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

From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Will Deacon <will@kernel.org>
Cc: catalin.marinas@arm.com, linuxarm@huawei.com,
	linux-kernel@vger.kernel.org, james.morse@arm.com,
	allison@lohutok.net, gregkh@linuxfoundation.org,
	Tian Tao <tiantao6@hisilicon.com>,
	tglx@linutronix.de, info@metux.net,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] arm32: fix flushcache syscall with device address
Date: Tue, 21 Apr 2020 12:16:51 +0100	[thread overview]
Message-ID: <20200421121651.000009f0@Huawei.com> (raw)
In-Reply-To: <20200421081239.GA15439@willie-the-truck>

On Tue, 21 Apr 2020 09:12:39 +0100
Will Deacon <will@kernel.org> 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
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
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