From: Matthew Wilcox <willy@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>,
Dennis Zhou <dennis@kernel.org>, Tejun Heo <tj@kernel.org>,
Christoph Lameter <cl@linux.com>, Linux-MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Kees Cook <keescook@chromium.org>
Subject: Re: [GIT PULL] percpu fix for v5.9-rc6
Date: Fri, 18 Sep 2020 21:02:52 +0100 [thread overview]
Message-ID: <20200918200252.GH32101@casper.infradead.org> (raw)
In-Reply-To: <CAHk-=wg=vvSf3M9O1VkwyYB4D4W6XS2AHVpQn6hEQY+usWrKGg@mail.gmail.com>
On Fri, Sep 18, 2020 at 12:37:48PM -0700, Linus Torvalds wrote:
> > Applying sizeof() to a structure containing a flex-array member is allowed,
>
> Yes, and that's wrong and inconsistent, but what else is new about the
> C standard. It's what allows these kinds of bugs to slip through.
Hmm. We actually do that in our implementation of struct_size()
#define struct_size(p, member, count) \
__ab_c_size(count, \
sizeof(*(p)->member) + __must_be_array((p)->member),\
sizeof(*(p)))
I suppose it's not really necessary, we could do offsetof here, right?
#define struct_size(p, member, count) \
__ab_c_size(count, \
sizeof(*(p)->member) + __must_be_array((p)->member),\
offsetof(typeof(*(p)), member))
next prev parent reply other threads:[~2020-09-18 20:03 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-17 20:45 [GIT PULL] percpu fix for v5.9-rc6 Dennis Zhou
2020-09-18 1:05 ` Linus Torvalds
2020-09-18 16:23 ` Gustavo A. R. Silva
2020-09-18 17:23 ` Linus Torvalds
2020-09-18 19:34 ` Gustavo A. R. Silva
2020-09-18 19:37 ` Linus Torvalds
2020-09-18 20:02 ` Matthew Wilcox [this message]
2020-09-18 20:14 ` Linus Torvalds
2020-09-18 20:29 ` Arvind Sankar
2020-09-18 20:40 ` Linus Torvalds
2020-09-18 21:00 ` Arvind Sankar
2020-09-18 21:18 ` Linus Torvalds
2020-09-18 22:39 ` Arvind Sankar
2020-09-19 1:28 ` Linus Torvalds
2020-09-19 2:53 ` Arvind Sankar
2020-09-19 3:02 ` Matthew Wilcox
2020-09-19 3:04 ` Linus Torvalds
2020-09-19 2:45 ` Matthew Wilcox
2020-09-19 3:37 ` Arvind Sankar
2020-09-19 15:15 ` David Laight
2020-09-18 20:03 ` Gustavo A. R. Silva
2020-09-18 1:10 ` pr-tracker-bot
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