Bug 216198

Created attachment 301322 [details]
oops

After upgrading ubuntu from 20.04 (had stock kernels 5.4, 5.8 and 5.13) to 22.04 with 5.15, I've started to experience page faults when hw acceleration on Radeon RX550 is working in Firefox.


2 times already in 5 days, same stacktraces / addresses of faulting instruction and the same zero $rbx register.
I've had the same configuration for over a year, never had such oopses before on previous kernels.


> [X77.269660] BUG: unable to handle page fault for address: fffffffffffffff8
> 
> ffffffff8111d4f0 <swake_up_locked>:
> ffffffff8111d4f0:       e8 fb 90 f6 ff          call   ffffffff810865f0
> <__fentry__>
> ffffffff8111d4f5:       48 8b 57 08             mov    0x8(%rdi),%rdx
> ffffffff8111d4f9:       48 8d 47 08             lea    0x8(%rdi),%rax
> ffffffff8111d4fd:       48 39 c2                cmp    %rax,%rdx
> ffffffff8111d500:       74 2d                   je     ffffffff8111d52f
> <swake_up_locked+0x3f>
> ffffffff8111d502:       55                      push   %rbp
> ffffffff8111d503:       48 89 e5                mov    %rsp,%rbp
> ffffffff8111d506:       53                      push   %rbx
> ffffffff8111d507:       48 8b 5f 08             mov    0x8(%rdi),%rbx
> ffffffff8111d50b:       48 8b 7b f8             mov    -0x8(%rbx),%rdi  
> !<<<<<<<<<
> ffffffff8111d50f:       e8 4c d6 fd ff          call   ffffffff810fab60
> <wake_up_process>
> 
> void swake_up_locked(struct swait_queue_head *q)
> {
>       struct swait_queue *curr;
>       if (list_empty(&q->task_list))
>               return;
>       curr = list_first_entry(&q->task_list, typeof(*curr), task_list);
>       wake_up_process(curr->task);
>       list_del_init(&curr->task_list);
> }