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16c4cb19fa
Applying dynamic usbcore quirks in early booting when the slab is
not yet ready would cause kernel panic of null pointer dereference
because the quirk_count has been counted as 1 while the quirk_list
was failed to allocate.
i.e.,
[ 1.044970] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 1.044995] IP: [<ffffffffb0953ec7>] usb_detect_quirks+0x88/0xd1
[ 1.045016] PGD 0
[ 1.045026] Oops: 0000 [#1] PREEMPT SMP
[ 1.046986] gsmi: Log Shutdown Reason 0x03
[ 1.046995] Modules linked in:
[ 1.047008] CPU: 0 PID: 81 Comm: kworker/0:3 Not tainted 4.4.154 #28
[ 1.047016] Hardware name: Google Coral/Coral, BIOS Google_Coral.10068.27.0 12/04/2017
[ 1.047028] Workqueue: usb_hub_wq hub_event
[ 1.047037] task: ffff88017a321c80 task.stack: ffff88017a384000
[ 1.047044] RIP: 0010:[<ffffffffb0953ec7>] [<ffffffffb0953ec7>] usb_detect_quirks+0x88/0xd1
To tackle this odd, let's balance the quirk_count to 0 when the kcalloc
call fails, and defer the quirk setting into a lower level callback
which ensures that the kernel memory management has been initialized.
Fixes:
|
||
|---|---|---|
| .. | ||
| atm | ||
| c67x00 | ||
| chipidea | ||
| class | ||
| common | ||
| core | ||
| dwc2 | ||
| dwc3 | ||
| early | ||
| gadget | ||
| host | ||
| image | ||
| isp1760 | ||
| misc | ||
| mon | ||
| mtu3 | ||
| musb | ||
| phy | ||
| renesas_usbhs | ||
| roles | ||
| serial | ||
| storage | ||
| typec | ||
| usbip | ||
| wusbcore | ||
| Kconfig | ||
| Makefile | ||
| README | ||
| usb-skeleton.c | ||
To understand all the Linux-USB framework, you'll use these resources:
* This source code. This is necessarily an evolving work, and
includes kerneldoc that should help you get a current overview.
("make pdfdocs", and then look at "usb.pdf" for host side and
"gadget.pdf" for peripheral side.) Also, Documentation/usb has
more information.
* The USB 2.0 specification (from www.usb.org), with supplements
such as those for USB OTG and the various device classes.
The USB specification has a good overview chapter, and USB
peripherals conform to the widely known "Chapter 9".
* Chip specifications for USB controllers. Examples include
host controllers (on PCs, servers, and more); peripheral
controllers (in devices with Linux firmware, like printers or
cell phones); and hard-wired peripherals like Ethernet adapters.
* Specifications for other protocols implemented by USB peripheral
functions. Some are vendor-specific; others are vendor-neutral
but just standardized outside of the www.usb.org team.
Here is a list of what each subdirectory here is, and what is contained in
them.
core/ - This is for the core USB host code, including the
usbfs files and the hub class driver ("hub_wq").
host/ - This is for USB host controller drivers. This
includes UHCI, OHCI, EHCI, and others that might
be used with more specialized "embedded" systems.
gadget/ - This is for USB peripheral controller drivers and
the various gadget drivers which talk to them.
Individual USB driver directories. A new driver should be added to the
first subdirectory in the list below that it fits into.
image/ - This is for still image drivers, like scanners or
digital cameras.
../input/ - This is for any driver that uses the input subsystem,
like keyboard, mice, touchscreens, tablets, etc.
../media/ - This is for multimedia drivers, like video cameras,
radios, and any other drivers that talk to the v4l
subsystem.
../net/ - This is for network drivers.
serial/ - This is for USB to serial drivers.
storage/ - This is for USB mass-storage drivers.
class/ - This is for all USB device drivers that do not fit
into any of the above categories, and work for a range
of USB Class specified devices.
misc/ - This is for all USB device drivers that do not fit
into any of the above categories.