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Subject: Re: [DRAFT] mm/kprobes: Add generic kprobe_fault_handler() fallback
 definition
To:     Guenter Roeck <linux@roeck-us.net>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Cc:     akpm@linux-foundation.org
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From:   Anshuman Khandual <anshuman.khandual@arm.com>
Message-ID: <fc68afaa-32e1-a265-aae2-e4a9440f4c95@arm.com>
Date:   Wed, 3 Jul 2019 11:05:27 +0530
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On 07/01/2019 06:58 PM, Guenter Roeck wrote:
> On 7/1/19 2:35 AM, Anshuman Khandual wrote:
>> Architectures like parisc enable CONFIG_KROBES without having a definition
>> for kprobe_fault_handler() which results in a build failure. Arch needs to
>> provide kprobe_fault_handler() as it is platform specific and cannot have
>> a generic working alternative. But in the event when platform lacks such a
>> definition there needs to be a fallback.
>>
>> This adds a stub kprobe_fault_handler() definition which not only prevents
>> a build failure but also makes sure that kprobe_page_fault() if called will
>> always return negative in absence of a sane platform specific alternative.
>>
>> While here wrap kprobe_page_fault() in CONFIG_KPROBES. This enables stud
>> definitions for generic kporbe_fault_handler() and kprobes_built_in() can
>> just be dropped. Only on x86 it needs to be added back locally as it gets
>> used in a !CONFIG_KPROBES function do_general_protection().
>>
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>> I am planning to go with approach unless we just want to implement a stub
>> definition for parisc to get around the build problem for now.
>>
>> Hello Guenter,
>>
>> Could you please test this in your parisc setup. Thank you.
>>
> 
> With this patch applied on top of next-20190628, parisc:allmodconfig builds
> correctly. I scheduled a full build for tonight for all architectures.

How did that come along ? Did this pass all build tests ?