From: Thomas Gleixner tglx@linutronix.de
mainline inclusion from mainline-5.7 commit 1f85b1f5e1f5541272abedc19ba7b6c5b564c228 category: bugfix bugzilla: NA CVE: NA
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In preparation for an interrupt injection interface which can be used safely by error injection mechanisms. e.g. PCI-E/ AER, add a return value to check_irq_resend() so errors can be propagated to the caller.
Split out the software resend code so the ugly #ifdef in check_irq_resend() goes away and the whole thing becomes readable.
Fix up the caller in debugfs. The caller in irq_startup() does not care about the return value as this is unconditionally invoked for all interrupts and the resend is best effort anyway.
Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: Marc Zyngier maz@kernel.org Link: https://lkml.kernel.org/r/20200306130623.775200917@linutronix.de Signed-off-by: Liao Chang liaochang1@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- kernel/irq/debugfs.c | 3 +- kernel/irq/internals.h | 2 +- kernel/irq/resend.c | 81 +++++++++++++++++++++++++----------------- 3 files changed, 50 insertions(+), 36 deletions(-)
diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c index 4eb5c62991feb..859412734183e 100644 --- a/kernel/irq/debugfs.c +++ b/kernel/irq/debugfs.c @@ -218,8 +218,7 @@ static ssize_t irq_debug_write(struct file *file, const char __user *user_buf, err = -EINVAL; } else { desc->istate |= IRQS_PENDING; - check_irq_resend(desc); - err = 0; + err = check_irq_resend(desc); }
raw_spin_unlock_irqrestore(&desc->lock, flags); diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index 207bac6ad4c30..36c193df9dace 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 irq_wait_for_poll(struct irq_desc *desc); void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action);
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c index 34f79ddfef182..1faf8991adbb5 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
static int try_retrigger(struct irq_desc *desc) @@ -66,48 +103,26 @@ static int try_retrigger(struct irq_desc *desc) * * 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) { + /* - * 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; + return -EBUSY; + if (desc->istate & IRQS_PENDING) { desc->istate &= ~IRQS_PENDING; desc->istate |= IRQS_REPLAY; - - if (!try_retrigger(desc)) { -#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 - } + if (!try_retrigger(desc)) + return irq_sw_resend(desc); } + return 0; }