linux-kernel - Re: [PATCH] more helpful WARN_ON and BUG

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

Message-ID: <45393CBD.8000400@goop.org>
Date:	Fri, 20 Oct 2006 14:16:45 -0700
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	Eric Sandeen <sandeen@...hat.com>
CC:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...l.org>
Subject: Re: [PATCH] more helpful WARN_ON and BUG_ON messages

Eric Sandeen wrote:
> After a few bugs I encountered in FC6 in buffer.c, with output like:
>
> Kernel BUG at fs/buffer.c: 2791
>
> where buffer.c contains:
>
> ...
>         BUG_ON(!buffer_locked(bh));
>         BUG_ON(!buffer_mapped(bh));
>         BUG_ON(!bh->b_end_io);
> ...
>
> around line 2790, it's awfully tedious to go get the exact failing kernel tree
> just to see -which- BUG_ON was encountered.
>
> Printing out the failing condition as a string would make this more helpful IMHO.
>   

This seems like a generally useful idea - certainly more valuable than 
storing+printing the function name.

You might want to look at the BUG patches I wrote, which are currently 
in -mm.  I added general machinery to allow architectures to easily 
implement BUG() efficiently (ie, with a minimal amount of BUG-related 
icache pollution).  If you were to store the BUG_ON expression, it would 
be best to extend struct bug_entry and store it there - doing it in 
asm-generic BUG_ON() means you still end up with code to set up the 
printk in the mainline code path, and it also won't honour 
CONFIG_DEBUG_BUGVERBOSE being disabled.

    J
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/