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From: Tejun Heo <tj@kernel.org>
To: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: Yinghai Lu <yinghai@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Chris Zankel <chris@zankel.net>,
	Max Filippov <jcmvbkbc@gmail.com>,
	Marc Gauthier <marc@tensilica.com>,
	Wanpeng Li <liwanp@linux.vnet.ibm.com>,
	Ingo Molnar <mingo@kernel.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] memblock: add assertion for zero allocation size
Date: Thu, 21 Feb 2013 11:36:39 -0800	[thread overview]
Message-ID: <20130221193639.GN3570@htj.dyndns.org> (raw)
In-Reply-To: <51267695.8090800@synopsys.com>

On Fri, Feb 22, 2013 at 01:03:41AM +0530, Vineet Gupta wrote:
> Where - you mean if user passes 0, just make it 1. Nah - it's better to complain
> and get the call site fixed !
> 
> > or BUG_ON(!align) instead?
> 
> That could be done too but you would also need BUG_ON(!size) - to catch another
> API abuse.
> BUG_ON(!size) however catches both the cases.

How about "if (WARN_ON(!align)) align = __alignof__(long long);"?
Early BUG_ON()s can be painful to debug depending on setup.

Thanks.

-- 
tejun

WARNING: multiple messages have this Message-ID (diff)
From: Tejun Heo <tj@kernel.org>
To: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: Yinghai Lu <yinghai@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Chris Zankel <chris@zankel.net>,
	Max Filippov <jcmvbkbc@gmail.com>,
	Marc Gauthier <marc@tensilica.com>,
	Wanpeng Li <liwanp@linux.vnet.ibm.com>,
	Ingo Molnar <mingo@kernel.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] memblock: add assertion for zero allocation size
Date: Thu, 21 Feb 2013 11:36:39 -0800	[thread overview]
Message-ID: <20130221193639.GN3570@htj.dyndns.org> (raw)
In-Reply-To: <51267695.8090800@synopsys.com>

On Fri, Feb 22, 2013 at 01:03:41AM +0530, Vineet Gupta wrote:
> Where - you mean if user passes 0, just make it 1. Nah - it's better to complain
> and get the call site fixed !
> 
> > or BUG_ON(!align) instead?
> 
> That could be done too but you would also need BUG_ON(!size) - to catch another
> API abuse.
> BUG_ON(!size) however catches both the cases.

How about "if (WARN_ON(!align)) align = __alignof__(long long);"?
Early BUG_ON()s can be painful to debug depending on setup.

Thanks.

-- 
tejun

--
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  reply	other threads:[~2013-02-21 19:36 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1361471962-25164-1-git-send-email-vgupta@synopsys.com>
2013-02-21 18:39 ` [PATCH 1/2] memblock: add assertion for zero allocation size Vineet Gupta
2013-02-21 18:39   ` Vineet Gupta
2013-02-21 19:27   ` Yinghai Lu
2013-02-21 19:27     ` Yinghai Lu
2013-02-21 19:33     ` Vineet Gupta
2013-02-21 19:33       ` Vineet Gupta
2013-02-21 19:36       ` Tejun Heo [this message]
2013-02-21 19:36         ` Tejun Heo
2013-02-21 19:43         ` Vineet Gupta
2013-02-21 19:43           ` Vineet Gupta
2013-02-21 20:10         ` [PATCH v2 1/2] memblock: add assertion for zero allocation alignment Vineet Gupta
2013-02-21 20:10           ` Vineet Gupta
2013-02-21 20:31           ` Yinghai Lu
2013-02-21 20:31             ` Yinghai Lu
2013-02-21 20:47             ` Vineet Gupta
2013-02-21 20:47               ` Vineet Gupta
2013-02-21 20:52             ` [PATCH v3 " Vineet Gupta
2013-02-21 20:52               ` Vineet Gupta
2013-02-21 20:53               ` Tejun Heo
2013-02-21 20:53                 ` Tejun Heo
2013-03-04 11:15                 ` Vineet Gupta
2013-03-04 11:15                   ` Vineet Gupta
2013-02-21 18:39 ` [PATCH 2/2] xtensa: Flat DeviceTree copy not future-safe Vineet Gupta
2013-02-21 20:06   ` Max Filippov
2013-05-29 13:10   ` Fwd: " Vineet Gupta
2013-05-31  1:01     ` Max Filippov

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