user/sven/linux.git/kernel/irq, branch v4.19.85

genirq: Prevent NULL pointer dereference in resend_irqs()

2019-09-19T07:09:34Z

commit eddf3e9c7c7e4d0707c68d1bb22cc6ec8aef7d4a upstream. The following crash was observed: Unable to handle kernel NULL pointer dereference at 0000000000000158 Internal error: Oops: 96000004 [#1] SMP pc : resend_irqs+0x68/0xb0 lr : resend_irqs+0x64/0xb0 ... Call trace: resend_irqs+0x68/0xb0 tasklet_action_common.isra.6+0x84/0x138 tasklet_action+0x2c/0x38 __do_softirq+0x120/0x324 run_ksoftirqd+0x44/0x60 smpboot_thread_fn+0x1ac/0x1e8 kthread+0x134/0x138 ret_from_fork+0x10/0x18 The reason for this is that the interrupt resend mechanism happens in soft interrupt context, which is a asynchronous mechanism versus other operations on interrupts. free_irq() does not take resend handling into account. Thus, the irq descriptor might be already freed before the resend tasklet is executed. resend_irqs() does not check the return value of the interrupt descriptor lookup and derefences the return value unconditionally. 1): __setup_irq irq_startup check_irq_resend // activate softirq to handle resend irq 2): irq_domain_free_irqs irq_free_descs free_desc call_rcu(&desc->rcu, delayed_free_desc) 3): __do_softirq tasklet_action resend_irqs desc = irq_to_desc(irq) desc->handle_irq(desc) // desc is NULL --> Ooops Fix this by adding a NULL pointer check in resend_irqs() before derefencing the irq descriptor. Fixes: a4633adcdbc1 ("[PATCH] genirq: add genirq sw IRQ-retrigger") Signed-off-by: Yunfeng Ye Signed-off-by: Thomas Gleixner Reviewed-by: Zhiqiang Liu Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1630ae13-5c8e-901e-de09-e740b6a426a7@huawei.com Signed-off-by: Greg Kroah-Hartman

genirq: Properly pair kobject_del() with kobject_add()

2019-08-29T06:28:57Z

commit d0ff14fdc987303aeeb7de6f1bd72c3749ae2a9b upstream. If alloc_descs() fails before irq_sysfs_init() has run, free_desc() in the cleanup path will call kobject_del() even though the kobject has not been added with kobject_add(). Fix this by making the call to kobject_del() conditional on whether irq_sysfs_init() has run. This problem surfaced because commit aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") makes kobject_del() stricter about pairing with kobject_add(). If the pairing is incorrrect, a WARNING and backtrace occur in sysfs_remove_group() because there is no parent. [ tglx: Add a comment to the code and make it work with CONFIG_SYSFS=n ] Fixes: ecb3f394c5db ("genirq: Expose interrupt information through sysfs") Signed-off-by: Michael Kelley Signed-off-by: Thomas Gleixner Acked-by: Greg Kroah-Hartman Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1564703564-4116-1-git-send-email-mikelley@microsoft.com Signed-off-by: Greg Kroah-Hartman

genirq: Add optional hardware synchronization for shutdown

2019-07-21T07:03:13Z

commit 62e0468650c30f0298822c580f382b16328119f6 upstream free_irq() ensures that no hardware interrupt handler is executing on a different CPU before actually releasing resources and deactivating the interrupt completely in a domain hierarchy. But that does not catch the case where the interrupt is on flight at the hardware level but not yet serviced by the target CPU. That creates an interesing race condition: CPU 0 CPU 1 IRQ CHIP interrupt is raised sent to CPU1 Unable to handle immediately (interrupts off, deep idle delay) mask() ... free() shutdown() synchronize_irq() release_resources() do_IRQ() -> resources are not available That might be harmless and just trigger a spurious interrupt warning, but some interrupt chips might get into a wedged state. Utilize the existing irq_get_irqchip_state() callback for the synchronization in free_irq(). synchronize_hardirq() is not using this mechanism as it might actually deadlock unter certain conditions, e.g. when called with interrupts disabled and the target CPU is the one on which the synchronization is invoked. synchronize_irq() uses it because that function cannot be called from non preemtible contexts as it might sleep. No functional change intended and according to Marc the existing GIC implementations where the driver supports the callback should be able to cope with that core change. Famous last words. Fixes: 464d12309e1b ("x86/vector: Switch IOAPIC to global reservation mode") Reported-by: Robert Hodaszi Signed-off-by: Thomas Gleixner Reviewed-by: Marc Zyngier Tested-by: Marc Zyngier Link: https://lkml.kernel.org/r/20190628111440.279463375@linutronix.de Signed-off-by: Greg Kroah-Hartman

genirq: Fix misleading synchronize_irq() documentation

2019-07-21T07:03:12Z

commit 1d21f2af8571c6a6a44e7c1911780614847b0253 upstream The function might sleep, so it cannot be called from interrupt context. Not even with care. Signed-off-by: Thomas Gleixner Cc: Marc Zyngier Link: https://lkml.kernel.org/r/20190628111440.189241552@linutronix.de Signed-off-by: Greg Kroah-Hartman

genirq: Delay deactivation in free_irq()

2019-07-21T07:03:12Z

commit 4001d8e8762f57d418b66e4e668601791900a1dd upstream When interrupts are shutdown, they are immediately deactivated in the irqdomain hierarchy. While this looks obviously correct there is a subtle issue: There might be an interrupt in flight when free_irq() is invoking the shutdown. This is properly handled at the irq descriptor / primary handler level, but the deactivation might completely disable resources which are required to acknowledge the interrupt. Split the shutdown code and deactivate the interrupt after synchronization in free_irq(). Fixup all other usage sites where this is not an issue to invoke the combined shutdown_and_deactivate() function instead. This still might be an issue if the interrupt in flight servicing is delayed on a remote CPU beyond the invocation of synchronize_irq(), but that cannot be handled at that level and needs to be handled in the synchronize_irq() context. Fixes: f8264e34965a ("irqdomain: Introduce new interfaces to support hierarchy irqdomains") Reported-by: Robert Hodaszi Signed-off-by: Thomas Gleixner Reviewed-by: Marc Zyngier Link: https://lkml.kernel.org/r/20190628111440.098196390@linutronix.de Signed-off-by: Greg Kroah-Hartman

genirq: Prevent use-after-free and work list corruption

2019-05-10T15:54:10Z

[ Upstream commit 59c39840f5abf4a71e1810a8da71aaccd6c17d26 ] When irq_set_affinity_notifier() replaces the notifier, then the reference count on the old notifier is dropped which causes it to be freed. But nothing ensures that the old notifier is not longer queued in the work list. If it is queued this results in a use after free and possibly in work list corruption. Ensure that the work is canceled before the reference is dropped. Signed-off-by: Prasad Sodagudi Signed-off-by: Thomas Gleixner Cc: marc.zyngier@arm.com Link: https://lkml.kernel.org/r/1553439424-6529-1-git-send-email-psodagud@codeaurora.org Signed-off-by: Sasha Levin

genirq: Initialize request_mutex if CONFIG_SPARSE_IRQ=n

2019-04-17T06:38:52Z

commit e8458e7afa855317b14915d7b86ab3caceea7eb6 upstream. When CONFIG_SPARSE_IRQ is disable, the request_mutex in struct irq_desc is not initialized which causes malfunction. Fixes: 9114014cf4e6 ("genirq: Add mutex to irq desc to serialize request/free_irq()") Signed-off-by: Kefeng Wang Signed-off-by: Thomas Gleixner Reviewed-by: Mukesh Ojha Cc: Marc Zyngier Cc: Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190404074512.145533-1-wangkefeng.wang@huawei.com Signed-off-by: Greg Kroah-Hartman

genirq: Respect IRQCHIP_SKIP_SET_WAKE in irq_chip_set_wake_parent()

2019-04-17T06:38:52Z

commit 325aa19598e410672175ed50982f902d4e3f31c5 upstream. If a child irqchip calls irq_chip_set_wake_parent() but its parent irqchip has the IRQCHIP_SKIP_SET_WAKE flag set an error is returned. This is inconsistent behaviour vs. set_irq_wake_real() which returns 0 when the irqchip has the IRQCHIP_SKIP_SET_WAKE flag set. It doesn't attempt to walk the chain of parents and set irq wake on any chips that don't have the flag set either. If the intent is to call the .irq_set_wake() callback of the parent irqchip, then we expect irqchip implementations to omit the IRQCHIP_SKIP_SET_WAKE flag and implement an .irq_set_wake() function that calls irq_chip_set_wake_parent(). The problem has been observed on a Qualcomm sdm845 device where set wake fails on any GPIO interrupts after applying work in progress wakeup irq patches to the GPIO driver. The chain of chips looks like this: QCOM GPIO -> QCOM PDC (SKIP) -> ARM GIC (SKIP) The GPIO controllers parent is the QCOM PDC irqchip which in turn has ARM GIC as parent. The QCOM PDC irqchip has the IRQCHIP_SKIP_SET_WAKE flag set, and so does the grandparent ARM GIC. The GPIO driver doesn't know if the parent needs to set wake or not, so it unconditionally calls irq_chip_set_wake_parent() causing this function to return a failure because the parent irqchip (PDC) doesn't have the .irq_set_wake() callback set. Returning 0 instead makes everything work and irqs from the GPIO controller can be configured for wakeup. Make it consistent by returning 0 (success) from irq_chip_set_wake_parent() when a parent chip has IRQCHIP_SKIP_SET_WAKE set. [ tglx: Massaged changelog ] Fixes: 08b55e2a9208e ("genirq: Add irqchip_set_wake_parent") Signed-off-by: Stephen Boyd Signed-off-by: Thomas Gleixner Acked-by: Marc Zyngier Cc: linux-arm-kernel@lists.infradead.org Cc: linux-gpio@vger.kernel.org Cc: Lina Iyer Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190325181026.247796-1-swboyd@chromium.org Signed-off-by: Greg Kroah-Hartman

genirq: Avoid summation loops for /proc/stat

2019-04-05T20:33:09Z

[ Upstream commit 1136b0728969901a091f0471968b2b76ed14d9ad ] Waiman reported that on large systems with a large amount of interrupts the readout of /proc/stat takes a long time to sum up the interrupt statistics. In principle this is not a problem. but for unknown reasons some enterprise quality software reads /proc/stat with a high frequency. The reason for this is that interrupt statistics are accounted per cpu. So the /proc/stat logic has to sum up the interrupt stats for each interrupt. This can be largely avoided for interrupts which are not marked as 'PER_CPU' interrupts by simply adding a per interrupt summation counter which is incremented along with the per interrupt per cpu counter. The PER_CPU interrupts need to avoid that and use only per cpu accounting because they share the interrupt number and the interrupt descriptor and concurrent updates would conflict or require unwanted synchronization. Reported-by: Waiman Long Signed-off-by: Thomas Gleixner Reviewed-by: Waiman Long Reviewed-by: Marc Zyngier Reviewed-by: Davidlohr Bueso Cc: Matthew Wilcox Cc: Andrew Morton Cc: Alexey Dobriyan Cc: Kees Cook Cc: linux-fsdevel@vger.kernel.org Cc: Davidlohr Bueso Cc: Miklos Szeredi Cc: Daniel Colascione Cc: Dave Chinner Cc: Randy Dunlap Link: https://lkml.kernel.org/r/20190208135020.925487496@linutronix.de 8<------------- v2: Undo the unintentional layout change of struct irq_desc. include/linux/irqdesc.h | 1 + kernel/irq/chip.c | 12 ++++++++++-- kernel/irq/internals.h | 8 +++++++- kernel/irq/irqdesc.c | 7 ++++++- 4 files changed, 24 insertions(+), 4 deletions(-) Signed-off-by: Sasha Levin

genirq: Make sure the initial affinity is not empty

2019-03-05T16:58:47Z

[ Upstream commit bddda606ec76550dd63592e32a6e87e7d32583f7 ] If all CPUs in the irq_default_affinity mask are offline when an interrupt is initialized then irq_setup_affinity() can set an empty affinity mask for a newly allocated interrupt. Fix this by falling back to cpu_online_mask in case the resulting affinity mask is zero. Signed-off-by: Srinivas Ramana Signed-off-by: Thomas Gleixner Cc: linux-arm-msm@vger.kernel.org Link: https://lkml.kernel.org/r/1545312957-8504-1-git-send-email-sramana@codeaurora.org Signed-off-by: Sasha Levin