Re: [PATCH V2 2/2] Documentation: kdump: describe VMCOREINFO export for RISCV64

Xianting Tian <xianting.tian@xxxxxxxxxxxxxxxxx> · Tue, 18 Oct 2022 10:41:50 +0800

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@xxxxxxxxxxxxxxxxx>
---
  .../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








