user/sven/linux.git/kernel/irq, branch v4.19.264

random: remove unused irq_flags argument from add_interrupt_randomness()

2022-06-25T09:49:01Z

commit 703f7066f40599c290babdb79dd61319264987e9 upstream. Since commit ee3e00e9e7101 ("random: use registers from interrupted code for CPU's w/o a cycle counter") the irq_flags argument is no longer used. Remove unused irq_flags. Cc: Borislav Petkov Cc: Dave Hansen Cc: Dexuan Cui Cc: H. Peter Anvin Cc: Haiyang Zhang Cc: Ingo Molnar Cc: K. Y. Srinivasan Cc: Stephen Hemminger Cc: Thomas Gleixner Cc: Wei Liu Cc: linux-hyperv@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Sebastian Andrzej Siewior Acked-by: Wei Liu Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

genirq: Synchronize interrupt thread startup

2022-05-12T10:20:24Z

commit 8707898e22fd665bc1d7b18b809be4b56ce25bdd upstream. A kernel hang can be observed when running setserial in a loop on a kernel with force threaded interrupts. The sequence of events is: setserial open("/dev/ttyXXX") request_irq() do_stuff() -> serial interrupt -> wake(irq_thread) desc->threads_active++; close() free_irq() kthread_stop(irq_thread) synchronize_irq() <- hangs because desc->threads_active != 0 The thread is created in request_irq() and woken up, but does not get on a CPU to reach the actual thread function, which would handle the pending wake-up. kthread_stop() sets the should stop condition which makes the thread immediately exit, which in turn leaves the stale threads_active count around. This problem was introduced with commit 519cc8652b3a, which addressed a interrupt sharing issue in the PCIe code. Before that commit free_irq() invoked synchronize_irq(), which waits for the hard interrupt handler and also for associated threads to complete. To address the PCIe issue synchronize_irq() was replaced with __synchronize_hardirq(), which only waits for the hard interrupt handler to complete, but not for threaded handlers. This was done under the assumption, that the interrupt thread already reached the thread function and waits for a wake-up, which is guaranteed to be handled before acting on the stop condition. The problematic case, that the thread would not reach the thread function, was obviously overlooked. Make sure that the interrupt thread is really started and reaches thread_fn() before returning from __setup_irq(). This utilizes the existing wait queue in the interrupt descriptor. The wait queue is unused for non-shared interrupts. For shared interrupts the usage might cause a spurious wake-up of a waiter in synchronize_irq() or the completion of a threaded handler might cause a spurious wake-up of the waiter for the ready flag. Both are harmless and have no functional impact. [ tglx: Amended changelog ] Fixes: 519cc8652b3a ("genirq: Synchronize only with single thread on free_irq()") Signed-off-by: Thomas Pfaff Signed-off-by: Thomas Gleixner Reviewed-by: Marc Zyngier Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/552fe7b4-9224-b183-bb87-a8f36d335690@pcs.com Signed-off-by: Greg Kroah-Hartman

genirq/msi: Ensure deactivation on teardown

2021-08-26T12:36:40Z

commit dbbc93576e03fbe24b365fab0e901eb442237a8a upstream. msi_domain_alloc_irqs() invokes irq_domain_activate_irq(), but msi_domain_free_irqs() does not enforce deactivation before tearing down the interrupts. This happens when PCI/MSI interrupts are set up and never used before being torn down again, e.g. in error handling pathes. The only place which cleans that up is the error handling path in msi_domain_alloc_irqs(). Move the cleanup from msi_domain_alloc_irqs() into msi_domain_free_irqs() to cure that. Fixes: f3b0946d629c ("genirq/msi: Make sure PCI MSIs are activated early") Signed-off-by: Bixuan Cui Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210518033117.78104-1-cuibixuan@huawei.com Signed-off-by: Greg Kroah-Hartman

genirq: Provide IRQCHIP_AFFINITY_PRE_STARTUP

2021-08-26T12:36:40Z

commit 826da771291fc25a428e871f9e7fb465e390f852 upstream. X86 IO/APIC and MSI interrupts (when used without interrupts remapping) require that the affinity setup on startup is done before the interrupt is enabled for the first time as the non-remapped operation mode cannot safely migrate enabled interrupts from arbitrary contexts. Provide a new irq chip flag which allows affected hardware to request this. This has to be opt-in because there have been reports in the past that some interrupt chips cannot handle affinity setting before startup. Fixes: 18404756765c ("genirq: Expose default irq affinity mask (take 3)") Signed-off-by: Thomas Gleixner Tested-by: Marc Zyngier Reviewed-by: Marc Zyngier Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210729222542.779791738@linutronix.de Signed-off-by: Greg Kroah-Hartman

genirq/matrix: Prevent allocation counter corruption

2021-05-22T08:59:14Z

[ Upstream commit c93a5e20c3c2dabef8ea360a3d3f18c6f68233ab ] When irq_matrix_free() is called for an unallocated vector the managed_allocated and total_allocated counters get out of sync with the real state of the matrix. Later, when the last interrupt is freed, these counters will underflow resulting in UINTMAX because the counters are unsigned. While this is certainly a problem of the calling code, this can be catched in the allocator by checking the allocation bit for the to be freed vector which simplifies debugging. An example of the problem described above: https://lore.kernel.org/lkml/20210318192819.636943062@linutronix.de/ Add the missing sanity check and emit a warning when it triggers. Suggested-by: Thomas Gleixner Signed-off-by: Vitaly Kuznetsov Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210319111823.1105248-1-vkuznets@redhat.com Signed-off-by: Sasha Levin

genirq: Disable interrupts for force threaded handlers

2021-03-24T10:07:38Z

commit 81e2073c175b887398e5bca6c004efa89983f58d upstream. With interrupt force threading all device interrupt handlers are invoked from kernel threads. Contrary to hard interrupt context the invocation only disables bottom halfs, but not interrupts. This was an oversight back then because any code like this will have an issue: thread(irq_A) irq_handler(A) spin_lock(&foo->lock); interrupt(irq_B) irq_handler(B) spin_lock(&foo->lock); This has been triggered with networking (NAPI vs. hrtimers) and console drivers where printk() happens from an interrupt which interrupted the force threaded handler. Now people noticed and started to change the spin_lock() in the handler to spin_lock_irqsave() which affects performance or add IRQF_NOTHREAD to the interrupt request which in turn breaks RT. Fix the root cause and not the symptom and disable interrupts before invoking the force threaded handler which preserves the regular semantics and the usefulness of the interrupt force threading as a general debugging tool. For not RT this is not changing much, except that during the execution of the threaded handler interrupts are delayed until the handler returns. Vs. scheduling and softirq processing there is no difference. For RT kernels there is no issue. Fixes: 8d32a307e4fa ("genirq: Provide forced interrupt threading") Reported-by: Johan Hovold Signed-off-by: Thomas Gleixner Reviewed-by: Johan Hovold Acked-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20210317143859.513307808@linutronix.de Signed-off-by: Greg Kroah-Hartman

genirq/msi: Activate Multi-MSI early when MSI_FLAG_ACTIVATE_EARLY is set

2021-02-10T08:21:07Z

commit 4c457e8cb75eda91906a4f89fc39bde3f9a43922 upstream. When MSI_FLAG_ACTIVATE_EARLY is set (which is the case for PCI), __msi_domain_alloc_irqs() performs the activation of the interrupt (which in the case of PCI results in the endpoint being programmed) as soon as the interrupt is allocated. But it appears that this is only done for the first vector, introducing an inconsistent behaviour for PCI Multi-MSI. Fix it by iterating over the number of vectors allocated to each MSI descriptor. This is easily achieved by introducing a new "for_each_msi_vector" iterator, together with a tiny bit of refactoring. Fixes: f3b0946d629c ("genirq/msi: Make sure PCI MSIs are activated early") Reported-by: Shameer Kolothum Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Tested-by: Shameer Kolothum Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210123122759.1781359-1-maz@kernel.org Signed-off-by: Greg Kroah-Hartman

genirq/irqdomain: Don't try to free an interrupt that has no mapping

2020-12-30T10:25:58Z

[ Upstream commit 4615fbc3788ddc8e7c6d697714ad35a53729aa2c ] When an interrupt allocation fails for N interrupts, it is pretty common for the error handling code to free the same number of interrupts, no matter how many interrupts have actually been allocated. This may result in the domain freeing code to be unexpectedly called for interrupts that have no mapping in that domain. Things end pretty badly. Instead, add some checks to irq_domain_free_irqs_hierarchy() to make sure that thiss does not follow the hierarchy if no mapping exists for a given interrupt. Fixes: 6a6544e520abe ("genirq/irqdomain: Remove auto-recursive hierarchy support") Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201129135551.396777-1-maz@kernel.org Signed-off-by: Sasha Levin

genirq: Let GENERIC_IRQ_IPI select IRQ_DOMAIN_HIERARCHY

2020-11-18T18:18:41Z

[ Upstream commit 151a535171be6ff824a0a3875553ea38570f4c05 ] kernel/irq/ipi.c otherwise fails to compile if nothing else selects it. Fixes: 379b656446a3 ("genirq: Add GENERIC_IRQ_IPI Kconfig symbol") Reported-by: Pavel Machek Tested-by: Pavel Machek Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20201015101222.GA32747@amd Signed-off-by: Sasha Levin

genirq/matrix: Deal with the sillyness of for_each_cpu() on UP

2020-09-03T09:24:29Z

commit 784a0830377d0761834e385975bc46861fea9fa0 upstream. Most of the CPU mask operations behave the same way, but for_each_cpu() and it's variants ignore the cpumask argument and claim that CPU0 is always in the mask. This is historical, inconsistent and annoying behaviour. The matrix allocator uses for_each_cpu() and can be called on UP with an empty cpumask. The calling code does not expect that this succeeds but until commit e027fffff799 ("x86/irq: Unbreak interrupt affinity setting") this went unnoticed. That commit added a WARN_ON() to catch cases which move an interrupt from one vector to another on the same CPU. The warning triggers on UP. Add a check for the cpumask being empty to prevent this. Fixes: 2f75d9e1c905 ("genirq: Implement bitmap matrix allocator") Reported-by: kernel test robot Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman