From: Sumit Garg <sumit.garg@linaro.org> maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7R4EN CVE: NA Reference: https://www.spinics.net/lists/arm-kernel/msg851005.html ------------------------------------------------- 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> Signed-off-by: Wei Li <liwei391@huawei.com> Reviewed-by: Xie XiuQi <xiexiuqi@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com> --- 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 fac08e18bcd5..9e926b4f7d47 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; int set_handle_irq(void (*handle_irq)(struct pt_regs *)); diff --git a/arch/arm64/kernel/ipi_nmi.c b/arch/arm64/kernel/ipi_nmi.c index a945dcf8015f..597dcf7fb59c 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) -- 2.34.1