linux-kernel - Re: [PATCH] mm/kmemleak: add support for re-enable kmemleak at runtime

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 for Android: free password hash cracker in your pocket

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

Message-ID: <52DA3E41.9050202@huawei.com>
Date:	Sat, 18 Jan 2014 16:41:37 +0800
From:	Jianguo Wu <wujianguo@...wei.com>
To:	Catalin Marinas <catalin.marinas@....com>
CC:	Andrew Morton <akpm@...ux-foundation.org>,
	"rob@...dley.net" <rob@...dley.net>,
	"linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	Li Zefan <lizefan@...wei.com>, Wang Nan <wangnan0@...wei.com>
Subject: Re: [PATCH] mm/kmemleak: add support for re-enable kmemleak at runtime

On 2014/1/17 20:04, Catalin Marinas wrote:

> On Fri, Jan 17, 2014 at 09:40:02AM +0000, Jianguo Wu wrote:
>> Now disabling kmemleak is an irreversible operation, but sometimes
>> we may need to re-enable kmemleak at runtime. So add a knob to enable
>> kmemleak at runtime:
>> echo on > /sys/kernel/debug/kmemleak
> 
> It is irreversible for very good reason: once it missed the initial
> memory allocations, there is no way for kmemleak to build the object
> reference graph and you'll get lots of false positives, pretty much
> making it unusable.
> 

Do you mean we didn't trace memory allocations during kmemleak disable period,
and these memory may reference to new allocated objects after re-enable? 

--
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/