Re: [PATCH 15/29] selftests/mm: uffd_open_{dev|sys}()

Mike Rapoport
2023-04-07T11:11:58Z

On Thu, Mar 30, 2023 at 12:07:49PM -0400, Peter Xu wrote:
> Provide two helpers to open an uffd handle. Drop the error checks around
> SKIPs because it's inside an errexit() anyway, which IMHO doesn't really
> help much if the test will not continue.
>
> Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
> tools/testing/selftests/mm/uffd-common.c | 28 +++++-------------------
> tools/testing/selftests/mm/vm_util.c | 24 ++++++++++++++++++++
> 2 files changed, 29 insertions(+), 23 deletions(-)
>
> diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c
> index 17f2bb82c3db..3a9b5c1aca9d 100644
> --- a/tools/testing/selftests/mm/uffd-common.c
> +++ b/tools/testing/selftests/mm/uffd-common.c
> @@ -192,34 +192,16 @@ void uffd_stats_report(struct uffd_stats *stats, int n_cpus)
> printf("\n");
> }
>
> -static int __userfaultfd_open_dev(void)
> -{
> - int fd, _uffd;
> -
> - fd = open("/dev/userfaultfd", O_RDWR | O_CLOEXEC);
> - if (fd < 0)
> - errexit(KSFT_SKIP, "opening /dev/userfaultfd failed");
> -
> - _uffd = ioctl(fd, USERFAULTFD_IOC_NEW, UFFD_FLAGS);
> - if (_uffd < 0)
> - errexit(errno == ENOTTY ? KSFT_SKIP : 1,
> - "creating userfaultfd failed");
> - close(fd);
> - return _uffd;
> -}
> -
> void userfaultfd_open(uint64_t *features)
> {
> struct uffdio_api uffdio_api;
>
> if (test_dev_userfaultfd)
> - uffd = __userfaultfd_open_dev();
> - else {
> - uffd = syscall(__NR_userfaultfd, UFFD_FLAGS);
> - if (uffd < 0)
> - errexit(errno == ENOSYS ? KSFT_SKIP : 1,
> - "creating userfaultfd failed");
> - }
> + uffd = uffd_open_dev(UFFD_FLAGS);
> + else
> + uffd = uffd_open_sys(UFFD_FLAGS);
> + if (uffd < 0)
> + err("uffd open failed (dev=%d)", test_dev_userfaultfd);
> uffd_flags = fcntl(uffd, F_GETFD, NULL);
>
> uffdio_api.api = UFFD_API;
> diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
> index 10e76400ed70..7c2bf88d6393 100644
> --- a/tools/testing/selftests/mm/vm_util.c
> +++ b/tools/testing/selftests/mm/vm_util.c
> @@ -3,6 +3,8 @@
> #include <fcntl.h>
> #include <sys/ioctl.h>
> #include <linux/userfaultfd.h>
> +#include <sys/syscall.h>
> +#include <unistd.h>
> #include "../kselftest.h"
> #include "vm_util.h"
>
> @@ -230,3 +232,25 @@ int uffd_unregister(int uffd, void *addr, uint64_t len)
>
> return ret;
> }
> +
> +int uffd_open_dev(unsigned int flags)
> +{
> + int fd, uffd;
> +
> + fd = open("/dev/userfaultfd", O_RDWR | O_CLOEXEC);
> + if (fd < 0)
> + return fd;
> + uffd = ioctl(fd, USERFAULTFD_IOC_NEW, flags);
> + close(fd);
> +
> + return uffd;
> +}
> +
> +int uffd_open_sys(unsigned int flags)
> +{
> +#ifdef __NR_userfaultfd
> + return syscall(__NR_userfaultfd, flags);
> +#else
> + return -1;
> +#endif
> +}
> --
> 2.39.1
>

--
Sincerely yours,
Mike.