From: Andrew Morton <akpm@linux-foundation.org>
To: Mike Kravetz <mike.kravetz@oracle.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Michal Hocko <mhocko@kernel.org>, Hugh Dickins <hughd@google.com>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
"Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>,
Andrea Arcangeli <aarcange@redhat.com>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Davidlohr Bueso <dave@stgolabs.net>,
Prakash Sangappa <prakash.sangappa@oracle.com>
Subject: Re: [PATCH 0/3] hugetlbfs: use i_mmap_rwsem for better synchronization
Date: Fri, 14 Dec 2018 13:22:39 -0800 [thread overview]
Message-ID: <20181214132239.9b74e2ca4bc4e38a409736dc@linux-foundation.org> (raw)
In-Reply-To: <20181203200850.6460-1-mike.kravetz@oracle.com>
On Mon, 3 Dec 2018 12:08:47 -0800 Mike Kravetz <mike.kravetz@oracle.com> wrote:
> These patches are a follow up to the RFC,
> http://lkml.kernel.org/r/20181024045053.1467-1-mike.kravetz@oracle.com
> Comments made by Naoya were addressed.
>
> There are two primary issues addressed here:
> 1) For shared pmds, huge PE pointers returned by huge_pte_alloc can become
> invalid via a call to huge_pmd_unshare by another thread.
> 2) hugetlbfs page faults can race with truncation causing invalid global
> reserve counts and state.
> Both issues are addressed by expanding the use of i_mmap_rwsem.
>
> These issues have existed for a long time. They can be recreated with a
> test program that causes page fault/truncation races. For simple mappings,
> this results in a negative HugePages_Rsvd count. If racing with mappings
> that contain shared pmds, we can hit "BUG at fs/hugetlbfs/inode.c:444!" or
> Oops! as the result of an invalid memory reference.
>
> I broke up the larger RFC into separate patches addressing each issue.
> Hopefully, this is easier to understand/review.
Three patches tagged for -stable and no reviewers yet. Could people
please take a close look?
prev parent reply other threads:[~2018-12-14 21:22 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-03 20:08 Mike Kravetz
2018-12-03 20:08 ` [PATCH 1/3] hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization Mike Kravetz
2018-12-04 13:54 ` Sasha Levin
2018-12-03 20:08 ` [PATCH 2/3] hugetlbfs: Use i_mmap_rwsem to fix page fault/truncate race Mike Kravetz
2018-12-04 13:54 ` Sasha Levin
2018-12-17 10:25 ` Aneesh Kumar K.V
2018-12-17 18:42 ` Mike Kravetz
2018-12-18 0:17 ` Mike Kravetz
2018-12-18 22:10 ` Andrew Morton
2018-12-18 22:34 ` Mike Kravetz
2019-06-14 21:56 ` Sasha Levin
2019-06-14 23:33 ` Mike Kravetz
2019-06-15 22:38 ` Sasha Levin
2018-12-03 20:08 ` [PATCH 3/3] hugetlbfs: remove unnecessary code after i_mmap_rwsem synchronization Mike Kravetz
2018-12-04 13:54 ` Sasha Levin
2018-12-17 10:34 ` Aneesh Kumar K.V
2018-12-14 21:22 ` Andrew Morton [this message]
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