From: "Matthew R. Ochs" <mrochs@linux.vnet.ibm.com>
To: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Cc: James Bottomley <jejb@linux.vnet.ibm.com>,
linux-scsi@vger.kernel.org,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Frederic Barrat <fbarrat@linux.vnet.ibm.com>,
"Manoj N. Kumar" <manoj@linux.vnet.ibm.com>,
Andrew Donnellan <andrew.donnellan@au1.ibm.com>,
linuxppc-dev@lists.ozlabs.org,
Christophe Lombard <clombard@linux.vnet.ibm.com>
Subject: Re: [PATCH v3 39/41] cxlflash: Synchronize reset and remove ops
Date: Wed, 28 Mar 2018 09:43:32 -0500 [thread overview]
Message-ID: <20180328144332.GA61145@p8tul1-build.aus.stglabs.ibm.com> (raw)
In-Reply-To: <1522082127-58900-1-git-send-email-ukrishn@linux.vnet.ibm.com>
On Mon, Mar 26, 2018 at 11:35:27AM -0500, Uma Krishnan wrote:
> The following Oops can be encountered if a device removal or system
> shutdown is initiated while an EEH recovery is in process:
>
> [c000000ff2f479c0] c008000015256f18 cxlflash_pci_slot_reset+0xa0/0x100
> [cxlflash]
> [c000000ff2f47a30] c00800000dae22e0 cxl_pci_slot_reset+0x168/0x290 [cxl]
> [c000000ff2f47ae0] c00000000003ef1c eeh_report_reset+0xec/0x170
> [c000000ff2f47b20] c00000000003d0b8 eeh_pe_dev_traverse+0x98/0x170
> [c000000ff2f47bb0] c00000000003f80c eeh_handle_normal_event+0x56c/0x580
> [c000000ff2f47c60] c00000000003fba4 eeh_handle_event+0x2a4/0x338
> [c000000ff2f47d10] c0000000000400b8 eeh_event_handler+0x1f8/0x200
> [c000000ff2f47dc0] c00000000013da48 kthread+0x1a8/0x1b0
> [c000000ff2f47e30] c00000000000b528 ret_from_kernel_thread+0x5c/0xb4
>
> The remove handler frees AFU memory while the EEH recovery is in progress,
> leading to a race condition. This can result in a crash if the recovery
> thread tries to access this memory.
>
> To resolve this issue, the cxlflash remove handler will evaluate the
> device state and yield to any active reset or probing threads.
>
> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Looks good!
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
WARNING: multiple messages have this Message-ID (diff)
From: "Matthew R. Ochs" <mrochs@linux.vnet.ibm.com>
To: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Cc: linux-scsi@vger.kernel.org,
James Bottomley <jejb@linux.vnet.ibm.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
"Manoj N. Kumar" <manoj@linux.vnet.ibm.com>,
linuxppc-dev@lists.ozlabs.org,
Andrew Donnellan <andrew.donnellan@au1.ibm.com>,
Frederic Barrat <fbarrat@linux.vnet.ibm.com>,
Christophe Lombard <clombard@linux.vnet.ibm.com>
Subject: Re: [PATCH v3 39/41] cxlflash: Synchronize reset and remove ops
Date: Wed, 28 Mar 2018 09:43:32 -0500 [thread overview]
Message-ID: <20180328144332.GA61145@p8tul1-build.aus.stglabs.ibm.com> (raw)
In-Reply-To: <1522082127-58900-1-git-send-email-ukrishn@linux.vnet.ibm.com>
On Mon, Mar 26, 2018 at 11:35:27AM -0500, Uma Krishnan wrote:
> The following Oops can be encountered if a device removal or system
> shutdown is initiated while an EEH recovery is in process:
>
> [c000000ff2f479c0] c008000015256f18 cxlflash_pci_slot_reset+0xa0/0x100
> [cxlflash]
> [c000000ff2f47a30] c00800000dae22e0 cxl_pci_slot_reset+0x168/0x290 [cxl]
> [c000000ff2f47ae0] c00000000003ef1c eeh_report_reset+0xec/0x170
> [c000000ff2f47b20] c00000000003d0b8 eeh_pe_dev_traverse+0x98/0x170
> [c000000ff2f47bb0] c00000000003f80c eeh_handle_normal_event+0x56c/0x580
> [c000000ff2f47c60] c00000000003fba4 eeh_handle_event+0x2a4/0x338
> [c000000ff2f47d10] c0000000000400b8 eeh_event_handler+0x1f8/0x200
> [c000000ff2f47dc0] c00000000013da48 kthread+0x1a8/0x1b0
> [c000000ff2f47e30] c00000000000b528 ret_from_kernel_thread+0x5c/0xb4
>
> The remove handler frees AFU memory while the EEH recovery is in progress,
> leading to a race condition. This can result in a crash if the recovery
> thread tries to access this memory.
>
> To resolve this issue, the cxlflash remove handler will evaluate the
> device state and yield to any active reset or probing threads.
>
> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Looks good!
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
next prev parent reply other threads:[~2018-03-28 14:43 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-26 16:29 [PATCH v3 00/41] cxlflash: OCXL transport support and miscellaneous fixes Uma Krishnan
2018-03-26 16:29 ` Uma Krishnan
2018-03-26 16:29 ` [PATCH v3 01/41] cxlflash: Preserve number of interrupts for master contexts Uma Krishnan
2018-03-26 16:29 ` Uma Krishnan
2018-03-26 16:30 ` [PATCH v3 02/41] cxlflash: Avoid clobbering context control register value Uma Krishnan
2018-03-26 16:30 ` Uma Krishnan
2018-03-26 16:30 ` [PATCH v3 03/41] cxlflash: Add argument identifier names Uma Krishnan
2018-03-26 16:30 ` Uma Krishnan
2018-03-26 16:30 ` [PATCH v3 04/41] cxlflash: Introduce OCXL backend Uma Krishnan
2018-03-26 16:30 ` Uma Krishnan
2018-03-26 16:31 ` [PATCH v3 05/41] cxlflash: Hardware AFU for OCXL Uma Krishnan
2018-03-26 16:31 ` Uma Krishnan
2018-03-26 16:31 ` [PATCH v3 06/41] cxlflash: Read host function configuration Uma Krishnan
2018-03-26 16:31 ` Uma Krishnan
2018-03-26 16:31 ` [PATCH v3 07/41] cxlflash: Setup function acTag range Uma Krishnan
2018-03-26 16:31 ` Uma Krishnan
2018-03-26 16:31 ` [PATCH v3 08/41] cxlflash: Read host AFU configuration Uma Krishnan
2018-03-26 16:31 ` Uma Krishnan
2018-03-26 16:31 ` [PATCH v3 09/41] cxlflash: Setup AFU acTag range Uma Krishnan
2018-03-26 16:31 ` Uma Krishnan
2018-03-26 16:31 ` [PATCH v3 10/41] cxlflash: Setup AFU PASID Uma Krishnan
2018-03-26 16:31 ` Uma Krishnan
2018-03-26 16:31 ` [PATCH v3 11/41] cxlflash: Adapter context support for OCXL Uma Krishnan
2018-03-26 16:31 ` Uma Krishnan
2018-03-26 16:32 ` [PATCH v3 12/41] cxlflash: Use IDR to manage adapter contexts Uma Krishnan
2018-03-26 16:32 ` Uma Krishnan
2018-03-26 16:32 ` [PATCH v3 13/41] cxlflash: Support adapter file descriptors for OCXL Uma Krishnan
2018-03-26 16:32 ` Uma Krishnan
2018-03-26 16:32 ` [PATCH v3 14/41] cxlflash: Support adapter context discovery Uma Krishnan
2018-03-26 16:32 ` Uma Krishnan
2018-03-26 16:32 ` [PATCH v3 15/41] cxlflash: Support image reload policy modification Uma Krishnan
2018-03-26 16:32 ` Uma Krishnan
2018-03-26 16:32 ` [PATCH v3 16/41] cxlflash: MMIO map the AFU Uma Krishnan
2018-03-26 16:32 ` Uma Krishnan
2018-03-26 16:32 ` [PATCH v3 17/41] cxlflash: Support starting an adapter context Uma Krishnan
2018-03-26 16:32 ` Uma Krishnan
2018-03-26 16:32 ` [PATCH v3 18/41] cxlflash: Support process specific mappings Uma Krishnan
2018-03-26 16:32 ` Uma Krishnan
2018-03-26 16:33 ` [PATCH v3 19/41] cxlflash: Support AFU state toggling Uma Krishnan
2018-03-26 16:33 ` Uma Krishnan
2018-03-26 16:33 ` [PATCH v3 20/41] cxlflash: Support reading adapter VPD data Uma Krishnan
2018-03-26 16:33 ` Uma Krishnan
2018-03-26 16:33 ` [PATCH v3 21/41] cxlflash: Setup function OCXL link Uma Krishnan
2018-03-26 16:33 ` Uma Krishnan
2018-03-26 16:33 ` [PATCH v3 22/41] cxlflash: Setup OCXL transaction layer Uma Krishnan
2018-03-26 16:33 ` Uma Krishnan
2018-03-26 16:33 ` [PATCH v3 23/41] cxlflash: Support process element lifecycle Uma Krishnan
2018-03-26 16:33 ` Uma Krishnan
2018-03-26 16:33 ` [PATCH v3 24/41] cxlflash: Support AFU interrupt management Uma Krishnan
2018-03-26 16:33 ` Uma Krishnan
2018-03-26 16:33 ` [PATCH v3 25/41] cxlflash: Support AFU interrupt mapping and registration Uma Krishnan
2018-03-26 16:33 ` Uma Krishnan
2018-03-26 16:33 ` [PATCH v3 26/41] cxlflash: Support starting user contexts Uma Krishnan
2018-03-26 16:33 ` Uma Krishnan
2018-03-26 16:34 ` [PATCH v3 27/41] cxlflash: Support adapter context polling Uma Krishnan
2018-03-26 16:34 ` Uma Krishnan
2018-03-26 16:34 ` [PATCH v3 28/41] cxlflash: Support adapter context reading Uma Krishnan
2018-03-26 16:34 ` Uma Krishnan
2018-03-26 16:34 ` [PATCH v3 29/41] cxlflash: Support adapter context mmap and release Uma Krishnan
2018-03-26 16:34 ` Uma Krishnan
2018-03-26 16:34 ` [PATCH v3 30/41] cxlflash: Support file descriptor mapping Uma Krishnan
2018-03-26 16:34 ` Uma Krishnan
2018-03-26 16:34 ` [PATCH v3 31/41] cxlflash: Introduce object handle fop Uma Krishnan
2018-03-26 16:34 ` Uma Krishnan
2018-03-26 16:34 ` [PATCH v3 32/41] cxlflash: Setup LISNs for user contexts Uma Krishnan
2018-03-26 16:34 ` Uma Krishnan
2018-03-26 16:34 ` [PATCH v3 33/41] cxlflash: Setup LISNs for master contexts Uma Krishnan
2018-03-26 16:34 ` Uma Krishnan
2018-03-26 16:34 ` [PATCH v3 34/41] cxlflash: Update synchronous interrupt status bits Uma Krishnan
2018-03-26 16:34 ` Uma Krishnan
2018-03-26 16:35 ` [PATCH v3 35/41] cxlflash: Introduce OCXL context state machine Uma Krishnan
2018-03-26 16:35 ` Uma Krishnan
2018-03-26 16:35 ` [PATCH v3 36/41] cxlflash: Register for translation errors Uma Krishnan
2018-03-26 16:35 ` Uma Krishnan
2018-03-26 16:35 ` [PATCH v3 37/41] cxlflash: Support AFU reset Uma Krishnan
2018-03-26 16:35 ` Uma Krishnan
2018-03-26 16:35 ` [PATCH v3 38/41] cxlflash: Enable OCXL operations Uma Krishnan
2018-03-26 16:35 ` Uma Krishnan
2018-03-26 16:35 ` [PATCH v3 39/41] cxlflash: Synchronize reset and remove ops Uma Krishnan
2018-03-26 16:35 ` Uma Krishnan
2018-03-28 14:43 ` Matthew R. Ochs [this message]
2018-03-28 14:43 ` Matthew R. Ochs
2018-03-26 16:35 ` [PATCH v3 40/41] cxlflash: Remove commmands from pending list on timeout Uma Krishnan
2018-03-26 16:35 ` Uma Krishnan
2018-03-28 14:50 ` Matthew R. Ochs
2018-03-28 14:50 ` Matthew R. Ochs
2018-03-26 16:35 ` [PATCH v3 41/41] cxlflash: Handle spurious interrupts Uma Krishnan
2018-03-26 16:35 ` Uma Krishnan
2018-03-28 15:03 ` Matthew R. Ochs
2018-03-28 15:03 ` Matthew R. Ochs
2018-03-28 21:34 ` [PATCH v3 00/41] cxlflash: OCXL transport support and miscellaneous fixes Martin K. Petersen
2018-03-28 21:34 ` Martin K. Petersen
2018-03-29 18:35 ` Uma Krishnan
2018-03-29 18:35 ` Uma Krishnan
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