linux-kernel - [x86] BUG()/BUG_ON() macros cannot be disabled

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <9516e4b3-f9f2-b150-f019-8b1ef465efb3@tu-dortmund.de>
Date:   Tue, 25 Sep 2018 13:35:29 +0200
From:   Alexander Lochmann <alexander.lochmann@...dortmund.de>
To:     arnd@...db.de
Cc:     linux-arch@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [x86] BUG()/BUG_ON() macros cannot be disabled

Hi Arnd,

I recently tried to disable the BUG macros on x86-32. I disabled the
config item in 'General Setup -> Configure standard kernel features
(expert users) -> BUG() support'.
However, BUG/BUG_ON is still defined. In the !CONFIG_BUG branch in
include/asm-generic/bug.h (line 181) the code checks for the existence
of architecture-specific variants of those macros.
Since x86 defines its own version of BUG(), line 182 is *not* used.
In the following, the x86 variant of BUG() is then used to define the
BUG_ON() macro.

I propose a patch that really disables both macros if the developer
wants it.
It undefines the respective x86 variants, and defines both macros as
'empty' macros.

Regards,
Alex

-- 
Technische Universität Dortmund
Alexander Lochmann                PGP key: 0xBC3EF6FD
Otto-Hahn-Str. 16                 phone:  +49.231.7556141
D-44227 Dortmund                  fax:    +49.231.7556116
http://ess.cs.tu-dortmund.de/Staff/al

View attachment "disable-bug-macro.patch" of type "text/x-patch" (741 bytes)

Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)