linux-kernel - Re: [PATCH] perf: Fix endianness argument compatibility

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]

Date:	Wed, 14 Apr 2010 11:28:43 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	David Miller <davem@...emloft.net>, git@...r.kernel.org
Cc:	imunsie@....ibm.com, linux-kernel@...r.kernel.org,
	a.p.zijlstra@...llo.nl, paulus@...ba.org, acme@...hat.com,
	kosaki.motohiro@...fujitsu.com, mitake@....info.waseda.ac.jp,
	rusty@...tcorp.com.au, fweisbec@...il.com, ebmunson@...ibm.com,
	Valdis.Kletnieks@...edu, amwang@...hat.com, tfransosi@...il.com,
	mhiramat@...hat.com, xiaoguangrong@...fujitsu.com,
	jaswinderrajput@...il.com, arjan@...ux.intel.com,
	hirofumi@...l.parknet.co.jp, efault@....de, tzanussi@...il.com,
	anton@...ba.org, jkacur@...hat.com, lizf@...fujitsu.com,
	rostedt@...dmis.org
Subject: Re: [PATCH] perf: Fix endianness argument compatibility


* David Miller <davem@...emloft.net> wrote:

> From: "Ian Munsie" <imunsie@....ibm.com>
> Date: Tue, 13 Apr 2010 18:37:33 +1000
> 
> > From: Ian Munsie <imunsie@...ibm.com>
> > 
> > Parsing an option from the command line with OPT_BOOLEAN on a bool data
> > type would not work on a big-endian machine due to the manner in which
> > the boolean was being cast into an int and incremented. For example,
> > running 'perf probe --list' on a PowerPC machine would fail to properly
> > set the list_events bool and would therefore print out the usage
> > information and terminate.
> > 
> > This patch makes OPT_BOOLEAN work as expected with a bool datatype. For
> > cases where the original OPT_BOOLEAN was intentionally being used to
> > increment an int each time it was passed in on the command line, this
> > patch introduces OPT_INCR with the old behaviour of OPT_BOOLEAN (the
> > verbose variable is currently the only such example of this).
> > 
> > I have reviewed every use of OPT_BOOLEAN to verify that a true C99 bool
> > was passed. Where integers were used, I verified that they were only
> > being used for boolean logic and changed them to bools to ensure that
> > they would not be mistakenly used as ints. The major exception was the
> > verbose variable which now uses OPT_INCR instead of OPT_BOOLEAN.
> > 
> > Signed-off-by: Ian Munsie <imunsie@...ibm.com>
> 
> Thanks for finding and fixing this bug.

Nice fix!

Btw., perf got the option parser from the Git project - i'm wondering how the 
Git folks solved this endianness problem?

	Ingo
--
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/