kernel: backport patch for specifying USB ports/devices in DT

[openwrt/staging/dedeckeh.git] / target / linux / generic / patches-4.4 / 082-0002-usb-core-usb_alloc_dev-fix-setting-of-portnum.patch

diff --git a/target/linux/generic/patches-4.4/082-0002-usb-core-usb_alloc_dev-fix-setting-of-portnum.patch b/target/linux/generic/patches-4.4/082-0002-usb-core-usb_alloc_dev-fix-setting-of-portnum.patch
new file mode 100644 (file)
index 0000000..15cf4ca
--- /dev/null
+++ b/target/linux/generic/patches-4.4/082-0002-usb-core-usb_alloc_dev-fix-setting-of-portnum.patch
@@ -0,0 +1,108 @@
+From 7222c832254a75dcd67d683df75753d4a4e125bb Mon Sep 17 00:00:00 2001
+From: Nicolai Stange <nicstange@gmail.com>
+Date: Thu, 17 Mar 2016 23:53:02 +0100
+Subject: [PATCH] usb/core: usb_alloc_dev(): fix setting of ->portnum
+
+With commit 69bec7259853 ("USB: core: let USB device know device node"),
+the port1 argument of usb_alloc_dev() gets overwritten as follows:
+
+  ... usb_alloc_dev(..., unsigned port1)
+  {
+    ...
+    if (!parent->parent) {
+      port1 = usb_hcd_find_raw_port_number(..., port1);
+    }
+    ...
+  }
+
+Later on, this now overwritten port1 gets assigned to ->portnum:
+
+  dev->portnum = port1;
+
+However, since xhci_find_raw_port_number() isn't idempotent, the
+aforementioned commit causes a number of KASAN splats like the following:
+
+  BUG: KASAN: slab-out-of-bounds in xhci_find_raw_port_number+0x98/0x170
+                                       at addr ffff8801d9311670
+  Read of size 8 by task kworker/2:1/87
+  [...]
+  Workqueue: usb_hub_wq hub_event
+   0000000000000188 000000005814b877 ffff8800cba17588 ffffffff8191447e
+   0000000041b58ab3 ffffffff82a03209 ffffffff819143a2 ffffffff82a252f4
+   ffff8801d93115e0 0000000000000188 ffff8801d9311628 ffff8800cba17588
+  Call Trace:
+   [<ffffffff8191447e>] dump_stack+0xdc/0x15e
+   [<ffffffff819143a2>] ? _atomic_dec_and_lock+0xa2/0xa2
+   [<ffffffff814e2cd1>] ? print_section+0x61/0xb0
+   [<ffffffff814e4939>] print_trailer+0x179/0x2c0
+   [<ffffffff814f0d84>] object_err+0x34/0x40
+   [<ffffffff814f4388>] kasan_report_error+0x2f8/0x8b0
+   [<ffffffff814eb91e>] ? __slab_alloc+0x5e/0x90
+   [<ffffffff812178c0>] ? __lock_is_held+0x90/0x130
+   [<ffffffff814f5091>] kasan_report+0x71/0xa0
+   [<ffffffff814ec082>] ? kmem_cache_alloc_trace+0x212/0x560
+   [<ffffffff81d99468>] ? xhci_find_raw_port_number+0x98/0x170
+   [<ffffffff814f33d4>] __asan_load8+0x64/0x70
+   [<ffffffff81d99468>] xhci_find_raw_port_number+0x98/0x170
+   [<ffffffff81db0105>] xhci_setup_addressable_virt_dev+0x235/0xa10
+   [<ffffffff81d9ea51>] xhci_setup_device+0x3c1/0x1430
+   [<ffffffff8121cddd>] ? trace_hardirqs_on+0xd/0x10
+   [<ffffffff81d9fac0>] ? xhci_setup_device+0x1430/0x1430
+   [<ffffffff81d9fad3>] xhci_address_device+0x13/0x20
+   [<ffffffff81d2081a>] hub_port_init+0x55a/0x1550
+   [<ffffffff81d28705>] hub_event+0xef5/0x24d0
+   [<ffffffff81d27810>] ? hub_port_debounce+0x2f0/0x2f0
+   [<ffffffff8195e1ee>] ? debug_object_deactivate+0x1be/0x270
+   [<ffffffff81210203>] ? print_rt_rq+0x53/0x2d0
+   [<ffffffff8121657d>] ? trace_hardirqs_off+0xd/0x10
+   [<ffffffff8226acfb>] ? _raw_spin_unlock_irqrestore+0x5b/0x60
+   [<ffffffff81250000>] ? irq_domain_set_hwirq_and_chip+0x30/0xb0
+   [<ffffffff81256339>] ? debug_lockdep_rcu_enabled+0x39/0x40
+   [<ffffffff812178c0>] ? __lock_is_held+0x90/0x130
+   [<ffffffff81196877>] process_one_work+0x567/0xec0
+  [...]
+
+Afterwards, xhci reports some functional errors:
+
+  xhci_hcd 0000:00:14.0: ERROR: unexpected setup address command completion
+                                code 0x11.
+  xhci_hcd 0000:00:14.0: ERROR: unexpected setup address command completion
+                                code 0x11.
+  usb 4-3: device not accepting address 2, error -22
+
+Fix this by not overwriting the port1 argument in usb_alloc_dev(), but
+storing the raw port number as required by OF in an additional variable,
+raw_port.
+
+Fixes: 69bec7259853 ("USB: core: let USB device know device node")
+Signed-off-by: Nicolai Stange <nicstange@gmail.com>
+Acked-by: Alan Stern <stern@rowland.harvard.edu>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/usb/core/usb.c | 5 +++--
+ 1 file changed, 3 insertions(+), 2 deletions(-)
+
+--- a/drivers/usb/core/usb.c
++++ b/drivers/usb/core/usb.c
+@@ -423,6 +423,7 @@ struct usb_device *usb_alloc_dev(struct
+       struct usb_device *dev;
+       struct usb_hcd *usb_hcd = bus_to_hcd(bus);
+       unsigned root_hub = 0;
++      unsigned raw_port = port1;
+ 
+       dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+       if (!dev)
+@@ -497,11 +498,11 @@ struct usb_device *usb_alloc_dev(struct
+ 
+               if (!parent->parent) {
+                       /* device under root hub's port */
+-                      port1 = usb_hcd_find_raw_port_number(usb_hcd,
++                      raw_port = usb_hcd_find_raw_port_number(usb_hcd,
+                               port1);
+               }
+               dev->dev.of_node = usb_of_get_child_node(parent->dev.of_node,
+-                              port1);
++                              raw_port);
+ 
+               /* hub driver sets up TT records */
+       }