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Message-ID: <9f4a058d-1f6d-69ab-3c31-5817db7d1f90@huawei.com>
Date:   Thu, 21 Apr 2022 15:21:25 +0800
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Subject: Re: [PATCH 5.10] fix csdlock_debug cause arm64 boot panic
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To:     Randy Dunlap <rdunlap@infradead.org>,
        <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>
CC:     <peterz@infradead.org>, <gor@linux.ibm.com>, <tglx@linutronix.de>,
        <axboe@kernel.dk>, <arnd@arndb.de>
References: <20220421033914.217622-1-chenzhongjin@huawei.com>
 <461fa8ba-82c1-73b0-b900-7fa1ffb774f9@infradead.org>
From:   Chen Zhongjin <chenzhongjin@huawei.com>
In-Reply-To: <461fa8ba-82c1-73b0-b900-7fa1ffb774f9@infradead.org>
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Hi,

On 2022/4/21 12:08, Randy Dunlap wrote:
> Hi--
> 
> On 4/20/22 20:39, Chen Zhongjin wrote:
>> ---
>>  kernel/smp.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/kernel/smp.c b/kernel/smp.c
>> index 65a630f62363..1ce64de460d0 100644
>> --- a/kernel/smp.c
>> +++ b/kernel/smp.c
>> @@ -176,7 +176,7 @@ static int __init csdlock_debug(char *str)
>>  
>>  	return 0;
> 
> ^^^ This should be
> 	return 1;
> 
> since __setup() functions return 1 on success -- opposite of
> early_param() return values.
> 

Fixed in v2.

By the way, below patch forced to open CONFIG_SPARSEMEM_VMEMMAP on arm64
from 5.12-rc3. By this __page_to_pfn won't call __nr_to_section and
causes this bug.

https://lore.kernel.org/all/20210420093559.23168-1-catalin.marinas@arm.com/

So this patch is only applied to 5.10-LTS.

>>  }
>> -early_param("csdlock_debug", csdlock_debug);
>> +__setup("csdlock_debug=", csdlock_debug);
>>  
>>  static DEFINE_PER_CPU(call_single_data_t *, cur_csd);
>>  static DEFINE_PER_CPU(smp_call_func_t, cur_csd_func);
> 
> Thanks.
> 

Thanks!