Hello,
On Thu, 19 May 2022 13:27:07 +0300 Kalle Valo wrote:
> > There are sleep in atomic context bugs when uploading device dump
> > data on usb interface. The root cause is that the operations that
> > may sleep are called in fw_dump_timer_fn which is a timer handler.
> > The call tree shows the execution paths that could lead to bugs:
> >
> > (Interrupt context)
> > fw_dump_timer_fn
> > mwifiex_upload_device_dump
> > dev_coredumpv(..., GFP_KERNEL)
> > dev_coredumpm()
> > kzalloc(sizeof(*devcd), gfp); //may sleep
> > dev_set_name
> > kobject_set_name_vargs
> > kvasprintf_const(GFP_KERNEL, ...); //may sleep
> > kstrdup(s, GFP_KERNEL); //may sleep
> >
> > This patch moves the operations that may sleep into a work item.
> > The work item will run in another kernel thread which is in
> > process context to execute the bottom half of the interrupt.
> > So it could prevent atomic context from sleeping.
> >
> > Fixes: f5ecd02a8b20 ("mwifiex: device dump support for usb interface")
> > Signed-off-by: Duoming Zhou <duoming@xxxxxxxxxx>
>
> Have you tested this on real hardware? Or is this just a theoretical
> fix?
This is a theoretical fix. I don't have the real hardware.
Best regards,
Duoming Zhou
