Since there's no point in doing anything in this case, immediately exit the process.
And take the opportunity to improve the error message.
Before:
# ./userfaultfd shmem 10 10 nr_pages: 160, nr_pages_per_cpu: 40 userfaultfd syscall not available in this kernel # echo $? 1
After:
# ./userfaultfd shmem 10 10 nr_pages: 160, nr_pages_per_cpu: 40 userfaultfd syscall not available in this kernel: Function not implemented # echo $? 4
Suggested-by: Mike Rapoport rppt@linux.vnet.ibm.com Signed-off-by: Thiago Jung Bauermann bauerman@linux.ibm.com Acked-by: Mike Rapoport rppt@linux.vnet.ibm.com --- tools/testing/selftests/vm/userfaultfd.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c index e4099afe7557..d728bd1cb33c 100644 --- a/tools/testing/selftests/vm/userfaultfd.c +++ b/tools/testing/selftests/vm/userfaultfd.c @@ -636,9 +636,11 @@ static int userfaultfd_open(int features)
uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK); if (uffd < 0) { - fprintf(stderr, - "userfaultfd syscall not available in this kernel\n"); - return 1; + int errnum = errno; + + perror("userfaultfd syscall not available in this kernel"); + + exit(errnum == ENOSYS ? KSFT_SKIP : 1); } uffd_flags = fcntl(uffd, F_GETFD, NULL);