From: Liao Chang liaochang1@huawei.com
mainline inclusion from mainline-5.7 commit c16816acd08697b02a53f56f8936497a9f6f6e7a category: bugfix bugzilla: NA CVE: NA
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In general calling generic_handle_irq() with interrupts disabled from non interrupt context is harmless. For some interrupt controllers like the x86 trainwrecks this is outright dangerous as it might corrupt state if an interrupt affinity change is pending.
Add infrastructure which allows to mark interrupts as unsafe and catch such usage in generic_handle_irq().
Reported-by: sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: Marc Zyngier maz@kernel.org Link: https://lkml.kernel.org/r/20200306130623.590923677@linutronix.de Signed-off-by: Liao Chang liaochang1@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- include/linux/irq.h | 13 +++++++++++++ kernel/irq/internals.h | 8 ++++++++ kernel/irq/irqdesc.c | 6 ++++++ kernel/irq/resend.c | 5 +++-- 4 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/include/linux/irq.h b/include/linux/irq.h index 014d5804c1b59..ca367d98a991e 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -210,6 +210,8 @@ struct irq_data { * IRQD_CAN_RESERVE - Can use reservation mode * IRQD_MSI_NOMASK_QUIRK - Non-maskable MSI quirk for affinity change * required + * IRQD_HANDLE_ENFORCE_IRQCTX - Enforce that handle_irq_*() is only invoked + * from actual interrupt context. * IRQD_AFFINITY_ON_ACTIVATE - Affinity is set on activation. Don't call * irq_chip::irq_set_affinity() when deactivated. */ @@ -235,6 +237,7 @@ enum { IRQD_DEFAULT_TRIGGER_SET = (1 << 25), IRQD_CAN_RESERVE = (1 << 26), IRQD_MSI_NOMASK_QUIRK = (1 << 27), + IRQD_HANDLE_ENFORCE_IRQCTX = (1 << 28), IRQD_AFFINITY_ON_ACTIVATE = (1 << 29), };
@@ -305,6 +308,16 @@ static inline bool irqd_is_single_target(struct irq_data *d) return __irqd_to_state(d) & IRQD_SINGLE_TARGET; }
+static inline void irqd_set_handle_enforce_irqctx(struct irq_data *d) +{ + __irqd_to_state(d) |= IRQD_HANDLE_ENFORCE_IRQCTX; +} + +static inline bool irqd_is_handle_enforce_irqctx(struct irq_data *d) +{ + return __irqd_to_state(d) & IRQD_HANDLE_ENFORCE_IRQCTX; +} + static inline bool irqd_is_wakeup_set(struct irq_data *d) { return __irqd_to_state(d) & IRQD_WAKEUP_STATE; diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index ed4843df6220c..207bac6ad4c30 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -422,6 +422,10 @@ 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) @@ -448,6 +452,10 @@ 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 dc4549fc71f95..ffdf02b01d816 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -633,9 +633,15 @@ 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/resend.c b/kernel/irq/resend.c index 98c04ca5fa43d..5064b13b80d60 100644 --- a/kernel/irq/resend.c +++ b/kernel/irq/resend.c @@ -72,8 +72,9 @@ void check_irq_resend(struct irq_desc *desc) desc->istate &= ~IRQS_PENDING; desc->istate |= IRQS_REPLAY;
- if (!desc->irq_data.chip->irq_retrigger || - !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) { + if ((!desc->irq_data.chip->irq_retrigger || + !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) && + !handle_enforce_irqctx(&desc->irq_data)) { #ifdef CONFIG_HARDIRQS_SW_RESEND unsigned int irq = irq_desc_get_irq(desc);