From 16acae729564ee0c3918342d8556cc42eeb29942 Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Fri, 6 Mar 2015 16:37:40 +0000 Subject: [PATCH] irqchip: gicv3-its: Fix ITS CPU init We skip initialisation of ITS in case the device-tree has no corresponding description, but we are still accessing to ITS bits while setting CPU interface what leads to the kernel panic: ITS: No ITS available, not enabling LPIs CPU0: found redistributor 0 region 0:0x000000002f100000 Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = ffffffc0007fb000 [00000000] *pgd=00000000fc407003, *pud=00000000fc407003, *pmd=00000000fc408003, *pte=006000002f000707 Internal error: Oops: 96000005 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.19.0-rc2+ #318 Hardware name: FVP Base (DT) task: ffffffc00077edb0 ti: ffffffc00076c000 task.ti: ffffffc00076c000 PC is at its_cpu_init+0x2c/0x320 LR is at gic_cpu_init+0x168/0x1bc It happens in gic_rdists_supports_plpis() because gic_rdists is NULL. The gic_rdists is set to non-NULL only when ITS node is presented in the device-tree. Fix this by moving the call to gic_rdists_supports_plpis() inside the !list_empty(&its_nodes) block, because it is that list that guards the validity of the rest of the information in this driver. Acked-by: Marc Zyngier Signed-off-by: Vladimir Murzin Signed-off-by: Marc Zyngier Link: https://lkml.kernel.org/r/1425659870-11832-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Jason Cooper --- drivers/irqchip/irq-gic-v3-its.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index d8996bdf0f61..c217ebcf7a48 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -1382,12 +1382,11 @@ static bool gic_rdists_supports_plpis(void) int its_cpu_init(void) { - if (!gic_rdists_supports_plpis()) { - pr_info("CPU%d: LPIs not supported\n", smp_processor_id()); - return -ENXIO; - } - if (!list_empty(&its_nodes)) { + if (!gic_rdists_supports_plpis()) { + pr_info("CPU%d: LPIs not supported\n", smp_processor_id()); + return -ENXIO; + } its_cpu_init_lpis(); its_cpu_init_collection(); } -- 2.39.5