Messages in this thread |  | | From | Nadav Amit <> | Subject | Re: + mm-madvise-fix-freeing-of-locked-page-with-madv_free.patch added to -mm tree | Date | Fri, 25 Aug 2017 22:02:57 +0000 |
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Michal Hocko <mhocko@kernel.org> wrote:
> Hmm, I do not see this neither in linux-mm nor LKML. Strange > > On Wed 23-08-17 14:41:21, Andrew Morton wrote: >> From: Eric Biggers <ebiggers@google.com> >> Subject: mm/madvise.c: fix freeing of locked page with MADV_FREE >> >> If madvise(..., MADV_FREE) split a transparent hugepage, it called >> put_page() before unlock_page(). This was wrong because put_page() can >> free the page, e.g. if a concurrent madvise(..., MADV_DONTNEED) has >> removed it from the memory mapping. put_page() then rightfully complained >> about freeing a locked page. >> >> Fix this by moving the unlock_page() before put_page().
Quick grep shows that a similar flow (put_page() followed by an unlock_page() ) also happens in hugetlbfs_fallocate(). Isn’t it a problem as well?
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