On 08/27/24 at 01:24pm, Will Deacon wrote:

On Mon, Aug 26, 2024 at 02:52:02PM +0800, Kuan-Ying Lee wrote:

quoted

Since arm64 supports 5-level page tables, we need to add this
information to vmcoreinfo to make debug tools know if 5-level
page table is enabled or not.

Missing this information will break the debug tool like crash [1].

[1] https://github.com/crash-utility/crash

Signed-off-by: Kuan-Ying Lee <redacted>
---
 Documentation/admin-guide/kdump/vmcoreinfo.rst | 6 ++++++
 arch/arm64/kernel/vmcore_info.c                | 3 +++
 2 files changed, 9 insertions(+)

In which case, wouldn't you also want to know about pgtable_l4_enabled()?

That is a good question. I guess it's deduced in code, mostly needed for
different PAGE_OFFSET, how to transfer virtual addr to physical addr,
etc.

Add Crash utility experts here.