Commit cd49b84d authored Jun 06, 2019 by Dan Carpenter Committed by Lee Jones Jun 17, 2019

mfd: stmfx: Uninitialized variable in stmfx_irq_handler()



The problem is that on 64bit systems then we don't clear the higher
bits of the "pending" variable.  So when we do:

        ack = pending & ~BIT(STMFX_REG_IRQ_SRC_EN_GPIO);
        if (ack) {

the if (ack) condition relies on uninitialized data.  The fix it that
I've changed "pending" from an unsigned long to a u32.  I changed "n" as
well, because that's a number in the 0-10 range and it fits easily
inside an int.  We do need to add a cast to "pending" when we use it in
the for_each_set_bit() loop, but that doesn't cause a problem, it's
fine.

Fixes: 06252ade ("mfd: Add ST Multi-Function eXpander (STMFX) core driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

parent a188339c

drivers/mfd/stmfx.c

+4 −6

Original line number	Diff line number	Diff line
		@@ -204,12 +204,10 @@ static struct irq_chip stmfx_irq_chip = {
		static irqreturn_t stmfx_irq_handler(int irq, void *data)
		{
		struct stmfx *stmfx = data;
		unsigned long n, pending;
		u32 ack;
		int ret;
		u32 pending, ack;
		int n, ret;

		ret = regmap_read(stmfx->map, STMFX_REG_IRQ_PENDING,
		(u32 *)&pending);
		ret = regmap_read(stmfx->map, STMFX_REG_IRQ_PENDING, &pending);
		if (ret)
		return IRQ_NONE;

		@@ -224,7 +222,7 @@ static irqreturn_t stmfx_irq_handler(int irq, void *data)
		return IRQ_NONE;
		}

		for_each_set_bit(n, &pending, STMFX_REG_IRQ_SRC_MAX)
		for_each_set_bit(n, (unsigned long *)&pending, STMFX_REG_IRQ_SRC_MAX)
		handle_nested_irq(irq_find_mapping(stmfx->irq_domain, n));

		return IRQ_HANDLED;

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