irqchip/riscv-aplic: Register syscore operations only once

Since commit 95a8ddde3660 ("irqchip/riscv-aplic: Preserve APLIC
states across suspend/resume"), when multiple NUMA nodes exist
and AIA is not configured as "none", aplic_probe() is called
multiple times. This leads to register_syscore(&aplic_syscore)
being invoked repeatedly, causing the following Oops:

 list_add double add: new=ffffffffb91461f0, prev=ffffffffb91461f0, next=ffffffffb915c408.
 [<ffffffffb7b5c8ca>] __list_add_valid_or_report+0x60/0xc0
 [<ffffffffb7cc3236>] register_syscore+0x3e/0x70
 [<ffffffffb7b8d61c>] aplic_probe+0xc6/0x112

Fix this by registering syscore operations only once, using a static
variable aplic_syscore_registered to track registration.

[ tglx: Trim backtrace properly ]

Fixes: 95a8ddde3660 ("irqchip/riscv-aplic: Preserve APLIC states across suspend/resume")
Signed-off-by: Jessica Liu <liu.xuemei1@zte.com.cn>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260310141731145xMwLsyvXl9Gw-m6A4VRYj@zte.com.cn

diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
index 8775f188ea4fc9ec2d7593762fbeaf259e1f8181..9f53979b69625fba41fd34d3ecef81f9c854360f 100644 (file)
--- a/drivers/irqchip/irq-riscv-aplic-main.c
+++ b/drivers/irqchip/irq-riscv-aplic-main.c
@@ -116,6 +116,16 @@ static struct syscore aplic_syscore = {
        .ops = &aplic_syscore_ops,
 };
 
+static bool aplic_syscore_registered __ro_after_init;
+
+static void aplic_syscore_init(void)
+{
+       if (!aplic_syscore_registered) {
+               register_syscore(&aplic_syscore);
+               aplic_syscore_registered = true;
+       }
+}
+
 static int aplic_pm_notifier(struct notifier_block *nb, unsigned long action, void *data)
 {
        struct aplic_priv *priv = container_of(nb, struct aplic_priv, genpd_nb);
@@ -379,7 +389,7 @@ static int aplic_probe(struct platform_device *pdev)
                return rc;
        }
 
-       register_syscore(&aplic_syscore);
+       aplic_syscore_init();
 
 #ifdef CONFIG_ACPI
        if (!acpi_disabled)