kernel/linux.git/include/linux/interrupt.h, branch v5.10.257

genirq: Provide new interfaces for affinity hints

2025-10-02T11:35:39+00:00

[ Upstream commit 65c7cdedeb3026fabcc967a7aae2f755ad4d0783 ] The discussion about removing the side effect of irq_set_affinity_hint() of actually applying the cpumask (if not NULL) as affinity to the interrupt, unearthed a few unpleasantries: 1) The modular perf drivers rely on the current behaviour for the very wrong reasons. 2) While none of the other drivers prevents user space from changing the affinity, a cursorily inspection shows that there are at least expectations in some drivers. #1 needs to be cleaned up anyway, so that's not a problem #2 might result in subtle regressions especially when irqbalanced (which nowadays ignores the affinity hint) is disabled. Provide new interfaces: irq_update_affinity_hint() - Only sets the affinity hint pointer irq_set_affinity_and_hint() - Set the pointer and apply the affinity to the interrupt Make irq_set_affinity_hint() a wrapper around irq_apply_affinity_hint() and document it to be phased out. Signed-off-by: Thomas Gleixner Signed-off-by: Nitesh Narayan Lal Signed-off-by: Thomas Gleixner Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20210501021832.743094-1-jesse.brandeburg@intel.com Link: https://lore.kernel.org/r/20210903152430.244937-2-nitesh@redhat.com Stable-dep-of: 915470e1b44e ("i40e: fix IRQ freeing in i40e_vsi_request_irq_msix error path") Signed-off-by: Sasha Levin

genirq: Export affinity setter for modules

2025-10-02T11:35:39+00:00

[ Upstream commit 4d80d6ca5d77fde9880da8466e5b64f250e5bf82 ] Perf modules abuse irq_set_affinity_hint() to set the affinity of system PMU interrupts just because irq_set_affinity() was not exported. The fact that irq_set_affinity_hint() actually sets the affinity is a non-documented side effect and the name is clearly saying it's a hint. To clean this up, export the real affinity setter. Signed-off-by: Thomas Gleixner Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20210518093117.968251441@linutronix.de Stable-dep-of: 915470e1b44e ("i40e: fix IRQ freeing in i40e_vsi_request_irq_msix error path") Signed-off-by: Sasha Levin

genirq/affinity: Add irq_update_affinity_desc()

2025-10-02T11:35:38+00:00

[ Upstream commit 1d3aec89286254487df7641c30f1b14ad1d127a5 ] Add a function to allow the affinity of an interrupt be switched to managed, such that interrupts allocated for platform devices may be managed. This new interface has certain limitations, and attempts to use it in the following circumstances will fail: - For when the kernel is configured for generic IRQ reservation mode (in config GENERIC_IRQ_RESERVATION_MODE). The reason being that it could conflict with managed vs. non-managed interrupt accounting. - The interrupt is already started, which should not be the case during init - The interrupt is already configured as managed, which means double init Suggested-by: Thomas Gleixner Signed-off-by: John Garry Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/1606905417-183214-2-git-send-email-john.garry@huawei.com Stable-dep-of: 915470e1b44e ("i40e: fix IRQ freeing in i40e_vsi_request_irq_msix error path") Signed-off-by: Sasha Levin

lockdep: Don't disable interrupts on RT in disable_irq_nosync_lockdep.*()

2025-04-10T12:30:56+00:00

[ Upstream commit 87886b32d669abc11c7be95ef44099215e4f5788 ] disable_irq_nosync_lockdep() disables interrupts with lockdep enabled to avoid false positive reports by lockdep that a certain lock has not been acquired with disabled interrupts. The user of this macros expects that a lock can be acquried without disabling interrupts because the IRQ line triggering the interrupt is disabled. This triggers a warning on PREEMPT_RT because after disable_irq_nosync_lockdep.*() the following spinlock_t now is acquired with disabled interrupts. On PREEMPT_RT there is no difference between spin_lock() and spin_lock_irq() so avoiding disabling interrupts in this case works for the two remaining callers as of today. Don't disable interrupts on PREEMPT_RT in disable_irq_nosync_lockdep.*(). Closes: https://lore.kernel.org/760e34f9-6034-40e0-82a5-ee9becd24438@roeck-us.net Fixes: e8106b941ceab ("[PATCH] lockdep: core, add enable/disable_irq_irqsave/irqrestore() APIs") Reported-by: Guenter Roeck Suggested-by: "Steven Rostedt (Google)" Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Peter Zijlstra (Intel) Tested-by: Guenter Roeck Link: https://lore.kernel.org/r/20250212103619.2560503-2-bigeasy@linutronix.de Signed-off-by: Sasha Levin

genirq: Add IRQF_NO_AUTOEN for request_irq/nmi()

2023-01-14T09:15:58+00:00

[ Upstream commit cbe16f35bee6880becca6f20d2ebf6b457148552 ] Many drivers don't want interrupts enabled automatically via request_irq(). So they are handling this issue by either way of the below two: (1) irq_set_status_flags(irq, IRQ_NOAUTOEN); request_irq(dev, irq...); (2) request_irq(dev, irq...); disable_irq(irq); The code in the second way is silly and unsafe. In the small time gap between request_irq() and disable_irq(), interrupts can still come. The code in the first way is safe though it's subobtimal. Add a new IRQF_NO_AUTOEN flag which can be handed in by drivers to request_irq() and request_nmi(). It prevents the automatic enabling of the requested interrupt/nmi in the same safe way as #1 above. With that the various usage sites of #1 and #2 above can be simplified and corrected. Signed-off-by: Barry Song Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Cc: dmitry.torokhov@gmail.com Link: https://lore.kernel.org/r/20210302224916.13980-2-song.bao.hua@hisilicon.com Stable-dep-of: 99c05e4283a1 ("iio: adis: add '__adis_enable_irq()' implementation") Signed-off-by: Sasha Levin

treewide: Convert macro and uses of section(foo) to section("foo")

2020-10-25T21:51:49+00:00

Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl Signed-off-by: Joe Perches Reviewed-by: Nick Desaulniers Reviewed-by: Miguel Ojeda Signed-off-by: Linus Torvalds

tasklet: Introduce new initialization API

2020-07-30T18:16:01+00:00

Nowadays, modern kernel subsystems that use callbacks pass the data structure associated with a given callback as argument to the callback. The tasklet subsystem remains one which passes an arbitrary unsigned long to the callback function. This has several problems: - This keeps an extra field for storing the argument in each tasklet data structure, it bloats the tasklet_struct structure with a redundant .data field - No type checking can be performed on this argument. Instead of using container_of() like other callback subsystems, it forces callbacks to do explicit type cast of the unsigned long argument into the required object type. - Buffer overflows can overwrite the .func and the .data field, so an attacker can easily overwrite the function and its first argument to whatever it wants. Add a new tasklet initialization API, via DECLARE_TASKLET() and tasklet_setup(), which will replace the existing ones. This work is greatly inspired by the timer_struct conversion series, see commit e99e88a9d2b0 ("treewide: setup_timer() -> timer_setup()") To avoid problems with both -Wcast-function-type (which is enabled in the kernel via -Wextra is several subsystems), and with mismatched function prototypes when build with Control Flow Integrity enabled, this adds the "use_callback" member to let the tasklet caller choose which union member to call through. Once all old API uses are removed, this and the .data member will be removed as well. (On 64-bit this does not grow the struct size as the new member fills the hole after atomic_t, which is also "int" sized.) Signed-off-by: Romain Perier Co-developed-by: Allen Pais Signed-off-by: Allen Pais Reviewed-by: Greg Kroah-Hartman Acked-by: Thomas Gleixner Co-developed-by: Kees Cook Signed-off-by: Kees Cook

treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()

2020-07-30T18:15:58+00:00

This converts all the existing DECLARE_TASKLET() (and ...DISABLED) macros with DECLARE_TASKLET_OLD() in preparation for refactoring the tasklet callback type. All existing DECLARE_TASKLET() users had a "0" data argument, it has been removed here as well. Reviewed-by: Greg Kroah-Hartman Acked-by: Thomas Gleixner Signed-off-by: Kees Cook

x86/entry: Unbreak __irqentry_text_start/end magic

2020-06-11T13:15:29+00:00

The entry rework moved interrupt entry code from the irqentry to the noinstr section which made the irqentry section empty. This breaks boundary checks which rely on the __irqentry_text_start/end markers to find out whether a function in a stack trace is interrupt/exception entry code. This affects the function graph tracer and filter_irq_stacks(). As the IDT entry points are all sequentialy emitted this is rather simple to unbreak by injecting __irqentry_text_start/end as global labels. To make this work correctly: - Remove the IRQENTRY_TEXT section from the x86 linker script - Define __irqentry so it breaks the build if it's used - Adjust the entry mirroring in PTI - Remove the redundant kprobes and unwinder bound checks Reported-by: Qian Cai Signed-off-by: Thomas Gleixner

genirq: Provide interrupt injection mechanism

2020-03-08T10:06:42+00:00

Error injection mechanisms need a half ways safe way to inject interrupts as invoking generic_handle_irq() or the actual device interrupt handler directly from e.g. a debugfs write is not guaranteed to be safe. On x86 generic_handle_irq() is unsafe due to the hardware trainwreck which is the base of x86 interrupt delivery and affinity management. Move the irq debugfs injection code into a separate function which can be used by error injection code as well. The implementation prevents at least that state is corrupted, but it cannot close a very tiny race window on x86 which might result in a stale and not serviced device interrupt under very unlikely circumstances. This is explicitly for debugging and testing and not for production use or abuse in random driver code. Signed-off-by: Thomas Gleixner Tested-by: Kuppuswamy Sathyanarayanan Reviewed-by: Kuppuswamy Sathyanarayanan Acked-by: Marc Zyngier Link: https://lkml.kernel.org/r/20200306130623.990928309@linutronix.de