Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Michael Ellerman <patch-notifications@ellerman.id.au>
To:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        fthain@linux-m68k.org, userm57@yahoo.com,
        Michael Ellerman <mpe@ellerman.id.au>
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
In-Reply-To: <4856f5574906e2aec0522be17bf3848a22b2cd0b.1629269345.git.christophe.leroy@csgroup.eu>
References: <4856f5574906e2aec0522be17bf3848a22b2cd0b.1629269345.git.christophe.leroy@csgroup.eu>
Subject: Re: [PATCH v2] powerpc/32s: Fix random crashes by adding isync() after locking/unlocking KUEP
Message-Id: <163007070021.56462.16976826768640062743.b4-ty@ellerman.id.au>
Date:   Fri, 27 Aug 2021 23:25:00 +1000
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8bit
Precedence: bulk

On Wed, 18 Aug 2021 06:49:29 +0000 (UTC), Christophe Leroy wrote:
> Commit b5efec00b671 ("powerpc/32s: Move KUEP locking/unlocking in C")
> removed the 'isync' instruction after adding/removing NX bit in user
> segments. The reasoning behind this change was that when setting the
> NX bit we don't mind it taking effect with delay as the kernel never
> executes text from userspace, and when clearing the NX bit this is
> to return to userspace and then the 'rfi' should synchronise the
> context.
> 
> [...]

Applied to powerpc/fixes.

[1/1] powerpc/32s: Fix random crashes by adding isync() after locking/unlocking KUEP
      https://git.kernel.org/powerpc/c/ef486bf448a057a6e2d50e40ae879f7add6585da

cheers