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Message-Id: <1404825038-547-1-git-send-email-marc.zyngier@arm.com>
Date: Tue, 8 Jul 2014 14:10:23 +0100
From: Marc Zyngier <marc.zyngier@....com>
To: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc: Russell King <linux@....linux.org.uk>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
Thomas Gleixner <tglx@...utronix.de>,
Jason Cooper <jason@...edaemon.net>,
Alexander Shiyan <shc_work@...l.ru>,
Barry Song <baohua@...nel.org>,
Maxime Ripard <maxime.ripard@...e-electrons.com>,
Kevin Hilman <khilman@...aro.org>,
Daniel Lezcano <daniel.lezcano@...aro.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
Larry Bassel <larry.bassel@...aro.org>,
Mark Rutland <mark.rutland@....com>,
Sudeep Holla <sudeep.holla@....com>
Subject: [PATCH 00/15] arm/arm64: fix use of irq_find_mapping outside of legal RCU context
A number of irqchip drivers are directly calling irq_find_mapping,
which may use a rcu_read_lock call when walking the radix tree.
Turns out that if you hit that point with CONFIG_PROVE_RCU enabled,
the kernel will shout at you, as using RCU in this context may be
illegal (specially if coming from the idle state, where RCU would be
in a quiescent state).
A possible fix would be to wrap calls to irq_find_mapping into a
RCU_NONIDLE macro, but that really looks ugly.
This patch series introduce another IRQ entry point on arm and arm64
(handle_domain_irq), which has the exact same behaviour as handle_IRQ,
except that it also takes a irq_domain pointer. This allows the
logical IRQ lookup to be done inside the irq_{enter,exit} section,
which contains a rcu_irq_{enter,exit}, making it safe.
A number of irqchips are then converted to this new entry point. I've
converted all the direct users of irq_find_mapping, except for the
cases where it was used as a chained handler (chained_irq_{enter,exit}
makes it safe). Users of irq_linear_revmap are safe as well.
I've given it some light testing on arm64. The series is also
available in my tree:
git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git handle_domain_irq
Marc Zyngier (15):
arm64: pass IRQ domain to the core IRQ handler
ARM: pass IRQ domain to the core IRQ handler
irqchip: GIC: convert to handle_domain_irq
irqchip: armada-370-xp: convert to handle_domain_irq
irqchip: clps711x: convert to handle_domain_irq
irqchip: mmp: convert to handle_domain_irq
irqchip: mxs: convert to handle_domain_irq
irqchip: orion: convert to handle_domain_irq
irqchip: s3c24xx: convert to handle_domain_irq
irqchip: sirfsoc: convert to handle_domain_irq
irqchip: sun4i: convert to handle_domain_irq
irqchip: versatile-fpga: convert to handle_domain_irq
irqchip: vic: convert to handle_domain_irq
irqchip: vt8500: convert to handle_domain_irq
irqchip: zevio: convert to handle_domain_irq
arch/arm/include/asm/irq.h | 2 ++
arch/arm/kernel/irq.c | 23 +++++++++++++++++++----
arch/arm64/include/asm/hardirq.h | 4 ++++
arch/arm64/kernel/irq.c | 23 ++++++++++++++++++++---
drivers/irqchip/irq-armada-370-xp.c | 19 ++++++++++---------
drivers/irqchip/irq-clps711x.c | 18 +++++++-----------
drivers/irqchip/irq-gic.c | 3 +--
drivers/irqchip/irq-mmp.c | 10 ++++------
drivers/irqchip/irq-mxs.c | 3 +--
drivers/irqchip/irq-orion.c | 5 ++---
drivers/irqchip/irq-s3c24xx.c | 4 +---
drivers/irqchip/irq-sirfsoc.c | 6 ++----
drivers/irqchip/irq-sun4i.c | 5 ++---
drivers/irqchip/irq-versatile-fpga.c | 2 +-
drivers/irqchip/irq-vic.c | 2 +-
drivers/irqchip/irq-vt8500.c | 5 ++---
drivers/irqchip/irq-zevio.c | 3 +--
17 files changed, 80 insertions(+), 57 deletions(-)
--
2.0.0
--
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