Re: BUG: unable to handle kernel paging request in scsi_device_unbusy

Bart Van Assche <bvanassche@xxxxxxx> · Thu, 15 Sep 2022 09:45:33 -0700

On 9/15/22 08:56, Rondreis wrote:
CPU: 0 PID: 12256 Comm: usb-storage Not tainted 6.0.0-rc4+ #20
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS

Does the above indicate an x86 CPU?

Call Trace:
  <TASK>
  instrument_atomic_write include/linux/instrumented.h:86 [inline]
  set_bit include/asm-generic/bitops/instrumented-atomic.h:28 [inline]
  sbitmap_deferred_clear_bit include/linux/sbitmap.h:327 [inline]
  sbitmap_put include/linux/sbitmap.h:336 [inline]
  scsi_device_unbusy+0x1aa/0x380 drivers/scsi/scsi_lib.c:301

There is some tricky code in the sbitmap implementation. How about 
checking the implementation of that code to see whether any memory 
barriers are missing?

Thanks,

Bart.