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From:   David Laight <David.Laight@ACULAB.COM>
To:     'Paul Moore' <paul@paul-moore.com>,
        =?iso-8859-1?Q?Christian_G=F6ttsche?= <cgzones@googlemail.com>,
        "selinux@vger.kernel.org" <selinux@vger.kernel.org>
CC:     Stephen Smalley <stephen.smalley.work@gmail.com>,
        Eric Paris <eparis@parisplace.org>,
        Ondrej Mosnacek <omosnace@redhat.com>,
        "GONG, Ruiqi" <gongruiqi1@huawei.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v2 5/9] selinux: services: update type for number of class
  permissions
Thread-Topic: [PATCH v2 5/9] selinux: services: update type for number of
 class  permissions
Thread-Index: AQHZxnpAfMoj5HezXkad2FNTf0iy46/aPz6Q
Date:   Fri, 4 Aug 2023 15:21:31 +0000
Message-ID: <764b3d9f340e403084fb44877d4a73b6@AcuMS.aculab.com>
References: <20230728155501.39632-4-cgzones@googlemail.com>
 <059e2bd127d8a6d59290d606a707a999.paul@paul-moore.com>
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From: Paul Moore
> Sent: 04 August 2023 03:20
> 
> On Jul 28, 2023 =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com> wrote:
> >
...
> > +		u16 i, n = mapping->num_perms;
...
> >  		for (; i < (sizeof(u32)*8); i++)

Don't dop arithmetic on types smaller than int.
You are pretty much requesting the compiler add code to mask the
result down to 16 bits after very operations.

	David

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