Re: [PATCH] arm32: fix flushcache syscall with device address

From: Jonathan Cameron
Date: Tue Apr 21 2020 - 07:17:11 EST


On Tue, 21 Apr 2020 09:12:39 +0100
Will Deacon <will@xxxxxxxxxx> wrote:

> On Tue, Apr 21, 2020 at 04:08:34PM +0800, Tian Tao wrote:
> > An issue has been observed on our Kungpeng916 systems when using a PCI
> > express GPU. This occurs when a 32 bit application running on a 64 bit
> > kernel issues a cache flush operation to a memory address that is in
> > a PCI BAR of the GPU.The results in an illegal operation and
> > subsequent crash.
>
> A kernel crash? If so, please can you include the log here?

Deploying my finest copy typing from the image Tian Tao sent out

KERNEL: /root/vmlinux-4.19.36-3patch-00228-debuginfo
DUMPFILE: vmcore [PARTIAL DUMP]
CPUS: 64
DATE: Fri Mar 20 06:59:56 2020
UPTIME: 07:01:01
LOAD AVERAGE: 33.76, 35.45, 35.79
TASKS: 59447
NODENAME: cpus-new-ondemand-0509
RELEASE: 4.19.36-3patch-0228
VERSION: #4 SMP Fri Feb 28 15:18:51 UTC 2020
MACHINE: aarch64 (unknown MHz)
MEMORY: 255.7 GB
PANIC: "kernel panic - not syncing: Asynchronous SError Interrupt"
PID: 175108
COMMAND: "UnityMain"
TASK: ffff80a96999dd00 [THREAD_INFO: ffff80a96999dd00]
CPU: 62
STATE: TASK_RUNNING (PANIC)

crash> bt
PID: 175108 TASK: ffff80a96999dd00 CPU: 62 COMMAND: "UnityMain"
#0 [ffff000194e1b920] machine_kexec at ffff0000080a265c
#1 [ffff000194e1b980] __crash_kexec at ffff0000081b3ba8
#2 [ffff000194e1bb10] panic at ffff0000080ecc98
#3 [ffff000194e1bbf0] nmi_panic at ffff0000080ec7f4
#4 [ffff000194e1bc10] arm64_serror_panic at fff00000809019c
#5 [ffff000194e1bc30] do_serror at ffff00000809039c
#6 [ffff000194e1bd90] el1_error at ffff000008083e50
#7 [ffff000194e1bda0] __flush_icache_range at ffff0000080a9ec4
#8 [ffff000194e1be60] el0_svc_common at fff0000080977d8
#9 [ffff000194e1bea0] el0_svc_compat_handler at ffff0000080979b4
#10 [ffff000194e1bff0] el0_svc_compat at ffff0000008083874

PC: c90fe7f8 LR: c90ff09c SP: d2afa8e0 PSTATE: 800b0010
X12: c56e96e4 X11: d2afaa48 X10: d0ff1000 X9: d2afab68
x8: 000000d6 X7: 000f0002 X6: d3c61840 X5: d3c61001
X4: d3c03000 X3: 0004d54a x2: 00000000 x1: d3c61040
X0: d3c61000


New advanced test for Mavis Beacon teaches typing.

In summary this is all we have to hand...

>
> Will
>
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