Re: [PATCH V5 5/6] riscv: crash_core: Export kernel vm layout, phys_ram_base

From: Bagas Sanjaya
Date: Wed Aug 10 2022 - 23:07:16 EST


On Tue, Aug 02, 2022 at 08:18:17PM +0800, Xianting Tian wrote:
> These infos are needed by the kdump crash tool. Since these values change
> from time to time, it is preferable to export them via vmcoreinfo than to
> change the crash's code frequently.
>

I have to agree with Conor.Dooley, that this patch is misleading (I see
documentation instead of real export). So IMO, the patch subject should
be "Documentation: kdump: describe VMCOREINFO export for RISCV64".

For MODULES_VADDR and friends, the doc can be improved, like:

diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst
index 6b76284a503ca5..6694acc32c3588 100644
--- a/Documentation/admin-guide/kdump/vmcoreinfo.rst
+++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst
@@ -615,14 +615,13 @@ 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
-----------------------------------------------------------------------
+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.
- KASAN_SHADOW_START ~ KASAN_SHADOW_END : kasan shadow space.
- KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END : Kernel link and BPF space.
+
+ * 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.
+ * KASAN_SHADOW_START ~ KASAN_SHADOW_END : kasan shadow space.
+ * KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END : Kernel link and BPF space.

Thanks.

--
An old man doll... just what I always wanted! - Clara