<div dir="ltr"><div dir="ltr">On Wed, Sep 5, 2018 at 9:00 AM Colin Ian King <<a href="mailto:colin.king@canonical.com">colin.king@canonical.com</a>> wrote: </div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On 05/09/18 16:48, Kamal Mostafa wrote: > From: Nicholas Piggin <<a href="mailto:npiggin@gmail.com" target="_blank">npiggin@gmail.com</a>> > > BugLink: <a href="http://bugs.launchpad.net/bugs/1790636" rel="noreferrer" target="_blank">http://bugs.launchpad.net/bugs/1790636</a> > > A kernel crash in process context that calls emergency_restart from > panic will end up calling opal_event_shutdown with interrupts disabled > but not in interrupt. This causes a sleeping function to be called > which gives the following warning with sysrq+c: > > Rebooting in 10 seconds.. > BUG: sleeping function called from invalid context at kernel/locking/mutex.c:238 > in_atomic(): 0, irqs_disabled(): 1, pid: 7669, name: bash > CPU: 20 PID: 7669 Comm: bash Tainted: G D W 4.17.0-rc5+ #3 > Call Trace: > dump_stack+0xb0/0xf4 (unreliable) > ___might_sleep+0x174/0x1a0 > mutex_lock+0x38/0xb0 > __free_irq+0x68/0x460 > free_irq+0x70/0xc0 > opal_event_shutdown+0xb4/0xf0 > opal_shutdown+0x24/0xa0 > pnv_shutdown+0x28/0x40 > machine_shutdown+0x44/0x60 > machine_restart+0x28/0x80 > emergency_restart+0x30/0x50 > panic+0x2a0/0x328 > oops_end+0x1ec/0x1f0 > bad_page_fault+0xe8/0x154 > handle_page_fault+0x34/0x38 > --- interrupt: 300 at sysrq_handle_crash+0x44/0x60 > LR = __handle_sysrq+0xfc/0x260 > flag_spec.62335+0x12b844/0x1e8db4 (unreliable) > __handle_sysrq+0xfc/0x260 > write_sysrq_trigger+0xa8/0xb0 > proc_reg_write+0xac/0x110 > __vfs_write+0x6c/0x240 > vfs_write+0xd0/0x240 > ksys_write+0x6c/0x110 > > Fixes: 9f0fd0499d30 ("powerpc/powernv: Add a virtual irqchip for opal events") > Signed-off-by: Nicholas Piggin <<a href="mailto:npiggin@gmail.com" target="_blank">npiggin@gmail.com</a>> > Signed-off-by: Michael Ellerman <<a href="mailto:mpe@ellerman.id.au" target="_blank">mpe@ellerman.id.au</a>> > Signed-off-by: Kamal Mostafa <<a href="mailto:kamal@canonical.com" target="_blank">kamal@canonical.com</a>> > (cherry picked from commit 8bf84f005346fd0ecfa595c2d497b19a6e291b4e) > Signed-off-by: Kamal Mostafa <<a href="mailto:kamal@canonical.com" target="_blank">kamal@canonical.com</a>> I can't find 8bf84f005346fd0ecfa595c2d497b19a6e291b4e in linux or linux-next. Where does it come from? </blockquote><div> </div>Ooops, that needs to be corrected, to:<div>(cherry picked from commit c0beffc4f4c658fde86d52c837e784326e9cc875)</div><div> </div><div> -Kamal</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> > --- > arch/powerpc/platforms/powernv/opal-irqchip.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/platforms/powernv/opal-irqchip.c b/arch/powerpc/platforms/powernv/opal-irqchip.c > index 9d1b8c0..05ffe05 100644 > --- a/arch/powerpc/platforms/powernv/opal-irqchip.c > +++ b/arch/powerpc/platforms/powernv/opal-irqchip.c > @@ -177,7 +177,7 @@ void opal_event_shutdown(void) > if (!opal_irqs[i]) > continue; > > - if (in_interrupt()) > + if (in_interrupt() || irqs_disabled()) > disable_irq_nosync(opal_irqs[i]); > else > free_irq(opal_irqs[i], NULL); > -- kernel-team mailing list <a href="mailto:kernel-team@lists.ubuntu.com" target="_blank">kernel-team@lists.ubuntu.com</a> <a href="https://lists.ubuntu.com/mailman/listinfo/kernel-team" rel="noreferrer" target="_blank">https://lists.ubuntu.com/mailman/listinfo/kernel-team</a> </blockquote></div></div>