Messages in this thread | | | Date | Thu, 10 Aug 2017 08:07:55 -0700 | From | Greg KH <> | Subject | Re: Question about apds990x.ko |
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On Thu, Aug 10, 2017 at 05:57:30PM +0300, Anton Volkov wrote: > Hello. > > While searching for races in the Linux kernel I've come across > "drivers/misc/apds990x.ko" module. Here are questions that I came up with > while analyzing results. Lines are given using the info from Linux v4.12. > > Consider the following case: > > Thread 1: Thread 2: > apds990x_suspend > apds990x_resume apds990x_irq > -> apds990x_chip_on if (!pm_runtime_suspended > (chip->client->dev)){ > -> apds990x_configure if (status & APDS990X_ST_AINT) { > chip->again_meas = 1 chip->again_meas = chip->again_next > (apds990x.c: line 571) (apds990x.c: line 505) > } > } > > First question. Is this race feasible from your point of view? > Second question. The check for the device suspension status > (pm_runtime_suspended()) is present in the interrupt handler, but the > functions pm_runtime_set_suspended / pm_runtime_set_active are not used in > apds990x_suspend / apds990x_resume respectively. Do you know about any other > method being used to make the modification of suspension status?
No idea, sorry. Maybe the driver authors know?
greg k-h
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