linux-kernel - Re: [PATCH] perf-event/cgroup: explicitly init the early

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <53563709.2000408@huawei.com>
Date:	Tue, 22 Apr 2014 17:31:53 +0800
From:	Li Zefan <lizefan@...wei.com>
To:	Jianyu Zhan <nasa4836@...il.com>
CC:	Ingo Molnar <mingo@...nel.org>, <a.p.zijlstra@...llo.nl>,
	<paulus@...ba.org>, <mingo@...hat.com>, <acme@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] perf-event/cgroup: explicitly init the early_init field

On 2014/4/22 15:12, Jianyu Zhan wrote:
> On Tue, Apr 22, 2014 at 2:06 PM, Ingo Molnar <mingo@...nel.org> wrote:
>> How can that field ever be nonzero?
>>
>> I.e. under what exact circumstances does this patch make sense?
> 
> Hi, Ingo,
> 
> More explanation.
> 
> Sure, for this global variable struct, if not initailized, its all
> fields will be initialized
> to 0 or null(depending on its type).  The point here is no to deprive
> the rights of compiler/linker of doing this initialization, it is mainly for
> documentation reason. Actually this field's value would affect how ->css_alloc
> should implemented.
> 
> Concretely, if early_init is nonzero, then ->css_alloc *must not* call kzalloc,
> because in cgroup implementation, ->css_alloc will be called earlier before
> mm_init().
> 
> I don't think that the value of one field(early_init) has a so subtle
> restrition on the another field(css_alloc) is a good thing,
> but since
> it is there,
> docment it should be needed.
> 
> I could resend the patch with  more comment.
> 

nack

As I said in another mail thread, this change makes no sense.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/