Re: [Crash-utility] [PATCH] SLUB: Fix for offset change of struct slab members on Linux 6.2-rc1

On 2022/12/22 16:50, lijiang wrote: > After applying the patch, I got another error based on the latest kernel > commit 9d2f6060fe4c3b49d0cdc1dce1c99296f33379c8: > > crash> kmem -S filp > CACHE OBJSIZE ALLOCATED TOTAL SLABS SSIZE NAME > ffff9d80c030a100 232 1125 3936 123 8k filp > CPU 0 KMEM_CACHE_CPU: > ffff9d81e7a38470 > CPU 0 SLAB: > SLAB MEMORY NODE TOTAL ALLOCATED FREE > fffff0f3841a7700 ffff9d80c69dc000 0 32 10 22 > FREE / [ALLOCATED] > kmem: filp: slab: fffff0f3841a7700 invalid freepointer: 4404c55079ecb7fe > CPU 1 KMEM_CACHE_CPU: > ffff9d81e7a78470 > CPU 1 SLAB: > SLAB MEMORY NODE TOTAL ALLOCATED FREE > fffff0f38446a600 ffff9d80d1a98000 0 32 0 32 > FREE / [ALLOCATED] > ... > > And this issue can not always be reproduced, I have tested it more than ten > times, the above error can be observed on my side, maybe one or two times. > > But anyway, I'm curious if this is another issue. Could you please also > double check it? Thank you for testing. I have not reproduced it with kdump, but did it with live system when repeating this: crash> kmem -S > /tmp/kmem-S crash> kmem -S > /tmp/kmem-S ... crash> kmem -S > /tmp/kmem-S kmem: kmalloc-16: slab: ffffdb3bc440bcc0 invalid freepointer: d3ec64863a077e7c As you say, it does not always happen, so it will be a timing issue or corner case. Maybe there was a change in managing freepointer list, but so far I'm not sure what the cause is.

Anyway, I think it's not due to the offset change of slab.slab_list and not the same issue. Can we apply this and look into it later?

Kazu