Re: [PATCH] irqchip/gic-v5: Install root IRQ handler last in gicv5_init_common()
From: Marc Zyngier <maz@kernel.org>
Date: 2026-09-02 15:52:10
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On Wed, 02 Sep 2026 15:32:55 +0100, Jiangshan Yi [off-list ref] wrote:
set_handle_irq() is irreversible: once installed, handle_arch_irq points at gicv5_handle_irq, which dereferences the PPI/SPI/LPI irqdomains. If gicv5_irs_enable() fails afterwards, the error path calls gicv5_free_domains() while handle_arch_irq still references those domains.
I don't think that's a massive problem. If you can't enable the IRS, you can't do much at all. Your system is already completely dead.
Move set_handle_irq() after gicv5_irs_enable() so the handler is only installed once all fallible steps have succeeded. Drop the no-op set_handle_irq(NULL) in the error path, which never worked because set_handle_irq() returns -EBUSY once a handler is set.
That is a reasonable cleanup.
quoted hunk ↗ jump to hunk
Fixes: 183750b276c2 ("irqchip/gic-v5: Fix gicv5_init_common() error paths") Signed-off-by: Jiangshan Yi <redacted> --- drivers/irqchip/irq-gic-v5.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)diff --git a/drivers/irqchip/irq-gic-v5.c b/drivers/irqchip/irq-gic-v5.c index ac2d423b1723..37184942dc11 100644 --- a/drivers/irqchip/irq-gic-v5.c +++ b/drivers/irqchip/irq-gic-v5.c@@ -1166,21 +1166,19 @@ static int __init gicv5_init_common(struct fwnode_handle *parent_domain) if (ret) goto out_int; - ret = set_handle_irq(gicv5_handle_irq); + ret = gicv5_irs_enable(); if (ret) goto out_int; - ret = gicv5_irs_enable(); + ret = set_handle_irq(gicv5_handle_irq); if (ret) - goto out_handle; + goto out_int;
Under which circumstance can this fail? There should be none. So if this ever returns an error, we should immediately stop with a panic. No need to clean anything up, just die on the spot.
gicv5_smp_init(); gicv5_irs_its_probe(); return 0; -out_handle: - set_handle_irq(NULL); out_int: gicv5_cpu_disable_interrupts(); gicv5_free_domains();
Thanks, M. -- Jazz isn't dead. It just smells funny.