Hello, On Thu, 23 Jun 2022 11:46:41 +0200 Greg KH wrote: > On Thu, Jun 23, 2022 at 01:59:12PM +0800, Duoming Zhou wrote: > > There are sleep in atomic context bugs when dm_fsync_timer_callback is > > executing. The root cause is that the memory allocation functions with > > GFP_KERNEL or GFP_NOIO parameters are called in dm_fsync_timer_callback > > which is a timer handler. The call paths that could trigger bugs are > > shown below: > > > > (interrupt context) > > dm_fsync_timer_callback > > write_nic_byte > > kzalloc(sizeof(data), GFP_KERNEL); //may sleep > > usb_control_msg > > kmalloc(.., GFP_NOIO); //may sleep > > write_nic_dword > > kzalloc(sizeof(data), GFP_KERNEL); //may sleep > > usb_control_msg > > kmalloc(.., GFP_NOIO); //may sleep > > > > This patch uses delayed work to replace timer and moves the operations > > that may sleep into the delayed work in order to mitigate bugs. > > > > Fixes: 8fc8598e61f6 ("Staging: Added Realtek rtl8192u driver to staging") > > Signed-off-by: Duoming Zhou <duoming@xxxxxxxxxx> > > --- > > Changes in v2: > > - Use delayed work to replace timer. > > Did you test this with real hardware to verify it still works? I am testing this and I will give you feedback within one or two days. Best regards, Duoming Zhou