Re: [Crash-utility] [PATCH] ppc64: do page traversal if vmemmap_list not populated
On 11-Sep-2023, at 3:00 PM, Aditya Gupta
<adityag(a)linux.ibm.com> wrote:
Currently 'crash-tool' fails on vmcore collected on upstream kernel on
PowerPC64 with the error:
crash: invalid kernel virtual address: 0 type: "first list entry
Presently the address translation for vmemmap addresses is done using
the vmemmap_list. But with the below commit in Linux, vmemmap_list can
be empty, in case of Radix MMU on PowerPC64
368a0590d954: (powerpc/book3s64/vmemmap: switch radix to use a
different vmemmap handling function)
In case vmemmap_list is empty, then it's head is NULL, which crash tries
to access and fails due to accessing NULL.
Instead of depending on 'vmemmap_list' for address translation for
vmemmap addresses, do a kernel pagetable walk to get the physical
address associated with given virtual address
Reviewed-by: Hari Bathini <hbathini(a)linux.ibm.com>
Signed-off-by: Aditya Gupta <adityag(a)linux.ibm.com>
Thanks for the patch.
With this patch applied (along with makedumpfile & kernel changes) I am able to
read a vmcore captured against a kernel which contains commit 8dc9a0ad0c3e
Tested-by: Sachin Sant <sachinp(a)linux.ibm.com>
- Sachin