From: William Kucharski <william.kucharski@oracle.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Keith Busch <keith.busch@intel.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Kees Cook <keescook@chromium.org>,
YueHaibing <yuehaibing@huawei.com>,
linux-mm@kvack.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] mm/gup_benchmark: prevent integer overflow in ioctl
Date: Thu, 1 Nov 2018 02:28:55 -0600 [thread overview]
Message-ID: <E7641C0F-C619-4054-BD14-685E8D448F49@oracle.com> (raw)
In-Reply-To: <20181101071613.7x3smxwz5wo57n2m@mwanda>
> On Nov 1, 2018, at 1:16 AM, Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> My patch lets people allocate 4MB. (U32_MAX / 4096 * sizeof(void *)).
> Surely, that's enough? I liked my check because it avoids the divide so
> it's faster and it is a no-op on 64bit systems.
It should be enough, and you're right, it does avoid extra math.
However, in that case I'd like to see a comment added so that anyone looking
at the code in the future knows why you limited the allocation to ULONG_MAX
bytes.
Thanks,
William Kucharski
prev parent reply other threads:[~2018-11-01 8:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-25 6:15 Dan Carpenter
2018-10-25 7:32 ` Kirill A. Shutemov
2018-11-01 6:38 ` William Kucharski
2018-11-01 7:16 ` Dan Carpenter
2018-11-01 8:28 ` William Kucharski [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=E7641C0F-C619-4054-BD14-685E8D448F49@oracle.com \
--to=william.kucharski@oracle.com \
--cc=akpm@linux-foundation.org \
--cc=dan.carpenter@oracle.com \
--cc=keescook@chromium.org \
--cc=keith.busch@intel.com \
--cc=kernel-janitors@vger.kernel.org \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-mm@kvack.org \
--cc=mst@redhat.com \
--cc=sfr@canb.auug.org.au \
--cc=yuehaibing@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox