Re: [PATCH v2 2/2] tests: add close_range() tests

Michael Ellerman
2019-05-28T02:33:41Z

Christian Brauner <christian@brauner.io> writes:
> This adds basic tests for the new close_range() syscall.
> - test that no invalid flags can be passed
> - test that a range of file descriptors is correctly closed
> - test that a range of file descriptors is correctly closed if there there
> are already closed file descriptors in the range
> - test that max_fd is correctly capped to the current fdtable maximum
>
> Signed-off-by: Christian Brauner <christian@brauner.io>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Jann Horn <jannh@google.com>
> Cc: David Howells <dhowells@redhat.com>
> Cc: Dmitry V. Levin <ldv@altlinux.org>
> Cc: Oleg Nesterov <oleg@redhat.com>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Florian Weimer <fweimer@redhat.com>
> Cc: linux-api@vger.kernel.org
> ---
> v1: unchanged
> v2:
> - Christian Brauner <christian@brauner.io>:
> - verify that close_range() correctly closes a single file descriptor
> ---
> tools/testing/selftests/Makefile | 1 +
> tools/testing/selftests/core/.gitignore | 1 +
> tools/testing/selftests/core/Makefile | 6 +
> .../testing/selftests/core/close_range_test.c | 142 ++++++++++++++++++
> 4 files changed, 150 insertions(+)
> create mode 100644 tools/testing/selftests/core/.gitignore
> create mode 100644 tools/testing/selftests/core/Makefile
> create mode 100644 tools/testing/selftests/core/close_range_test.c
>
> diff --git a/tools/testing/selftests/core/.gitignore b/tools/testing/selftests/core/.gitignore
> new file mode 100644
> index 000000000000..6e6712ce5817
> --- /dev/null
> +++ b/tools/testing/selftests/core/.gitignore
> @@ -0,0 +1 @@
> +close_range_test
> diff --git a/tools/testing/selftests/core/Makefile b/tools/testing/selftests/core/Makefile
> new file mode 100644
> index 000000000000..de3ae68aa345
> --- /dev/null
> +++ b/tools/testing/selftests/core/Makefile
> @@ -0,0 +1,6 @@
> +CFLAGS += -g -I../../../../usr/include/ -I../../../../include

Your second -I pulls the unexported kernel headers in, userspace
programs shouldn't include unexported kernel headers.

It breaks the build on powerpc with eg:

powerpc64le-linux-gnu-gcc -g -I../../../../usr/include/ -I../../../../include close_range_test.c -o /output/kselftest/core/close_range_test
In file included from /usr/powerpc64le-linux-gnu/include/bits/fcntl-linux.h:346,
from /usr/powerpc64le-linux-gnu/include/bits/fcntl.h:62,
from /usr/powerpc64le-linux-gnu/include/fcntl.h:35,
from close_range_test.c:5:
../../../../include/linux/falloc.h:13:2: error: unknown type name '__s16'
__s16 l_type;
^~~~~

Did you do that on purpose or just copy it from one of the other
Makefiles? :)

If you're just wanting to get the syscall number when the headers
haven't been exported, I think the best solution is to do eg:

diff --git a/tools/testing/selftests/core/close_range_test.c b/tools/testing/selftests/core/close_range_test.c
index d6e6079d3d53..34c6f02f25de 100644
--- a/tools/testing/selftests/core/close_range_test.c
+++ b/tools/testing/selftests/core/close_range_test.c
@@ -14,6 +14,10 @@

#include "../kselftest.h"

+#ifndef __NR_close_range
+#define __NR_close_range 435
+#endif
+
static inline int sys_close_range(unsigned int fd, unsigned int max_fd,
unsigned int flags)
{

cheers