6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Samuel Holland <samuel.holland@xxxxxxxxxx>
commit e306a894bd511804ba9db7c00ca9cc05b55df1f2 upstream.
Now that the PLIC uses a platform driver, the driver is probed later in the
boot process, where interrupts from peripherals might already be pending.
As a result, plic_handle_irq() may be called as early as the call to
irq_set_chained_handler() completes. But this call happens before the
per-context handler is completely set up, so there is a window where
plic_handle_irq() can see incomplete per-context state and crash.
Avoid this by delaying the call to irq_set_chained_handler() until all
handlers from all PLICs are initialized.
Fixes: 8ec99b033147 ("irqchip/sifive-plic: Convert PLIC driver into a platform driver")
Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Samuel Holland <samuel.holland@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20240529215458.937817-1-samuel.holland@xxxxxxxxxx
Closes: https://lore.kernel.org/r/CAMuHMdVYFFR7K5SbHBLY-JHhb7YpgGMS_hnRWm8H0KD-wBo+4A@xxxxxxxxxxxxxx/
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/irqchip/irq-sifive-plic.c | 34 +++++++++++++++++-----------------
1 file changed, 17 insertions(+), 17 deletions(-)
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -85,7 +85,7 @@ struct plic_handler {
struct plic_priv *priv;
};
static int plic_parent_irq __ro_after_init;
-static bool plic_cpuhp_setup_done __ro_after_init;
+static bool plic_global_setup_done __ro_after_init;
static DEFINE_PER_CPU(struct plic_handler, plic_handlers);
static int plic_irq_set_type(struct irq_data *d, unsigned int type);
@@ -490,10 +490,8 @@ static int plic_probe(struct platform_de
unsigned long plic_quirks = 0;
struct plic_handler *handler;
u32 nr_irqs, parent_hwirq;
- struct irq_domain *domain;
struct plic_priv *priv;
irq_hw_number_t hwirq;
- bool cpuhp_setup;
if (is_of_node(dev->fwnode)) {
const struct of_device_id *id;
@@ -552,14 +550,6 @@ static int plic_probe(struct platform_de
continue;
}
- /* Find parent domain and register chained handler */
- domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(), DOMAIN_BUS_ANY);
- if (!plic_parent_irq && domain) {
- plic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
- if (plic_parent_irq)
- irq_set_chained_handler(plic_parent_irq, plic_handle_irq);
- }
-
/*
* When running in M-mode we need to ignore the S-mode handler.
* Here we assume it always comes later, but that might be a
@@ -600,25 +590,35 @@ done:
goto fail_cleanup_contexts;
/*
- * We can have multiple PLIC instances so setup cpuhp state
+ * We can have multiple PLIC instances so setup global state
* and register syscore operations only once after context
* handlers of all online CPUs are initialized.
*/
- if (!plic_cpuhp_setup_done) {
- cpuhp_setup = true;
+ if (!plic_global_setup_done) {
+ struct irq_domain *domain;
+ bool global_setup = true;
+
for_each_online_cpu(cpu) {
handler = per_cpu_ptr(&plic_handlers, cpu);
if (!handler->present) {
- cpuhp_setup = false;
+ global_setup = false;
break;
}
}
- if (cpuhp_setup) {
+
+ if (global_setup) {
+ /* Find parent domain and register chained handler */
+ domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(), DOMAIN_BUS_ANY);
+ if (domain)
+ plic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
+ if (plic_parent_irq)
+ irq_set_chained_handler(plic_parent_irq, plic_handle_irq);
+
cpuhp_setup_state(CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
"irqchip/sifive/plic:starting",
plic_starting_cpu, plic_dying_cpu);
register_syscore_ops(&plic_irq_syscore_ops);
- plic_cpuhp_setup_done = true;
+ plic_global_setup_done = true;
}
}
