From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Tue, 8 Dec 2015 10:51:52 +0000 Subject: ARM64: kernel oops in 4.4-rc4+ In-Reply-To: <20151208103013.GA19612@arm.com> References: <20151208103013.GA19612@arm.com> Message-ID: <20151208105152.GB19612@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Dec 08, 2015 at 10:30:13AM +0000, Will Deacon wrote: > On Tue, Dec 08, 2015 at 02:30:33PM +0800, Ming Lei wrote: > > The attached kernel oops can be triggered immediately after > > running the following command on APM Mustang: > > > > $stress-ng --all 8 -t 10m > > > > [1] kernel oops log > > stress-ng: info: [5220] 5 failures reached, aborting stress process > > [ 265.782659] kernel BUG at ./arch/arm64/include/asm/pgtable.h:282! > > Yikes, this means we're replacing a writable pte with a clean pte, so > there's a potential race w/ hardware DBM. > > Could you dump pte and *ptep please? I tried running this on my Juno and pretty quickly saw the OOM killer coming in. Perhaps, in your case, pte is a swap entry and its confusing the checks (so pte_dirty/pte_young are looking at random bits of the file offset)? Anyway, I'll wait for you to dump those values. Will