On Thu, Aug 23, 2018 at 06:20:31PM +0300, Sergei Shtylyov wrote:
> 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@xxxxxxxxxxxxxxxxxx>
> >>>>
> >>>> 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@xxxxxxxxxxxxxxxxxx>
> >>>> [lorenzo.pieralisi@xxxxxxx: split commit/updated the commit log]
> >>>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> >>>> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> >>>> Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> >>>> [Backport just for the new api which other patches need - gregkh]
> >>>> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> >>>>
> >>>> ---
> >>>> 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. :-(
Really? Why not? What is missing here?
greg k-h
