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From: Oleg Nesterov <oleg@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>,
	Hugh Dickins <hughd@google.com>,
	Kirill Shutemov <kirill.shutemov@linux.intel.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Pavel Emelyanov <xemul@parallels.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 0/3] special_mapping_fault() is broken
Date: Fri, 10 Jul 2015 18:51:21 +0200	[thread overview]
Message-ID: <20150710165121.GA10341@redhat.com> (raw)

Hello,

special_mapping_fault() is absolutely broken. It seems it was always
wrong, but this didn't matter until vdso/vvar started to use more than
one page.

The patches are the same, just 1/3 was re-diffed on top of the recent
6b7339f4c31ad "mm: avoid setting up anonymous pages into file mapping"
from Kirill.

And after this change vma_is_anonymous() becomes really trivial, it
simply checks vm_ops == NULL. However, I do think the helper makes
sense. There are a lot of ->vm_ops != NULL checks, the helper makes
the caller's code more understandable (self-documented) and this is
more grep-friendly.

Oleg.

 include/linux/mm.h |    5 +++++
 mm/memory.c        |    8 ++++----
 mm/mmap.c          |   14 +++-----------
 3 files changed, 12 insertions(+), 15 deletions(-)


             reply	other threads:[~2015-07-10 16:53 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-10 16:51 Oleg Nesterov [this message]
2015-07-10 16:51 ` [PATCH v2 1/3] mm: introduce vma_is_anonymous(vma) helper Oleg Nesterov
2015-07-10 16:51 ` [PATCH v2 2/3] mmap: fix the usage of ->vm_pgoff in special_mapping paths Oleg Nesterov
2015-07-10 16:51 ` [PATCH v2 3/3] mremap: fix the wrong !vma->vm_file check in copy_vma() Oleg Nesterov
2015-07-10 17:08 ` [PATCH v2 0/3] special_mapping_fault() is broken Kirill A. Shutemov
2015-07-10 18:20 ` Davidlohr Bueso
2015-07-10 21:52 ` Andrew Morton
2015-07-11 23:43   ` Oleg Nesterov

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