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From: stigge@antcom.de (Roland Stigge)
To: linux-arm-kernel@lists.infradead.org
Subject: irq_set_chained_handler() called too early for hwirq to be initialized
Date: Sun, 28 Oct 2012 16:56:57 +0100	[thread overview]
Message-ID: <508D55C9.3030702@antcom.de> (raw)

Hi,

consider arch/arm/mach-lpc32xx/irq.c: irq_set_chained_handler() is
called at a point where it accesses
irq_to_desc(IRQ_LPC32XX_SUB2IRQ)->irq_data.hwirq but which is not yet
initialized.

(This bug just surfaced on lpc32xx when the chained interrupt controller
SIC2 wasn't working. SIC1 does, but just by chance: The uninitialized
value 0 is just coincidentally the correct one.)

...->hwirq is actually defined only later on in lpc32xx_init_irq() at
irq_domain_add_legacy(). Ideally, I would just move the
irq_set_chained_handler() calls to after of_irq_init() and
irq_domain_add_legacy(). Is this OK or does this produce any race condition?

Thanks in advance,

Roland

WARNING: multiple messages have this Message-ID (diff)
From: Roland Stigge <stigge@antcom.de>
To: "linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	tglx@linutronix.de, paul.gortmaker@windriver.com,
	benh@kernel.crashing.org
Subject: irq_set_chained_handler() called too early for hwirq to be initialized
Date: Sun, 28 Oct 2012 16:56:57 +0100	[thread overview]
Message-ID: <508D55C9.3030702@antcom.de> (raw)

Hi,

consider arch/arm/mach-lpc32xx/irq.c: irq_set_chained_handler() is
called at a point where it accesses
irq_to_desc(IRQ_LPC32XX_SUB2IRQ)->irq_data.hwirq but which is not yet
initialized.

(This bug just surfaced on lpc32xx when the chained interrupt controller
SIC2 wasn't working. SIC1 does, but just by chance: The uninitialized
value 0 is just coincidentally the correct one.)

...->hwirq is actually defined only later on in lpc32xx_init_irq() at
irq_domain_add_legacy(). Ideally, I would just move the
irq_set_chained_handler() calls to after of_irq_init() and
irq_domain_add_legacy(). Is this OK or does this produce any race condition?

Thanks in advance,

Roland

             reply	other threads:[~2012-10-28 15:56 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-28 15:56 Roland Stigge [this message]
2012-10-28 15:56 ` irq_set_chained_handler() called too early for hwirq to be initialized Roland Stigge
2012-10-28 17:34 ` Thomas Gleixner
2012-10-28 17:34   ` Thomas Gleixner
2012-10-28 18:36   ` Roland Stigge
2012-10-28 18:36     ` Roland Stigge
2012-10-28 18:46     ` Thomas Gleixner
2012-10-28 18:46       ` Thomas Gleixner

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