Messages in this thread | | | Date | Fri, 24 Jun 2022 14:02:56 +0800 (GMT+08:00) | From | duoming@zju ... | Subject | Re: [PATCH v2] staging: rtl8192u: Fix sleep in atomic context bug in dm_fsync_timer_callback |
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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@zju.edu.cn> > > --- > > 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 | |