linux-kernel - RE: [PATCH v3 net-next] net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)

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: <MW2PR2101MB08925118BDF20EFA9AAAC947BF739@MW2PR2101MB0892.namprd21.prod.outlook.com>
Date:   Fri, 9 Apr 2021 00:47:52 +0000
From:   Dexuan Cui <decui@...rosoft.com>
To:     David Miller <davem@...emloft.net>
CC:     "kuba@...nel.org" <kuba@...nel.org>,
        KY Srinivasan <kys@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        Stephen Hemminger <sthemmin@...rosoft.com>,
        "wei.liu@...nel.org" <wei.liu@...nel.org>,
        Wei Liu <liuwe@...rosoft.com>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "leon@...nel.org" <leon@...nel.org>,
        "andrew@...n.ch" <andrew@...n.ch>,
        "bernd@...rovitsch.priv.at" <bernd@...rovitsch.priv.at>,
        "rdunlap@...radead.org" <rdunlap@...radead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-hyperv@...r.kernel.org" <linux-hyperv@...r.kernel.org>
Subject: RE: [PATCH v3 net-next] net: mana: Add a driver for Microsoft Azure
 Network Adapter (MANA)

> From: David Miller <davem@...emloft.net>
> Sent: Thursday, April 8, 2021 5:41 PM
> > ...
> > In the driver code, all the structs/unions marked by __packed are used to
> > talk with the hardware, so I think __packed is necessary here?
> 
> It actually isan't in many cases, check with and without the __packed directive
> and see if anything chasnges.

Will do.

> > Do you think if it's better if we remove all the __packed, and add
> > static_assert(sizeof(struct XXX) == YYY) instead? e.g.
> >
> > @@ -105,7 +105,8 @@ struct gdma_msg_hdr {
> >         u16 msg_version;
> >         u16 hwc_msg_id;
> >         u32 msg_size;
> > -} __packed;
> > +};
> > +static_assert(sizeof(struct gdma_msg_hdr) == 16);
> 
> This won't make sure the structure member offsets are what you expect.
> 
> I think you'll have to go through the structures one-by-one by hand to
> figure out which ones really require the __packed attribute and which do not.

Got it. Let me see if I can remove all the __packed.