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authorLinus Torvalds <torvalds@linux-foundation.org>2020-03-30 17:35:14 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-03-30 17:35:14 -0700
commit2d385336afcc43732aef1d51528c03f177ecd54e (patch)
treefff0780aea481a225c4d3460aad286c8e95aa1e7 /kernel
parent673b41e04a035d760bc0aff83fa9ee24fd9c2779 (diff)
parent8a13b02a010a743ea0725e9a5454f42cddb65cf0 (diff)
Merge tag 'irq-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner: "Updates for the interrupt subsystem: Treewide: - Cleanup of setup_irq() which is not longer required because the memory allocator is available early. Most cleanup changes come through the various maintainer trees, so the final removal of setup_irq() is postponed towards the end of the merge window. Core: - Protection against unsafe invocation of interrupt handlers and unsafe interrupt injection including a fixup of the offending PCI/AER error injection mechanism. Invoking interrupt handlers from arbitrary contexts, i.e. outside of an actual interrupt, can cause inconsistent state on the fragile x86 interrupt affinity changing hardware trainwreck. Drivers: - Second wave of support for the new ARM GICv4.1 - Multi-instance support for Xilinx and PLIC interrupt controllers - CPU-Hotplug support for PLIC - The obligatory new driver for X1000 TCU - Enhancements, cleanups and fixes all over the place" * tag 'irq-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits) unicore32: Replace setup_irq() by request_irq() sh: Replace setup_irq() by request_irq() hexagon: Replace setup_irq() by request_irq() c6x: Replace setup_irq() by request_irq() alpha: Replace setup_irq() by request_irq() irqchip/gic-v4.1: Eagerly vmap vPEs irqchip/gic-v4.1: Add VSGI property setup irqchip/gic-v4.1: Add VSGI allocation/teardown irqchip/gic-v4.1: Move doorbell management to the GICv4 abstraction layer irqchip/gic-v4.1: Plumb set_vcpu_affinity SGI callbacks irqchip/gic-v4.1: Plumb get/set_irqchip_state SGI callbacks irqchip/gic-v4.1: Plumb mask/unmask SGI callbacks irqchip/gic-v4.1: Add initial SGI configuration irqchip/gic-v4.1: Plumb skeletal VSGI irqchip irqchip/stm32: Retrigger both in eoi and unmask callbacks irqchip/gic-v3: Move irq_domain_update_bus_token to after checking for NULL domain irqchip/xilinx: Do not call irq_set_default_host() irqchip/xilinx: Enable generic irq multi handler irqchip/xilinx: Fill error code when irq domain registration fails irqchip/xilinx: Add support for multiple instances ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/irq/Kconfig5
-rw-r--r--kernel/irq/chip.c2
-rw-r--r--kernel/irq/debugfs.c28
-rw-r--r--kernel/irq/internals.h10
-rw-r--r--kernel/irq/irqdesc.c6
-rw-r--r--kernel/irq/irqdomain.c14
-rw-r--r--kernel/irq/resend.c143
7 files changed, 136 insertions, 72 deletions
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index f92d9a687372..20d501af4f2e 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -43,6 +43,10 @@ config GENERIC_IRQ_MIGRATION
config AUTO_IRQ_AFFINITY
bool
+# Interrupt injection mechanism
+config GENERIC_IRQ_INJECTION
+ bool
+
# Tasklet based software resend for pending interrupts on enable_irq()
config HARDIRQS_SW_RESEND
bool
@@ -127,6 +131,7 @@ config SPARSE_IRQ
config GENERIC_IRQ_DEBUGFS
bool "Expose irq internals in debugfs"
depends on DEBUG_FS
+ select GENERIC_IRQ_INJECTION
default n
---help---
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index b3fa2d87d2f3..41e7e37a0928 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -278,7 +278,7 @@ int irq_startup(struct irq_desc *desc, bool resend, bool force)
}
}
if (resend)
- check_irq_resend(desc);
+ check_irq_resend(desc, false);
return ret;
}
diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c
index a949bd39e343..4f9f844074db 100644
--- a/kernel/irq/debugfs.c
+++ b/kernel/irq/debugfs.c
@@ -190,33 +190,7 @@ static ssize_t irq_debug_write(struct file *file, const char __user *user_buf,
return -EFAULT;
if (!strncmp(buf, "trigger", size)) {
- unsigned long flags;
- int err;
-
- /* Try the HW interface first */
- err = irq_set_irqchip_state(irq_desc_get_irq(desc),
- IRQCHIP_STATE_PENDING, true);
- if (!err)
- return count;
-
- /*
- * Otherwise, try to inject via the resend interface,
- * which may or may not succeed.
- */
- chip_bus_lock(desc);
- raw_spin_lock_irqsave(&desc->lock, flags);
-
- if (irq_settings_is_level(desc) || desc->istate & IRQS_NMI) {
- /* Can't do level nor NMIs, sorry */
- err = -EINVAL;
- } else {
- desc->istate |= IRQS_PENDING;
- check_irq_resend(desc);
- err = 0;
- }
-
- raw_spin_unlock_irqrestore(&desc->lock, flags);
- chip_bus_sync_unlock(desc);
+ int err = irq_inject_interrupt(irq_desc_get_irq(desc));
return err ? err : count;
}
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index c9d8eb7f5c02..7db284b10ac9 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -108,7 +108,7 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc);
irqreturn_t handle_irq_event(struct irq_desc *desc);
/* Resending of interrupts :*/
-void check_irq_resend(struct irq_desc *desc);
+int check_irq_resend(struct irq_desc *desc, bool inject);
bool irq_wait_for_poll(struct irq_desc *desc);
void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action);
@@ -425,6 +425,10 @@ static inline struct cpumask *irq_desc_get_pending_mask(struct irq_desc *desc)
{
return desc->pending_mask;
}
+static inline bool handle_enforce_irqctx(struct irq_data *data)
+{
+ return irqd_is_handle_enforce_irqctx(data);
+}
bool irq_fixup_move_pending(struct irq_desc *desc, bool force_clear);
#else /* CONFIG_GENERIC_PENDING_IRQ */
static inline bool irq_can_move_pcntxt(struct irq_data *data)
@@ -451,6 +455,10 @@ static inline bool irq_fixup_move_pending(struct irq_desc *desc, bool fclear)
{
return false;
}
+static inline bool handle_enforce_irqctx(struct irq_data *data)
+{
+ return false;
+}
#endif /* !CONFIG_GENERIC_PENDING_IRQ */
#if !defined(CONFIG_IRQ_DOMAIN) || !defined(CONFIG_IRQ_DOMAIN_HIERARCHY)
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 98a5f10d1900..1a7723604399 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -638,9 +638,15 @@ void irq_init_desc(unsigned int irq)
int generic_handle_irq(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
+ struct irq_data *data;
if (!desc)
return -EINVAL;
+
+ data = irq_desc_get_irq_data(desc);
+ if (WARN_ON_ONCE(!in_irq() && handle_enforce_irqctx(data)))
+ return -EPERM;
+
generic_handle_irq_desc(desc);
return 0;
}
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 7527e5ef6fe5..35b8d97c3a1d 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -46,11 +46,11 @@ const struct fwnode_operations irqchip_fwnode_ops;
EXPORT_SYMBOL_GPL(irqchip_fwnode_ops);
/**
- * irq_domain_alloc_fwnode - Allocate a fwnode_handle suitable for
+ * __irq_domain_alloc_fwnode - Allocate a fwnode_handle suitable for
* identifying an irq domain
* @type: Type of irqchip_fwnode. See linux/irqdomain.h
- * @name: Optional user provided domain name
* @id: Optional user provided id if name != NULL
+ * @name: Optional user provided domain name
* @pa: Optional user-provided physical address
*
* Allocate a struct irqchip_fwid, and return a poiner to the embedded
@@ -1310,6 +1310,11 @@ int irq_domain_alloc_irqs_hierarchy(struct irq_domain *domain,
unsigned int irq_base,
unsigned int nr_irqs, void *arg)
{
+ if (!domain->ops->alloc) {
+ pr_debug("domain->ops->alloc() is NULL\n");
+ return -ENOSYS;
+ }
+
return domain->ops->alloc(domain, irq_base, nr_irqs, arg);
}
@@ -1347,11 +1352,6 @@ int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
return -EINVAL;
}
- if (!domain->ops->alloc) {
- pr_debug("domain->ops->alloc() is NULL\n");
- return -ENOSYS;
- }
-
if (realloc && irq_base >= 0) {
virq = irq_base;
} else {
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c
index 98c04ca5fa43..27634f4022d0 100644
--- a/kernel/irq/resend.c
+++ b/kernel/irq/resend.c
@@ -47,6 +47,43 @@ static void resend_irqs(unsigned long arg)
/* Tasklet to handle resend: */
static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
+static int irq_sw_resend(struct irq_desc *desc)
+{
+ unsigned int irq = irq_desc_get_irq(desc);
+
+ /*
+ * Validate whether this interrupt can be safely injected from
+ * non interrupt context
+ */
+ if (handle_enforce_irqctx(&desc->irq_data))
+ return -EINVAL;
+
+ /*
+ * If the interrupt is running in the thread context of the parent
+ * irq we need to be careful, because we cannot trigger it
+ * directly.
+ */
+ if (irq_settings_is_nested_thread(desc)) {
+ /*
+ * If the parent_irq is valid, we retrigger the parent,
+ * otherwise we do nothing.
+ */
+ if (!desc->parent_irq)
+ return -EINVAL;
+ irq = desc->parent_irq;
+ }
+
+ /* Set it pending and activate the softirq: */
+ set_bit(irq, irqs_resend);
+ tasklet_schedule(&resend_tasklet);
+ return 0;
+}
+
+#else
+static int irq_sw_resend(struct irq_desc *desc)
+{
+ return -EINVAL;
+}
#endif
/*
@@ -54,49 +91,83 @@ static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
*
* Is called with interrupts disabled and desc->lock held.
*/
-void check_irq_resend(struct irq_desc *desc)
+int check_irq_resend(struct irq_desc *desc, bool inject)
{
+ int err = 0;
+
/*
- * We do not resend level type interrupts. Level type
- * interrupts are resent by hardware when they are still
- * active. Clear the pending bit so suspend/resume does not
- * get confused.
+ * We do not resend level type interrupts. Level type interrupts
+ * are resent by hardware when they are still active. Clear the
+ * pending bit so suspend/resume does not get confused.
*/
if (irq_settings_is_level(desc)) {
desc->istate &= ~IRQS_PENDING;
- return;
+ return -EINVAL;
}
+
if (desc->istate & IRQS_REPLAY)
- return;
- if (desc->istate & IRQS_PENDING) {
- desc->istate &= ~IRQS_PENDING;
+ return -EBUSY;
+
+ if (!(desc->istate & IRQS_PENDING) && !inject)
+ return 0;
+
+ desc->istate &= ~IRQS_PENDING;
+
+ if (!desc->irq_data.chip->irq_retrigger ||
+ !desc->irq_data.chip->irq_retrigger(&desc->irq_data))
+ err = irq_sw_resend(desc);
+
+ /* If the retrigger was successfull, mark it with the REPLAY bit */
+ if (!err)
desc->istate |= IRQS_REPLAY;
+ return err;
+}
- if (!desc->irq_data.chip->irq_retrigger ||
- !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) {
-#ifdef CONFIG_HARDIRQS_SW_RESEND
- unsigned int irq = irq_desc_get_irq(desc);
-
- /*
- * If the interrupt is running in the thread
- * context of the parent irq we need to be
- * careful, because we cannot trigger it
- * directly.
- */
- if (irq_settings_is_nested_thread(desc)) {
- /*
- * If the parent_irq is valid, we
- * retrigger the parent, otherwise we
- * do nothing.
- */
- if (!desc->parent_irq)
- return;
- irq = desc->parent_irq;
- }
- /* Set it pending and activate the softirq: */
- set_bit(irq, irqs_resend);
- tasklet_schedule(&resend_tasklet);
-#endif
- }
- }
+#ifdef CONFIG_GENERIC_IRQ_INJECTION
+/**
+ * irq_inject_interrupt - Inject an interrupt for testing/error injection
+ * @irq: The interrupt number
+ *
+ * This function must only be used for debug and testing purposes!
+ *
+ * Especially on x86 this can cause a premature completion of an interrupt
+ * affinity change causing the interrupt line to become stale. Very
+ * unlikely, but possible.
+ *
+ * The injection can fail for various reasons:
+ * - Interrupt is not activated
+ * - Interrupt is NMI type or currently replaying
+ * - Interrupt is level type
+ * - Interrupt does not support hardware retrigger and software resend is
+ * either not enabled or not possible for the interrupt.
+ */
+int irq_inject_interrupt(unsigned int irq)
+{
+ struct irq_desc *desc;
+ unsigned long flags;
+ int err;
+
+ /* Try the state injection hardware interface first */
+ if (!irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, true))
+ return 0;
+
+ /* That failed, try via the resend mechanism */
+ desc = irq_get_desc_buslock(irq, &flags, 0);
+ if (!desc)
+ return -EINVAL;
+
+ /*
+ * Only try to inject when the interrupt is:
+ * - not NMI type
+ * - activated
+ */
+ if ((desc->istate & IRQS_NMI) || !irqd_is_activated(&desc->irq_data))
+ err = -EINVAL;
+ else
+ err = check_irq_resend(desc, true);
+
+ irq_put_desc_busunlock(desc, flags);
+ return err;
}
+EXPORT_SYMBOL_GPL(irq_inject_interrupt);
+#endif