lkml.org 
[lkml]   [2018]   [Nov]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v6 23/24] arm64: Skip irqflags tracing for NMI in IRQs disabled context
Date
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 <julien.thierry@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/kernel/entry.S | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index e02ee55..f175f18 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -629,7 +629,17 @@ 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
+ /* Irqs were disabled, don't trace */
+ tbz x20, GIC_PRIO_STATUS_SHIFT, 1f
+#endif
bl trace_hardirqs_off
+1:
#endif

irq_handler
@@ -651,8 +661,17 @@ 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.
+ */
+ tbz x20, GIC_PRIO_STATUS_SHIFT, 1f
+#endif
bl trace_hardirqs_on
+1:
#endif
+
kernel_exit 1
ENDPROC(el1_irq)

--
1.9.1
\
 
 \ /
  Last update: 2018-11-12 12:59    [W:0.138 / U:0.288 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site