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Message-ID: <4050b7723f6f205c9afc3bdfa3888a6e8befa12a.camel@kernel.org>
Subject: Re: [PATCH v8 2/2] x86/sgx: Add an attribute for the amount of SGX
 memory in a NUMA node
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Dave Hansen <dave.hansen@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
        reinette.chatre@intel.com, tony.luck@intel.com,
        linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org
Date:   Sat, 23 Oct 2021 04:02:48 +0300
In-Reply-To: <YW2GLE89WxAeMZH4@kroah.com>
References: <20211018135744.45527-1-jarkko@kernel.org>
         <20211018135744.45527-2-jarkko@kernel.org> <YW2GLE89WxAeMZH4@kroah.com>
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On Mon, 2021-10-18 at 16:35 +0200, Greg Kroah-Hartman wrote:
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0ret =3D sysfs_create_group(&dev->kobj, &sgx_node_attr_=
group);
>=20
> A huge hint, if a driver has to call a sysfs_* call, something is wrong.
>=20
> Something is wrong here.
>=20
> Why are you messing around with a kobject?=C2=A0 This is a device, that y=
ou
> control, you can just set the default attribute group for it and then
> the driver core will add and remove the sysfs group at the proper time,
> in the proper way.=C2=A0 Right now you are racing userspace and loosing.
>=20
> Use the default group list, that is what it is there for.

I used sysfs_create_group() because node_devices is not owned by SGX
code. It is managed in drivers/base/node.c, and also initialized before
SGX.

/Jarkko