linux-kernel - RE: [PATCH v2] acpica: fix -Wnull-pointer-arithmetic warnings

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <c98fa373a004472b979255a93b414fe1@AcuMS.aculab.com>
Date:   Mon, 29 Jul 2019 10:24:27 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     "'Moore, Robert'" <robert.moore@...el.com>, Qian Cai <cai@....pw>,
        "Wysocki, Rafael J" <rafael.j.wysocki@...el.com>
CC:     "Schmauss, Erik" <erik.schmauss@...el.com>,
        "jkim@...eBSD.org" <jkim@...eBSD.org>,
        "lenb@...nel.org" <lenb@...nel.org>,
        "ndesaulniers@...gle.com" <ndesaulniers@...gle.com>,
        "linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
        "devel@...ica.org" <devel@...ica.org>,
        "clang-built-linux@...glegroups.com" 
        <clang-built-linux@...glegroups.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH v2] acpica: fix -Wnull-pointer-arithmetic warnings

From: Moore, Robert
> Sent: 26 July 2019 20:36
...
> This is because pointer arithmetic
> on a pointer not pointing to an array is an undefined behavior (C11 6.5.6, constraint 8).
...

The standards committee as smoking dope again :-)
If that is enforced as a compiler warning/error a lot of code 'breaks'.
Anything that does:
	struct foo *foo = ...;
      struct bar *bar = (void *)(foo + 1);
suddenly becomes 'invalid'.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)