From: Michal Nazarewicz <mpn@google.com>
To: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Marek Szyprowski <m.szyprowski@samsung.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] cma: use unsigned type for count argument
Date: Thu, 27 Dec 2012 03:05:49 +0100 [thread overview]
Message-ID: <xa1tzk10ntaa.fsf@mina86.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1212261755450.4150@chino.kir.corp.google.com>
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> On Sat, 22 Dec 2012, Michal Nazarewicz wrote:
>> So I think just adding the following, should be sufficient to make
>> everyone happy:
>>
>> diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
>> index e34e3e0..e91743b 100644
>> --- a/drivers/base/dma-contiguous.c
>> +++ b/drivers/base/dma-contiguous.c
>> @@ -320,7 +320,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, unsigned int count,
>> pr_debug("%s(cma %p, count %u, align %u)\n", __func__, (void *)cma,
>> count, align);
>>
>> - if (!count)
>> + if (!count || count > INT_MAX)
>> return NULL;
>>
>> mask = (1 << align) - 1;
>
On Thu, Dec 27 2012, David Rientjes <rientjes@google.com> wrote:
> How is this different than leaving the formal to have a signed type, i.e.
> drop your patch, and testing for count <= 0 instead?
Not much different I guess. I don't have strong opinions to be honest,
except that I feel unsigned is the proper type to use, on top of which
I think bitmap_set() should use unsigned, so in case anyone ever bothers
to change it, CMA will be ready. :P
--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michał “mina86” Nazarewicz (o o)
ooo +----<email/xmpp: mpn@google.com>--------------ooO--(_)--Ooo--
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prev parent reply other threads:[~2012-12-27 2:05 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-19 17:44 Michal Nazarewicz
2012-12-20 23:35 ` Andrew Morton
2012-12-21 0:03 ` David Rientjes
2012-12-22 15:31 ` Michal Nazarewicz
2012-12-27 1:59 ` David Rientjes
2012-12-27 2:05 ` Michal Nazarewicz [this message]
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