| Message ID | 1604317487-14543-6-git-send-email-sumit.garg@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Add framework to turn an IPI as NMI | expand |
On Mon, Nov 02, 2020 at 05:14:45PM +0530, Sumit Garg wrote: > Enable NMI backtrace support on arm64 using IPI turned as an NMI > leveraging pseudo NMIs support. It is now possible for users to get a > backtrace of a CPU stuck in hard-lockup using magic SYSRQ. > > Signed-off-by: Sumit Garg <sumit.garg@linaro.org> > --- > arch/arm64/include/asm/irq.h | 6 ++++++ > arch/arm64/kernel/ipi_nmi.c | 18 ++++++++++++++++-- > 2 files changed, 22 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h > index b2b0c64..ef018a8 100644 > --- a/arch/arm64/include/asm/irq.h > +++ b/arch/arm64/include/asm/irq.h > @@ -6,6 +6,12 @@ > > #include <asm-generic/irq.h> > > +#ifdef CONFIG_SMP > +extern bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, > + bool exclude_self); > +#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace > +#endif > + > struct pt_regs; > > static inline int nr_legacy_irqs(void) > diff --git a/arch/arm64/kernel/ipi_nmi.c b/arch/arm64/kernel/ipi_nmi.c > index a945dcf..597dcf7 100644 > --- a/arch/arm64/kernel/ipi_nmi.c > +++ b/arch/arm64/kernel/ipi_nmi.c > @@ -8,6 +8,7 @@ > > #include <linux/interrupt.h> > #include <linux/irq.h> > +#include <linux/nmi.h> > #include <linux/smp.h> > > #include <asm/nmi.h> > @@ -31,11 +32,24 @@ void arm64_send_nmi(cpumask_t *mask) > __ipi_send_mask(ipi_nmi_desc, mask); > } > > +bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) > +{ > + if (!ipi_nmi_desc) > + return false; > + > + nmi_trigger_cpumask_backtrace(mask, exclude_self, arm64_send_nmi); > + > + return true; > +} > + > static irqreturn_t ipi_nmi_handler(int irq, void *data) > { > - /* nop, NMI handlers for special features can be added here. */ > + irqreturn_t ret = IRQ_NONE; > + > + if (nmi_cpu_backtrace(get_irq_regs())) > + ret = IRQ_HANDLED; > > - return IRQ_NONE; > + return ret; > } > > void dynamic_ipi_setup(int cpu) > -- It works well with sysrq l trigger. Please feel free to add: Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Thanks! Masa
diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h index b2b0c64..ef018a8 100644 --- a/arch/arm64/include/asm/irq.h +++ b/arch/arm64/include/asm/irq.h @@ -6,6 +6,12 @@ #include <asm-generic/irq.h> +#ifdef CONFIG_SMP +extern bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, + bool exclude_self); +#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace +#endif + struct pt_regs; static inline int nr_legacy_irqs(void) diff --git a/arch/arm64/kernel/ipi_nmi.c b/arch/arm64/kernel/ipi_nmi.c index a945dcf..597dcf7 100644 --- a/arch/arm64/kernel/ipi_nmi.c +++ b/arch/arm64/kernel/ipi_nmi.c @@ -8,6 +8,7 @@ #include <linux/interrupt.h> #include <linux/irq.h> +#include <linux/nmi.h> #include <linux/smp.h> #include <asm/nmi.h> @@ -31,11 +32,24 @@ void arm64_send_nmi(cpumask_t *mask) __ipi_send_mask(ipi_nmi_desc, mask); } +bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) +{ + if (!ipi_nmi_desc) + return false; + + nmi_trigger_cpumask_backtrace(mask, exclude_self, arm64_send_nmi); + + return true; +} + static irqreturn_t ipi_nmi_handler(int irq, void *data) { - /* nop, NMI handlers for special features can be added here. */ + irqreturn_t ret = IRQ_NONE; + + if (nmi_cpu_backtrace(get_irq_regs())) + ret = IRQ_HANDLED; - return IRQ_NONE; + return ret; } void dynamic_ipi_setup(int cpu)
Enable NMI backtrace support on arm64 using IPI turned as an NMI leveraging pseudo NMIs support. It is now possible for users to get a backtrace of a CPU stuck in hard-lockup using magic SYSRQ. Signed-off-by: Sumit Garg <sumit.garg@linaro.org> --- arch/arm64/include/asm/irq.h | 6 ++++++ arch/arm64/kernel/ipi_nmi.c | 18 ++++++++++++++++-- 2 files changed, 22 insertions(+), 2 deletions(-)