[Crash-utility] RISCV64: Use va_kernel_pa_offset in VTOP()

[HAGIO KAZUHITO(萩尾 一仁)]

On 2023/07/24 17:44, Song Shuai wrote:
> 在 2023/7/24 15:41, Conor Dooley 写道:
>> Hey,
>>
>> On Mon, Jul 24, 2023 at 12:06:49PM +0800, Song Shuai wrote:
>>> Since RISC-V Linux v6.4, the commit 3335068f8721 ("riscv: Use
>>> PUD/P4D/PGD pages for the linear mapping") changes the
>>> phys_ram_base from the kernel_map.phys_addr to the start of DRAM.
>>>
>>> The Crash's VTOP() still uses phys_ram_base and kernel_map.virt_addr
>>> to translate kernel virtual address, that made Crash boot failed with
>>> Linux v6.4 and later version.
>>>
>>> Let Linux export kernel_map.va_kernel_pa_offset in v6.5 and Crash can
>>> use "va_kernel_pa_offset" to translate the kernel virtual address in
>>> VTOP() correctly.
>>>
>>> Signed-off-by: Song Shuai <suagrfillet at gmail.com>
>>> ---
>>> You can check/test the Linux changes from this link:
>>> https://github.com/sugarfillet/linux/commits/6.5-rc3-crash
>>>
>>> And I'll send the Linux changes to riscv/for-next If you're ok with 
>>> this patch.
>>
>> If you want this to go into 6.5, you'll need to send it for riscv/fixes
>> instead. It sounds like a fix for this would need to go into 6.4 too,
>> no?
> You're right, that should be riscv/fixes for 6.5 and this issue also 
> need to be fixed in 6.4 stable.
> 
> How about waiting for Crash guys' comments on the introduction of the 
> "va_kernel_pa_offset" in vmcoreinfo
> and then determine which stable version should be taken in the first 
> "if" of kernel_version.

I don't have any specific comment on this, it looks necessary and if 
it's accepted in vmcoreinfo, then we can accept a crash patch for it.

Thanks,
Kazu