Duoming Zhou <duoming@xxxxxxxxxx> writes:
> 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?
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