On 03/02/2018 06:29 PM, Marc Zyngier wrote:
On Fri, 02 Mar 2018 09:02:32 +0000, Alex Shi wrote:
On 03/02/2018 12:46 AM, Greg KH wrote:
On Thu, Mar 01, 2018 at 08:53:37PM +0800, Alex Shi wrote:
Hi All,
Resent without non-upstream patches.
This backport patchset fixed the spectre issue, it's original branch: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/log/?h=kpti A few dependency or fixingpatches are also picked up, if they are necessary and no functional changes.
No bug found from kernelci.org and lkft testing. It also could be gotten from:
git://git.linaro.org/kernel/linux-linaro-stable.git v4.9-spectre-upstream-only
Also, how did you test, what platforms did you test, and did you test that this actually did fix the spectre issue on your platforms? If so, what test did you use?
On the kernelci, there are 18 kinds of platoforms with different configure tested booting, detailed info is here: https://kernelci.org/boot/all/job/lsk/branch/linux-linaro-lsk-v4.9-test/kern...
I also tested the qemu boot on hikey620. and normal boot on
Did you try QEMU in conjunction with KVM? Or just in emulation?
Many many thanks for response!
Yes, I tried both of type boot with or w/o KVM. Both works.
hikey620/db410c/junor2. The other testing include the LKFT testing which is reported by email, same as test for LTS. None of testing show regressions.
As testing the spectre bug fix, that's a good question. I also asked this question to original patch authors, like Marc. They said they just figure out these patches could block spectre or meltdown issue. From my side, I just reproduced the process internal spectre. But all fix on arm can not resolve the user space internal spectre. It can block from user to kernel or kernel to user spectre according the code purose. So I believe these patch could do their job. And arm cpu would drop the spectre branches if it has 20+ 'nop' instructions...
What are you talking about? What's that story about NOPs? There are clear mitigation guidelines for ARM cores, please don't make things up.
Oops, sorry for misunderstanding! what's I meaning is, among many kind of solution to mitigation issues, like ATF changes, compiler change, BT changes, 'nop' is interesting for me. Sorry for bad expression.
Regards Alex