From mboxrd@z Thu Jan 1 00:00:00 1970 From: jglauber@cavium.com (Jan Glauber) Date: Wed, 28 Feb 2018 11:23:35 +0100 Subject: [PATCH -stable] arm64: mm: don't write garbage into TTBR1_EL1 register In-Reply-To: <20180226113050.GE8736@arm.com> References: <20180223182902.24873-1-ard.biesheuvel@linaro.org> <20180224083424.GC9681@kroah.com> <20180226113050.GE8736@arm.com> Message-ID: <20180228102335.GA6619@wintermute> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Feb 26, 2018 at 11:30:50AM +0000, Will Deacon wrote: > Damnit, sorry again. I changed the argument order of phys_to_ttbr along > the way, so must've confused myself during the backporting exercise. It's > also one of those things that will lead to potential TLB corruption in rare > circumstances where the junk in TTBR1 ends up giving a valid translation, > so it didn't crop up in my testing. How did Nicolas see this? The bug > report I saw didn't look related. FWIW, we've been hitting this bug with a distribution backport on ThunderX2 on every boot. Due to bad luck there was a non-zero value in TTBR1 that crashed the kernel immediately and dropped us to firmware. --Jan