On Wed, Jun 01, 2022 at 02:09:48PM -0700, Axel Rasmussen wrote:
> We clearly want to ensure both userfaultfd(2) and /dev/userfaultfd keep
> working into the future, so just run the test twice, using each
> interface.
>
> Signed-off-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
> ---
> tools/testing/selftests/vm/userfaultfd.c | 37 +++++++++++++++++++++---
> 1 file changed, 33 insertions(+), 4 deletions(-)
>
> diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
> index 0bdfc1955229..1badb5d31bf9 100644
> --- a/tools/testing/selftests/vm/userfaultfd.c
> +++ b/tools/testing/selftests/vm/userfaultfd.c
> @@ -77,6 +77,9 @@ static int bounces;
> #define TEST_SHMEM 3
> static int test_type;
>
> +/* test using /dev/userfaultfd, instead of userfaultfd(2) */
> +static bool test_dev_userfaultfd;
> +
> /* exercise the test_uffdio_*_eexist every ALARM_INTERVAL_SECS */
> #define ALARM_INTERVAL_SECS 10
> static volatile bool test_uffdio_copy_eexist = true;
> @@ -154,12 +157,14 @@ static void usage(void)
> ret, __LINE__); \
> } while (0)
>
> -#define err(fmt, ...) \
> +#define errexit(exitcode, fmt, ...) \
> do { \
> _err(fmt, ##__VA_ARGS__); \
> - exit(1); \
> + exit(exitcode); \
> } while (0)
>
> +#define err(fmt, ...) errexit(1, fmt, ##__VA_ARGS__)
> +
> static void uffd_stats_reset(struct uffd_stats *uffd_stats,
> unsigned long n_cpus)
> {
> @@ -383,13 +388,31 @@ static void assert_expected_ioctls_present(uint64_t mode, uint64_t ioctls)
> }
> }
>
> +static void __userfaultfd_open_dev(void)
> +{
> + int fd;
> +
> + uffd = -1;
> + fd = open("/dev/userfaultfd", O_RDWR | O_CLOEXEC);
> + if (fd < 0)
> + return;
> +
> + uffd = ioctl(fd, USERFAULTFD_IOC_NEW,
> + O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY);
> + close(fd);
> +}
> +
> static void userfaultfd_open(uint64_t *features)
> {
> struct uffdio_api uffdio_api;
>
> - uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY);
> + if (test_dev_userfaultfd)
> + __userfaultfd_open_dev();
I can understand uffd is a global var, but still AFAICT that's trivially
easy to do the return to match the syscall case..
uffd = __userfaultfd_open_dev();
And since at it, it'll be great to make a macro:
#define UFFD_FLAGS (O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY)
Thanks,
> + else
> + uffd = syscall(__NR_userfaultfd,
> + O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY);
> if (uffd < 0)
> - err("userfaultfd syscall not available in this kernel");
> + errexit(KSFT_SKIP, "creating userfaultfd failed");
> uffd_flags = fcntl(uffd, F_GETFD, NULL);
>
> uffdio_api.api = UFFD_API;
> @@ -1691,6 +1714,12 @@ int main(int argc, char **argv)
> }
> printf("nr_pages: %lu, nr_pages_per_cpu: %lu\n",
> nr_pages, nr_pages_per_cpu);
> +
> + test_dev_userfaultfd = false;
> + if (userfaultfd_stress())
> + return 1;
> +
> + test_dev_userfaultfd = true;
> return userfaultfd_stress();
> }
>
> --
> 2.36.1.255.ge46751e96f-goog
>
--
Peter Xu
