Hello,
On Thu, 19 May 2022 17:58:47 +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 <[email protected]>
>
> mwifiex patches go to wireless-next, not net tree.
>
> > ---
> > Changes in v2:
> > - Fix compile problem.
>
> So you don't even compile test your patches? That's bad and in that case
> I'll just directly drop this. We expect that the patches are properly
> tested.
Ok, I will properly test this patch.
Best regards,
Duoming Zhou
On 5/19/2022 8:14 AM, [email protected] wrote:
> Hello,
>
> On Thu, 19 May 2022 17:58:47 +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)
just looking at this description, why isn't the simple fix just to
change this call to use GFP_ATOMIC?