linux-kernel - Re: [v3 PATCH 6/8] clocksource/drivers/riscv: Add required checks during clock source init

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Message-ID: <7e6afb87-73e1-9688-7602-b7579fb94590@wdc.com>
Date:   Fri, 8 Feb 2019 14:56:13 -0800
From:   Atish Patra <atish.patra@....com>
To:     Christoph Hellwig <hch@...radead.org>
Cc:     Damien Le Moal <Damien.LeMoal@....com>,
        Albert Ou <aou@...s.berkeley.edu>,
        Jason Cooper <jason@...edaemon.net>,
        Alan Kao <alankao@...estech.com>,
        Dmitriy Cherkasov <dmitriy@...-tech.org>,
        Anup Patel <anup@...infault.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Patrick Stählin <me@...ki.ch>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Marc Zyngier <marc.zyngier@....com>,
        Palmer Dabbelt <palmer@...ive.com>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Andreas Schwab <schwab@...e.de>,
        "linux-riscv@...ts.infradead.org" <linux-riscv@...ts.infradead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Zong Li <zongbox@...il.com>
Subject: Re: [v3 PATCH 6/8] clocksource/drivers/riscv: Add required checks
 during clock source init

On 2/8/19 1:04 AM, Christoph Hellwig wrote:
> On Thu, Feb 07, 2019 at 05:51:19PM -0800, Atish Patra wrote:
>> Currently, clocksource registration happens for an invalid cpu
>> for non-smp kernels. This lead to kernel panic as cpu hotplug
>> registration will fail for those cpus. Moreover,
>> riscv_hartid_to_cpuid can return errors now.
>>
>> Do not proceed if hartid or cpuid is invalid. Take this opprtunity
>> to print appropriate error strings for different failure cases.
>>
>> Signed-off-by: Atish Patra <atish.patra@....com>
>> ---
>>   drivers/clocksource/timer-riscv.c | 23 ++++++++++++++++++++---
>>   1 file changed, 20 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
>> index 43189220..3c7ea75b 100644
>> --- a/drivers/clocksource/timer-riscv.c
>> +++ b/drivers/clocksource/timer-riscv.c
>> @@ -95,13 +95,30 @@ static int __init riscv_timer_init_dt(struct device_node *n)
>>   	struct clocksource *cs;
>>   
>>   	hartid = riscv_of_processor_hartid(n);
>> +	if (hartid < 0) {
>> +		pr_warn("Not valid hartid for node [%pOF] error = [%d]\n",
>> +			n, hartid);
>> +		return hartid;
>> +	}
>> +
>>   	cpuid = riscv_hartid_to_cpuid(hartid);
>> +	if (cpuid < 0) {
>> +		pr_warn("Invalid cpuid for hartid [%d]\n", hartid);
>> +		return cpuid;
>> +	}
>>   
>>   	if (cpuid != smp_processor_id())
>>   		return 0;
>>   
>> +	pr_err("%s: Registering clocksource cpuid [%d] hartid [%d]\n",
>> +	       __func__, cpuid, hartid);
> 
> This does not look like an error case to me.  At best it is info,
> if not debug.
> 
Thanks for catching. It was a typo. I will fix it in next version.

Regards,
Atish
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
>

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