Pull x86 build changes from Ingo Molnar:
"Two small changes"
* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, defconfig: Add DEVTMPFS and DEVTMPFS_MOUNT to *86*_defconfig
x86, build: move build output statistics away from stderr
Pull x86 user access changes from Ingo Molnar:
"This tree contains two copy_[from/to]_user() build time checking
changes/enhancements from Jan Beulich.
The desired outcome is to get better compiler warnings with
CONFIG_DEBUG_STRICT_USER_COPY_CHECKS=y, to keep people from
introducing bugs such as overflows and information leaks"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Unify copy_to_user() and add size checking to it
x86: Unify copy_from_user() size checking
Pull x86/apic fix from Ingo Molnar:
"A single fix to the IO-APIC / local-APIC shutdown sequence"
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apic: Disable I/O APIC before shutdown of the local APIC
Pull timer changes from Ingo Molnar:
"Main changes in this cycle were:
- Updated full dynticks support.
- Event stream support for architected (ARM) timers.
- ARM clocksource driver updates.
- Move arm64 to using the generic sched_clock framework & resulting
cleanup in the generic sched_clock code.
- Misc fixes and cleanups"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
x86/time: Honor ACPI FADT flag indicating absence of a CMOS RTC
clocksource: sun4i: remove IRQF_DISABLED
clocksource: sun4i: Report the minimum tick that we can program
clocksource: sun4i: Select CLKSRC_MMIO
clocksource: Provide timekeeping for efm32 SoCs
clocksource: em_sti: convert to clk_prepare/unprepare
time: Fix signedness bug in sysfs_get_uname() and its callers
timekeeping: Fix some trivial typos in comments
alarmtimer: return EINVAL instead of ENOTSUPP if rtcdev doesn't exist
clocksource: arch_timer: Do not register arch_sys_counter twice
timer stats: Add a 'Collection: active/inactive' line to timer usage statistics
sched_clock: Remove sched_clock_func() hook
arch_timer: Move to generic sched_clock framework
clocksource: tcb_clksrc: Remove IRQF_DISABLED
clocksource: tcb_clksrc: Improve driver robustness
clocksource: tcb_clksrc: Replace clk_enable/disable with clk_prepare_enable/disable_unprepare
clocksource: arm_arch_timer: Use clocksource for suspend timekeeping
clocksource: dw_apb_timer_of: Mark a few more functions as __init
clocksource: Put nodes passed to CLOCKSOURCE_OF_DECLARE callbacks centrally
arm: zynq: Enable arm_global_timer
...
fix a trivial copy'n'paste error in the regmap kerneldoc, s/write/read/
for the regmap_read(), regmap_raw_read() and regmap_bulk_read() routines
Signed-off-by: Gerhard Sittig <gsi@denx.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Pull scheduler changes from Ingo Molnar:
"The main changes in this cycle are:
- (much) improved CONFIG_NUMA_BALANCING support from Mel Gorman, Rik
van Riel, Peter Zijlstra et al. Yay!
- optimize preemption counter handling: merge the NEED_RESCHED flag
into the preempt_count variable, by Peter Zijlstra.
- wait.h fixes and code reorganization from Peter Zijlstra
- cfs_bandwidth fixes from Ben Segall
- SMP load-balancer cleanups from Peter Zijstra
- idle balancer improvements from Jason Low
- other fixes and cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits)
ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED
stop_machine: Fix race between stop_two_cpus() and stop_cpus()
sched: Remove unnecessary iteration over sched domains to update nr_busy_cpus
sched: Fix asymmetric scheduling for POWER7
sched: Move completion code from core.c to completion.c
sched: Move wait code from core.c to wait.c
sched: Move wait.c into kernel/sched/
sched/wait: Fix __wait_event_interruptible_lock_irq_timeout()
sched: Avoid throttle_cfs_rq() racing with period_timer stopping
sched: Guarantee new group-entities always have weight
sched: Fix hrtimer_cancel()/rq->lock deadlock
sched: Fix cfs_bandwidth misuse of hrtimer_expires_remaining
sched: Fix race on toggling cfs_bandwidth_used
sched: Remove extra put_online_cpus() inside sched_setaffinity()
sched/rt: Fix task_tick_rt() comment
sched/wait: Fix build breakage
sched/wait: Introduce prepare_to_wait_event()
sched/wait: Add ___wait_cond_timeout() to wait_event*_timeout() too
sched: Remove get_online_cpus() usage
sched: Fix race in migrate_swap_stop()
...
Pull perf updates from Ingo Molnar:
"As a first remark I'd like to note that the way to build perf tooling
has been simplified and sped up, in the future it should be enough for
you to build perf via:
cd tools/perf/
make install
(ie without the -j option.) The build system will figure out the
number of CPUs and will do a parallel build+install.
The various build system inefficiencies and breakages Linus reported
against the v3.12 pull request should now be resolved - please
(re-)report any remaining annoyances or bugs.
Main changes on the perf kernel side:
* Performance optimizations:
. perf ring-buffer code optimizations, by Peter Zijlstra
. perf ring-buffer code optimizations, by Oleg Nesterov
. x86 NMI call-stack processing optimizations, by Peter Zijlstra
. perf context-switch optimizations, by Peter Zijlstra
. perf sampling speedups, by Peter Zijlstra
. x86 Intel PEBS processing speedups, by Peter Zijlstra
* Enhanced hardware support:
. for Intel Ivy Bridge-EP uncore PMUs, by Zheng Yan
. for Haswell transactions, by Andi Kleen, Peter Zijlstra
* Core perf events code enhancements and fixes by Oleg Nesterov:
. for uprobes, if fork() is called with pending ret-probes
. for uprobes platform support code
* New ABI details by Andi Kleen:
. Report x86 Haswell TSX transaction abort cost as weight
Main changes on the perf tooling side (some of these tooling changes
utilize the above kernel side changes):
* 'perf report/top' enhancements:
. Convert callchain children list to rbtree, greatly reducing the
time taken for callchain processing, from Namhyung Kim.
. Add new COMM infrastructure, further improving histogram
processing, from Frédéric Weisbecker, one fix from Namhyung Kim.
. Add /proc/kcore based live-annotation improvements, including
build-id cache support, multi map 'call' instruction navigation
fixes, kcore address validation, objdump workarounds. From
Adrian Hunter.
. Show progress on histogram collapsing, that can take a long
time, from Namhyung Kim.
. Add --max-stack option to limit callchain stack scan in 'top'
and 'report', improving callchain processing when reducing the
stack depth is an option, from Waiman Long.
. Add new option --ignore-vmlinux for perf top, from Willy
Tarreau.
* 'perf trace' enhancements:
. 'perf trace' now can can use a 'perf probe' dynamic tracepoints
to hook into the userspace -> kernel pathname copy so that it
can map fds to pathnames without reading /proc/pid/fd/ symlinks.
From Arnaldo Carvalho de Melo.
. Show VFS path associated with fd in live sessions, using a
'vfs_getname' 'perf probe' created dynamic tracepoint or by
looking at /proc/pid/fd, from Arnaldo Carvalho de Melo.
. Add 'trace' beautifiers for lots of syscall arguments, from
Arnaldo Carvalho de Melo.
. Implement more compact 'trace' output by suppressing zeroed
args, from Arnaldo Carvalho de Melo.
. Show thread COMM by default in 'trace', from Arnaldo Carvalho de
Melo.
. Add option to show full timestamp in 'trace', from David Ahern.
. Add 'record' command in 'trace', to record raw_syscalls:*, from
David Ahern.
. Add summary option to dump syscall statistics in 'trace', from
David Ahern.
. Improve error messages in 'trace', providing hints about system
configuration steps needed for using it, from Ramkumar
Ramachandra.
. 'perf trace' now emits hints as to why tracing is not possible,
helping the user to setup the system to allow tracing in the
desired permission granularity, telling if the problem is due to
debugfs not being mounted or with not enough permission for
!root, /proc/sys/kernel/perf_event_paranoit value, etc. From
Arnaldo Carvalho de Melo.
* 'perf record' enhancements:
. Check maximum frequency rate for record/top, emitting better
error messages, from Jiri Olsa.
. 'perf record' code cleanups, from David Ahern.
. Improve write_output error message in 'perf record', from Adrian
Hunter.
. Allow specifying B/K/M/G unit to the --mmap-pages arguments,
from Jiri Olsa.
. Fix command line callchain attribute tests to handle the new
-g/--call-chain semantics, from Arnaldo Carvalho de Melo.
* 'perf kvm' enhancements:
. Disable live kvm command if timerfd is not supported, from David
Ahern.
. Fix detection of non-core features, from David Ahern.
* 'perf list' enhancements:
. Add usage to 'perf list', from David Ahern.
. Show error in 'perf list' if tracepoints not available, from
Pekka Enberg.
* 'perf probe' enhancements:
. Support "$vars" meta argument syntax for local variables,
allowing asking for all possible variables at a given probe
point to be collected when it hits, from Masami Hiramatsu.
* 'perf sched' enhancements:
. Address the root cause of that 'perf sched' stack initialization
build slowdown, by programmatically setting a big array after
moving the global variable back to the stack. Fix from Adrian
Hunter.
* 'perf script' enhancements:
. Set up output options for in-stream attributes, from Adrian
Hunter.
. Print addr by default for BTS in 'perf script', from Adrian
Juntmer
* 'perf stat' enhancements:
. Improved messages when doing profiling in all or a subset of
CPUs using a workload as the session delimitator, as in:
'perf stat --cpu 0,2 sleep 10s'
from Arnaldo Carvalho de Melo.
. Add units to nanosec-based counters in 'perf stat', from David
Ahern.
. Remove bogus info when using 'perf stat' -e cycles/instructions,
from Ramkumar Ramachandra.
* 'perf lock' enhancements:
. 'perf lock' fixes and cleanups, from Davidlohr Bueso.
* 'perf test' enhancements:
. Fixup PERF_SAMPLE_TRANSACTION handling in sample synthesizing
and 'perf test', from Adrian Hunter.
. Clarify the "sample parsing" test entry, from Arnaldo Carvalho
de Melo.
. Consider PERF_SAMPLE_TRANSACTION in the "sample parsing" test,
from Arnaldo Carvalho de Melo.
. Memory leak fixes in 'perf test', from Felipe Pena.
* 'perf bench' enhancements:
. Change the procps visible command-name of invididual benchmark
tests plus cleanups, from Ingo Molnar.
* Generic perf tooling infrastructure/plumbing changes:
. Separating data file properties from session, code
reorganization from Jiri Olsa.
. Fix version when building out of tree, as when using one of
these:
$ make help | grep perf
perf-tar-src-pkg - Build perf-3.12.0.tar source tarball
perf-targz-src-pkg - Build perf-3.12.0.tar.gz source tarball
perf-tarbz2-src-pkg - Build perf-3.12.0.tar.bz2 source tarball
perf-tarxz-src-pkg - Build perf-3.12.0.tar.xz source tarball
$
from David Ahern.
. Enhance option parse error message, showing just the help lines
of the options affected, from Namhyung Kim.
. libtraceevent updates from upstream trace-cmd repo, from Steven
Rostedt.
. Always use perf_evsel__set_sample_bit to set sample_type, from
Adrian Hunter.
. Memory and mmap leak fixes from Chenggang Qin.
. Assorted build fixes for from David Ahern and Jiri Olsa.
. Speed up and prettify the build system, from Ingo Molnar.
. Implement addr2line directly using libbfd, from Roberto Vitillo.
. Separate the GTK support in a separate libperf-gtk.so DSO, that
is only loaded when --gtk is specified, from Namhyung Kim.
. perf bash completion fixes and improvements from Ramkumar
Ramachandra.
. Support for Openembedded/Yocto -dbg packages, from Ricardo
Ribalda Delgado.
And lots and lots of other fixes and code reorganizations that did not
make it into the list, see the shortlog, diffstat and the Git log for
details!"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (300 commits)
uprobes: Fix the memory out of bound overwrite in copy_insn()
uprobes: Fix the wrong usage of current->utask in uprobe_copy_process()
perf tools: Remove unneeded include
perf record: Remove post_processing_offset variable
perf record: Remove advance_output function
perf record: Refactor feature handling into a separate function
perf trace: Don't relookup fields by name in each sample
perf tools: Fix version when building out of tree
perf evsel: Ditch evsel->handler.data field
uprobes: Export write_opcode() as uprobe_write_opcode()
uprobes: Introduce arch_uprobe->ixol
uprobes: Kill module_init() and module_exit()
uprobes: Move function declarations out of arch
perf/x86/intel: Add Ivy Bridge-EP uncore IRP box support
perf/x86/intel/uncore: Add filter support for IvyBridge-EP QPI boxes
perf: Factor out strncpy() in perf_event_mmap_event()
tools/perf: Add required memory barriers
perf: Fix arch_perf_out_copy_user default
perf: Update a stale comment
perf: Optimize perf_output_begin() -- address calculation
...
Pull leftover IRQ fixes from Ingo Molnar:
"Two (minor) fixlets that missed v3.12"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Set the irq thread policy without checking CAP_SYS_NICE
irq: DocBook/genericirq.tmpl: Correct various typos
Pull IRQ changes from Ingo Molnar:
"The biggest change this cycle are the softirq/hardirq stack
interaction and nesting fixes, cleanups and reorganizations from
Frederic. This is the longer followup story to the softirq nesting
fix that is already upstream (commit ded7975475: "irq: Force hardirq
exit's softirq processing on its own stack")"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip: bcm2835: Convert to use IRQCHIP_DECLARE macro
powerpc: Tell about irq stack coverage
x86: Tell about irq stack coverage
irq: Optimize softirq stack selection in irq exit
irq: Justify the various softirq stack choices
irq: Improve a bit softirq debugging
irq: Optimize call to softirq on hardirq exit
irq: Consolidate do_softirq() arch overriden implementations
x86/irq: Correct comment about i8259 initialization
Pull RCU updates from Ingo Molnar:
"The main RCU changes in this cycle are:
- Idle entry/exit changes, to throttle callback execution and other
refinements to speed up kbuild, primarily to address performance
issues located by Tibor Billes.
- Grace-period related changes, primarily to aid in debugging,
inspired by an -rt debugging session.
- Code reorganization moving RCU's source files into its own
kernel/rcu/ directory.
- RCU documentation updates
- Miscellaneous fixes.
Note, the following commit:
5c889690aa mm: Place preemption point in do_mlockall() loop
is identical to the commit already in your tree via email:
22356f447c mm: Place preemption point in do_mlockall() loop
[ Your version of the changelog nicely demonstrates it how kernel oops
messages should be trimmed properly :-/ ]"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
rcu: Move RCU-related source code to kernel/rcu directory
rcu: Fix occurrence of "the the" in checklist.txt
kthread: Add pointer to vmstat-avoidance patch
rcu: Update stall-warning documentation
rcu: Consistent rcu_is_watching() naming
rcu: Change EXPORT_SYMBOL() to EXPORT_SYMBOL_GPL()
rcu: Is it safe to enter an RCU read-side critical section?
rcu: Throttle invoke_rcu_core() invocations due to non-lazy callbacks
rcu: Throttle rcu_try_advance_all_cbs() execution
rcu: Remove redundant code from rcu_cleanup_after_idle()
rcu: Fix CONFIG_RCU_NOCB_CPU_ALL panic on machines with sparse CPU mask
rcu: Avoid sparse warnings in rcu_nocb_wake trace event
rcu: Track rcu_nocb_kthread()'s sleeping and awakening
rcu: Distinguish between NOCB and non-NOCB rcu_callback trace events
rcu: Add tracing for rcuo no-CBs CPU wakeup handshake
rcu: Add tracing of normal (non-NOCB) grace-period requests
rcu: Add tracing to rcu_gp_kthread()
rcu: Flag lockless access to ->gp_flags with ACCESS_ONCE()
rcu: Prevent spurious-wakeup DoS attack on rcu_gp_kthread()
rcu: Improve grace-period start logic
...
Fixed a coding style issue - removed a blank before a tab.
Signed-off-by: Joachim Adolf Schuetz <jas@catbull.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove unnecessary variable ioctl from get_bypass_info().
As a consequence, this patch removes an assignment to ioctl in an if condition,
reported by checkpatch.pl.
Signed-off-by: Rupert Muchembled <rupert@rmuch.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove unnecessary variable ioctl from do_cmd().
As a consequence, this patch removes an assignment to ioctl in an if condition,
reported by checkpatch.pl.
Signed-off-by: Rupert Muchembled <rupert@rmuch.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
use ether_crc already in kernel and remove local version.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
White space and formatting clean up.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move structures to vnt_private and convert to pointers in
device_init_registers.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since typedef enum __device_init_type is only ever called
in one state.
Remove the typedef from main_usb.c:device_init_registers and
replace with macro values. The other values may be needed later.
Apply cold value to sInitCmd.byInitClass.
Remove if braces and correct formatting within.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Again no apparent user of the driver data field.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The lock sequence of dcon_blank_fb(fb_info->lock ---> console_lock) is against
with the one of console_callback(console_lock ---> fb_info->lock), it'll
lead to a potential dead lock, so reorder the lock sequence of dcon_blank_fb
to avoid the potential dead lock.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Get rid of the needless __GFP_ZERO flag for kzalloc() at oz_elt_stream_create().
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixed the following coding style issues:
Lines 84-91,99-106,275,514: Replaced spaces at the start of the lines
with tabs.
Lines 205,271: Inserted spaces after the commas.
Lines 275,1060,1065: Indented the code with tabs instead of spaces.
Line 275: Inserted spaces around '=' and '<', also moved the trailing
statement on the next line.
Line 512: Removed space between function name and open parenthesis.
Line 839: Removed space after '&'.
Line 853: Removed space after '&'.
Signed-off-by: Aldo Iljazi <mail@aldo.io>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixed the following styling issues:
Line 30:
Removed space before open square bracket '['
Lines 31 to 155:
Moved the commas that were in the start of the lines, to the end of the lines.
Inserted spaces after the commas.
Inserted a one tab indentation to each line.
Signed-off-by: Aldo Iljazi <mail@aldo.io>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If SERIAL_PORT_DFNS isn't present by platform, it need be defined to
"nothing", like the 8250 serial driver does it.
All related macros also need be removed: IRQF_SHARED is defined in
"linux/interrupt.h", others will be defined when related architecture
has SERIAL_PORT_DFNS.
Or it will cause issue (for arc, with allmodconfig):
CC [M] drivers/staging/speakup/serialio.o
drivers/staging/speakup/serialio.c:12:2: error: initializer element is not constant
SERIAL_PORT_DFNS
^
drivers/staging/speakup/serialio.c:12:2: error: (near initialization for 'rs_table[0].baud_base')
drivers/staging/speakup/serialio.c:12:2: error: initializer element is not constant
drivers/staging/speakup/serialio.c:12:2: error: (near initialization for 'rs_table[1].baud_base')
drivers/staging/speakup/serialio.c:12:2: error: initializer element is not constant
drivers/staging/speakup/serialio.c:12:2: error: (near initialization for 'rs_table[2].baud_base')
drivers/staging/speakup/serialio.c:12:2: error: initializer element is not constant
drivers/staging/speakup/serialio.c:12:2: error: (near initialization for 'rs_table[3].baud_base')
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a comedi device is automatically detached by `comedi_auto_unconfig()`
any data buffers associated with subdevices that support asynchronous
commands will be freed. If the buffer is mmapped at the time, bad
things are likely to happen! Prevent this by moving some of the buffer
details from `struct comedi_async` into a new, dynamically allocated,
and kref-counted `struct comedi_buf_map`. This holds a list of pages, a
reference count, and enough information to free the pages. The new
member `buf_map` of `struct comedi_async` points to a `struct
comedi_buf_map` when the buffer size is non-zero.
Provide a new helper function `comedi_buf_is_mapped()` to check whether
an a buffer is mmapped. If it is mmapped, the buffer is not allowed to
be resized and the device is not allowed to be manually detached by the
`COMEDI_DEVCONFIG` ioctl. Provide helper functions
`comedi_buf_map_get()` and `comedi_buf_map_put()` to manipulate the
reference count of the `struct comedi_buf_map`, which will be freed
along with its contents via the 'release' callback of the `kref_put()`
call. The reference count is manipulated by the vma operations and the
mmap file operation.
Now, when the comedi device is automatically detached, the buffer will
be effectively freed by calling `comedi_buf_alloc()` with a new buffer
size of 0. That calls local function `__comedi_buf_free()` which calls
`comedi_buf_map_put()` on the `buf_map` member to free it. It won't
actually be freed until the final 'put'.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
`comedi_read_subdevice()` and `comedi_write_subdevice()` respectively
determine the read and write subdevice to use for a comedi device,
depending on a minor device number passed in. The comedi device has a
main "board" minor device number and may also have dynamically assigned,
subdevice-specific minor device numbers, in a range of numbers shared by
all comedi devices. If the minor device number is within the range of
subdevice-specific minor device numbers, both functions call
`comedi_subdevice_from_minor()` to determine what subdevice is
associated with the minor device number (if any) and then check the
subdevice belongs to the comedi device. Since the subdevice might
belong to a different comedi device, the check is not protected against
the subdevice being freed. Perform the check in
`comedi_subdevice_from_minor()` instead, where it is protected against
the subdevice being freed. Make it return `NULL` if the subdevice does
not belong to the device.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The `comedi_dev_from_minor()` function is no longer used, so remove it.
Calls to it have either been replaced by calls to
`comedi_dev_get_from_minor()` or by using the `private_data` member of
the open file object.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since the `struct comedi_device` should now be protected from being
freed while an open file object is using it, use the `private_data`
member of the `struct file` to point to it. Set it in `comedi_open()`
and use it in the other file operation handlers instead of calling
`comedi_dev_from_minor()` and checking the result.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The functions in "kcomedilib" need to prevent the comedi device being
detached during their operation. This can be done by acquiring either
the main mutex or the "attach lock" semaphore in the `struct
comedi_device`. Use the attach lock when merely checking whether the
device is attached. Use the mutex when processing a comedi instruction.
Also, don't bother trying to manipulate the module use count of
low-level comedi driver in `comedi_open()` and `comedi_close()`. If the
device gets detached while it is "open", we wouldn't be able to
decrement the module use count anyway.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Low-level comedi drivers that use the "kcomedilib" module (currently only
the "comedi_bond" driver) call `comedi_open()` to "open" another comedi
device (not as a file) and `comedi_close()` to "close" it. (Note: these
are the functions exported by the "kcomedilib" module, not the
identically named, statically linked functions in the core "comedi"
module.)
In `comedi_open()`, call `comedi_dev_get_from_minor()` instead of
`comedi_dev_from_minor()` to get the pointer to the `struct
comedi_device` being "opened". This increments its reference count to
prevent it being freed. Call `comedi_dev_put()` if `comedi_open()`
returns `NULL`, and also call it from `comedi_close()`. This decrements
the reference count.
Note that although we now protect against the `struct comedi_device`
being freed, we do not yet protect against it being "detached" while it
is being used. This will be addressed by a later patch.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Call `comedi_dev_get_from_minor()` instead of `comedi_dev_from_minor()`
in the sysfs attribute handler functions to increment the reference of
the `struct comedi_device` during the operation. Call
`comedi_dev_put()` to decrement the reference afterwards.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the seq_file 'show' handler for "/proc/comedi" - `comedi_read()` in
"comedi/proc.c", call `comedi_dev_get_from_minor()` instead of
`comedi_dev_from_minor()` to increment the reference counter for the
`struct comedi_device` while it is being examined. Call
`comedi_dev_put()` to decrement the reference afterwards. Also acquire
the `attach_lock` rwsem while checking whether the device is attached.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change `comedi_driver_unregister()` to call
`comedi_dev_get_from_minor()` instead of `comedi_dev_from_minor()` when
finding devices using the driver. This increments the reference count
to prevent the device being removed while it is being checked to see if
it is attached to the driver. Call `comedi_dev_put()` to decrement the
reference afterwards.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the 'open' file operation handler `comedi_open()` in "comedi_fops.c",
call `comedi_dev_get_from_minor()` instead of `comedi_dev_from_minor()`
to get the pointer to the `struct comedi_device`. This increments the
reference to prevent it being freed. Call `comedi_dev_put()` to
decrement the reference on failure, and also call it from the 'release'
file operation handler `comedi_close()`.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add function `struct comedi_device *comedi_dev_get_from_minor(unsigned
minor)`. This behaves like the existing `comedi_dev_from_minor()`
except that it also increments the `struct kref refcount` member (via
new helper function `comedi_dev_get()`) to prevent it being freed. If
it returns a valid pointer, the caller is responsible for calling
`comedi_dev_put()` to decrement the reference count.
Export `comedi_dev_get_from_minor()` and `comedi_dev_put()` as they will
be used by the "kcomedilib" module in addition to the "comedi" module
itself.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a `struct kref refcount` member to `struct comedi_device` to allow
safe destruction of the comedi device. Only free the comedi device via
the 'release' callback `kref_put()`. Currently, nothing calls
`kref_put()`, so the safe destruction is ineffective, but this will be
addressed by later patches.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 'read' file operation for comedi devices does not use the main mutex
in the `struct comedi_device` to avoid contention with some ioctls that
may take a while to complete. Use the `attach_lock` semaphore to
protect against detachment while the 'read' operation is in progress.
This is a `struct rw_semaphore` and we read-lock it to protect against
device detachment.
Note that `comedi_device_cancel_all()` is called during device
detachment, which cancels any ongoing asynchronous commands. This will
wake up any blocked readers which will then release the `attach_lock`
semaphore and complete the 'read' operation early.
The only time the 'read' file operation does use the main mutex is at
the end of the command when it has to call `do_become_nonbusy()` to mark
the subdevice as no longer busy handling an asynchronous command. To
avoid deadlock, it has to remove the task from the wait queue and
release the `attach_lock` semaphore before acquiring the main mutex. It
then needs to confirm the device is still attached. Unfortunately, we
do not yet protect against a dynamically allocated `struct
comedi_device` being deleted during the operation. This will be
addressed by a later patch.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 'write' file operation for comedi devices does not use the main
mutex in the `struct comedi_device` to avoid contention with some ioctls
that may take a while to complete. Use the `attach_lock` semaphore to
protect against detachment while the 'write' operation is in progress.
This is a `struct rw_semaphore` and we read-lock it to protect against
device detachment.
Note that `comedi_device_cancel_all()` is called during device
detachment, which cancels any ongoing asynchronous commands. This will
wake up any blocked writers which will then release the `attach_lock`
semaphore and complete the 'write' operation early.
The only time the 'write' file operation does use the main mutex is at
the end of the command when it has to call `do_become_nonbusy()` to mark
the subdevice as no longer busy handling an asynchronous command. To
avoid deadlock, it has to remove the task from the wait queue and
release the `attach_lock` semaphore before acquiring the main mutex. It
then needs to confirm that the device is still attached. Unfortunately,
we do not yet protect against a dynamically allocated `struct
comedi_device` being deleted during the operation. This will be
addressed by a later patch.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a member `detach_count` to `struct comedi_device` that is
incremented every time the device gets detached. This will be used in
some validity checks in the 'read' and 'write' file operations to make
sure the attachment remains valid.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The comedi core module's handling of the `COMEDI_DEVCONFIG` ioctl will
not allow a device to be detached if it is busy. However, comedi
devices can also be auto-detached due to a removal of a hardware device.
One of the things we should do in that case is cancel any asynchronous
commands that are running. Add a new function
`comedi_device_cancel_all()` to do that and call it from
`comedi_device_detach()`.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Wake up all waiters on the comedi subdevice's async wait queue whenever
the subdevice is marked "non-busy". This happens when an asynchronous
command is cancelled or when a command is terminated and all data has
been read or written. Note: use `wake_up_interruptible_all()` as we
only use interruptible waits.
Remove the call to `wake_up_interruptible()` from `do_cancel_ioctl()` as
it will call `wake_up_interruptible_all()` indirectly via `do_cancel()`
and `do_become_nonbusy()`.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Rename the local function `cleanup_device()` to
`comedi_device_detach_cleanup()`. It is only called from the
`comedi_device_detach()` function and that is called from
`comedi_device_cleanup()` and other places. The more specific function
name seems less confusing.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acquire the `attach_lock` semaphore in the `struct comedi_device` while
modifying the `attached` flag. This is a "write" acquire. Note that
the main mutex in the `struct comedi_device` is also held at this time.
Tasks wishing to check the device is attached will need to either
acquire the main mutex, or "read" acquire the `attach_lock` semaphore,
or both in that order.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 'read' and 'write' file operations on comedi devices do not use the
main mutex in the `struct comedi_device` to avoid contention with ioctls
that may take a while to complete. However, it is necessary to protect
against the device being detached while the operation is in progress.
Add member `struct rw_semaphore attach_lock` to `struct comedi_device`
for this purpose and initialize it on creation.
The actual locking and unlocking will be implemented by subsequent
patches. Tasks that are attaching or detaching comedi devices will
write-acquire the new semaphore whilst also holding the main mutex in
the `struct comedi_device`. Tasks that wish to protect against the
comedi device being detached need to acquire either the main mutex, or
read-acquire the new semaphore, or both in that order.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Two structures defined in "comedidev.h" have an element of type
`spinlock_t`, so add `#include <linux/spinlock_types.h>` to declare it.
One structure has an element of type `struct mutex` so add `#include
<linux/mutex.h>` to declare it.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
