Re: [PATCH 4.14 210/217] PCI: OF: Fix I/O space page leak

Sergei Shtylyov
2018-08-23T15:20:37Z

On 08/23/2018 02:56 PM, Greg Kroah-Hartman wrote:
> On Thu, Aug 23, 2018 at 01:17:28PM +0200, Greg Kroah-Hartman wrote:
>> On Thu, Aug 23, 2018 at 01:57:35PM +0300, Sergei Shtylyov wrote:
>>> On 08/23/2018 10:55 AM, Greg Kroah-Hartman wrote:
>>>
>>>> 4.14-stable review patch. If anyone has any objections, please let me know.
>>>>
>>>> ------------------
>>>>
>>>> From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>>>
>>>> commit a5fb9fb023a1435f2b42bccd7f547560f3a21dc3 upstream.
>>>>
>>>> When testing the R-Car PCIe driver on the Condor board, if the PCIe PHY
>>>> driver was left disabled, the kernel crashed with this BUG:
>>>>
>>>> kernel BUG at lib/ioremap.c:72!
>>>> Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
>>>> Modules linked in:
>>>> CPU: 0 PID: 39 Comm: kworker/0:1 Not tainted 4.17.0-dirty #1092
>>>> Hardware name: Renesas Condor board based on r8a77980 (DT)
>>>> Workqueue: events deferred_probe_work_func
>>>> pstate: 80000005 (Nzcv daif -PAN -UAO)
>>>> pc : ioremap_page_range+0x370/0x3c8
>>>> lr : ioremap_page_range+0x40/0x3c8
>>>> sp : ffff000008da39e0
>>>> x29: ffff000008da39e0 x28: 00e8000000000f07
>>>> x27: ffff7dfffee00000 x26: 0140000000000000
>>>> x25: ffff7dfffef00000 x24: 00000000000fe100
>>>> x23: ffff80007b906000 x22: ffff000008ab8000
>>>> x21: ffff000008bb1d58 x20: ffff7dfffef00000
>>>> x19: ffff800009c30fb8 x18: 0000000000000001
>>>> x17: 00000000000152d0 x16: 00000000014012d0
>>>> x15: 0000000000000000 x14: 0720072007200720
>>>> x13: 0720072007200720 x12: 0720072007200720
>>>> x11: 0720072007300730 x10: 00000000000000ae
>>>> x9 : 0000000000000000 x8 : ffff7dffff000000
>>>> x7 : 0000000000000000 x6 : 0000000000000100
>>>> x5 : 0000000000000000 x4 : 000000007b906000
>>>> x3 : ffff80007c61a880 x2 : ffff7dfffeefffff
>>>> x1 : 0000000040000000 x0 : 00e80000fe100f07
>>>> Process kworker/0:1 (pid: 39, stack limit = 0x (ptrval))
>>>> Call trace:
>>>> ioremap_page_range+0x370/0x3c8
>>>> pci_remap_iospace+0x7c/0xac
>>>> pci_parse_request_of_pci_ranges+0x13c/0x190
>>>> rcar_pcie_probe+0x4c/0xb04
>>>> platform_drv_probe+0x50/0xbc
>>>> driver_probe_device+0x21c/0x308
>>>> __device_attach_driver+0x98/0xc8
>>>> bus_for_each_drv+0x54/0x94
>>>> __device_attach+0xc4/0x12c
>>>> device_initial_probe+0x10/0x18
>>>> bus_probe_device+0x90/0x98
>>>> deferred_probe_work_func+0xb0/0x150
>>>> process_one_work+0x12c/0x29c
>>>> worker_thread+0x200/0x3fc
>>>> kthread+0x108/0x134
>>>> ret_from_fork+0x10/0x18
>>>> Code: f9004ba2 54000080 aa0003fb 17ffff48 (d4210000)
>>>>
>>>> It turned out that pci_remap_iospace() wasn't undone when the driver's
>>>> probe failed, and since devm_phy_optional_get() returned -EPROBE_DEFER,
>>>> the probe was retried, finally causing the BUG due to trying to remap
>>>> already remapped pages.
>>>>
>>>> Introduce the devm_pci_remap_iospace() managed API and replace the
>>>> pci_remap_iospace() call with it to fix the bug.
>>>>
>>>> Fixes: dbf9826d5797 ("PCI: generic: Convert to DT resource parsing API")
>>>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>>> [lorenzo.pieralisi@arm.com: split commit/updated the commit log]
>>>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>>>> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
>>>> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
>>>> [Backport just for the new api which other patches need - gregkh]
>>>> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>>>
>>>> ---
>>>> drivers/pci/pci.c | 38 ++++++++++++++++++++++++++++++++++++++
>>>> include/linux/pci.h | 2 ++
>>>> 2 files changed, 40 insertions(+)
>>>
>>> You missed a chnage to drivers/pci/host/pci-host-common.c (and
>>> also drivers/pci/host/pcie-rcar.c which wasn't using the generic mode back

s/mode/code/, of course. :-)

>>> then)...
>>
>> Yes I totally messed this up, let me fix it...
>
> Ok, below is the patch that I replaced the 4.14 and 4.9 versions with,
> it should now be resolved, but verifying this would be nice :)

Unfortunately, it doesn't fix anything on R-Car where this bug was originally
encountered and the fix was tested... and you leave no way for it to be fixed. :-(

> thanks,
>
> greg k-h
>
> ------------------------
>
> From a5fb9fb023a1435f2b42bccd7f547560f3a21dc3 Mon Sep 17 00:00:00 2001
> From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> Date: Wed, 18 Jul 2018 15:40:26 -0500
> Subject: PCI: OF: Fix I/O space page leak
>
> From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>
> commit a5fb9fb023a1435f2b42bccd7f547560f3a21dc3 upstream.
>
> When testing the R-Car PCIe driver on the Condor board, if the PCIe PHY
> driver was left disabled, the kernel crashed with this BUG:
>
> kernel BUG at lib/ioremap.c:72!
> Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> Modules linked in:
> CPU: 0 PID: 39 Comm: kworker/0:1 Not tainted 4.17.0-dirty #1092
> Hardware name: Renesas Condor board based on r8a77980 (DT)
> Workqueue: events deferred_probe_work_func
> pstate: 80000005 (Nzcv daif -PAN -UAO)
> pc : ioremap_page_range+0x370/0x3c8
> lr : ioremap_page_range+0x40/0x3c8
> sp : ffff000008da39e0
> x29: ffff000008da39e0 x28: 00e8000000000f07
> x27: ffff7dfffee00000 x26: 0140000000000000
> x25: ffff7dfffef00000 x24: 00000000000fe100
> x23: ffff80007b906000 x22: ffff000008ab8000
> x21: ffff000008bb1d58 x20: ffff7dfffef00000
> x19: ffff800009c30fb8 x18: 0000000000000001
> x17: 00000000000152d0 x16: 00000000014012d0
> x15: 0000000000000000 x14: 0720072007200720
> x13: 0720072007200720 x12: 0720072007200720
> x11: 0720072007300730 x10: 00000000000000ae
> x9 : 0000000000000000 x8 : ffff7dffff000000
> x7 : 0000000000000000 x6 : 0000000000000100
> x5 : 0000000000000000 x4 : 000000007b906000
> x3 : ffff80007c61a880 x2 : ffff7dfffeefffff
> x1 : 0000000040000000 x0 : 00e80000fe100f07
> Process kworker/0:1 (pid: 39, stack limit = 0x (ptrval))
> Call trace:
> ioremap_page_range+0x370/0x3c8
> pci_remap_iospace+0x7c/0xac
> pci_parse_request_of_pci_ranges+0x13c/0x190
> rcar_pcie_probe+0x4c/0xb04
> platform_drv_probe+0x50/0xbc
> driver_probe_device+0x21c/0x308
> __device_attach_driver+0x98/0xc8
> bus_for_each_drv+0x54/0x94
> __device_attach+0xc4/0x12c
> device_initial_probe+0x10/0x18
> bus_probe_device+0x90/0x98
> deferred_probe_work_func+0xb0/0x150
> process_one_work+0x12c/0x29c
> worker_thread+0x200/0x3fc
> kthread+0x108/0x134
> ret_from_fork+0x10/0x18
> Code: f9004ba2 54000080 aa0003fb 17ffff48 (d4210000)
>
> It turned out that pci_remap_iospace() wasn't undone when the driver's
> probe failed, and since devm_phy_optional_get() returned -EPROBE_DEFER,
> the probe was retried, finally causing the BUG due to trying to remap
> already remapped pages.
>
> Introduce the devm_pci_remap_iospace() managed API and replace the
> pci_remap_iospace() call with it to fix the bug.
>
> Fixes: dbf9826d5797 ("PCI: generic: Convert to DT resource parsing API")
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> [lorenzo.pieralisi@arm.com: split commit/updated the commit log]
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>