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author | Peter Xu <peterx@redhat.com> | 2023-04-12 19:38:52 +0300 |
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committer | Andrew Morton <akpm@linux-foundation.org> | 2023-04-16 20:41:26 +0300 |
commit | 2ff559f31a5d50c31a3f9d849f8af90dc36c7105 (patch) | |
tree | 40ece38e4052a27e22948a6dd6c15c696afe38af /mm/hugetlb.c | |
parent | 1ba1199ec5747f475538c0d25a32804e5ba1dfde (diff) | |
download | linux-2ff559f31a5d50c31a3f9d849f8af90dc36c7105.tar.xz |
Revert "userfaultfd: don't fail on unrecognized features"
This is a proposal to revert commit 914eedcb9ba0ff53c33808.
I found this when writing a simple UFFDIO_API test to be the first unit
test in this set. Two things breaks with the commit:
- UFFDIO_API check was lost and missing. According to man page, the
kernel should reject ioctl(UFFDIO_API) if uffdio_api.api != 0xaa. This
check is needed if the api version will be extended in the future, or
user app won't be able to identify which is a new kernel.
- Feature flags checks were removed, which means UFFDIO_API with a
feature that does not exist will also succeed. According to the man
page, we should (and it makes sense) to reject ioctl(UFFDIO_API) if
unknown features passed in.
Link: https://lore.kernel.org/r/20220722201513.1624158-1-axelrasmussen@google.com
Link: https://lkml.kernel.org/r/20230412163922.327282-2-peterx@redhat.com
Fixes: 914eedcb9ba0 ("userfaultfd: don't fail on unrecognized features")
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Zach O'Keefe <zokeefe@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/hugetlb.c')
0 files changed, 0 insertions, 0 deletions