netdev - Re: [EXT] Re: [PATCH net] octeontx2-af: Initialize bitmap arrays.

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

Message-ID: <20240124103755.GY254773@kernel.org>
Date: Wed, 24 Jan 2024 10:37:55 +0000
From: Simon Horman <horms@...nel.org>
To: Ratheesh Kannoth <rkannoth@...vell.com>
Cc: Subbaraya Sundeep Bhatta <sbhatta@...vell.com>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Sunil Kovvuri Goutham <sgoutham@...vell.com>,
	"davem@...emloft.net" <davem@...emloft.net>,
	"edumazet@...gle.com" <edumazet@...gle.com>,
	"kuba@...nel.org" <kuba@...nel.org>,
	"pabeni@...hat.com" <pabeni@...hat.com>,
	Geethasowjanya Akula <gakula@...vell.com>,
	Hariprasad Kelam <hkelam@...vell.com>,
	Suman Ghosh <sumang@...vell.com>
Subject: Re: [EXT] Re: [PATCH net] octeontx2-af: Initialize bitmap arrays.

On Wed, Jan 24, 2024 at 03:01:15AM +0000, Ratheesh Kannoth wrote:
> > From: Simon Horman <horms@...nel.org>
> > Subject: [EXT] Re: [PATCH net] octeontx2-af: Initialize bitmap arrays.
> > 
> > Hi Ratheesh,
> > 
> > I assume that the reason that the cited commit moved away from devm_
> > allocations was to allow more natural management of the resources
> > independently of the life cycle of the driver instance. Or in other words, the
> > need to free the bitmaps in npc_mcam_rsrcs_deinit() probably indicates that
> > devm_ allocations of them aren't giving us anything.
> > 
> > So, perhaps kcalloc() is more appropriate than devm_kcalloc() ?
> This was a comment from @Subbaraya Sundeep Bhatta during our internal review.  
> Could you please help with below questions/doubts ?
> 1. why devm_kfree() API  is available if it is done independently 

Hi Ratheesh,

I think the question is: if the devm_kfree() calls are removed,
then is the lifecycle of the objects in question managed correctly?

> 2. I could see instances of devm_kfree() usage in current kernel where it does explicit calls.

Sure. But in this case the use of devm_* doesn't seem to be adding
anything if the memory is _always_ freed by explicit calls to
devm_kfree().