Both the per cpu stats and the accumulated count are accessed lockless and
can be concurrently modified. That's intentional and the stats are a rough
estimate anyway. Annotate them with data_race().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194043.067097663@linutronix.de
A number of architectures implement IPI statistics directly,
duplicating the core kstat_irqs accounting. As we move IPIs to
being actual IRQs, we would end-up with a confusing display
in /proc/interrupts (where the IPIs would appear twice).
In order to solve this, allow interrupts to be flagged as
"hidden", which excludes them from /proc/interrupts.
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Qian Cai reported that the WARN_ON() in the x86/msi affinity setting code,
which catches cases where the affinity setting is not done on the CPU which
is the current target of the interrupt, triggers during CPU hotplug stress
testing.
It turns out that the warning which was added with the commit addressing
the MSI affinity race unearthed yet another long standing bug.
If user space writes a bogus affinity mask, i.e. it contains no online CPUs,
then it calls irq_select_affinity_usr(). This was introduced for ALPHA in
eee45269b0 ("[PATCH] Alpha: convert to generic irq framework (generic part)")
and subsequently made available for all architectures in
1840475676 ("genirq: Expose default irq affinity mask (take 3)")
which introduced the circumvention of the affinity setting restrictions for
interrupt which cannot be moved in process context.
The whole exercise is bogus in various aspects:
1) If the interrupt is already started up then there is absolutely
no point to honour a bogus interrupt affinity setting from user
space. The interrupt is already assigned to an online CPU and it
does not make any sense to reassign it to some other randomly
chosen online CPU.
2) If the interupt is not yet started up then there is no point
either. A subsequent startup of the interrupt will invoke
irq_setup_affinity() anyway which will chose a valid target CPU.
So the only correct solution is to just return -EINVAL in case user space
wrote an affinity mask which does not contain any online CPUs, except for
ALPHA which has it's own magic sauce for this.
Fixes: 1840475676 ("genirq: Expose default irq affinity mask (take 3)")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Qian Cai <cai@lca.pw>
Link: https://lkml.kernel.org/r/878sl8xdbm.fsf@nanos.tec.linutronix.de
Since commit 425a5072dc ("genirq: Free irq_desc with rcu"),
show_interrupts() can be switched to rcu locking, which removes possible
contention on sparse_irq_lock.
The per_cpu count scan and print can be done without holding desc spinlock.
And there is no need to call kstat_irqs_cpu() and abuse irq_to_desc() while
holding rcu read lock, since desc and desc->kstat_irqs wont disappear or
change.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Link: https://lkml.kernel.org/r/20180620150332.163320-1-edumazet@google.com
Variants of proc_create{,_data} that directly take a seq_file show
callback and drastically reduces the boilerplate code in the callers.
All trivial callers converted over.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Remove pointless references to the file name itself and condense the
information so it wastes less space.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Link: https://lkml.kernel.org/r/20180314212030.412095827@linutronix.de
Pull irq core updates from Thomas Gleixner:
"A rather large update for the interrupt core code and the irq chip drivers:
- Add a new bitmap matrix allocator and supporting changes, which is
used to replace the x86 vector allocator which comes with separate
pull request. This allows to replace the convoluted nested loop
allocation function in x86 with a facility which supports the
recently added property of managed interrupts proper and allows to
switch to a best effort vector reservation scheme, which addresses
problems with vector exhaustion.
- A large update to the ARM GIC-V3-ITS driver adding support for
range selectors.
- New interrupt controllers:
- Meson and Meson8 GPIO
- BCM7271 L2
- Socionext EXIU
If you expected that this will stop at some point, I have to
disappoint you. There are new ones posted already. Sigh!
- STM32 interrupt controller support for new platforms.
- A pile of fixes, cleanups and updates to the MIPS GIC driver
- The usual small fixes, cleanups and updates all over the place.
Most visible one is to move the irq chip drivers Kconfig switches
into a separate Kconfig menu"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
genirq: Fix type of shifting literal 1 in __setup_irq()
irqdomain: Drop pointless NULL check in virq_debug_show_one
genirq/proc: Return proper error code when irq_set_affinity() fails
irq/work: Use llist_for_each_entry_safe
irqchip: mips-gic: Print warning if inherited GIC base is used
irqchip/mips-gic: Add pr_fmt and reword pr_* messages
irqchip/stm32: Move the wakeup on interrupt mask
irqchip/stm32: Fix initial values
irqchip/stm32: Add stm32h7 support
dt-bindings/interrupt-controllers: Add compatible string for stm32h7
irqchip/stm32: Add multi-bank management
irqchip/stm32: Select GENERIC_IRQ_CHIP
irqchip/exiu: Add support for Socionext Synquacer EXIU controller
dt-bindings: Add description of Socionext EXIU interrupt controller
irqchip/gic-v3-its: Fix VPE activate callback return value
irqchip: mips-gic: Make IPI bitmaps static
irqchip: mips-gic: Share register writes in gic_set_type()
irqchip: mips-gic: Remove gic_vpes variable
irqchip: mips-gic: Use num_possible_cpus() to reserve IPIs
irqchip: mips-gic: Configure EIC when CPUs come online
...
write_irq_affinity() returns the number of written bytes, which means
success, unconditionally whether the actual irq_set_affinity() call
succeeded or not.
Add proper error handling and pass the error code returned from
irq_set_affinity() back to user space in case of failure.
[ tglx: Fixed coding style and massaged changelog ]
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Cc: zhong.weidong@zte.com.cn
Link: https://lkml.kernel.org/r/1510106103-184761-1-git-send-email-wen.yang99@zte.com.cn
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel/irq/proc.c: In function ‘show_irq_affinity’:
include/linux/cpumask.h:24:29: warning: ‘mask’ may be used uninitialized in this function [-Wmaybe-uninitialized]
#define cpumask_bits(maskp) ((maskp)->bits)
gcc is silly, but admittedly it can't know that this won't be called with
anything else than the enumerated constants.
Shut up the warning by creating a default clause.
Fixes: 6bc6d4abd2 ("genirq/proc: Use the the accessor to report the effective affinity
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK is defined, but that the
interrupt is not single target, the effective affinity reported in
/proc/irq/x/effective_affinity will be empty, which is not the truth.
Instead, use the accessor to report the affinity, which will pick
the right mask.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Wei Xu <xuwei5@hisilicon.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: http://lkml.kernel.org/r/20170818083925.10108-3-marc.zyngier@arm.com
There is currently no way to evaluate the effective affinity mask of a
given interrupt. Many irq chips allow only a single target CPU or a subset
of CPUs in the affinity mask.
Updating the mask at the time of setting the affinity to the subset would
be counterproductive because information for cpu hotplug about assigned
interrupt affinities gets lost. On CPU hotplug it's also pointless to force
migrate an interrupt, which is not targeted at the CPU effectively. But
currently the information is not available.
Provide a seperate mask to be updated by the irq_chip->irq_set_affinity()
implementations. Implement the read only proc files so the user can see the
effective mask as well w/o trying to deduce it from /proc/interrupts.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.247834245@linutronix.de
The proc file setup repeats the same ugly type cast for the irq number over
and over. Do it once and hand in the local void pointer.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.160866358@linutronix.de
The third argument of the internal helper function is unused. Remove it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.004958600@linutronix.de
No point to have this alloc/free dance of cpumasks. Provide a static mask
for setup_affinity() and protect it proper.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235444.851571573@linutronix.de
If the irq_desc being output does not have a domain associated the
information following the 'name' is not aligned correctly.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Link: http://lkml.kernel.org/r/20170210165416.5629-1-hsweeten@visionengravers.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
sprintf() and snprintf() implementation of kernel guarantees that
its result is terminated with null byte if size is larger than 0. So we
don't need to call memset() at all.
Signed-off-by: Weongyo Jeong <weongyo.linux@gmail.com>
Link: http://lkml.kernel.org/r/1459451703-5744-1-git-send-email-weongyo.linux@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The irq code browses the list of actions differently to inspect the element
one by one. Even if it is not a problem, for the sake of consistent code,
provide a macro similar to for_each_irq_desc in order to have the same loop to
go through the actions list and use it in the code.
[ tglx: Renamed the macro ]
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: http://lkml.kernel.org/r/1452765253-31148-1-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Commit e509bd7da1 ("genirq: Allow migration of chained interrupts
by installing default action") breaks PCS wake up IRQ behaviour on
TI OMAP based platforms (dra7-evm).
TI OMAP IRQ wake up configuration:
GIC-irqchip->PCM_IRQ
|- omap_prcm_register_chain_handler
|- PRCM-irqchip -> PRCM_IO_IRQ
|- pcs_irq_chain_handler
|- pinctrl-irqchip -> PCS_uart1_wakeup_irq
This happens because IRQ PM code (irq/pm.c) is expected to ignore
chained interrupts by default:
static bool suspend_device_irq(struct irq_desc *desc)
{
if (!desc->action || desc->no_suspend_depth)
return false;
- it's expected !desc->action = true for chained interrupts;
but, after above change, all chained interrupt descriptors will
have default action handler installed - chained_action.
As result, chained interrupts will be silently disabled during system
suspend.
Hence, fix it by introducing helper function irq_desc_is_chained() and
use it in suspend_device_irq() for chained interrupts identification
and skip them, once detected.
Fixes: e509bd7da1 ("genirq: Allow migration of chained interrupts..")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: <nsekhar@ti.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Tony Lindgren <tony@atomide.com>
Link: http://lkml.kernel.org/r/1447149492-20699-1-git-send-email-grygorii.strashko@ti.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When a CPU is offlined all interrupts that have an action are migrated to
other still online CPUs. However, if the interrupt has chained handler
installed this is not done. Chained handlers are used by GPIO drivers which
support interrupts, for instance.
When the affinity is not corrected properly we end up in situation where
most interrupts are not arriving to the online CPUs anymore. For example on
Intel Braswell system which has SD-card card detection signal connected to
a GPIO the IO-APIC routing entries look like below after CPU1 is offlined:
pin30, enabled , level, low , V(52), IRR(0), S(0), logical , D(03), M(1)
pin31, enabled , level, low , V(42), IRR(0), S(0), logical , D(03), M(1)
pin32, enabled , level, low , V(62), IRR(0), S(0), logical , D(03), M(1)
pin5b, enabled , level, low , V(72), IRR(0), S(0), logical , D(03), M(1)
The problem here is that the destination mask still contains both CPUs even
if CPU1 is already offline. This means that the IO-APIC still routes
interrupts to the other CPU as well.
We solve the problem by providing a default action for chained interrupts.
This action allows the migration code to correct affinity (as it finds
desc->action != NULL).
Also make the default action handler to emit a warning if for some reason a
chained handler ends up calling it.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/1444039935-30475-1-git-send-email-mika.westerberg@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Per-IRQ directories in procfs are created only when a handler is first
added to the irqdesc, not when the irqdesc is created. In the case of
a shared IRQ, multiple tasks can race to create a directory. This
race condition seems to have been present forever, but is easier to
hit with async probing.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Link: http://lkml.kernel.org/r/1443266636.2004.2.camel@decadent.org.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Irq affinity mask is per-irq instead of per irqchip, so move it into
struct irq_common_data.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: http://lkml.kernel.org/r/1433303281-27688-1-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Introduce helper function irq_data_get_node() and variants thereof to
hide struct irq_data implementation details.
Convert the core code to use them.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: http://lkml.kernel.org/r/1433145945-789-5-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
printk and friends can now format bitmaps using '%*pb[l]'. cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since the rework of the sparse interrupt code to actually free the
unused interrupt descriptors there exists a race between the /proc
interfaces to the irq subsystem and the code which frees the interrupt
descriptor.
CPU0 CPU1
show_interrupts()
desc = irq_to_desc(X);
free_desc(desc)
remove_from_radix_tree();
kfree(desc);
raw_spinlock_irq(&desc->lock);
/proc/interrupts is the only interface which can actively corrupt
kernel memory via the lock access. /proc/stat can only read from freed
memory. Extremly hard to trigger, but possible.
The interfaces in /proc/irq/N/ are not affected by this because the
removal of the proc file is serialized in procfs against concurrent
readers/writers. The removal happens before the descriptor is freed.
For architectures which have CONFIG_SPARSE_IRQ=n this is a non issue
as the descriptor is never freed. It's merely cleared out with the irq
descriptor lock held. So any concurrent proc access will either see
the old correct value or the cleared out ones.
Protect the lookup and access to the irq descriptor in
show_interrupts() with the sparse_irq_lock.
Provide kstat_irqs_usr() which is protecting the lookup and access
with sparse_irq_lock and switch /proc/stat to use it.
Document the existing kstat_irqs interfaces so it's clear that the
caller needs to take care about protection. The users of these
interfaces are either not affected due to SPARSE_IRQ=n or already
protected against removal.
Fixes: 1f5a5b87f7 "genirq: Implement a sane sparse_irq allocator"
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Includes:
- /proc/irq/default_smp_affinity
- /proc/irq/*/affinity_hint
- /proc/irq/*/smp_affinity
- /proc/irq/*/smp_affinity_list
Users can distill the same information by reading /proc/interrupts.
Signed-off-by: Chema Gonzalez <chema@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Link: http://lkml.kernel.org/r/1394765455-1217-1-git-send-email-chema@google.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add the hardware interrupt number to the output of /proc/interrupts.
It is often important to have access to the hardware interrupt number because
it identifies exactly how an interrupt signal is wired up to the interrupt
controller. This is especially important when using irq_domains since irq
numbers get dynamically allocated in that case, and have no relation to the
actual hardware number.
Note: This output is currently conditional on whether or not the irq_domain
pointer is set; however hwirq could still be used without irq_domain. It
may be worthwhile to always output the hwirq number regardless of the
domain pointer.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Olof Johansson <olof@lixom.net>
Cc: Ben Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
The only part of proc_dir_entry the code outside of fs/proc
really cares about is PDE(inode)->data. Provide a helper
for that; static inline for now, eventually will be moved
to fs/proc, along with the knowledge of struct proc_dir_entry
layout.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
commit 4b06042(bitmap, irq: add smp_affinity_list interface to
/proc/irq) causes the following warning:
[ 274.239500] WARNING: at fs/proc/generic.c:850 remove_proc_entry+0x24c/0x27a()
[ 274.251761] remove_proc_entry: removing non-empty directory 'irq/184',
leaking at least 'smp_affinity_list'
Remove the new file in the exit path.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Mike Travis <travis@sgi.com>
Link: http://lkml.kernel.org/r/4DDDE094.6050505@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Manually adjusting the smp_affinity for IRQ's becomes unwieldy when the
cpu count is large.
Setting smp affinity to cpus 256 to 263 would be:
echo 000000ff,00000000,00000000,00000000,00000000,00000000,00000000,00000000 > smp_affinity
instead of:
echo 256-263 > smp_affinity_list
Think about what it looks like for cpus around say, 4088 to 4095.
We already have many alternate "list" interfaces:
/sys/devices/system/cpu/cpuX/indexY/shared_cpu_list
/sys/devices/system/cpu/cpuX/topology/thread_siblings_list
/sys/devices/system/cpu/cpuX/topology/core_siblings_list
/sys/devices/system/node/nodeX/cpulist
/sys/devices/pci***/***/local_cpulist
Add a companion interface, smp_affinity_list to use cpu lists instead of
cpu maps. This conforms to other companion interfaces where both a map
and a list interface exists.
This required adding a bitmap_parselist_user() function in a manner
similar to the bitmap_parse_user() function.
[akpm@linux-foundation.org: make __bitmap_parselist() static]
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit ab7798ffcf ("genirq: Expand generic
show_interrupts()") added the Kconfig option GENERIC_IRQ_SHOW_LEVEL to
accomodate PowerPC, but this doesn't actually enable the functionality due
to a typo in the #ifdef check.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linux/PPC Development <linuxppc-dev@lists.ozlabs.org>
Link: http://lkml.kernel.org/r/%3Calpine.DEB.2.00.1104302251370.19068%40ayla.of.borg%3E
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The only subtle difference is that alpha uses ACTUAL_NR_IRQS and
prints the IRQF_DISABLED flag.
Change the generic implementation to deal with ACTUAL_NR_IRQS if
defined.
The IRQF_DISABLED printing is pointless, as we nowadays run all
interrupts with irqs disabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Some archs want to print extra information for certain irq_chips which
is per irq and not per chip. Allow them to provide a chip callback to
print the chip name and the extra information.
PowerPC wants to print the LEVEL/EDGE type information. Make it configurable.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
chip implementations need to know about it. Keep status in sync until
all users are fixed.
Accessor function: irqd_is_setaffinity_pending(irqdata)
Coders who access them directly will be tracked down and slapped with
stinking trouts.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
All archs implement show_interrupts() in more or less the same
way. That's tons of duplicated code with different bugs with no
value. Implement a generic version and deprecate show_interrupts()
Unfortunately we need some ifdeffery for !GENERIC_HARDIRQ archs.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
While rumaging through arch code I found that there are a few
workarounds which deal with the fact that the initial affinity setting
from request_irq() copies the mask into irq_data->affinity before the
chip code is called. In the normal path we unconditionally copy the
mask when the chip code returns 0.
Copy after the code is called and add a return code
IRQ_SET_MASK_OK_NOCOPY for the chip functions, which prevents the
copy. That way we see the real mask when the chip function decided to
truncate it further as some arches do. IRQ_SET_MASK_OK is 0, which is
the current behaviour.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Since commit a1afb637(switch /proc/irq/*/spurious to seq_file) all
/proc/irq/XX/spurious files show the information of irq 0.
Current irq_spurious_proc_open() passes on NULL as the 3rd argument,
which is used as an IRQ number in irq_spurious_proc_show(), to the
single_open(). Because of this, all the /proc/irq/XX/spurious file
shows IRQ 0 information regardless of the IRQ number.
To fix the problem, irq_spurious_proc_open() must pass on the
appropreate data (IRQ number) to single_open().
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
LKML-Reference: <4CF4B778.90604@jp.fujitsu.com>
Cc: stable@kernel.org [2.6.33+]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
/proc/irq never removes any entries, but when irq descriptors can be
freed for real this is necessary. Otherwise we'd reference a freed
descriptor in /proc/irq/N
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Wrap the old chip function set_affinity() until the migration is
complete and the old chip functions are removed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.732894108@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Thomas Gleixner