Re: [RESEND PATCH 2/2] userfaultfd: selftest: Add tests for UFFD_FREATURE_SIGBUS

From	Andrea Arcangeli <aarcange@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [RESEND PATCH 2/2] userfaultfd: selftest: Add tests for UFFD_FREATURE_SIGBUS
Date	2017-07-26 16:30 +0200
Message-ID	<u7vu5-1s1-103@gated-at.bofh.it> (permalink)
References	<u6ZXb-6Gy-5@gated-at.bofh.it> <u6ZXb-6Gy-15@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Tue, Jul 25, 2017 at 12:47:42AM -0400, Prakash Sangappa wrote:
> Signed-off-by: Prakash Sangappa <prakash.sangappa@oracle.com>
> ---
>  tools/testing/selftests/vm/userfaultfd.c |  121 +++++++++++++++++++++++++++++-
>  1 files changed, 118 insertions(+), 3 deletions(-)

Like Mike said, some comment about the test would be better, commit
messages are never one liners in the kernel.

> @@ -408,6 +409,7 @@ static int copy_page(int ufd, unsigned long offset)
>  				userfaults++;
>  			break;
>  		case UFFD_EVENT_FORK:
> +			close(uffd);
>  			uffd = msg.arg.fork.ufd;
>  			pollfd[0].fd = uffd;
>  			break;

Isn't this fd leak bugfix independent of the rest of the changes? The
only side effects should have been that it could run out of fds, but I
assume this was found by source review as I doubt it could run out of fds.
This could be splitted off in a separate patch.

Overall it looks a good test also exercising UFFD_EVENT_FORK at the
same time.

Thanks,
Andrea

Thread

[RESEND PATCH 0/2] userfaultfd: Add feature to request for a signal delivery Prakash Sangappa <prakash.sangappa@oracle.com> - 2017-07-25 06:50 +0200
  [RESEND PATCH 1/2] userfaultfd: Add feature to request for a signal delivery Prakash Sangappa <prakash.sangappa@oracle.com> - 2017-07-25 06:50 +0200
    Re: [RESEND PATCH 1/2] userfaultfd: Add feature to request for a  signal delivery Mike Rapoport <rppt@linux.vnet.ibm.com> - 2017-07-26 10:00 +0200
    Re: [RESEND PATCH 1/2] userfaultfd: Add feature to request for a  signal delivery Andrea Arcangeli <aarcange@redhat.com> - 2017-07-26 16:40 +0200
    Re: [RESEND PATCH 1/2] userfaultfd: Add feature to request for a  signal delivery Michal Hocko <mhocko@kernel.org> - 2017-07-27 14:00 +0200
      Re: [RESEND PATCH 1/2] userfaultfd: Add feature to request for a  signal delivery Prakash Sangappa <prakash.sangappa@oracle.com> - 2017-07-28 03:20 +0200
  [RESEND PATCH 2/2] userfaultfd: selftest: Add tests for UFFD_FREATURE_SIGBUS Prakash Sangappa <prakash.sangappa@oracle.com> - 2017-07-25 06:50 +0200
    Re: [RESEND PATCH 2/2] userfaultfd: selftest: Add tests for  UFFD_FREATURE_SIGBUS Mike Rapoport <rppt@linux.vnet.ibm.com> - 2017-07-26 10:00 +0200
      Re: [RESEND PATCH 2/2] userfaultfd: selftest: Add tests for  UFFD_FREATURE_SIGBUS Prakash Sangappa <prakash.sangappa@oracle.com> - 2017-07-26 21:00 +0200
    Re: [RESEND PATCH 2/2] userfaultfd: selftest: Add tests for  UFFD_FREATURE_SIGBUS Andrea Arcangeli <aarcange@redhat.com> - 2017-07-26 16:30 +0200
      Re: [RESEND PATCH 2/2] userfaultfd: selftest: Add tests for  UFFD_FREATURE_SIGBUS Prakash Sangappa <prakash.sangappa@oracle.com> - 2017-07-26 21:10 +0200

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