From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Wed, 30 Oct 2013 10:45:35 -0600
From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
To: Peter Huewe <peterhuewe@gmx.de>
Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org,
	Rajiv Andrade <mail@srajiv.net>,
	tpmdd-devel@lists.sourceforge.net,
	Xiaoyan Zhang <xiaoyan.zhang@intel.com>,
	Gang Wei <gang.wei@intel.com>
Subject: Re: [tpmdd-devel] [PATCH 1/2] tpm/tpm_ppi: Do not compare strcmp(a,
 b) == -1
Message-ID: <20131030164535.GA3511@obsidianresearch.com>
References: <1383093628-31580-1-git-send-email-peterhuewe@gmx.de>
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On Wed, Oct 30, 2013 at 01:40:27AM +0100, Peter Huewe wrote:
> strcmp does return the difference between two strings not only -1,0,1
> consequently
>  if (strcmp (a,b) == -1)
> might lead to taking the wrong branch
> 
> -> compare with <= instead.

I've always thought this was the preferred idiom:

cmp(a,b) == 0
cmp(a,b) < 0
cmp(a,b) > 0

As the operator matches what is actually happening in all cases.

'>= -1' doesn't mean a >= b.

Regards,
Jason