kernel/linux.git/tools/testing/selftests/vm/userfaultfd.c, branch v5.9.12

userfaultfd: selftests: add write-protect test

2020-04-07T17:43:40+00:00

Add uffd tests for write protection. Instead of introducing new tests for it, let's simply squashing uffd-wp tests into existing uffd-missing test cases. Changes are: (1) Bouncing tests We do the write-protection in two ways during the bouncing test: - By using UFFDIO_COPY_MODE_WP when resolving MISSING pages: then we'll make sure for each bounce process every single page will be at least fault twice: once for MISSING, once for WP. - By direct call UFFDIO_WRITEPROTECT on existing faulted memories: To further torture the explicit page protection procedures of uffd-wp, we split each bounce procedure into two halves (in the background thread): the first half will be MISSING+WP for each page as explained above. After the first half, we write protect the faulted region in the background thread to make sure at least half of the pages will be write protected again which is the first half to test the new UFFDIO_WRITEPROTECT call. Then we continue with the 2nd half, which will contain both MISSING and WP faulting tests for the 2nd half and WP-only faults from the 1st half. (2) Event/Signal test Mostly previous tests but will do MISSING+WP for each page. For sigbus-mode test we'll need to provide standalone path to handle the write protection faults. For all tests, do statistics as well for uffd-wp pages. Signed-off-by: Peter Xu Signed-off-by: Andrew Morton Cc: Andrea Arcangeli Cc: Bobby Powers Cc: Brian Geffon Cc: David Hildenbrand Cc: Denis Plotnikov Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Jerome Glisse Cc: Johannes Weiner Cc: "Kirill A . Shutemov" Cc: Martin Cracauer Cc: Marty McFadden Cc: Maya Gokhale Cc: Mel Gorman Cc: Mike Kravetz Cc: Mike Rapoport Cc: Pavel Emelyanov Cc: Rik van Riel Cc: Shaohua Li Link: http://lkml.kernel.org/r/20200220163112.11409-20-peterx@redhat.com Signed-off-by: Linus Torvalds

userfaultfd: selftests: refactor statistics

2020-04-07T17:43:40+00:00

Introduce uffd_stats structure for statistics of the self test, at the same time refactor the code to always pass in the uffd_stats for either read() or poll() typed fault handling threads instead of using two different ways to return the statistic results. No functional change. With the new structure, it's very easy to introduce new statistics. Signed-off-by: Peter Xu Signed-off-by: Andrew Morton Reviewed-by: Mike Rapoport Cc: Andrea Arcangeli Cc: Bobby Powers Cc: Brian Geffon Cc: David Hildenbrand Cc: Denis Plotnikov Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Jerome Glisse Cc: Johannes Weiner Cc: "Kirill A . Shutemov" Cc: Martin Cracauer Cc: Marty McFadden Cc: Maya Gokhale Cc: Mel Gorman Cc: Mike Kravetz Cc: Pavel Emelyanov Cc: Rik van Riel Cc: Shaohua Li Link: http://lkml.kernel.org/r/20200220163112.11409-19-peterx@redhat.com Signed-off-by: Linus Torvalds

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499

2019-06-19T15:09:53+00:00

Based on 1 normalized pattern(s): this work is licensed under the terms of the gnu gpl version 2 see the copying file in the top level directory extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 35 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Kate Stewart Reviewed-by: Enrico Weigelt Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.797835076@linutronix.de Signed-off-by: Greg Kroah-Hartman

userfaultfd: selftest: fix compiler warning

2019-05-30T14:21:36+00:00

Fixes following compiler warning userfaultfd.c: In function ‘usage’: userfaultfd.c:126:2: warning: format not a string literal and no format arguments [-Wformat-security] fprintf(stderr, examples); Signed-off-by: Alakesh Haloi Reviewed-by: Peter Xu Reviewed-by: Mike Rapoport Signed-off-by: Shuah Khan

userfaultfd: selftest: recycle lock threads first

2018-10-26T23:26:35+00:00

Now we recycle the uffd servicing threads earlier than the lock threads. It might happen that when the lock thread is still blocked at a pthread mutex lock while the servicing thread has already quitted for the cpu so the lock thread will be blocked forever and hang the test program. To fix the possible race, recycle the lock threads first. This never happens with current missing-only tests, but when I start to run the write-protection tests (the feature is not yet posted upstream) it happens every time of the run possibly because in that new test we'll need to service two page faults for each lock operation. Link: http://lkml.kernel.org/r/20180930074259.18229-4-peterx@redhat.com Signed-off-by: Peter Xu Acked-by: Mike Rapoport Cc: Shuah Khan Cc: Mike Kravetz Cc: Jerome Glisse Cc: Zi Yan Cc: "Kirill A . Shutemov" Cc: Shaohua Li Cc: Andrea Arcangeli Cc: "Dr . David Alan Gilbert" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

userfaultfd: selftest: generalize read and poll

2018-10-26T23:26:35+00:00

We do very similar things in read and poll modes, but we're copying the codes around. Share the codes properly on reading the message and handling the page fault to make the code cleaner. Meanwhile this solves previous mismatch of behaviors between the two modes on that the old code: - did not check EAGAIN case in read() mode - ignored BOUNCE_VERIFY check in read() mode Link: http://lkml.kernel.org/r/20180930074259.18229-3-peterx@redhat.com Signed-off-by: Peter Xu Acked-by: Mike Rapoport Cc: Shuah Khan Cc: Mike Kravetz Cc: Jerome Glisse Cc: Zi Yan Cc: "Kirill A . Shutemov" Cc: Shaohua Li Cc: Andrea Arcangeli Cc: "Dr . David Alan Gilbert" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

userfaultfd: selftest: cleanup help messages

2018-10-26T23:26:35+00:00

Firstly, the help in the comment region is obsolete, now we support three parameters. Since at it, change it and move it into the help message of the program. Also, the help messages dumped here and there is obsolete too. Use a single usage() helper. Link: http://lkml.kernel.org/r/20180930074259.18229-2-peterx@redhat.com Signed-off-by: Peter Xu Acked-by: Mike Rapoport Cc: Shuah Khan Cc: Mike Kravetz Cc: Jerome Glisse Cc: Zi Yan Cc: "Kirill A . Shutemov" Cc: Shaohua Li Cc: Andrea Arcangeli Cc: "Dr . David Alan Gilbert" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

selftests: vm: return Kselftest Skip code for skipped tests

2018-06-18T15:11:10+00:00

When vm test is skipped because of unmet dependencies and/or unsupported configuration, it exits with error which is treated as a fail by the Kselftest framework. This leads to false negative result even when the test could not be run. Change it to return kselftest skip code when a test gets skipped to clearly report that the test could not be run. Kselftest framework SKIP code is 4 and the framework prints appropriate messages to indicate that the test is skipped. Signed-off-by: Shuah Khan (Samsung OSG) Acked-by: Mike Rapoport Signed-off-by: Shuah Khan (Samsung OSG)

userfaultfd: selftest: exercise -EEXIST only in background transfer

2017-10-13T23:18:32+00:00

I was stress testing some backports and with high load, after some time, the latest version of the selftest showed some false positive in connection with the uffdio_copy_retry. This seems to fix it while still exercising -EEXIST in the background transfer once in a while. The fork child will quit after the last UFFDIO_COPY is run, so a repeated UFFDIO_COPY may not return -EEXIST. This change restricts the -EEXIST stress to the background transfer where the memory can't go away from under it. Also updated uffdio_zeropage, so the interface is consistent. Link: http://lkml.kernel.org/r/20171004171541.1495-2-aarcange@redhat.com Signed-off-by: Andrea Arcangeli Cc: Pavel Emelyanov Cc: Mike Rapoport Cc: "Dr. David Alan Gilbert" Cc: Mike Kravetz Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

userfaultfd: selftest: explicit failure if the SIGBUS test failed

2017-09-07T00:27:29+00:00

Showing zero in the output isn't very self explanatory as a successful result. Show a more explicit error output if the test fails. Link: http://lkml.kernel.org/r/20170802165145.22628-4-aarcange@redhat.com Signed-off-by: Andrea Arcangeli Cc: "Dr. David Alan Gilbert" Cc: Alexey Perevalov Cc: Maxime Coquelin Cc: Mike Kravetz Cc: Mike Rapoport Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds