On Fri, 13 Nov 2020 at 14:42, Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote: > On Fri, Nov 13, 2020 at 2:28 PM Sebastian Andrzej Siewior > <bigeasy@xxxxxxxxxxxxx> wrote: > > > > On 2020-11-13 13:51:19 [+0100], Andrey Konovalov wrote: > > > Hi Sebastian, > > > > Hi Andrey, > > > > > Replaced with what and why? > > > > Linus requested in > > https://lkml.kernel.org/r/CAHk-=wht7kAeyR5xEW2ORj7m0hibVxZ3t+2ie8vNHLQfdbN2_g@xxxxxxxxxxxxxx/ > > > > that drivers should not change their behaviour on context magic like > > in_atomic(), in_interrupt() and so on. > > The USB bits were posted in > > https://lkml.kernel.org/r/20201019100629.419020859@xxxxxxxxxxxxx Arguably this patch is *not* changing "driver behaviour", it's only changing how and when KCOV collects coverage, which is not related to how the driver behaves. > > and merged (which is probably the same time as this patch). > > > > I haven't look what this code should do or does but there are HCDs for > > which this is never true like the UHCI/OHCI controller for instance. > > We could go back to adding softirq-specific kcov callbacks. Perhaps > with a simpler implementation than what we had before to only cover > this case. Something like kcov_remote_start_usb_softirq() and > kcov_remote_stop_softirq() that do the softirq check internally. Is this a matter of simply banning such functions entirely without understanding their use? Because that sounds wrong. But if it is, we probably have to just add some static inline functions in include/linux/kcov.h that simply does the check. Thanks, -- Marco
