer wrote:
> On 10/19/2017 09:13 PM, Carlos O'Donell wrote:
>>> +  TEST_VERIFY (IOV_MAX == uio_maxiov_value ());
>>> +  TEST_VERIFY (UIO_MAXIOV == uio_maxiov_value ());
>>> +  TEST_VERIFY (sysconf (_SC_UIO_MAXIOV) == uio_maxiov_value ());
>>> +  TEST_VERIFY (sysconf (_SC_IOV_MAX) == uio_maxiov_value ());
> 
>> Is there an expectation that the value, although consistent,
>> should not be -1?
>>
>> e.g.
>> TEST_VERIFY (IOV_MAX != -1);
>> TEST_VERIFY (UIOV_MAX != -1);
>>
>> Do we need to verify it is >= _XOPEN_IOV_MAX?
>>
>> e.g.
>> TEST_VERIFY (IOV_MAX >= _XOPEN_IOV_MAX);
>> TEST_VERIFY (UIOV_MAX >= _XOPEN_IOV_MAX);
> 
> Should I add
> 
>   TEST_VERIFY (uio_maxiov_value () >= _XOPEN_IOV_MAX);
> 
> ?
> 
> That would indirectly cover all the additional tests you suggest.

... unless _XOPEN_IOV_MAX is incorrectly defined to -1? :-)
  

Patch

diff --git a/sysdeps/posix/sysconf.c b/sysdeps/posix/sysconf.c
index a95e1b3f05..254f87c437 100644
--- a/sysdeps/posix/sysconf.c
+++ b/sysdeps/posix/sysconf.c
@@ -29,6 +29,7 @@ 
 #include <sys/stat.h>
 #include <sys/sysinfo.h>
 #include <sys/types.h>
+#include <sys/uio.h>
 #include <regex.h>
 
 #define NEED_SPEC_ARRAY 0
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 30bd167bae..0c8a009b5e 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -50,7 +50,7 @@  sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
 		  bits/siginfo-arch.h bits/siginfo-consts-arch.h
 
 tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
-	 tst-quota tst-sync_file_range test-errno-linux
+	 tst-quota tst-sync_file_range test-errno-linux tst-sysconf-iov_max
 
 # Generate the list of SYS_* macros for the system calls (__NR_*
 # macros).  The file syscall-names.list contains all possible system
@@ -95,6 +95,9 @@  $(objpfx)tst-syscall-list.out: \
   $(objpfx)tst-syscall-list-sys.list
 	$(BASH) $^ $(AWK) > $@; $(evaluate-test)
 
+# Separate object file for access to the constant from the UAPI header.
+$(objpfx)tst-sysconf-iov_max: $(objpfx)tst-sysconf-iov_max-uapi.o
+
 endif # $(subdir) == misc
 
 ifeq ($(subdir),time)
diff --git a/sysdeps/unix/sysv/linux/tst-sysconf-iov_max-uapi.c b/sysdeps/unix/sysv/linux/tst-sysconf-iov_max-uapi.c
new file mode 100644
index 0000000000..1240b846e6
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-sysconf-iov_max-uapi.c
@@ -0,0 +1,27 @@ 
+/* Check IOV_MAX definition: Helper function to capture UAPI header value.
+   Copyright (C) 2017 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
+   <http://www.gnu.org/licenses/>.  */
+
+/* Use a separate function to avoid header compatibility issues.  */
+
+#include <linux/uio.h>
+
+long
+uio_maxiov_value (void)
+{
+  return UIO_MAXIOV;
+}
diff --git a/sysdeps/unix/sysv/linux/tst-sysconf-iov_max.c b/sysdeps/unix/sysv/linux/tst-sysconf-iov_max.c
new file mode 100644
index 0000000000..e85bd59550
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-sysconf-iov_max.c
@@ -0,0 +1,38 @@ 
+/* Check IOV_MAX definition for consistency (bug 22321).
+   Copyright (C) 2017 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
+   <http://www.gnu.org/licenses/>.  */
+
+/* Defined in tst-sysconf-iov_max-uapi.c.  */
+long uio_maxiov_value (void);
+
+
+#include <limits.h>
+#include <support/check.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+static int
+do_test (void)
+{
+  TEST_VERIFY (IOV_MAX == uio_maxiov_value ());
+  TEST_VERIFY (UIO_MAXIOV == uio_maxiov_value ());
+  TEST_VERIFY (sysconf (_SC_UIO_MAXIOV) == uio_maxiov_value ());
+  TEST_VERIFY (sysconf (_SC_IOV_MAX) == uio_maxiov_value ());
+  return 0;
+}
+
+#include <support/test-driver.c>