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| author | Julien Thierry <julien.thierry@arm.com> | 2019-06-11 10:38:09 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2019-06-21 15:49:58 +0100 |
| commit | 17ce302f3117e9518395847a3120c8a108b587b8 (patch) | |
| tree | c45f4cc064924854caedfd9c0ca7a78fc0838d71 /drivers/irqchip | |
| parent | f57065782f245ca96f1472209a485073bbc11247 (diff) | |
| download | linux-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 'drivers/irqchip')
| -rw-r--r-- | drivers/irqchip/irq-gic-v3.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index f44cd89cfc40..b176700bb387 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -472,8 +472,12 @@ static void gic_deactivate_unhandled(u32 irqnr) static inline void gic_handle_nmi(u32 irqnr, struct pt_regs *regs) { + bool irqs_enabled = interrupts_enabled(regs); int err; + if (irqs_enabled) + nmi_enter(); + if (static_branch_likely(&supports_deactivate_key)) gic_write_eoir(irqnr); /* @@ -485,6 +489,9 @@ static inline void gic_handle_nmi(u32 irqnr, struct pt_regs *regs) err = handle_domain_nmi(gic_data.domain, irqnr, regs); if (err) gic_deactivate_unhandled(irqnr); + + if (irqs_enabled) + nmi_exit(); } static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs) |