Re: [PATCH v8 23/70] mm/mmap: change do_brk_flags() to expand existing VMA and add do_brk_munmap()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 5/3/22 23:55, Liam Howlett wrote:
* Heiko Carstens <hca@xxxxxxxxxxxxx> [220503 15:49]:
On Mon, May 02, 2022 at 08:50:04PM +0200, Heiko Carstens wrote:
On Mon, May 02, 2022 at 01:31:00PM +0000, Liam Howlett wrote:
* Heiko Carstens <hca@xxxxxxxxxxxxx> [220502 06:18]:
On Sun, May 01, 2022 at 05:24:12PM -0700, Andrew Morton wrote:
(cc S390 maintainers)
(cc stable & Greg)
...
booting.  The last thing I see is:

"[    4.668916] Spectre V2 mitigation: execute trampolines"

I've bisected back to commit e553f62f10d9 (mm, page_alloc: fix
build_zonerefs_node())

With the this commit, I am unable to boot one out of three times.  When
using the previous commit I was not able to get it to hang after trying
10+ times.  This is a qemu s390 install with KASAN on and I see no error
messages.  I think it's likely it is this patch, but no guaranteed.
...
Liam, could you share your kernel config?

Sure thing.  See attached.

So, I can reproduce the hanging system now. However this looks like a
qemu problem on s390, since I can reproduce this only with Qemu+TCG.
Qemu with kvm works without any problems (same if I use z/VM as
hypervisor).

Janosch, Claudio, can you have a look at this please?

So, at least for me this problem also exists with plain v5.17.
Switching off KASAN, or alternatively switching to KASAN_INLINE
"fixes" it for me with Qemu+TCG.

Liam, could you please also try to disable KASAN in your config? With
that I think we can be almost sure this could be some bug in Qemu.

With KASAN, my tree fails 100% of the time (mm-stable + my maple tree
patches)

Without KASAN, it boots 100% of the time.

I think this verifies with you say above?

Thanks,
Liam

I had a short look yesterday and the boot usually hangs in the raid6 code. Disabling vector instructions didn't make a difference but a few interruptions via GDB solve the problem for some reason.

CCing David and Thomas for TCG




[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux