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From: Matthew Wilcox <willy@infradead.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>,
	linux-mm@kvack.org, Kees Cook <keescook@chromium.org>,
	linux-kernel@vger.kernel.org,
	kernel-hardening@lists.openwall.com,
	Joe Perches <joe@perches.com>
Subject: [PATCH v2 0/8] Add kvzalloc_struct to complement kvzalloc_array
Date: Wed, 14 Feb 2018 12:11:46 -0800	[thread overview]
Message-ID: <20180214201154.10186-1-willy@infradead.org> (raw)

From: Matthew Wilcox <mawilcox@microsoft.com>

We all know the perils of multiplying a value provided from userspace
by a constant and then allocating the resulting number of bytes.  That's
why we have kvmalloc_array(), so we don't have to think about it.
This solves the same problem when we embed one of these arrays in a
struct like this:

struct {
        int n;
        unsigned long array[];
};

Using kvzalloc_struct() to allocate this will save precious thinking
time and reduce the possibilities of bugs.

v2: Minor fixes pointed out by Kees
    Added sample conversions

I added a few more sample conversions for demonstration purposes, and
one thing I noticed is that the kvmalloc family of functions live in
<linux/mm.h> which (contrary to popular belief) is not already
automatically included everywhere.

Should they be moved to slab.h to be with kmalloc, a new file
(malloc.h? kvmalloc.h?), or even kernel.h?

Matthew Wilcox (8):
  mm: Add kernel-doc for kvfree
  mm: Add kvmalloc_ab_c and kvzalloc_struct
  Convert virtio_console to kvzalloc_struct
  Convert dax device to kvzalloc_struct
  Convert infiniband uverbs to kvzalloc_struct
  Convert v4l2 event to kvzalloc_struct
  Convert vhost to kvzalloc_struct
  Convert jffs2 acl to kvzalloc_struct

 drivers/char/virtio_console.c        |  3 +--
 drivers/dax/device.c                 |  2 +-
 drivers/infiniband/core/uverbs_cmd.c |  4 +--
 drivers/media/v4l2-core/v4l2-event.c |  3 +--
 drivers/vhost/vhost.c                |  2 +-
 fs/jffs2/acl.c                       |  3 ++-
 fs/jffs2/acl.h                       |  1 +
 include/linux/mm.h                   | 51 ++++++++++++++++++++++++++++++++++++
 include/rdma/ib_verbs.h              |  5 +---
 mm/util.c                            | 10 +++++++
 10 files changed, 71 insertions(+), 13 deletions(-)

-- 
2.15.1

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             reply	other threads:[~2018-02-14 20:11 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-14 20:11 Matthew Wilcox [this message]
2018-02-14 20:11 ` [PATCH v2 1/8] mm: Add kernel-doc for kvfree Matthew Wilcox
2018-02-14 20:11 ` [PATCH v2 2/8] mm: Add kvmalloc_ab_c and kvzalloc_struct Matthew Wilcox
2018-02-14 20:45   ` Joe Perches
2018-02-14 21:12     ` Matthew Wilcox
2018-02-14 21:24       ` Joe Perches
2018-02-14 21:27         ` Joe Perches
2018-02-14 21:29         ` Matthew Wilcox
2018-02-14 23:58       ` Andrew Morton
2018-02-15  3:40         ` Matthew Wilcox
2018-02-15 17:36           ` Matthew Wilcox
2018-02-14 20:11 ` [PATCH v2 3/8] Convert virtio_console to kvzalloc_struct Matthew Wilcox
2018-02-14 20:19   ` Joe Perches
2018-02-14 20:28     ` Matthew Wilcox
2018-02-14 20:30       ` Joe Perches
2018-02-14 20:11 ` [PATCH v2 4/8] Convert dax device " Matthew Wilcox
2018-02-14 20:11 ` [PATCH v2 5/8] Convert infiniband uverbs " Matthew Wilcox
2018-02-14 20:11 ` [PATCH v2 6/8] Convert v4l2 event " Matthew Wilcox
2018-02-14 20:11 ` [PATCH v2 7/8] Convert vhost " Matthew Wilcox
2018-02-14 20:11 ` [PATCH v2 8/8] Convert jffs2 acl " Matthew Wilcox

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