Re: [RFC] arm64: failed when run the command: timedatectl set-timezone Asia/Shanghai

[Steve Capper]

On 12 January 2016 at 03:32, Xishi Qiu <qiuxishi@xxxxxxxxxx> wrote:
> On 2016/1/12 10:47, Xishi Qiu wrote:
>
>> Failed when run the command: timedatectl set-timezone Asia/Shanghai
>> But CONFIG_PGTABLE_LEVELS=3 is OK, and CONFIG_PGTABLE_LEVELS=4 is failed.
>> The kernel is v4.1, and this command need the lib polikit.
>>
>> Is this the bug of kernel?
>>
>> Thanks,
>> Xishi Qiu
>
> [  241.310558] polkitd[3531]: unhandled level 0 translation fault (11) at 0x7fff9010c040, esr 0x92000004
> [  241.319838] pgd = ffff801fb3e05000
> [  241.323259] [7fff9010c040] *pgd=0000000000000000
>
> [  241.329407] CPU: 0 PID: 3531 Comm: polkitd Not tainted 4.1.12+ #1
> [  241.336312] Hardware name: Huawei Taishan 2160 /BC11SPCA, BIOS 1.12 12/30/2015
> [  241.343566] task: ffff801fb8772f00 ti: ffff80003f454000 task.ti: ffff80003f454000
> [  241.351089] PC is at 0xffff91d281ec
> [  241.354594] LR is at 0xffff91cb5b24
> [  241.358099] pc : [<0000ffff91d281ec>] lr : [<0000ffff91cb5b24>] pstate: 20000000
> [  241.365526] sp : 0000ffffd47a4380
> [  241.368858] x29: 0000ffffd47a47c0 x28: 0000000078e8107e
> [  241.374215] x27: 0000aaaafaf68020 x26: 00007fff9010c040
> [  241.379571] x25: 0000aaaafaf6c2b0 x24: 0000ffff91ed4000
> [  241.384931] x23: 0000000000000005 x22: 0000000000000000
> [  241.390288] x21: 0000000000000000 x20: 0000000000000008
> [  241.395644] x19: 0000ffff91ed4000 x18: 00000000000007df
> [  241.401004] x17: 0000ffff91ed5740 x16: 0000ffff91ce84ec
> [  241.406360] x15: 0000ffffd47a46a0 x14: 0000ffff91c07370
> [  241.411716] x13: 00000000000003d0 x12: 0000ffff92340000
> [  241.417074] x11: 0000000000000000 x10: 0101010101010101
> [  241.422431] x9 : 0000ffff90108218 x8 : 00000000f20217f7
> [  241.427786] x7 : 0000aaaafaf6db40 x6 : 0000ffff90109060
> [  241.433146] x5 : 0000000000000000 x4 : 0000aaaafaf6dc30
> [  241.438502] x3 : 0000000000000001 x2 : 0000000000000008
> [  241.443858] x1 : 0000aaaafaf68020 x0 : 00007fff9010c040
>
>
>

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.

Cheers,
-- 
Steve