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

Greg Kroah-Hartman
2018-08-23T11:56:35Z

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
> > 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 :)

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>

--- a/drivers/pci/host/pci-host-common.c
+++ b/drivers/pci/host/pci-host-common.c
@@ -612,7 +612,7 @@ int pci_parse_request_of_pci_ranges(struct device *dev,

switch (resource_type(res)) {
case IORESOURCE_IO:
- err = pci_remap_iospace(res, iobase);
+ err = devm_pci_remap_iospace(dev, res, iobase);
if (err) {
dev_warn(dev, "error %d: failed to map resource %pR\n",
err, res);
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 97acba712e4e..316496e99da9 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3579,6 +3579,44 @@ void pci_unmap_iospace(struct resource *res)
}
EXPORT_SYMBOL(pci_unmap_iospace);

+static void devm_pci_unmap_iospace(struct device *dev, void *ptr)
+{
+ struct resource **res = ptr;
+
+ pci_unmap_iospace(*res);
+}
+
+/**
+ * devm_pci_remap_iospace - Managed pci_remap_iospace()
+ * @dev: Generic device to remap IO address for
+ * @res: Resource describing the I/O space
+ * @phys_addr: physical address of range to be mapped
+ *
+ * Managed pci_remap_iospace(). Map is automatically unmapped on driver
+ * detach.
+ */
+int devm_pci_remap_iospace(struct device *dev, const struct resource *res,
+ phys_addr_t phys_addr)
+{
+ const struct resource **ptr;
+ int error;
+
+ ptr = devres_alloc(devm_pci_unmap_iospace, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+
+ error = pci_remap_iospace(res, phys_addr);
+ if (error) {
+ devres_free(ptr);
+ } else {
+ *ptr = res;
+ devres_add(dev, ptr);
+ }
+
+ return error;
+}
+EXPORT_SYMBOL(devm_pci_remap_iospace);
+
/**
* devm_pci_remap_cfgspace - Managed pci_remap_cfgspace()
* @dev: Generic device to remap IO address for
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 340029b2fb38..abd5d5e17aee 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1240,6 +1240,8 @@ int pci_register_io_range(struct fwnode_handle *fwnode, phys_addr_t addr,
unsigned long pci_address_to_pio(phys_addr_t addr);
phys_addr_t pci_pio_to_address(unsigned long pio);
int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr);
+int devm_pci_remap_iospace(struct device *dev, const struct resource *res,
+ phys_addr_t phys_addr);
void pci_unmap_iospace(struct resource *res);
void __iomem *devm_pci_remap_cfgspace(struct device *dev,
resource_size_t offset,