From: Sumit Garg <sumit.garg@linaro.org>
To: maz@kernel.org, catalin.marinas@arm.com, will@kernel.org
Cc: mark.rutland@arm.com, Sumit Garg <sumit.garg@linaro.org>,
daniel.thompson@linaro.org, jason@lakedaemon.net,
kgdb-bugreport@lists.sourceforge.net, dianders@chromium.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, jason.wessel@windriver.com,
tglx@linutronix.de, julien.thierry.kdev@gmail.com
Subject: [PATCH v4 5/5] arm64: ipi_nmi: Add support for NMI backtrace
Date: Fri, 11 Sep 2020 18:58:44 +0530 [thread overview]
Message-ID: <1599830924-13990-6-git-send-email-sumit.garg@linaro.org> (raw)
In-Reply-To: <1599830924-13990-1-git-send-email-sumit.garg@linaro.org>
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 | 12 +++++++++++-
2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h
index b2b0c64..e840bf1 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 void 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 627bc11..d3aa430 100644
--- a/arch/arm64/kernel/ipi_nmi.c
+++ b/arch/arm64/kernel/ipi_nmi.c
@@ -9,6 +9,7 @@
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kgdb.h>
+#include <linux/nmi.h>
#include <linux/smp.h>
#include <asm/nmi.h>
@@ -25,12 +26,21 @@ void arch_send_call_nmi_func_ipi_mask(cpumask_t *mask)
__ipi_send_mask(ipi_desc, mask);
}
+void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
+{
+ nmi_trigger_cpumask_backtrace(mask, exclude_self,
+ arch_send_call_nmi_func_ipi_mask);
+}
+
static irqreturn_t ipi_nmi_handler(int irq, void *data)
{
unsigned int cpu = smp_processor_id();
- ipi_kgdb_nmicallback(cpu, get_irq_regs());
+ if (nmi_cpu_backtrace(get_irq_regs()))
+ goto out;
+ ipi_kgdb_nmicallback(cpu, get_irq_regs());
+out:
return IRQ_HANDLED;
}
--
2.7.4
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prev parent reply other threads:[~2020-09-11 13:36 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-11 13:28 [PATCH v4 0/5] arm64: Add framework to turn an IPI as NMI Sumit Garg
2020-09-11 13:28 ` [PATCH v4 1/5] arm64: Add framework to turn " Sumit Garg
2020-10-10 1:58 ` Masayoshi Mizuma
2020-10-10 9:34 ` Marc Zyngier
2020-10-10 15:13 ` Masayoshi Mizuma
2020-10-12 12:19 ` Sumit Garg
2020-10-13 3:23 ` Masayoshi Mizuma
2020-10-12 12:21 ` Sumit Garg
2020-09-11 13:28 ` [PATCH v4 2/5] irqchip/gic-v3: Enable support for SGIs to act as NMIs Sumit Garg
2020-09-11 13:28 ` [PATCH v4 3/5] arm64: smp: Allocate and setup IPI as NMI Sumit Garg
2020-09-11 13:28 ` [PATCH v4 4/5] arm64: kgdb: Round up cpus using " Sumit Garg
2020-09-11 13:28 ` Sumit Garg [this message]
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