Re: [Crash-utility] kernel module parsing failure - mips

On Sun, Dec 4, 2016 at 8:16 AM, Rabin Vincent <rabin(a)rab.in&gt; wrote: >> read_netdump: READ_ERROR: offset not found for paddr: 271e9cc0 >> >> crash: read error: kernel virtual address: c0bc9cc0 type: "module struct" > > Here's the error. Either 271e9cc0 is a valid physical address and the dump is > incomplete, or it's not and the page table translation is returning a bogus > physical address for c0bc9cc0. crash> vtop c0bc9cc0 VIRTUAL PHYSICAL c0bc9cc0 271e9cc0 SEGMENT: ksseg PAGE DIRECTORY: 82c30000 PGD: 82c300c0 => 83018000 PTE: 03018bc8 => 271e87cf PAGE: 271e8000 PTE PHYSICAL FLAGS 271e87cf 271e8000 (PRESENT|WRITE|ACCESSED|MODIFIED|GLOBAL|VALID|DIRTY) PAGE PHYSICAL MAPPING INDEX CNT FLAGS 82dc0f40 271e8000 0 0 1 40000000 0x271e9cc0 is a valid address but it belongs to high mem(0x20000000 onwards for this platform). Also I don't think there is any problem in dump as I have done several testing of crash without modules and every time I have got correct result.

> To check the page table translation, use "vtop <addr>" (example below) > to see how crash comes to its result. You'll have to then manually walk > the page tables for this particular virtual address and verify that the > correct PGD and PTE entries are being read. It could be easier if use > vmalloc_to_page() and page_address() first in your kernel to print out > the correct physical address for some known vmalloc'd address. As the driver works fine, I think kernel translation looks ok. Wrong physical address translation would have failed the nvme driver to run. Stress testing with the driver is fine. But still would go through the PTE entries.