From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Jia-Ju Bai <baijiaju1990@gmail.com>,
Linus Walleij <linus.walleij@linaro.org>,
Sasha Levin <sashal@kernel.org>,
linux-gpio@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 044/459] gpio: gpio-grgpio: fix possible sleep-in-atomic-context bugs in grgpio_irq_map/unmap()
Date: Fri, 14 Feb 2020 10:54:54 -0500 [thread overview]
Message-ID: <20200214160149.11681-44-sashal@kernel.org> (raw)
In-Reply-To: <20200214160149.11681-1-sashal@kernel.org>
From: Jia-Ju Bai <baijiaju1990@gmail.com>
[ Upstream commit e36eaf94be8f7bc4e686246eed3cf92d845e2ef8 ]
The driver may sleep while holding a spinlock.
The function call path (from bottom to top) in Linux 4.19 is:
drivers/gpio/gpio-grgpio.c, 261:
request_irq in grgpio_irq_map
drivers/gpio/gpio-grgpio.c, 255:
_raw_spin_lock_irqsave in grgpio_irq_map
drivers/gpio/gpio-grgpio.c, 318:
free_irq in grgpio_irq_unmap
drivers/gpio/gpio-grgpio.c, 299:
_raw_spin_lock_irqsave in grgpio_irq_unmap
request_irq() and free_irq() can sleep at runtime.
To fix these bugs, request_irq() and free_irq() are called without
holding the spinlock.
These bugs are found by a static analysis tool STCheck written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Link: https://lore.kernel.org/r/20191218132605.10594-1-baijiaju1990@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpio/gpio-grgpio.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/gpio/gpio-grgpio.c b/drivers/gpio/gpio-grgpio.c
index 08234e64993a9..3224933f4c8f4 100644
--- a/drivers/gpio/gpio-grgpio.c
+++ b/drivers/gpio/gpio-grgpio.c
@@ -253,17 +253,16 @@ static int grgpio_irq_map(struct irq_domain *d, unsigned int irq,
lirq->irq = irq;
uirq = &priv->uirqs[lirq->index];
if (uirq->refcnt == 0) {
+ spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
ret = request_irq(uirq->uirq, grgpio_irq_handler, 0,
dev_name(priv->dev), priv);
if (ret) {
dev_err(priv->dev,
"Could not request underlying irq %d\n",
uirq->uirq);
-
- spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
-
return ret;
}
+ spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
}
uirq->refcnt++;
@@ -309,8 +308,11 @@ static void grgpio_irq_unmap(struct irq_domain *d, unsigned int irq)
if (index >= 0) {
uirq = &priv->uirqs[lirq->index];
uirq->refcnt--;
- if (uirq->refcnt == 0)
+ if (uirq->refcnt == 0) {
+ spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
free_irq(uirq->uirq, priv);
+ return;
+ }
}
spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
--
2.20.1
next prev parent reply other threads:[~2020-02-14 17:45 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200214160149.11681-1-sashal@kernel.org>
2020-02-14 15:54 ` [PATCH AUTOSEL 5.4 024/459] pinctrl: sh-pfc: r8a77965: Fix DU_DOTCLKIN3 drive/bias control Sasha Levin
2020-02-14 15:54 ` [PATCH AUTOSEL 5.4 029/459] pinctrl: sh-pfc: sh7264: Fix CAN function GPIOs Sasha Levin
2020-02-14 15:54 ` Sasha Levin [this message]
2020-02-14 15:55 ` [PATCH AUTOSEL 5.4 053/459] pinctrl: baytrail: Do not clear IRQ flags on direct-irq enabled pins Sasha Levin
2020-02-14 15:58 ` [PATCH AUTOSEL 5.4 235/459] pinctrl: sh-pfc: r8a7778: Fix duplicate SDSELF_B and SD1_CLK_B Sasha Levin
2020-02-14 15:58 ` [PATCH AUTOSEL 5.4 236/459] pinctrl: sh-pfc: sh7269: Fix CAN function GPIOs Sasha Levin
2020-02-14 15:59 ` [PATCH AUTOSEL 5.4 315/459] gpiolib: Set lockdep class for hierarchical irq domains Sasha Levin
2020-02-14 15:59 ` [PATCH AUTOSEL 5.4 332/459] gpio: Fix the no return statement warning Sasha Levin
2020-02-15 0:46 ` Kevin Hao
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