Received-SPF: pass (google.com: domain of linux-kernel+bounces-177598-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Message-ID: <dba181a54e76ba2916ecd4747f76e40e6fbbb757.camel@huaweicloud.com>
Subject: Re: [PATCH] arch/x86/um: Disable UBSAN sanitization
From: Roberto Sassu <roberto.sassu@huaweicloud.com>
To: Johannes Berg <johannes@sipsolutions.net>, richard@nod.at, 
	anton.ivanov@cambridgegreys.com, tglx@linutronix.de, mingo@redhat.com, 
	bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com
Cc: x86@kernel.org, linux-um@lists.infradead.org,
 linux-kernel@vger.kernel.org,  zohar@linux.ibm.com,
 linux-integrity@vger.kernel.org, Roberto Sassu <roberto.sassu@huawei.com>
Date: Mon, 13 May 2024 14:58:46 +0200
In-Reply-To: <f88384a305b90708db3b30012f9edf09690dc5ee.camel@sipsolutions.net>
References: <20240513122754.1282833-1-roberto.sassu@huaweicloud.com>
	 <d4f4666bf745e83ea00b466b7a7cfb5132b8c7b9.camel@sipsolutions.net>
	 <096121b3e74a7971b5e6a3d77ca8889380de1885.camel@huaweicloud.com>
	 <f88384a305b90708db3b30012f9edf09690dc5ee.camel@sipsolutions.net>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.44.4-0ubuntu2 
Precedence: bulk
MIME-Version: 1.0

On Mon, 2024-05-13 at 14:52 +0200, Johannes Berg wrote:
> On Mon, 2024-05-13 at 14:42 +0200, Roberto Sassu wrote:
> > On Mon, 2024-05-13 at 14:29 +0200, Johannes Berg wrote:
> > > On Mon, 2024-05-13 at 14:27 +0200, Roberto Sassu wrote:
> > > > From: Roberto Sassu <roberto.sassu@huawei.com>
> > > >=20
> > > > Disable UBSAN sanitization on UML, since UML does not support it.
> > > >=20
> > >=20
> > > Luckily, that isn't actually true, nor does it actually do this at al=
l.
> > > Please fix the commit message.
> >=20
> > Thanks, I was actually wondering. I based that statement based on
> > ARCH_HAS_UBSAN=3Dn.
> >=20
> > Any other solution would be ok.
>=20
> Not sure I get it. What you're doing in the patch is perfectly fine and
> almost certainly required, but you're definitely not disabling UBSAN on
> ARCH=3Dum as you described in the commit message?

Ok, I guess the right word is instrumentation (got it from commit
d4be85d068b44). And the reason is that the vDSO is executing in user
space. Will fix it.

Thanks

Roberto