Thread (45 messages) 45 messages, 4 authors, 2018-12-21
STALE2743d
Revisions (7)
  1. v4 [diff vs current]
  2. v5 [diff vs current]
  3. v6 [diff vs current]
  4. v7 current
  5. v8 [diff vs current]
  6. v9 [diff vs current]
  7. v10 [diff vs current]

[PATCH v7 24/25] arm64: Skip irqflags tracing for NMI in IRQs disabled context

From: Julien Thierry <hidden>
Date: 2018-12-12 16:48:48
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 7c9555c..82fbe7c 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -630,7 +630,18 @@ 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
@@ -652,8 +663,18 @@ 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


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help