| Message ID | 20220601210951.3916598-4-axelrasmussen@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | userfaultfd: add /dev/userfaultfd for fine grained access control | expand |
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@google.com> > --- > 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 >
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(); + 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(); }
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@google.com> --- tools/testing/selftests/vm/userfaultfd.c | 37 +++++++++++++++++++++--- 1 file changed, 33 insertions(+), 4 deletions(-)