Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when allocate a odd alignment area

From	zijun_hu <zijun_hu@zoho.com>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when allocate a odd alignment area
Date	2016-10-12 12:00 +0200
Message-ID	<sroul-2vS-5@gated-at.bofh.it> (permalink)
References	(3 earlier) <srlGa-Ku-33@gated-at.bofh.it> <srm9b-19E-1@gated-at.bofh.it> <srnoC-1RR-5@gated-at.bofh.it> <srnoC-1RR-3@gated-at.bofh.it> <sroul-2vS-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 10/12/2016 05:54 PM, Michal Hocko wrote:
> 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?
> 
i am sorry for reply late
i don't know whether it is necessary
i just find there are so many sanity checkup in current internal interfaces

Thread

[RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when allocate a  odd alignment area zijun_hu <zijun_hu@zoho.com> - 2016-10-11 15:30 +0200
  Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when  allocate a odd alignment area Michal Hocko <mhocko@kernel.org> - 2016-10-11 19:30 +0200
    Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when  allocate a odd alignment area zijun_hu <zijun_hu@zoho.com> - 2016-10-12 02:30 +0200
      Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when  allocate a odd alignment area Michal Hocko <mhocko@kernel.org> - 2016-10-12 09:00 +0200
        Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when  allocate a odd alignment area zijun_hu <zijun_hu@zoho.com> - 2016-10-12 09:30 +0200
          Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when  allocate a odd alignment area zijun_hu <zijun_hu@zoho.com> - 2016-10-12 10:50 +0200
            Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when  allocate a odd alignment area Michal Hocko <mhocko@kernel.org> - 2016-10-12 12:00 +0200
              Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when  allocate a odd alignment area zijun_hu <zijun_hu@zoho.com> - 2016-10-12 12:00 +0200
          Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when  allocate a odd alignment area Michal Hocko <mhocko@kernel.org> - 2016-10-12 11:30 +0200
        Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when  allocate a odd alignment area zijun_hu <zijun_hu@zoho.com> - 2016-10-12 09:30 +0200

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