From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Thu, 14 Jan 2016 10:34:30 +0000 Subject: [RFC] arm64: failed when run the command: timedatectl set-timezone Asia/Shanghai In-Reply-To: <5696FE81.8070904@huawei.com> References: <56946932.70601@huawei.com> <569473B2.3030909@huawei.com> <5695A57B.1060905@huawei.com> <20160113110900.GA23370@leverpostej> <5696FE81.8070904@huawei.com> Message-ID: <20160114103430.GA25670@leverpostej> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jan 14, 2016 at 09:48:49AM +0800, Xishi Qiu wrote: > On 2016/1/13 19:09, Mark Rutland wrote: > > > On Wed, Jan 13, 2016 at 09:16:43AM +0800, Xishi Qiu wrote: > >> On 2016/1/12 18:59, Steve Capper wrote: > >>> Hi Xishi, > >>> This looks like a bug in the Mozilla Javascript engine (which is used > >>> by polkitd). It incorrectly assumes that virtual addresses are at most > >>> 47 bit and uses the upper bits for pointer tagging. > >>> When we enable a 48-bit VA on arm64, this then exacerbates the problem > >>> (your VA of 0x7fff9010c040 should likely be 0xffff9010c040). > >>> > >>> I have raised this issue at: > >>> https://bugzilla.mozilla.org/show_bug.cgi?id=1143022 > >>> > >>> I'm not sure as to the best way of getting this fixed, I would suggest > >>> adding to the bug report above as a first step. > >>> > >> > >> Hi Steve, > >> > >> I find another issue at: > >> https://bugzilla.redhat.com/show_bug.cgi?id=1242326 > > > > Per your question below, the proposed patch is incorrect. > > > > Userspace can only assume ownership of the upper 8 bits, and only in the > > cases described in [1]. Userspace MUST NOT assume it can use other bits > > for its own purposes. > > > > This was a deliberate decision such that the address space can be > > enlarged in future. For example, ARMv8.2 expands addresses to 52 bits > > [2], and addresses could grow further in future. > > > >> In your issue, Tom Schuster said it sounds like bug 910845 > >> https://bugzilla.mozilla.org/show_bug.cgi?id=910845 > > > > Hi Mark, > > Thank you very much. So the patch above only cover Itanium, and there is > no solution for arm64 now, right? Yes, the patch only covers Itanium. I am not aware of a patch solving the issue for arm64. I have not been following the development of the Mozilla javasript engine. The best thing to do is probably to respond to the first ticket (https://bugzilla.mozilla.org/show_bug.cgi?id=1143022), querying whether or not anyone is able to take a look at it. If you do, please cite this thread, in particular: http://lists.infradead.org/pipermail/linux-arm-kernel/2016-January/399178.html), Which should help to avoid an erroneous solution. Thanks, Mark.