From: vladimir.murzin@arm•com (Vladimir Murzin)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] irqchip: gicv3-its: fix ITS CPU init
Date: Fri, 23 Jan 2015 10:03:30 +0000 [thread overview]
Message-ID: <54C21C72.2030302@arm.com> (raw)
In-Reply-To: <54AFFD76.7060401@arm.com>
On 09/01/15 16:10, Marc Zyngier wrote:
> Hi Vladimir,
>
> On 09/01/15 15:50, Vladimir Murzin wrote:
>> 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.
>>
>> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm•com>
>
> Looks good to me.
>
> Acked-by: Marc Zyngier <marc.zyngier@arm•com>
>
> M.
>
Thomas, Jason, are you OK with this patch?
Vladimir
>> ---
>> 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 86e4684..128a12b 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();
>> }
>>
>
>
prev parent reply other threads:[~2015-01-23 10:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-09 15:50 [PATCH] irqchip: gicv3-its: fix ITS CPU init Vladimir Murzin
2015-01-09 16:10 ` Marc Zyngier
2015-01-23 10:03 ` Vladimir Murzin [this message]
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