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Message-ID: <a4d2dc7e-7f45-00b7-6c31-cc934ba9c1f5@linux.alibaba.com>
Date:   Tue, 18 Oct 2022 10:41:50 +0800
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Subject: Re: [PATCH V2 2/2] Documentation: kdump: describe VMCOREINFO export
 for RISCV64
To:     Conor Dooley <conor@kernel.org>
Cc:     paul.walmsley@sifive.com, palmer@dabbelt.com,
        aou@eecs.berkeley.edu, anup@brainfault.org, heiko@sntech.de,
        guoren@kernel.org, mick@ics.forth.gr,
        alexandre.ghiti@canonical.com, bhe@redhat.com, vgoyal@redhat.com,
        dyoung@redhat.com, corbet@lwn.net, Conor.Dooley@microchip.com,
        bagasdotme@gmail.com, kexec@lists.infradead.org,
        linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org, crash-utility@redhat.com,
        heinrich.schuchardt@canonical.com, k-hagio-ab@nec.com,
        hschauhan@nulltrace.org, yixun.lan@gmail.com
References: <20221014134139.5151-1-xianting.tian@linux.alibaba.com>
 <20221014134139.5151-3-xianting.tian@linux.alibaba.com>
 <Y02vm7FrhdEoSXZ+@spud>
From:   Xianting Tian <xianting.tian@linux.alibaba.com>
In-Reply-To: <Y02vm7FrhdEoSXZ+@spud>
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在 2022/10/18 上午3:40, Conor Dooley 写道:
> On Fri, Oct 14, 2022 at 09:41:39PM +0800, Xianting Tian wrote:
>> The following interrelated definitions and ranges are needed by the kdump
>> crash tool, they are exported by "arch/riscv/kernel/crash_core.c":
>>      VA_BITS,
>>      PAGE_OFFSET,
>>      phys_ram_base,
>>      MODULES_VADDR ~ MODULES_END,
>>      VMALLOC_START ~ VMALLOC_END,
>>      VMEMMAP_START ~ VMEMMAP_END,
>>      KASAN_SHADOW_START ~ KASAN_SHADOW_END,
>>      KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END
>>
>> Document these RISCV64 exports above.
>>
>> Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com>
>> ---
>>   .../admin-guide/kdump/vmcoreinfo.rst          | 30 +++++++++++++++++++
>>   1 file changed, 30 insertions(+)
>>
>> diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst
>> index 6726f439958c..8e2e164cf3db 100644
>> --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst
>> +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst
>> @@ -595,3 +595,33 @@ X2TLB
>>   -----
>>   
>>   Indicates whether the crashed kernel enabled SH extended mode.
>> +
>> +RISCV64
>> +=======
>> +
>> +VA_BITS
>> +-------
>> +
>> +The maximum number of bits for virtual addresses. Used to compute the
>> +virtual memory ranges.
>> +
>> +PAGE_OFFSET
>> +-----------
>> +
>> +Indicates the virtual kernel start address of direct-mapped RAM region.
> Apologies for not seeing this sooner, but should there not be a "the"
> prior to "direct-mapped"?
will fix in v3
>
>> +
>> +phys_ram_base
>> +-------------
>> +
>> +Indicates the start physical RAM address.
>> +
>> +MODULES_VADDR|MODULES_END|VMALLOC_START|VMALLOC_END|VMEMMAP_START|VMEMMAP_END|KASAN_SHADOW_START|KASAN_SHADOW_END|KERNEL_LINK_ADDR|ADDRESS_SPACE_END
>> +----------------------------------------------------------------------------------------------------------------------------------------------------
>> +
>> +Used to get the correct ranges:
>> +
>> +  * MODULES_VADDR ~ MODULES_END : Kernel module space.
>> +  * VMALLOC_START ~ VMALLOC_END : vmalloc() / ioremap() space.
>> +  * VMEMMAP_START ~ VMEMMAP_END : vmemmap region, used for struct page array.
> Since I'm in pedant mode, it does look a little odd that you're using
> region for vmemmap but space for the others but idc that much.

Sorry, I didn't get your point :(

it contains vmemmap area with reference wth arch/arm64/kernel/crash_core.c.

>
> Thanks,
> Conor.
>
>> +  * KASAN_SHADOW_START ~ KASAN_SHADOW_END : kasan shadow space.
>> +  * KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END : Kernel link and BPF space.
>> -- 
>> 2.17.1
>>
>>