Hi Marc, On 24/09/2020 14:09, Guillaume Tucker wrote: > On 24/09/2020 10:29, Marc Zyngier wrote: >> Hi Guillaume, >> >> On Thu, 24 Sep 2020 10:00:09 +0100, >> Guillaume Tucker <guillaume.tuc...@collabora.com> wrote: >>> >>> Hi Marc, >>> >>> On 01/09/2020 15:43, Marc Zyngier wrote: >>>> Let's switch the arm code to the core accounting, which already >>>> does everything we need. >>>> >>>> Reviewed-by: Valentin Schneider <valentin.schnei...@arm.com> >>>> Signed-off-by: Marc Zyngier <m...@kernel.org> >>>> --- >>>> arch/arm/include/asm/hardirq.h | 17 ----------------- >>>> arch/arm/kernel/smp.c | 20 ++++---------------- >>>> 2 files changed, 4 insertions(+), 33 deletions(-) >>> >>> This appears to be causing a NULL pointer dereference on >>> beaglebone-black, it got bisected automatically several times. >>> None of the other platforms in the KernelCI labs appears to be >>> affected. >> >> Hmm. My bet is that because this is a UP machine running an SMP >> kernel, and I fell into the trap of forgetting about this 32bit >> configuration. >> >> I expect the following patch to fix it. Please give it a go if you can >> (I'm away at the moment and can't test much, and do not have any >> physical 32bit machine to test this on). > > OK thanks, that worked: > > https://lava.baylibre.com/scheduler/job/143170 > > I've added this fix to the kernel branch used on > staging.kernelci.org which is based on linux-next, so it will get > fully verified a bit later today. > > Guillaume > > >> diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c >> index 00327fa74b01..b4e3d336dc33 100644 >> --- a/arch/arm/kernel/smp.c >> +++ b/arch/arm/kernel/smp.c >> @@ -531,7 +531,12 @@ void show_ipi_list(struct seq_file *p, int prec) >> unsigned int cpu, i; >> >> for (i = 0; i < NR_IPI; i++) { >> - unsigned int irq = irq_desc_get_irq(ipi_desc[i]); >> + unsigned int irq; >> + >> + if (!ipi_desc[i]) >> + continue; >> + >> + irq = irq_desc_get_irq(ipi_desc[i]); >> seq_printf(p, "%*s%u: ", prec - 1, "IPI", i); >> >> for_each_online_cpu(cpu)
This fix has been all tested now, with no visible side effects: https://staging.kernelci.org/test/job/kernelci/branch/staging.kernelci.org/kernel/staging-20200928.1/plan/baseline/ In the meantime, the same issue was detected (without the fix) and bisected on sun5i-a13-olinuxino-micro and landed on the same commit. A few more platforms are also impacted such as imx53-qsb as mentioned by Fabio. The commit is in your irqchip tree so I guess we should wait for you to apply the fix. If you do make a separate commit to fix the issue, please add: Reported-by: kernelci.org bot <b...@kernelci.org> and also: Tested-by: Guillaume Tucker <guillaume.tuc...@collabora.com> Thanks, Guillaume