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From: Michal Hocko <mhocko@kernel.org>
To: zijun_hu <zijun_hu@zoho.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	zijun_hu@htc.com, tj@kernel.org, akpm@linux-foundation.org,
	cl@linux.com
Subject: Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when allocate a odd alignment area
Date: Wed, 12 Oct 2016 11:54:39 +0200	[thread overview]
Message-ID: <20161012095439.GI17128@dhcp22.suse.cz> (raw)
In-Reply-To: <57FDF7EF.6070606@zoho.com>

On Wed 12-10-16 16:44:31, zijun_hu wrote:
> On 10/12/2016 04:25 PM, Michal Hocko wrote:
> > On Wed 12-10-16 15:24:33, zijun_hu wrote:
[...]
> >> i found the following code segments in mm/vmalloc.c
> >> static struct vmap_area *alloc_vmap_area(unsigned long size,
> >>                                 unsigned long align,
> >>                                 unsigned long vstart, unsigned long vend,
> >>                                 int node, gfp_t gfp_mask)
> >> {
> >> ...
> >>
> >>         BUG_ON(!size);
> >>         BUG_ON(offset_in_page(size));
> >>         BUG_ON(!is_power_of_2(align));
> > 
> > See a recent Linus rant about BUG_ONs. These BUG_ONs are quite old and
> > from a quick look they are even unnecessary. So rather than adding more
> > of those, I think removing those that are not needed is much more
> > preferred.
> >
> i notice that, and the above code segments is used to illustrate that
> input parameter checking is necessary sometimes

Why do you think it is necessary here?

-- 
Michal Hocko
SUSE Labs

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  reply	other threads:[~2016-10-12  9:54 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-11 13:24 zijun_hu
2016-10-11 17:22 ` Michal Hocko
2016-10-12  0:28   ` zijun_hu
2016-10-12  6:53     ` Michal Hocko
2016-10-12  7:20       ` zijun_hu
2016-10-12  7:24       ` zijun_hu
2016-10-12  8:25         ` Michal Hocko
2016-10-12  8:44           ` zijun_hu
2016-10-12  9:54             ` Michal Hocko [this message]
2016-10-12  9:59               ` zijun_hu
2016-10-13 23:31 ` Tejun Heo
2016-10-14  0:23   ` zijun_hu
2016-10-14  0:28     ` Tejun Heo
2016-10-14  0:58       ` zijun_hu

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