From: Arnd Bergmann <arnd@kernel.org>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Hans de Goede <hdegoede@redhat.com>,
Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
linux-sparse@vger.kernel.org,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Al Viro <viro@zeniv.linux.org.uk>, Arnd Bergmann <arnd@arndb.de>,
Linux FS-devel Mailing List <linux-fsdevel@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
llvm@lists.linux.dev
Subject: Re: [PATCH] vboxsf: fix old signature detection
Date: Mon, 27 Sep 2021 15:21:49 +0200 [thread overview]
Message-ID: <CAK8P3a3YFh4QTC6dk6onsaKcqCM3Nmb2JhMXK5QdZpHtffjyLg@mail.gmail.com> (raw)
In-Reply-To: <20210927130253.GH2083@kadam>
On Mon, Sep 27, 2021 at 3:02 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> GCC handles it the same way as Clang. '\377' is -1 but in Sparse it's
> 255. I've added the Sparse mailing list to the CC.
More specifically, ' think '\377' may be either -1 or 255 depending on
the architecture.
On most architectures, 'char' is implicitly signed, but on some others
it is not.
The original code before 9d682ea6bcc7 should have worked either way because
both sides of the comparison were the same 'char' type, marking one of them
as explicitly 'unsigned char' seems to have broken all architectures on which
the type is implicitly 'signed'.
Arnd
next prev parent reply other threads:[~2021-09-27 13:22 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210927094123.576521-1-arnd@kernel.org>
[not found] ` <40217483-1b8d-28ec-bbfc-8f979773b166@redhat.com>
2021-09-27 13:02 ` [PATCH] vboxsf: fix old signature detection Dan Carpenter
2021-09-27 13:21 ` Arnd Bergmann [this message]
2021-09-27 18:33 ` Linus Torvalds
2021-09-28 9:39 ` Hans de Goede
2021-09-28 10:11 ` Arnd Bergmann
2021-09-28 10:31 ` Hans de Goede
2021-09-28 10:40 ` Arnd Bergmann
2021-09-28 9:56 ` Rasmus Villemoes
2022-05-22 19:08 ` [PATCH] fix zero/sign extension of integer character constants Luc Van Oostenryck
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=CAK8P3a3YFh4QTC6dk6onsaKcqCM3Nmb2JhMXK5QdZpHtffjyLg@mail.gmail.com \
--to=arnd@kernel.org \
--cc=arnd@arndb.de \
--cc=dan.carpenter@oracle.com \
--cc=hdegoede@redhat.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sparse@vger.kernel.org \
--cc=llvm@lists.linux.dev \
--cc=luc.vanoostenryck@gmail.com \
--cc=nathan@kernel.org \
--cc=ndesaulniers@google.com \
--cc=viro@zeniv.linux.org.uk \
/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).