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authorJulien Thierry <julien.thierry@arm.com>2019-06-11 10:38:09 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2019-06-21 15:49:58 +0100
commit17ce302f3117e9518395847a3120c8a108b587b8 (patch)
treec45f4cc064924854caedfd9c0ca7a78fc0838d71 /kernel/irq
parentf57065782f245ca96f1472209a485073bbc11247 (diff)
downloadlinux-17ce302f3117e9518395847a3120c8a108b587b8.tar.bz2
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>
Diffstat (limited to 'kernel/irq')
-rw-r--r--kernel/irq/irqdesc.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index c52b737ab8e3..a92b33593b8d 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -680,6 +680,8 @@ int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
* @hwirq: The HW irq number to convert to a logical one
* @regs: Register file coming from the low-level handling code
*
+ * This function must be called from an NMI context.
+ *
* Returns: 0 on success, or -EINVAL if conversion has failed
*/
int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
@@ -689,7 +691,10 @@ int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
unsigned int irq;
int ret = 0;
- nmi_enter();
+ /*
+ * NMI context needs to be setup earlier in order to deal with tracing.
+ */
+ WARN_ON(!in_nmi());
irq = irq_find_mapping(domain, hwirq);
@@ -702,7 +707,6 @@ int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
else
ret = -EINVAL;
- nmi_exit();
set_irq_regs(old_regs);
return ret;
}