simultaneously detaching kernel drivers on the same USB device we can
get stuck in the "usb_wait_pending_ref_locked()" function because the
conditions needed for allowing detach are not met. The "destroy_dev()"
function waits for all system calls involving the given character
device to return. Character device system calls may lock the USB
enumeration lock, which is also held when "destroy_dev()" is
called. This can sometimes lead to a deadlock not noticed by
WITNESS. The current solution is to ensure the calling thread is the
only one holding the USB enumeration lock and prevent other threads
from getting refs while a USB device detach is ongoing. This turned
out not to be sufficient. To solve this deadlock we could use
"destroy_dev_sched()" to schedule the device destruction in the
background, but then we don't know when it is safe to free() the
private data of the character device. Instead a callback function is
executed by the USB explore process to kill off any leftover USB
character devices synchronously after the USB device explore code is
finished and the USB enumeration lock is no longer locked. This makes
porting easier and also ensures us that character devices must
eventually go away after a USB device detach.
While at it ensure that "flag_iserror" is only written when "priv_mtx"
is locked, which is protecting it.
MFC after: 5 days
These changes prevent sysctl(8) from returning proper output,
such as:
1) no output from sysctl(8)
2) erroneously returning ENOMEM with tools like truss(1)
or uname(1)
truss: can not get etype: Cannot allocate memory
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.
Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.
MFC after: 2 weeks
Sponsored by: Mellanox Technologies
on USB HUBs by moving the code into the USB explore threads. The
deadlock happens because child devices of the USB HUB don't have the
expected reference count when called from outside the explore
thread. Only the HUB device itself, which the IOCTL interface locks,
gets the correct reference count.
MFC after: 3 days
create character devices. The deadlock can happen if an application is
issuing IOCTLs which require USB refcounting, at the same time the USB
device is detaching.
There is already a counter in place in the USB device structure to
detect this situation, but it was not always checked ahead of invoking
functions that might destroy character devices, like detach, set
configuration, set alternate interface or detach active kernel driver.
Reported by: Daniel O'Connor <doconnor@gsoft.com.au>
MFC after: 1 week
with USB device detach when using character device handles. This also
includes LibUSB. It turns out that "usb_close()" cannot always get a
reference to clean up its USB transfers and such, if called during the
kernel USB device detach.
Analysis by: hselasky @
Reported by: Juergen Lock <nox@jelal.kn-bremen.de>
MFC after: 1 week
enumeration lock. Make sure all callers of usbd_enum_lock() check the return
value. Remove the control transfer specific lock. Bump the FreeBSD version
number, hence external USB modules may need to be recompiled due to a USB
device structure change.
MFC after: 1 week
into the FreeBSD boot loader, typically for non-USB aware BIOSes, EFI systems
or embedded platforms. This is also useful for out of the system compilation
of the FreeBSD USB stack for various purposes. The USB kernel files can
now optionally include a global header file which should include all needed
definitions required to compile the FreeBSD USB stack. When the global USB
header file is included, no other USB header files will be included by
default.
Add new file containing the USB stack configuration for the
FreeBSD loader build.
Replace some __FBSDID()'s by /* $FreeBSD$ */ comments. Now all
USB files follow the same style.
Use cases:
- console in loader via USB
- loading kernel via USB
Discussed with: Hiroki Sato, hrs @ EuroBSDCon
Code should just use the devtoname() function to obtain the name of a
character device. Also add const keywords to pieces of code that need it
to build properly.
MFC after: 2 weeks
- Make it easier to port the USB code to other platforms by only using
one set of memory functions for clearing and copying memory. None of
the memory copies are overlapping. This means using bcopy() is not
required.
- Fix a compile warning when USB_HAVE_BUSDMA=0
- Add missing semicolon in avr32dci.
- Update some comments.
MFC after: 1 week
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.
Reviewed by: rwatson
Approved by: re (bz)
device having the same name like a previous one is not created before the old
one is gone. This fixes some panics due to asserts in the devfs code which
were added recently.
Approved by: re (kib)
MFC after: 1 week
via %s
Most of the cases looked harmless, but this is done for the sake of
correctness. In one case it even allowed to drop an intermediate buffer.
Found by: clang
MFC after: 2 week
message has been printed is enough to get someones attention. Also remove the
line number for DPRINTF/DPRINTFN, it already prints the funtion name and a
unique message.
being polled.
- Remove the need for Giant from the USB HUB driver.
- Leave device unconfigured instead of disabling the USB port
when Huawei Autoinstall disk detection triggers. This should
fix problems that the Huawei device is not detected after
Autoinstall eject is issued.
- Reported by: Nikolay Antsiferov
- Fix memory use after free race for USB character devices.
- Reported by: Lucius Windschuh
- Factor out the enumeration lock into three functions to make the
coming newbus lock conversion more easy.
- usbd_enum_lock
- usbd_enum_unlock
- usbd_enum_is_locked
Submitted by: hps
The newbus lock is responsible for protecting newbus internIal structures,
device states and devclass flags. It is necessary to hold it when all
such datas are accessed. For the other operations, softc locking should
ensure enough protection to avoid races.
Newbus lock is automatically held when virtual operations on the device
and bus are invoked when loading the driver or when the suspend/resume
take place. For other 'spourious' operations trying to access/modify
the newbus topology, newbus lock needs to be automatically acquired and
dropped.
For the moment Giant is also acquired in some key point (modules subsystem)
in order to avoid problems before the 8.0 release as module handlers could
make assumptions about it. This Giant locking should go just after
the release happens.
Please keep in mind that the public interface can be expanded in order
to provide more support, if there are really necessities at some point
and also some bugs could arise as long as the patch needs a bit of
further testing.
Bump __FreeBSD_version in order to reflect the newbus lock introduction.
Reviewed by: ed, hps, jhb, imp, mav, scottl
No answer by: ariff, thompsa, yongari
Tested by: pho,
G. Trematerra <giovanni dot trematerra at gmail dot com>,
Brandon Gooch <jamesbrandongooch at gmail dot com>
Sponsored by: Yahoo! Incorporated
Approved by: re (ksmith)
- add support for defragging of written device data.
- improve handling of alternate settings in device side mode.
- correct return value from usbd_get_no_alts() function.
- reported by: HPS
- P4 ID: 166156, 166168
- report USB device release information to devd and pnpinfo.
- reported by: MIHIRA Sanpei Yoshiro
- P4 ID: 166221
Submitted by: hps
Approved by: re
