From: Nick Desaulniers <ndesaulniers@google.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>,
Josef Bacik <josef@toxicpanda.com>, Jens Axboe <axboe@kernel.dk>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <sashal@kernel.org>,
llvm@lists.linux.dev, stable <stable@vger.kernel.org>,
Arnd Bergmann <arnd@kernel.org>,
Naresh Kamboju <naresh.kamboju@linaro.org>,
Nathan Chancellor <nathan@kernel.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Pavel Machek <pavel@ucw.cz>
Subject: Re: [PATCH 5.10] overflow.h: use new generic division helpers to avoid / operator
Date: Tue, 14 Sep 2021 12:50:44 -0700 [thread overview]
Message-ID: <CAKwvOdk9yqEMLTAxgZNmHgRSww0AnJ-x9qd7HK3v2Vepi1BdLw@mail.gmail.com> (raw)
In-Reply-To: <CAHk-=wjf6ABFwPdsbk2674DwSLQCH0jr7w-BYvG-f2nvRQDqtQ@mail.gmail.com>
On Tue, Sep 14, 2021 at 12:46 PM Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> On Tue, Sep 14, 2021 at 12:10 PM Nick Desaulniers
> <ndesaulniers@google.com> wrote:
> >
> > Isn't the parameter `blksize` of `nbd_set_size` declared as `loff_t`?
>
> So?
>
> I'm not seeing your point.
>
> We've checked the range of it - in loff_t.
>
> So the *value* is already checked, and most definitely fits in 'unsigned long'.
>
> So __ffs() is perfectly fine. It will truncate that loff_t to a sane type.
>
> What is the problem you're trying to solve?
Just making sure __ffs() works as expected should blksize > LONG_MAX
on 32b targets. I don't see the range check you're referring to.
loff_t is a long long, yeah?
--
Thanks,
~Nick Desaulniers
next prev parent reply other threads:[~2021-09-14 19:50 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-13 20:32 [PATCH 5.10] overflow.h: use new generic division helpers to avoid / operator Nick Desaulniers
2021-09-13 21:05 ` Rasmus Villemoes
2021-09-14 0:23 ` [PATCH v2] " Nick Desaulniers
2021-09-14 17:22 ` Greg Kroah-Hartman
2021-09-14 18:07 ` Nick Desaulniers
2021-09-14 18:12 ` Greg Kroah-Hartman
2021-09-14 17:32 ` [PATCH 5.10] " Kees Cook
2021-09-14 18:14 ` Linus Torvalds
2021-09-14 18:30 ` Linus Torvalds
2021-09-14 18:44 ` Nick Desaulniers
2021-09-14 18:48 ` Linus Torvalds
2021-09-14 18:56 ` Linus Torvalds
2021-09-14 19:10 ` Nick Desaulniers
2021-09-14 19:45 ` Linus Torvalds
2021-09-14 19:50 ` Nick Desaulniers [this message]
2021-09-14 19:57 ` Linus Torvalds
2021-09-14 18:47 ` Kees Cook
2021-09-14 18:54 ` Linus Torvalds
2021-09-14 19:12 ` Nick Desaulniers
2021-09-14 19:52 ` Linus Torvalds
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=CAKwvOdk9yqEMLTAxgZNmHgRSww0AnJ-x9qd7HK3v2Vepi1BdLw@mail.gmail.com \
--to=ndesaulniers@google.com \
--cc=arnd@kernel.org \
--cc=axboe@kernel.dk \
--cc=gregkh@linuxfoundation.org \
--cc=josef@toxicpanda.com \
--cc=keescook@chromium.org \
--cc=linux@rasmusvillemoes.dk \
--cc=llvm@lists.linux.dev \
--cc=naresh.kamboju@linaro.org \
--cc=nathan@kernel.org \
--cc=pavel@ucw.cz \
--cc=sashal@kernel.org \
--cc=sfr@canb.auug.org.au \
--cc=stable@vger.kernel.org \
--cc=torvalds@linux-foundation.org \
/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;
as well as URLs for NNTP newsgroup(s).