[PATCH v8 25/26] arm64: Skip irqflags tracing for NMI in IRQs disabled context
From: Julien Thierry <hidden>
Date: 2019-01-08 14:09:00
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
When an NMI is raised while interrupts where disabled, the IRQ tracing already is in the correct state (i.e. hardirqs_off) and should be left as such when returning to the interrupted context. Check whether PMR was masking interrupts when the NMI was raised and skip IRQ tracing if necessary. Signed-off-by: Julien Thierry <redacted> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <redacted> Cc: Marc Zyngier <redacted> --- arch/arm64/kernel/entry.S | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index a0b0a22..bd0b078 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S@@ -617,7 +617,18 @@ el1_irq: kernel_entry 1 enable_da_f #ifdef CONFIG_TRACE_IRQFLAGS +#ifdef CONFIG_ARM64_PSEUDO_NMI +alternative_if ARM64_HAS_IRQ_PRIO_MASKING + ldr x20, [sp, #S_PMR_SAVE] +alternative_else + mov x20, #GIC_PRIO_IRQON +alternative_endif + cmp x20, #GIC_PRIO_IRQOFF + /* Irqs were disabled, don't trace */ + b.ls 1f +#endif bl trace_hardirqs_off +1: #endif irq_handler
@@ -637,8 +648,18 @@ alternative_else_nop_endif 1: #endif #ifdef CONFIG_TRACE_IRQFLAGS +#ifdef CONFIG_ARM64_PSEUDO_NMI + /* + * if IRQs were disabled when we received the interrupt, we have an NMI + * and we are not re-enabling interrupt upon eret. Skip tracing. + */ + cmp x20, #GIC_PRIO_IRQOFF + b.ls 1f +#endif bl trace_hardirqs_on +1: #endif + kernel_exit 1 ENDPROC(el1_irq)
--
1.9.1
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