arm64: Fix interrupt tracing in the presence of NMIs
authorJulien Thierry <julien.thierry@arm.com>
Tue, 11 Jun 2019 09:38:09 +0000 (10:38 +0100)
committerCatalin Marinas <catalin.marinas@arm.com>
Fri, 21 Jun 2019 14:49:58 +0000 (15:49 +0100)
commit17ce302f3117e9518395847a3120c8a108b587b8
treec45f4cc064924854caedfd9c0ca7a78fc0838d71
parentf57065782f245ca96f1472209a485073bbc11247
arm64: Fix interrupt tracing in the presence of NMIs

In the presence of any form of instrumentation, nmi_enter() should be
done before calling any traceable code and any instrumentation code.

Currently, nmi_enter() is done in handle_domain_nmi(), which is much
too late as instrumentation code might get called before. Move the
nmi_enter/exit() calls to the arch IRQ vector handler.

On arm64, it is not possible to know if the IRQ vector handler was
called because of an NMI before acknowledging the interrupt. However, It
is possible to know whether normal interrupts could be taken in the
interrupted context (i.e. if taking an NMI in that context could
introduce a potential race condition).

When interrupting a context with IRQs disabled, call nmi_enter() as soon
as possible. In contexts with IRQs enabled, defer this to the interrupt
controller, which is in a better position to know if an interrupt taken
is an NMI.

Fixes: bc3c03ccb464 ("arm64: Enable the support of pseudo-NMIs")
Cc: <stable@vger.kernel.org> # 5.1.x-
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arch/arm64/kernel/entry.S
arch/arm64/kernel/irq.c
drivers/irqchip/irq-gic-v3.c
kernel/irq/irqdesc.c