path: root/kernel/irq/handle.c
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2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-03-30Merge tag 'x86-entry-2020-03-30' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 entry code updates from Thomas Gleixner: - Convert the 32bit syscalls to be pt_regs based which removes the requirement to push all 6 potential arguments onto the stack and consolidates the interface with the 64bit variant - The first small portion of the exception and syscall related entry code consolidation which aims to address the recently discovered issues vs. RCU, int3, NMI and some other exceptions which can interrupt any context. The bulk of the changes is still work in progress and aimed for 5.8. - A few lockdep namespace cleanups which have been applied into this branch to keep the prerequisites for the ongoing work confined. * tag 'x86-entry-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits) x86/entry: Fix build error x86 with !CONFIG_POSIX_TIMERS lockdep: Rename trace_{hard,soft}{irq_context,irqs_enabled}() lockdep: Rename trace_softirqs_{on,off}() lockdep: Rename trace_hardirq_{enter,exit}() x86/entry: Rename ___preempt_schedule x86: Remove unneeded includes x86/entry: Drop asmlinkage from syscalls x86/entry/32: Enable pt_regs based syscalls x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments x86/entry/32: Rename 32-bit specific syscalls x86/entry/32: Clean up syscall_32.tbl x86/entry: Remove ABI prefixes from functions in syscall tables x86/entry/64: Add __SYSCALL_COMMON() x86/entry: Remove syscall qualifier support x86/entry/64: Remove ptregs qualifier from syscall table x86/entry: Move max syscall number calculation to syscallhdr.sh x86/entry/64: Split X32 syscall table into its own file x86/entry/64: Move sys_ni_syscall stub to common.c x86/entry/64: Use syscall wrappers for x32_rt_sigreturn x86/entry: Refactor SYS_NI macros ...
2020-03-21lockdep: Introduce wait-type checksPeter Zijlstra
Extend lockdep to validate lock wait-type context. The current wait-types are: LD_WAIT_FREE, /* wait free, rcu etc.. */ LD_WAIT_SPIN, /* spin loops, raw_spinlock_t etc.. */ LD_WAIT_CONFIG, /* CONFIG_PREEMPT_LOCK, spinlock_t etc.. */ LD_WAIT_SLEEP, /* sleeping locks, mutex_t etc.. */ Where lockdep validates that the current lock (the one being acquired) fits in the current wait-context (as generated by the held stack). This ensures that there is no attempt to acquire mutexes while holding spinlocks, to acquire spinlocks while holding raw_spinlocks and so on. In other words, its a more fancy might_sleep(). Obviously RCU made the entire ordeal more complex than a simple single value test because RCU can be acquired in (pretty much) any context and while it presents a context to nested locks it is not the same as it got acquired in. Therefore its necessary to split the wait_type into two values, one representing the acquire (outer) and one representing the nested context (inner). For most 'normal' locks these two are the same. [ To make static initialization easier we have the rule that: .outer == INV means .outer == .inner; because INV == 0. ] It further means that its required to find the minimal .inner of the held stack to compare against the outer of the new lock; because while 'normal' RCU presents a CONFIG type to nested locks, if it is taken while already holding a SPIN type it obviously doesn't relax the rules. Below is an example output generated by the trivial test code: raw_spin_lock(&foo); spin_lock(&bar); spin_unlock(&bar); raw_spin_unlock(&foo); [ BUG: Invalid wait context ] ----------------------------- swapper/0/1 is trying to lock: ffffc90000013f20 (&bar){....}-{3:3}, at: kernel_init+0xdb/0x187 other info that might help us debug this: 1 lock held by swapper/0/1: #0: ffffc90000013ee0 (&foo){+.+.}-{2:2}, at: kernel_init+0xd1/0x187 The way to read it is to look at the new -{n,m} part in the lock description; -{3:3} for the attempted lock, and try and match that up to the held locks, which in this case is the one: -{2,2}. This tells that the acquiring lock requires a more relaxed environment than presented by the lock stack. Currently only the normal locks and RCU are converted, the rest of the lockdep users defaults to .inner = INV which is ignored. More conversions can be done when desired. The check for spinlock_t nesting is not enabled by default. It's a separate config option for now as there are known problems which are currently addressed. The config option allows to identify these problems and to verify that the solutions found are indeed solving them. The config switch will be removed and the checks will permanently enabled once the vast majority of issues has been addressed. [ bigeasy: Move LD_WAIT_FREE,… out of CONFIG_LOCKDEP to avoid compile failure with CONFIG_DEBUG_SPINLOCK + !CONFIG_LOCKDEP] [ tglx: Add the config option ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200321113242.427089655@linutronix.de
2019-04-09treewide: Switch printk users from %pf and %pF to %ps and %pS, respectivelySakari Ailus
%pF and %pf are functionally equivalent to %pS and %ps conversion specifiers. The former are deprecated, therefore switch the current users to use the preferred variant. The changes have been produced by the following command: git grep -l '%p[fF]' | grep -v '^\(tools\|Documentation\)/' | \ while read i; do perl -i -pe 's/%pf/%ps/g; s/%pF/%pS/g;' $i; done And verifying the result. Link: http://lkml.kernel.org/r/20190325193229.23390-1-sakari.ailus@linux.intel.com Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: linux-arm-kernel@lists.infradead.org Cc: sparclinux@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: xen-devel@lists.xenproject.org Cc: linux-acpi@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: drbd-dev@lists.linbit.com Cc: linux-block@vger.kernel.org Cc: linux-mmc@vger.kernel.org Cc: linux-nvdimm@lists.01.org Cc: linux-pci@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: linux-btrfs@vger.kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net Cc: linux-mm@kvack.org Cc: ceph-devel@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Acked-by: David Sterba <dsterba@suse.com> (for btrfs) Acked-by: Mike Rapoport <rppt@linux.ibm.com> (for mm/memblock.c) Acked-by: Bjorn Helgaas <bhelgaas@google.com> (for drivers/pci) Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-01-15genirq: Correctly annotate implicit fall throughMathieu Malaterre
There is a plan to build the kernel with -Wimplicit-fallthrough. The fallthrough in __handle_irq_event_percpu() has a fallthrough annotation which is followed by an additional comment and is not recognized by GCC. Separate the 'fall through' and the rest of the comment with a dash so the regular expression used by GCC matches. Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190114203633.18557-1-malat@debian.org
2018-03-20genirq: Add missing SPDX identifiersThomas Gleixner
Add SPDX identifiers to files - which contain an explicit license boiler plate or reference - which do not contain a license reference and were not updated in the initial SPDX conversion because the license was deduced by the scanners via EXPORT_SYMBOL_GPL as GPL2.0 only. [ tglx: Moved adding identifiers from the patch which removes the references/boilerplate ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> 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/20180314212030.668321222@linutronix.de
2018-03-20genirq: Cleanup top of file commentsThomas Gleixner
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
2018-03-14genirq: Add CONFIG_GENERIC_IRQ_MULTI_HANDLERPalmer Dabbelt
The arm multi irq handler registration mechanism has been copied into a handful of architectures, including arm64 and openrisc. RISC-V needs the same mechanism. Instead of adding yet another copy for RISC-V copy the arm implementation into the core code depending on a new Kconfig symbol: CONFIG_GENERIC_MULTI_IRQ_HANDLER. Subsequent patches will convert the various architectures. Signed-off-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: jonas@southpole.se Cc: catalin.marinas@arm.com Cc: Will Deacon <will.deacon@arm.com> Cc: linux@armlinux.org.uk Cc: stefan.kristiansson@saunalahti.fi Cc: openrisc@lists.librecores.org Cc: shorne@gmail.com Cc: linux-riscv@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lkml.kernel.org/r/20180307235731.22627-2-palmer@sifive.com
2017-07-03Merge tag 'docs-4.13' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "There has been a fair amount of activity in the docs tree this time around. Highlights include: - Conversion of a bunch of security documentation into RST - The conversion of the remaining DocBook templates by The Amazing Mauro Machine. We can now drop the entire DocBook build chain. - The usual collection of fixes and minor updates" * tag 'docs-4.13' of git://git.lwn.net/linux: (90 commits) scripts/kernel-doc: handle DECLARE_HASHTABLE Documentation: atomic_ops.txt is core-api/atomic_ops.rst Docs: clean up some DocBook loose ends Make the main documentation title less Geocities Docs: Use kernel-figure in vidioc-g-selection.rst Docs: fix table problems in ras.rst Docs: Fix breakage with Sphinx 1.5 and upper Docs: Include the Latex "ifthen" package doc/kokr/howto: Only send regression fixes after -rc1 docs-rst: fix broken links to dynamic-debug-howto in kernel-parameters doc: Document suitability of IBM Verse for kernel development Doc: fix a markup error in coding-style.rst docs: driver-api: i2c: remove some outdated information Documentation: DMA API: fix a typo in a function name Docs: Insert missing space to separate link from text doc/ko_KR/memory-barriers: Update control-dependencies example Documentation, kbuild: fix typo "minimun" -> "minimum" docs: Fix some formatting issues in request-key.rst doc: ReSTify keys-trusted-encrypted.txt doc: ReSTify keys-request-key.txt ...
2017-06-24genirq/timings: Add infrastructure to track the interrupt timingsDaniel Lezcano
The interrupt framework gives a lot of information about each interrupt. It does not keep track of when those interrupts occur though, which is a prerequisite for estimating the next interrupt arrival for power management purposes. Add a mechanism to record the timestamp for each interrupt occurrences in a per-CPU circular buffer to help with the prediction of the next occurrence using a statistical model. Each CPU can store up to IRQ_TIMINGS_SIZE events <irq, timestamp>, the current value of IRQ_TIMINGS_SIZE is 32. Each event is encoded into a single u64, where the high 48 bits are used for the timestamp and the low 16 bits are for the irq number. A static key is introduced so when the irq prediction is switched off at runtime, the overhead is near to zero. It results in most of the code in internals.h for inline reasons and a very few in the new file timings.c. The latter will contain more in the next patch which will provide the statistical model for the next event prediction. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Hannes Reinecke <hare@suse.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: "Rafael J . Wysocki" <rafael@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Link: http://lkml.kernel.org/r/1498227072-5980-1-git-send-email-daniel.lezcano@linaro.org
2017-05-16irq: update genericirq book locationMauro Carvalho Chehab
This book got converted from DocBook. Update its references to point to the current location. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-18genirq: Add untracked irq handlerKeith Busch
This adds a software irq handler for controllers that multiplex interrupts from multiple devices, but don't know which device generated the interrupt. For these devices, the irq handler that demuxes must check every action for every software irq using the same h/w irq in order to find out which device generated the interrupt. This will inevitably trigger spurious interrupt detection if we are noting the irq. The new irq handler does not track the handling for spurious interrupt detection. An irq that uses this also won't get stats tracked since it didn't generate the interrupt, nor added to randomness since they are not random. Signed-off-by: Keith Busch <keith.busch@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-pci@vger.kernel.org Cc: Jon Derrick <jonathan.derrick@intel.com> Link: http://lkml.kernel.org/r/1466200821-29159-1-git-send-email-keith.busch@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-15genirq: Use a common macro to go through the actions listDaniel Lezcano
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>
2016-01-14genirq: Validate action before dereferencing it in handle_irq_event_percpu()Thomas Gleixner
commit 71f64340fc0e changed the handling of irq_desc->action from CPU 0 CPU 1 free_irq() lock(desc) lock(desc) handle_edge_irq() if (desc->action) { handle_irq_event() action = desc->action unlock(desc) desc->action = NULL handle_irq_event_percpu(desc, action) action->xxx to CPU 0 CPU 1 free_irq() lock(desc) lock(desc) handle_edge_irq() if (desc->action) { handle_irq_event() unlock(desc) desc->action = NULL handle_irq_event_percpu(desc, action) action = desc->action action->xxx So if free_irq manages to set the action to NULL between the unlock and before the readout, we happily dereference a null pointer. We could simply revert 71f64340fc0e, but we want to preserve the better code generation. A simple solution is to change the action loop from a do {} while to a while {} loop. This is safe because we either see a valid desc->action or NULL. If the action is about to be removed it is still valid as free_irq() is blocked on synchronize_irq(). CPU 0 CPU 1 free_irq() lock(desc) lock(desc) handle_edge_irq() handle_irq_event(desc) set(INPROGRESS) unlock(desc) handle_irq_event_percpu(desc) action = desc->action desc->action = NULL while (action) { action->xxx ... action = action->next; sychronize_irq() while(INPROGRESS); lock(desc) clr(INPROGRESS) free(action) That's basically the same mechanism as we have for shared interrupts. action->next can become NULL while handle_irq_event_percpu() runs. Either it sees the action or NULL. It does not matter, because action itself cannot go away before the interrupt in progress flag has been cleared. Fixes: commit 71f64340fc0e "genirq: Remove the second parameter from handle_irq_event_percpu()" Reported-by: zyjzyj2000@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Huang Shijie <shijie.huang@arm.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1601131224190.3575@nanos
2015-10-13Merge branch 'linus' into irq/coreThomas Gleixner
Bring in upstream updates for patches which depend on them
2015-10-09genirq: Fix handle_bad_irq kerneldoc commentArnd Bergmann
A recent cleanup removed the 'irq' parameter from many functions, but left the documentation for this in place for at least one function. This removes it. Fixes: bd0b9ac405e1 ("genirq: Remove irq argument from irq flow handlers") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: kbuild-all@01.org Cc: Austin Schuh <austin@peloton-tech.com> Cc: Santosh Shilimkar <ssantosh@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/5400000.cD19rmgWjV@wuerfel Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-10-09genirq: Export handle_bad_irqArnd Bergmann
A cleanup of the omap gpio driver introduced a use of the handle_bad_irq() function in a device driver that can be a loadable module. This broke the ARM allmodconfig build: ERROR: "handle_bad_irq" [drivers/gpio/gpio-omap.ko] undefined! This patch exports the handle_bad_irq symbol in order to allow the use in modules. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Santosh Shilimkar <ssantosh@kernel.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Austin Schuh <austin@peloton-tech.com> Cc: Tony Lindgren <tony@atomide.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/5847725.4IBopItaOr@wuerfel Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-22genirq: Remove the second parameter from handle_irq_event_percpu()Huang Shijie
Actually, we always use the first irq action of the @desc->action chain, so remove the second parameter from handle_irq_event_percpu() which makes the code more tidy. Signed-off-by: Huang Shijie <shijie.huang@arm.com> Reviewed-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: peterz@infradead.org Cc: marc.zyngier@arm.com Link: http://lkml.kernel.org/r/1441160695-19809-1-git-send-email-shijie.huang@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-16genirq: Remove irq argument from irq flow handlersThomas Gleixner
Most interrupt flow handlers do not use the irq argument. Those few which use it can retrieve the irq number from the irq descriptor. Remove the argument. Search and replace was done with coccinelle and some extra helper scripts around it. Thanks to Julia for her help! Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Jiang Liu <jiang.liu@linux.intel.com>
2015-07-11genirq: Remove the irq argument from note_interrupt()Jiang Liu
Only required for the slow path. Retrieve it from irq descriptor if necessary. [ tglx: Split out from combo patch. Left [try_]misrouted_irq() untouched as there is no win in the slow path ] 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/1433391238-19471-19-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-11genirq: Remove the parameter 'irq' of kstat_incr_irqs_this_cpu()Jiang Liu
The first parameter 'irq' is never used by kstat_incr_irqs_this_cpu(). Remove it. 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> Link: http://lkml.kernel.org/r/1433391238-19471-16-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-03-22genirq: Export symbol no_action()Alexander Shiyan
This will allow to use the dummy IRQ handler no_action() from drivers compiled as module. Drivers which use ARM FIQ interrupts can use this to request the interrupt via the normal request_irq() mechanism w/o having to copy the dummy handler to their own code. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Link: http://lkml.kernel.org/r/1395476431-16070-1-git-send-email-shc_work@mail.ru Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-02-19genirq: Provide irq_wake_thread()Thomas Gleixner
In course of the sdhci/sdio discussion with Russell about killing the sdio kthread hackery we discovered the need to be able to wake an interrupt thread from software. The rationale for this is, that sdio hardware can lack proper interrupt support for certain features. So the driver needs to poll the status registers, but at the same time it needs to be woken up by an hardware interrupt. To be able to get rid of the home brewn kthread construct of sdio we need a way to wake an irq thread independent of an actual hardware interrupt. Provide an irq_wake_thread() function which wakes up the thread which is associated to a given dev_id. This allows sdio to invoke the irq thread from the hardware irq handler via the IRQ_WAKE_THREAD return value and provides a possibility to wake it via a timer for the polling scenarios. That allows to simplify the sdio logic significantly. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Chris Ball <chris@printf.net> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140215003823.772565780@linutronix.de
2012-07-14random: make 'add_interrupt_randomness()' do something saneTheodore Ts'o
We've been moving away from add_interrupt_randomness() for various reasons: it's too expensive to do on every interrupt, and flooding the CPU with interrupts could theoretically cause bogus floods of entropy from a somewhat externally controllable source. This solves both problems by limiting the actual randomness addition to just once a second or after 64 interrupts, whicever comes first. During that time, the interrupt cycle data is buffered up in a per-cpu pool. Also, we make sure the the nonblocking pool used by urandom is initialized before we start feeding the normal input pool. This assures that /dev/urandom is returning unpredictable data as soon as possible. (Based on an original patch by Linus, but significantly modified by tytso.) Tested-by: Eric Wustrow <ewust@umich.edu> Reported-by: Eric Wustrow <ewust@umich.edu> Reported-by: Nadia Heninger <nadiah@cs.ucsd.edu> Reported-by: Zakir Durumeric <zakir@umich.edu> Reported-by: J. Alex Halderman <jhalderm@umich.edu>. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
2012-03-29genirq: Minor readablity improvement in irq_wake_thread()Alexander Gordeev
exit_irq_thread() clears IRQTF_RUNTHREAD flag and drops the thread's bit in desc->threads_oneshot then. The bit must not be set again in between and it does not, since irq_wake_thread() sees PF_EXITING flag first and returns. Due to above the order or checking PF_EXITING and IRQTF_RUNTHREAD flags in irq_wake_thread() is important. This change just makes it more visible in the source code. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Link: http://lkml.kernel.org/r/20120321162212.GO24806@dhcp-26-207.brq.redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-03-14genirq: Flush the irq thread on synchronizationIdo Yariv
The current implementation does not always flush the threaded handler when disabling the irq. In case the irq handler was called, but the threaded handler hasn't started running yet, the interrupt will be flagged as pending, and the handler will not run. This implementation has some issues: First, if the interrupt is a wake source and flagged as pending, the system will not be able to suspend. Second, when quickly disabling and re-enabling the irq, the threaded handler might continue to run after the irq is re-enabled without the irq handler being called first. This might be an unexpected behavior. In addition, it might be counter-intuitive that the threaded handler will not be called even though the irq handler was called and returned IRQ_WAKE_THREAD. Fix this by always waiting for the threaded handler to complete in synchronize_irq(). [ tglx: Massaged comments, added WARN_ONs and the missing IRQTF_RUNTHREAD check in exit_irq_thread() ] Signed-off-by: Ido Yariv <ido@wizery.com> Link: http://lkml.kernel.org/r/1322843052-7166-1-git-send-email-ido@wizery.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-03-09genirq: Get rid of unnecessary IRQTF_DIED flagAlexander Gordeev
Currently IRQTF_DIED flag is set when a IRQ thread handler calls do_exit() But also PF_EXITING per process flag gets set when a thread exits. This fix eliminates the duplicate by using PF_EXITING flag. Also, there is a race condition in exit_irq_thread(). In case a thread's bit is cleared in desc->threads_oneshot (and the IRQ line gets unmasked), but before IRQTF_DIED flag is set, a new interrupt might come in and set just cleared bit again, this time forever. This fix throws IRQTF_DIED flag away, eliminating the race as a result. [ tglx: Test THREAD_EXITING first as suggested by Oleg ] Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Link: http://lkml.kernel.org/r/20120309135958.GD2114@dhcp-26-207.brq.redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-06-03irq: Handle spurios irq detection for threaded irqsSebastian Andrzej Siewior
The detection of spurios interrupts is currently limited to first level handler. In force-threaded mode we never notice if the threaded irq does not feel responsible. This patch catches the return value of the threaded handler and forwards it to the spurious detector. If the primary handler returns only IRQ_WAKE_THREAD then the spourious detector ignores it because it gets called again from the threaded handler. [ tglx: Report the erroneous return value early and bail out ] Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Link: http://lkml.kernel.org/r/1306824972-27067-2-git-send-email-sebastian@breakpoint.cc Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-29genirq: Remove compat codeThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-28genirq: Remove handle_IRQ_eventThomas Gleixner
Last user gone. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-28genirq: Move INPROGRESS, MASKED and DISABLED state flags to irq_dataThomas Gleixner
We really need these flags for some of the interrupt chips. Move it from internal state to irq_data and provide proper accessors. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Daney <ddaney@caviumnetworks.com>
2011-02-25genirq: Prepare the handling of shared oneshot interruptsThomas Gleixner
For level type interrupts we need to track how many threads are on flight to avoid useless interrupt storms when not all thread handlers have finished yet. Keep track of the woken threads and only unmask when there are no more threads in flight. Yes, I'm lazy and using a bitfield. But not only because I'm lazy, the main reason is that it's way simpler than using a refcount. A refcount based solution would need to keep track of various things like crashing the irq thread, spurious interrupts coming in, disables/enables, free_irq() and some more. The bitfield keeps the tracking simple and makes things just work. It's also nicely confined to the thread code pathes and does not require additional checks all over the place. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.388095876@linutronix.de>
2011-02-25genirq: Make warning in handle_percpu_event usefulThomas Gleixner
The WARN_ON_ONCE in handle_percpu_event() which emits a warning when an action handler returns with interrupts enabled is not really useful. It does not reveal the interrupt number and handler function which caused it. Make it WARN_ONCE() and add the information. Reported-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-22genirq: Use the correct variable for note_interruptThomas Gleixner
note_interrupt wants to be called with the combined result of all handlers called, not with the last one. If it's a shared interrupt then the last handler might return IRQ_NONE often enough to trigger the spurious dectector which turns off a perfectly fine working interrupt line. Bug was introduced in commit 1277a532(genirq: Simplify handle_irq_event()). Yes, I really messed up there. First the variable ret should not have been named differently to avoid similarity with retval. Second it should have been declared in the do {} loop. Rename it to res and move it into the do {} loop and vanish under a huge brown paperbag. Reported-bisected-tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19genirq: Force wrapped access to desc->status in core codeThomas Gleixner
Force the usage of wrappers by another nasty CPP substitution. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19genirq: Move IRQ_PENDING flag to coreThomas Gleixner
Keep status in sync until all users are fixed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19genirq: Add IRQ_INPROGRESS to coreThomas Gleixner
We need to maintain the flag for now in both fields status and istate. Add a CONFIG_GENERIC_HARDIRQS_NO_COMPAT switch to allow testing w/o the status one. Wrap the access to status IRQ_INPROGRESS in a inline which can be turned of with CONFIG_GENERIC_HARDIRQS_NO_COMPAT along with the define. There is no reason that anything outside of core looks at this. That needs some modifications, but we'll get there. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19genirq: Simplify handle_irq_event()Thomas Gleixner
Now that all core users are converted one layer can go. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19genirq: Implement handle_irq_event()Thomas Gleixner
Core code replacement for the ugly camel case. It contains all the code which is shared in all handlers. clear status flags set INPROGRESS flag unlock call action chain note_interrupt lock clr INPROGRESS flag Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19genirq: Warn when handler enables interruptsThomas Gleixner
We run all handlers with interrupts disabled and expect them not to enable them. Warn when we catch one who does. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-01-21genirq: Remove __do_IRQThomas Gleixner
All architectures are finally converted. Remove the cruft. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Henderson <rth@twiddle.net> Cc: Mike Frysinger <vapier@gentoo.org> Cc: David Howells <dhowells@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Greg Ungerer <gerg@uclinux.org> Cc: Michal Simek <monstr@monstr.eu> Acked-by: David Howells <dhowells@redhat.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jeff Dike <jdike@addtoit.com>
2010-10-12genirq: Distangle kernel/irq/handle.cThomas Gleixner
kernel/irq/handle.c has become a dumpground for random code in random order. Split out the irq descriptor management and the dummy irq_chip implementation into separate files. Cleanup the include maze while at it. No code change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide config option to disable deprecated codeThomas Gleixner
This option covers now the old chip functions and the irq_desc data fields which are moving to struct irq_data. More stuff will follow. Pretty handy for testing a conversion, whether something broke or not. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->startup()Thomas Gleixner
Wrap the old chip function startup() 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: <20100927121842.635152961@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->disable()/shutdown()Thomas Gleixner
Wrap the old chip functions disable() and shutdown() 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: <20100927121842.532070631@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->enable()Thomas Gleixner
Wrap the old chip function enable() 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: <20100927121842.437159182@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->ack()Thomas Gleixner
Wrap the old chip function ack() 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: <20100927121842.142624725@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->unmask()Thomas Gleixner
Wrap the old chip function unmask() 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: <20100927121842.043608928@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->mask()Thomas Gleixner
Wrap the old chip function mask() 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: <20100927121841.940355859@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Add new functions to dummy chipsThomas Gleixner
The compat functions go away when the core code is converted. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>