netdev - RE: [PATCH v5 iwl-next 3/6] ice: rename verify_cached to has_ready

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: <CO1PR11MB508991A8A05697AE2E62F289D6722@CO1PR11MB5089.namprd11.prod.outlook.com>
Date: Wed, 17 Jan 2024 22:10:03 +0000
From: "Keller, Jacob E" <jacob.e.keller@...el.com>
To: Simon Horman <horms@...nel.org>, "Kolacinski, Karol"
	<karol.kolacinski@...el.com>
CC: "intel-wired-lan@...ts.osuosl.org" <intel-wired-lan@...ts.osuosl.org>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>, "Nguyen, Anthony L"
	<anthony.l.nguyen@...el.com>, "Brandeburg, Jesse"
	<jesse.brandeburg@...el.com>
Subject: RE: [PATCH v5 iwl-next 3/6] ice: rename verify_cached to
 has_ready_bitmap



> -----Original Message-----
> From: Simon Horman <horms@...nel.org>
> Sent: Monday, January 15, 2024 2:37 AM
> To: Kolacinski, Karol <karol.kolacinski@...el.com>
> Cc: intel-wired-lan@...ts.osuosl.org; netdev@...r.kernel.org; Nguyen, Anthony L
> <anthony.l.nguyen@...el.com>; Brandeburg, Jesse
> <jesse.brandeburg@...el.com>; Keller, Jacob E <jacob.e.keller@...el.com>
> Subject: Re: [PATCH v5 iwl-next 3/6] ice: rename verify_cached to
> has_ready_bitmap
> 
> On Mon, Jan 08, 2024 at 01:47:14PM +0100, Karol Kolacinski wrote:
> > From: Jacob Keller <jacob.e.keller@...el.com>
> >
> > The tx->verify_cached flag is used to inform the Tx timestamp tracking
> > code whether it needs to verify the cached Tx timestamp value against
> > a previous captured value. This is necessary on E810 hardware which does
> > not have a Tx timestamp ready bitmap.
> >
> > In addition, we currently rely on the fact that the
> > ice_get_phy_tx_tstamp_ready() function returns all 1s for E810 hardware.
> > Instead of introducing a brand new flag, rename and verify_cached to
> > has_ready_bitmap, inverting the relevant checks.
> 
> From the above I understand what this patch does.
> But not why this change is desirable.
> I think it would be useful to state that.
> 

The main motivation is that it is easier to understand the resulting behavior than to rely on a hidden assumption of how ice_get_phy_tx_stamp_ready() works.

> Also, perhaps it just me, but it seems that
> renaming verify_cached and weeding out assumptions
> about the return value of ice_get_phy_tx_tstamp_ready()
> are separate, albeit related changes:
> I might have gone for two patches instead of one.
> 

It could possibly be split up. The motivation was to stop relying on the fact that ice_get_phy_tx_tstamp_ready() returns all 1s, since we already know whether we can safely check it or not. But then using "verify_cached" to do so reads weird with the code because its name no longer clearly indicates its purpose. Instead, we rename it to better reflect its intention.

Thanks,
Jake

> > Signed-off-by: Jacob Keller <jacob.e.keller@...el.com>
> > Signed-off-by: Karol Kolacinski <karol.kolacinski@...el.com>
> > Reviewed-by: Jacob Keller <jacob.e.keller@...el.com>
> 
> ...