[Crash-utility] Re: seek error when loading /proc/kcore with type: "page_offset_base"

On 24/08/02 06:54PM, Tao Liu wrote: > Hi Jose, > > Thanks for reporting the issue. It looks like a known issue which we > are currently dealing with. > > On Fri, Aug 2, 2024 at 6:11 PM Jose Fernandez <jose.fernandez(a)linux.dev&gt; wrote: >> >> I'm trying to get crash to work on Arch Linux but I keep running into this error: >> >> crash: seek error: kernel virtual address: ffffffff82b195c0 type: "page_offset_base" >> > It looks like some kaslr issue to me, could you please execute the > following cmd and show me the results? > > $ nm vmlinux | grep kaslr_regions > > If there is no output, aka no such symbol is found, then you hit a > known kaslr issue. Hi Tao, here is the output for the CachyOS kernel: nm /usr/src/debug/linux-cachyos/vmlinux | grep kaslr ffffffff820af590 T init_trampoline_kaslr ffffffff82014e60 T kaslr_get_random_long ffffffff83a9d940 d kaslr_regions ffffffff820af580 T __pfx_init_trampoline_kaslr ffffffff82014e50 T __pfx_kaslr_get_random_long And here is the output for the upstream 6.11RC I built myself: nm vmlinux | grep kaslr ffffffff810ae060 T init_trampoline_kaslr ffffffff81deb600 T kaslr_get_random_long ffffffff83871940 d kaslr_regions ffffffff810ae050 T __pfx_init_trampoline_kaslr ffffffff81deb5f0 T __pfx_kaslr_get_random_long Thanks, Jose > > Thanks, > Tao Liu > >> I've the upstream 6.11RC and the latest CachyOS kernel (6.10.2). I boot into >> the target kernel and then run crash with the respective vmlinux file. I'm >> simply trying to load /proc/kcore with this command: >> >> crash /usr/src/debug/linux-cachyos/vmlinux /proc/kcore -d10 >> >> Here is the full output: >> >> crash 8.0.5

>> crash: seek error: kernel virtual address: ffffffff82b195c0 type: "page_offset_base"