Re: [RFC PATCH v2 6.1] wifi: cfg80211: fix cqm_config access race

[Johannes Berg <johannes@sipsolutions.net>]

Hi,

This is ... pretty odd?

> h63 kernel: Unable to handle kernel paging request at virtual address ffff8061d9850028
> h63 kernel: Mem abort info:
> h63 kernel:   ESR = 0x0000000096000004
> h63 kernel:   EC = 0x25: DABT (current EL), IL = 32 bits
> h63 kernel:   SET = 0, FnV = 0
> h63 kernel:   EA = 0, S1PTW = 0
> h63 kernel:   FSC = 0x04: level 0 translation fault
> h63 kernel: Data abort info:
> h63 kernel:   ISV = 0, ISS = 0x00000004
> h63 kernel:   CM = 0, WnR = 0
> h63 kernel: [ffff8061d9850028] address between user and kernel address ranges
> h63 kernel: Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
> h63 kernel: Modules linked in: [...]
> h63 kernel: CPU: 3 PID: 493 Comm: Xorg Tainted: G         C 6.1.45-v8-gdc69f9d60872 #3
> h63 kernel: Hardware name: Raspberry Pi Compute Module 4 Rev 1.0 (DT)
> h63 kernel: pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> h63 kernel: pc : dma_resv_add_fence+0x80/0x260

I mean, that's in some other code entirely?

> h63 kernel: Call trace:
> h63 kernel:  dma_resv_add_fence+0x80/0x260
> h63 kernel:  v3d_attach_fences_and_unlock_reservation+0x6c/0x1c0 [v3d]
> h63 kernel:  v3d_submit_cl_ioctl+0x540/0x70c [v3d]
> h63 kernel:  drm_ioctl_kernel+0xcc/0x180 [drm]
> h63 kernel:  drm_ioctl+0x210/0x440 [drm]
> h63 kernel:  __arm64_sys_ioctl+0xb0/0xf4
> h63 kernel:  invoke_syscall+0x50/0x120
> h63 kernel:  el0_svc_common.constprop.0+0x68/0x124
> h63 kernel:  do_el0_svc+0x34/0xd0
> h63 kernel:  el0_svc+0x30/0x94
> h63 kernel:  el0t_64_sync_handler+0xb8/0xbc
> h63 kernel:  el0t_64_sync+0x18c/0x190
> h63 kernel: Code: fa401044 54000061 d4210000 d503201f (f9401678)

Unless my code caused some really bad corruption somewhere, I'm not sure
I see how that would happen?


Were you able to reproduce it multiple times? Maybe we can see a pattern
out of multiple reports.

johannes