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[2/8] PCI: of: Fix I/O space page leak

Message ID 181e8c62-b486-c6b1-4fce-f32cbf377cdd@cogentembedded.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Sergei Shtylyov July 15, 2018, 4:06 p.m. UTC
When testing the R-Car PCIe driver on the Condor board,  I noticed that if
I left  the PCIe PHY driver disabled, the kernel crashed with this BUG:

[    1.225819] kernel BUG at lib/ioremap.c:72!
[    1.230007] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[    1.235496] Modules linked in:
[    1.238561] CPU: 0 PID: 39 Comm: kworker/0:1 Not tainted 4.17.0-dirty #1092
[    1.245526] Hardware name: Renesas Condor board based on r8a77980 (DT)
[    1.252075] Workqueue: events deferred_probe_work_func
[    1.257220] pstate: 80000005 (Nzcv daif -PAN -UAO)
[    1.262024] pc : ioremap_page_range+0x370/0x3c8
[    1.266558] lr : ioremap_page_range+0x40/0x3c8
[    1.271002] sp : ffff000008da39e0
[    1.274317] x29: ffff000008da39e0 x28: 00e8000000000f07
[    1.279636] x27: ffff7dfffee00000 x26: 0140000000000000
[    1.284954] x25: ffff7dfffef00000 x24: 00000000000fe100
[    1.290272] x23: ffff80007b906000 x22: ffff000008ab8000
[    1.295590] x21: ffff000008bb1d58 x20: ffff7dfffef00000
[    1.300909] x19: ffff800009c30fb8 x18: 0000000000000001
[    1.306226] x17: 00000000000152d0 x16: 00000000014012d0
[    1.311544] x15: 0000000000000000 x14: 0720072007200720
[    1.316862] x13: 0720072007200720 x12: 0720072007200720
[    1.322180] x11: 0720072007300730 x10: 00000000000000ae
[    1.327498] x9 : 0000000000000000 x8 : ffff7dffff000000                      
[    1.332816] x7 : 0000000000000000 x6 : 0000000000000100
[    1.338134] x5 : 0000000000000000 x4 : 000000007b906000
[    1.343452] x3 : ffff80007c61a880 x2 : ffff7dfffeefffff
[    1.348770] x1 : 0000000040000000 x0 : 00e80000fe100f07
[    1.354090] Process kworker/0:1 (pid: 39, stack limit = 0x        (ptrval))  
[    1.361056] Call trace:
[    1.363504]  ioremap_page_range+0x370/0x3c8
[    1.367695]  pci_remap_iospace+0x7c/0xac
[    1.371624]  pci_parse_request_of_pci_ranges+0x13c/0x190
[    1.376945]  rcar_pcie_probe+0x4c/0xb04
[    1.380786]  platform_drv_probe+0x50/0xbc
[    1.384799]  driver_probe_device+0x21c/0x308
[    1.389072]  __device_attach_driver+0x98/0xc8
[    1.393431]  bus_for_each_drv+0x54/0x94
[    1.397269]  __device_attach+0xc4/0x12c
[    1.401107]  device_initial_probe+0x10/0x18
[    1.405292]  bus_probe_device+0x90/0x98
[    1.409130]  deferred_probe_work_func+0xb0/0x150
[    1.413756]  process_one_work+0x12c/0x29c
[    1.417768]  worker_thread+0x200/0x3fc
[    1.421522]  kthread+0x108/0x134
[    1.424755]  ret_from_fork+0x10/0x18
[    1.428334] 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.

The  most feasible solution seemed to introduce devm_pci_remap_iospace() --
which was done in the XGene PCIe driver patch posted earlier...

Fixes: dbf9826d5797 ("PCI: generic: Convert to DT resource parsing API")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

---
 drivers/pci/of.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox

Patch

Index: pci/drivers/pci/of.c
===================================================================
--- pci.orig/drivers/pci/of.c
+++ pci/drivers/pci/of.c
@@ -612,7 +612,7 @@  int pci_parse_request_of_pci_ranges(stru
 
 		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);