Re: [Crash-utility] [PATCH v2] ppc64: do page traversal if vmemmap_list not populated

On 2023/09/26 15:12, lijiang wrote: > Hi, Aditya > Thank you for the update. > On Mon, Sep 25, 2023 at 5:28 PM Aditya Gupta <adityag(a)linux.ibm.com&gt; 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 >> >> Tested-by: Sachin Sant <sachinp(a)linux.ibm.com&gt; >> Reviewed-by: Hari Bathini <hbathini(a)linux.ibm.com&gt; >> Signed-off-by: Aditya Gupta <adityag(a)linux.ibm.com&gt; >> >> --- >> >> Testing >> ======= >> >> Git tree with patch applied: >> https://github.com/adi-g15-ibm/crash/tree/bugzilla-203296-list-v2 >> >> This can be tested with '/proc/vmcore' as the vmcore, since makedumpfile >> also fails in absence of 'vmemmap_list' in upstream linux >> >> The fix for makedumpfile will also been sent to upstream >> >> Changelog >> ========= >> >> V2 >> + handle the case of 'vmemmap_list' symbol missing according to reviews >> >> > The v2 looks good to me, so: Ack. Looks good, and applied. https://github.com/crash-utility/crash/commit/a9291fc1bf61309c74078f757f5...

Thanks, Kazu