There is checking NULL before dereferncing but
it need to add "return".
Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
By specifying NO_UNION_NORMAL the ACM driver does only use the first two
USB interfaces (modem data & control). The AT Port, Diagnostic and NMEA
interfaces are left to the USB serial driver.
Signed-off-by: Michael Ulbricht <michael.ulbricht@systec-electronic.com>
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Power control of hub ports target the CLEAR_FEATURE and SET_FEATURE
requests to ports, not to the hub. Fix the hub control function to
detect the request correctly.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ret variable is not initialized in all code paths of the
ohci_jz4740_hub_control function. Fix it.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To avoid memory fetch underflows with larger USB transfers, Tegra SoCs
need txfill_tuning's txfifothresh register field set to a non-default
value. Add a custom reset override in order to set this up.
These values are recommended practice for all Tegra chips. However,
I've only noticed practical problems when not setting them this way on
systems using Tegra124. Hence, CC: stable only for recent kernels which
actually support Tegra124.
Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Patch 'b8efdaf USB: EHCI: add check for wakeup/suspend race'
adds a check for possible race between suspend and wakeup interrupt,
and thereby it returns -EBUSY as error code if there's a wakeup
interrupt.
So the platform host controller should not proceed further with
its suspend callback, rather should return immediately to avoid
powering down the essential things, like phy.
Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Patch 'b8efdaf USB: EHCI: add check for wakeup/suspend race'
adds a check for possible race between suspend and wakeup interrupt,
and thereby it returns -EBUSY as error code if there's a wakeup
interrupt.
So the platform host controller should not proceed further with
its suspend callback, rather should return immediately to avoid
powering down the essential things, like phy.
Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The code in hcd-pci.c that matches up EHCI controllers with their
companion UHCI or OHCI controllers assumes that the private drvdata
fields don't get set too early. However, it turns out that this field
gets set by usb_create_hcd(), before hcd-pci expects it, and this can
result in a crash when two controllers are probed in parallel (as can
happen when a new controller card is hotplugged).
The companions_rwsem lock was supposed to prevent this sort of thing,
but usb_create_hcd() is called outside the scope of the rwsem.
A simple solution is to check that the root-hub pointer has been
initialized as well as the drvdata field. This doesn't happen until
usb_add_hcd() is called; that call and the check are both protected by
the rwsem.
This patch should be applied to stable kernels from 3.10 onward.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Stefani Seibold <stefani@seibold.net>
Tested-by: Stefani Seibold <stefani@seibold.net>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If acm_submit_read_urbs() fails in acm_port_activate(), error handling
code calls usb_autopm_put_interface() while it is already called
before acm_submit_read_urbs(). The patch reorganizes error handling code
to avoid double decrement of USB interface's PM-usage counter.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix regression introduced by commit 8e493ca176 ("USB: usb_wwan: fix
bulk-urb allocation") by making sure to require both bulk-in and out
endpoints during port probe.
The original option driver (which usb_wwan is based on) was written
under the assumption that either endpoint could be missing, but
evidently this cannot have been tested properly. Specifically, it would
handle opening a device without bulk-in (but would blow up during resume
which was implemented later), but not a missing bulk-out in write()
(although it is handled in some places such as write_room()).
Fortunately (?), the driver also got the test for missing endpoints
wrong so the urbs were in fact always allocated, although they would be
initialised using the wrong endpoint address (0) and any submission of
such an urb would fail.
The commit mentioned above fixed the test for missing endpoints but
thereby exposed the other bugs which would now generate null-pointer
exceptions rather than failed urb submissions.
The regression was introduced in v3.7, but the offending commit was also
marked for stable.
Reported-by: Rafał Miłecki <zajec5@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Tested-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 1ebca9dad5.
This device was erroneously added to the sierra driver even though it's
not a Sierra device and was already handled by the option driver.
Cc: Richard Farina <sidhayn@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Zero-initializing ether_type masked that the ether type would never be
obtained for 8021x packets and the comparison against eapol_type
would always fail.
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Zero-initializing ether_type masked that the ether type would never be
obtained for 8021x packets and the comparison against eapol_type
would always fail.
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
chameleon_parse_cells() bails out if chameleon descriptor type is
invalid but does not free the storage 'header' points to.
Signed-off-by: Christoph Jaeger <christophjaeger@linux.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@men.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Ignore client writing state during cb completion to fix a memory
leak.
When moving cbs to the completion list we should not look at
writing_state as this state can be already overwritten by next
write, the fact that a cb is on the write waiting list means
that it was already written to the HW and we can safely complete it.
Same pays for wait in poll handler, we do not have to check the state
wake is done after completion list processing.
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
NM and SPS FW types that may run on ME device on server platforms
do not have valid MEI/HECI interface and driver should not
be bound to it as this might lead to system hung.
In practice not all BIOSes effectively hide such devices from the
OS and in some cases it is not possible.
We determine FW type by examining Host FW status registers in order to
unbind the driver.
In this patch we are adding check for ME on Cougar Point, Lynx Point
Devices
Cc: stable <stable@vger.kernel.org> # 3.10+
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This buffer over was detected using static analysis:
drivers/isdn/icn/icn.c:1325 icn_command()
error: format string overflow. buf_size: 60 length: 98
The calculation for the length of the string is off because it assumes
that the dial[] buffer holds a 50 character string, but actually it is
at most 31 characters and NUL. I have removed the dial[] buffer because
it isn't needed.
The maximum length of the string is actually 79 characters and a NUL. I
have made the cbuf[] array large enough to hold it and changed the
sprintf() to an snprintf() as a further safety enhancement.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Because the netdevice may be in another netns than the i/o netns, we should
use the i/o netns instead of dev_net(dev).
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Because the netdevice may be in another netns than the i/o netns, we should
use the i/o netns instead of dev_net(dev).
Note that netdev_priv(dev) cannot bu NULL, hence we can remove these useless
checks.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Because the netdevice may be in another netns than the i/o netns, we should
use the i/o netns instead of dev_net(dev).
The variable 'tunnel' was used only to get 'itn', hence to simplify code I
remove it and use 't' instead.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make sys_recv a first class citizen by using the SYSCALL_DEFINEx
macro. Besides being cleaner this will also generate meta data
for the system call so tracing tools like ftrace or LTTng can
resolve this system call.
Signed-off-by: Jan Glauber <jan.glauber@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When being used in a multithreaded application there were problems
with memory pages/cachelines accessed by multiple threads/cpus at the
same time, while doing DMA transfers to/from those. To avoid such
situations this fix is creating a copy of the first and the last page
if it is not fully used. The data is copied from user-space into those
pages and results are copied back when the DDCB-request is
successfully finished.
Signed-off-by: Frank Haverkamp <haver@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rc is not initialized, so genwqe_finish_queue() either returns -EIO or
garbage. Fortunately the return is not being checked by any callers,
so this has not yet caused any problems. Even so, it makes sense to
fix this small bug in case is is checked in future.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Frank Haverkamp <haver@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Needed to add wmb() before we send the DDCB for execution.
Without the syncronizing it failed on System p.
Signed-off-by: Frank Haverkamp <haver@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In addition to the two flash partitions we used so far, there is a 3rd
one which is enabled for usage by this fix.
Signed-off-by: Frank Haverkamp <haver@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Guenter Roeck says:
====================
net: mdio-gpio enhancements
The following series of patches adds support for active-low gpio pins
as well as for systems with separate MDI and MDO pins to the mdio-gpio
driver.
A board using those features is based on a COM Express CPU board.
The COM Express standard supports GPIO pins on its connector,
with one caveat: The pins on the connector have fixed direction
and are hard configured either as input or output pins.
The COM Express Design Guide [1] provides additional details.
The hardware uses three of the GPO/GPI pins from the COM Express board
to drive an MDIO bus. Connectivity between GPI/GPO pins and the MDIO bus
is as follows.
GPI2 --------------------+------------ MDIO
|
+--------+ |
GPO2 ---+---G | |
| | | |
4.7k | 2N7002 D---+
| | |
+---S |
| +--------+
GND
GPO1 --------------------------------- MDC
To support this hardware, two extensions to the driver were necessary.
- Due to the FET in the MDO path (GPO2), the MDO signal is inverted.
The driver therefore has to support active-low GPIO pins.
- The MDIO signal must be separated into MDI and MDO.
Those changes are implemented in patch 2/3 and 3/3.
Patch 1/3 simplifies the error path and thus the subsequent
patches.
[1] http://www.picmg.org/pdf/picmg_comdg_100.pdf
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This is for a system with fixed assignments of input and output pins
(various variants of Kontron COMe).
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some systems using mdio-gpio may use active-low gpio pins
(eg with inverters or FETs connected to all or some of the
gpio pins).
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This simplifies error path and deinit/removal functions.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Chris Healy <cphealy@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cong Wang says:
====================
ipv4: fix flowi4_iif for input routing
This patchset fixes ->flowi4_iif for input routing and rp filter,
based on suggestion from Julian. See per patch for details.
v1 -> v2:
* merge the first two patches into one
* fix fib_check_nh() too
* add this cover letter
====================
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
In my special case, when a packet is redirected from veth0 to lo,
its skb->dev->ifindex would be LOOPBACK_IFINDEX. Meanwhile we
pass the hard-coded LOOPBACK_IFINDEX to fib_validate_source()
in ip_route_input_slow(). This would cause the following check
in fib_validate_source() fail:
(dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))
when rp_filter is disabeld on loopback. As suggested by Julian,
the caller should pass 0 here so that we will not end up by
calling __fib_validate_source().
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As suggested by Julian:
Simply, flowi4_iif must not contain 0, it does not
look logical to ignore all ip rules with specified iif.
because in fib_rule_match() we do:
if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
goto out;
flowi4_iif should be LOOPBACK_IFINDEX by default.
We need to move LOOPBACK_IFINDEX to include/net/flow.h:
1) It is mostly used by flowi_iif
2) Fix the following compile error if we use it in flow.h
by the patches latter:
In file included from include/linux/netfilter.h:277:0,
from include/net/netns/netfilter.h:5,
from include/net/net_namespace.h:21,
from include/linux/netdevice.h:43,
from include/linux/icmpv6.h:12,
from include/linux/ipv6.h:61,
from include/net/ipv6.h:16,
from include/linux/sunrpc/clnt.h:27,
from include/linux/nfs_fs.h:30,
from init/do_mounts.c:32:
include/net/flow.h: In function ‘flowi4_init_output’:
include/net/flow.h:84:32: error: ‘LOOPBACK_IFINDEX’ undeclared (first use in this function)
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The mlx4 driver is triggering schedules while atomic inside
mlx4_en_netpoll:
spin_lock_irqsave(&cq->lock, flags);
napi_synchronize(&cq->napi);
^^^^^ msleep here
mlx4_en_process_rx_cq(dev, cq, 0);
spin_unlock_irqrestore(&cq->lock, flags);
This was part of a patch by Alexander Guller from Mellanox in 2011,
but it still isn't upstream.
Signed-off-by: Chris Mason <clm@fb.com>
cc: stable@vger.kernel.org
Acked-By: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
All device_schedule_callback_owner() users are converted to use
device_remove_file_self(). Remove now unused
{sysfs|device}_schedule_callback_owner().
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernfs_iattrs is allocated lazily when operations which require it
take place; unfortunately, the lazy allocation and returning weren't
properly synchronized and when there are multiple concurrent
operations, it might end up returning kernfs_iattrs which hasn't
finished initialization yet or different copies to different callers.
Fix it by synchronizing with a mutex. This can be smarter with memory
barriers but let's go there if it actually turns out to be necessary.
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/g/533ABA32.9080602@oracle.com
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Cc: stable@vger.kernel.org # 3.14
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 9e30cc9595 removed an internal mount. This
has the side-effect that rootfs now has FSID 0. Many
userspace utilities assume that st_dev in struct stat
is never 0, so this change breaks a number of tools in
early userspace.
Since we don't know how many userspace programs are affected,
make sure that FSID is at least 1.
References: http://article.gmane.org/gmane.linux.kernel/1666905
References: http://permalink.gmane.org/gmane.linux.utilities.util-linux-ng/8557
Cc: 3.14 <stable@vger.kernel.org>
Signed-off-by: Thomas Bächler <thomas@archlinux.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Tested-by: Alexandre Demers <alexandre.f.demers@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In SMB2_set_compression(), the "res_key" variable is only initialized to NULL
and later kfreed. It is therefore useless and should be removed.
Found with the following semantic patch:
<smpl>
@@
identifier foo;
identifier f;
type T;
@@
* f(...) {
...
* T *foo = NULL;
... when forall
when != foo
* kfree(foo);
...
}
</smpl>
Signed-off-by: Cyril Roelandt <tipecaml@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
xfstest 020 detected a problem with cifs xattr handling. When a file
had an empty xattr list, we returned success (with an empty xattr value)
on query of particular xattrs rather than returning ENODATA.
This patch fixes it so that query of an xattr returns ENODATA when the
xattr list is empty for the file.
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Problem reported in Red Hat bz 1040329 for strict writes where we cache
only when we hold oplock and write direct to the server when we don't.
When we receive an oplock break, we first change the oplock value for
the inode in cifsInodeInfo->oplock to indicate that we no longer hold
the oplock before we enqueue a task to flush changes to the backing
device. Once we have completed flushing the changes, we return the
oplock to the server.
There are 2 ways here where we can have data corruption
1) While we flush changes to the backing device as part of the oplock
break, we can have processes write to the file. These writes check for
the oplock, find none and attempt to write directly to the server.
These direct writes made while we are flushing from cache could be
overwritten by data being flushed from the cache causing data
corruption.
2) While a thread runs in cifs_strict_writev, the machine could receive
and process an oplock break after the thread has checked the oplock and
found that it allows us to cache and before we have made changes to the
cache. In that case, we end up with a dirty page in cache when we
shouldn't have any. This will be flushed later and will overwrite all
subsequent writes to the part of the file represented by this page.
Before making any writes to the server, we need to confirm that we are
not in the process of flushing data to the server and if we are, we
should wait until the process is complete before we attempt the write.
We should also wait for existing writes to complete before we process
an oplock break request which changes oplock values.
We add a version specific downgrade_oplock() operation to allow for
differences in the oplock values set for the different smb versions.
Cc: stable@vger.kernel.org
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
This makes the follow-on check for psta != NULL pointless and makes
the whole exercise rather pointless. This is another case of why
blindly zero-initializing variables when they are declared is bad.
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mmapping a comedi data buffer with lockdep checking enabled produced the
following kernel debug messages:
======================================================
[ INFO: possible circular locking dependency detected ]
3.5.0-rc3-ija1+ #9 Tainted: G C
-------------------------------------------------------
comedi_test/4160 is trying to acquire lock:
(&dev->mutex#2){+.+.+.}, at: [<ffffffffa00313f4>] comedi_mmap+0x57/0x1d9 [comedi]
but task is already holding lock:
(&mm->mmap_sem){++++++}, at: [<ffffffff810c96fe>] vm_mmap_pgoff+0x41/0x76
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&mm->mmap_sem){++++++}:
[<ffffffff8106d0e8>] lock_acquire+0x97/0x105
[<ffffffff810ce3bc>] might_fault+0x6d/0x90
[<ffffffffa0031ffb>] do_devinfo_ioctl.isra.7+0x11e/0x14c [comedi]
[<ffffffffa003227f>] comedi_unlocked_ioctl+0x256/0xe48 [comedi]
[<ffffffff810f7fcd>] vfs_ioctl+0x18/0x34
[<ffffffff810f87fd>] do_vfs_ioctl+0x382/0x43c
[<ffffffff810f88f9>] sys_ioctl+0x42/0x65
[<ffffffff81415c62>] system_call_fastpath+0x16/0x1b
-> #0 (&dev->mutex#2){+.+.+.}:
[<ffffffff8106c528>] __lock_acquire+0x101d/0x1591
[<ffffffff8106d0e8>] lock_acquire+0x97/0x105
[<ffffffff8140c894>] mutex_lock_nested+0x46/0x2a4
[<ffffffffa00313f4>] comedi_mmap+0x57/0x1d9 [comedi]
[<ffffffff810d5816>] mmap_region+0x281/0x492
[<ffffffff810d5c92>] do_mmap_pgoff+0x26b/0x2a7
[<ffffffff810c971a>] vm_mmap_pgoff+0x5d/0x76
[<ffffffff810d493f>] sys_mmap_pgoff+0xc7/0x10d
[<ffffffff81004d36>] sys_mmap+0x16/0x20
[<ffffffff81415c62>] system_call_fastpath+0x16/0x1b
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&mm->mmap_sem);
lock(&dev->mutex#2);
lock(&mm->mmap_sem);
lock(&dev->mutex#2);
*** DEADLOCK ***
To avoid the circular dependency, just try to get the lock in
`comedi_mmap()` instead of blocking. Since the comedi device's main mutex
is heavily used, do a down-read of its `attach_lock` rwsemaphore
instead. Trying to down-read `attach_lock` should only fail if
some task has down-write locked it, and that is only done while the
comedi device is being attached to or detached from a low-level hardware
device.
Unfortunately, acquiring the `attach_lock` doesn't prevent another
task replacing the comedi data buffer we are trying to mmap. The
details of the buffer are held in a `struct comedi_buf_map` and pointed
to by `s->async->buf_map` where `s` is the comedi subdevice whose buffer
we are trying to map. The `struct comedi_buf_map` is already reference
counted with a `struct kref`, so we can stop it being freed prematurely.
Modify `comedi_mmap()` to call new function
`comedi_buf_map_from_subdev_get()` to read the subdevice's current
buffer map pointer and increment its reference instead of accessing
`async->buf_map` directly. Call `comedi_buf_map_put()` to decrement the
reference once the buffer map structure has been dealt with. (Note that
`comedi_buf_map_put()` does nothing if passed a NULL pointer.)
`comedi_buf_map_from_subdev_get()` checks the subdevice's buffer map
pointer has been set and the buffer map has been initialized enough for
`comedi_mmap()` to deal with it (specifically, check the `n_pages`
member has been set to a non-zero value). If all is well, the buffer
map's reference is incremented and a pointer to it is returned. The
comedi subdevice's spin-lock is used to protect the checks. Also use
the spin-lock in `__comedi_buf_alloc()` and `__comedi_buf_free()` to
protect changes to the subdevice's buffer map structure pointer and the
buffer map structure's `n_pages` member. (This checking of `n_pages` is
a bit clunky and I [Ian Abbott] plan to deal with it in the future.)
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: <stable@vger.kernel.org> # 3.14.x, 3.15.x
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/rtl8723au/core/rtw_wlan_util.c: In function ‘WMMOnAssocRsp23a’:
drivers/staging/rtl8723au/core/rtw_wlan_util.c:684: warning: ‘change_inx’ may be used uninitialized in this function
Depending on the uninitialized data on the stack, the array may not be
sorted correctly.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
