I got a deadloop report while doing device(ds2482) add/remove test:
[ 162.241881] w1_master_driver w1_bus_master1: Waiting for w1_bus_master1 to become free: refcnt=1.
[ 163.272251] w1_master_driver w1_bus_master1: Waiting for w1_bus_master1 to become free: refcnt=1.
[ 164.296157] w1_master_driver w1_bus_master1: Waiting for w1_bus_master1 to become free: refcnt=1.
...
__w1_remove_master_device() can't return, because the dev->refcnt is not zero.
w1_add_master_device() |
w1_alloc_dev() |
atomic_set(&dev->refcnt, 2) |
kthread_run() |
|__w1_remove_master_device()
| kthread_stop()
// KTHREAD_SHOULD_STOP is set, |
// threadfn(w1_process) won't be |
// called. |
kthread() |
| // refcnt will never be 0, it's deadloop.
| while (atomic_read(&dev->refcnt)) {...}
After calling w1_add_master_device(), w1_process() is not really
invoked, before w1_process() starting, if kthread_stop() is called
in __w1_remove_master_device(), w1_process() will never be called,
the refcnt can not be decreased, then it causes deadloop in remove
function because of non-zero refcnt.
We need to make sure w1_process() is really started, so move the
set refcnt into w1_process() to fix this problem.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221205080434.3149205-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 3 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [kishon] [vijay] [abraham]
[i] [kishon]@[ti] [com] this program is distributed in the hope that
it will be useful but without any warranty without even the implied
warranty of merchantability or fitness for a particular purpose see
the gnu general public license for more details
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [graeme] [gregory]
[gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
[kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
[hk] [hemahk]@[ti] [com] this program is distributed in the hope
that it will be useful but without any warranty without even the
implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1105 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Like other subsystems we should be able to define slave devices outside
of the w1 directory. To do this we move public facing interface
definitions to include/linux/w1.h and rename the internal definition
file to w1_internal.h.
As w1_family.h and w1_int.h contained almost entirely public
driver interface definitions we simply removed these files and
moved the remaining definitions into w1_internal.h.
With this we can now start to move slave devices out of w1/slaves and
into the subsystem based on the function they implement, again like
other drivers.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Reviewed-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Structures and functions should be ordered such that forward declaration
use is minimized.
MODULE_* macros should immediately follow the structures and functions
upon which they act.
Remaining MODULE_* macros should be at the end of the file in
alphabetical order.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The only use of assert() is in matrox_w1.c and is used to check the input
to probe() from the PCI subsystem for NULL values, these are guaranteed
to be populated and no other PCI driver makes this check, remove this.
As this was the only definition in w1_log.h, remove this also.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Remove filename from file, this is not done anymore as it doesn't
add anything and usually is incorrect as filename change often.
Also shorten the GPL to the more common address-less version and
remove excess white-space.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, memsetting and kfreeing the device is bad behaviour. The
device will have a reference count of 1 and hence can cause trouble
because it has kfree'd. Proper way to handle a failed device_register is
to call put_device right after it fails.
Signed-off-by: Levente Kurusa <levex@linux.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch replaces all calls to the "printk" function within the main "w1"
directory by calls to the appropriate "pr_*" function thus addressing
the following warning generated by the checkpatch script:
WARNING: Prefer [subsystem eg: netdev]_err([subsystem]dev, ...
then dev_err(dev, ... then pr_err(... to printk(KERN_ERR ...
Signed-off-by: Fjodor Schelichow <fjodor.schelichow@hotmail.com>
Signed-off-by: Roman Sommer <romsom2@yahoo.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replace spaces at beginning of the string with tabs, and replace foo * bar with foo *bar in a pointer declaration.
Signed-off-by: Thomas Wood <tommyandrena@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
w1_process_callbacks() expects to be called with dev->list_mutex held,
but it is the fact only in w1_process(). __w1_remove_master_device()
calls w1_process_callbacks() after it releases list_mutex.
The patch fixes __w1_remove_master_device() to acquire list_mutex
for w1_process_callbacks().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: David Fries <david@fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: stable <stable@vger.kernel.org> # 3.15
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Switch the code documentation format style to DocBook format, enable
DocBook documentation generation, and fix some comments.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Netlink is a socket interface and is expected to be asynchronous.
Clients can now make w1 requests without blocking by making use of the
w1_master thread to process netlink commands which was previously only
used for doing an automatic bus search.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Before 63706172f3 "rework kthread_stop()" kthread_should_stop()
always returned false when called from a non-kthread task, after it
would oops as a non-kthread didn't have that structure and netlink was
calling search from a thread which wasn't a kthread. 9d1817cab2
"w1: fix oops when w1_search is called from netlink connector",
modified the code to avoid calling kthread_stop from a netlink thread.
Introduce a w1_master flag and bit W1_ABORT_SEARCH to identify abort
to cleanly support both kthread and netlink search abort. A search
can take seconds to run, so it is important to abort early if the
hardware is removed in the middle of a search.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Marcin Jurkowski <marcin1j@gmail.com>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Sven Geggus <lists@fuchsschwanzdomain.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 'mutex' in struct w1_master is use for two very different
purposes.
Firstly it protects various data structures such as the list of all
slaves.
Secondly it protects the w1 buss against concurrent accesses.
This can lead to deadlocks when the ->probe code called while adding a
slave needs to talk on the bus, as is the case for power_supply
devices.
ds2780 and ds2781 drivers contain a work around to track which
process hold the lock simply to avoid this deadlock. bq27000 doesn't
have that work around and so deadlocks.
There are other possible deadlocks involving sysfs.
When removing a device the sysfs s_active lock is held, so the lock
that protects the slave list must take precedence over s_active.
However when access power_supply attributes via sysfs, the s_active
lock must take precedence over the lock that protects accesses to
the bus.
So to avoid deadlocks between w1 slaves and sysfs, these must be
two separate locks. Making them separate means that the work around
in ds2780 and ds2781 can be removed.
So this patch:
- adds a new mutex: "bus_mutex" which serialises access to the bus.
- takes in mutex in w1_search and ds1wm_search while they access
the bus for searching. The mutex is dropped before calling the
callback which adds the slave.
- changes all slaves to use bus_mutex instead of mutex to
protect access to the bus
- removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the
related code from drivers/power/ds278[01]_battery.c which
calls them.
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
It doesn't need the full module.h but it was getting moduleparam.h
from the fact that module.h was everywhere.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Give these files export.h so that they can reliably get the EXPORT_SYMBOL
and THIS_MODULE macros in the future, once module.h isn't implicitly
everywhere.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
