From 6d3dab7d84177f836b14961b4d252d0959d66768 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Date: Tue, 7 Jul 2015 13:08:39 +0200
Subject: PM / wakeirq: Avoid setting power.wakeirq too hastily
If dev_pm_attach_wake_irq() fails, the device's power.wakeirq field
should not be set to point to the struct wake_irq passed to that
function, as that object will be freed going forward.
For this reason, make dev_pm_attach_wake_irq() first call
device_wakeup_attach_irq() and only set the device's power.wakeirq
field if that's successful.
That requires device_wakeup_attach_irq() to be called under the
device's power.lock lock, but since dev_pm_attach_wake_irq() is
the only caller of it, the requisite changes are easy to make.
Fixes: 4990d4fe327b (PM / Wakeirq: Add automated device wake IRQ handling)
Reported-by: Felipe Balbi <balbi@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/base/power/wakeirq.c | 12 +++++-------
drivers/base/power/wakeup.c | 31 ++++++++++---------------------
2 files changed, 15 insertions(+), 28 deletions(-)
(limited to 'drivers/base')
diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c
index 7470004..eb6e674 100644
--- a/drivers/base/power/wakeirq.c
+++ b/drivers/base/power/wakeirq.c
@@ -45,14 +45,12 @@ static int dev_pm_attach_wake_irq(struct device *dev, int irq,
return -EEXIST;
}
- dev->power.wakeirq = wirq;
- spin_unlock_irqrestore(&dev->power.lock, flags);
-
err = device_wakeup_attach_irq(dev, wirq);
- if (err)
- return err;
+ if (!err)
+ dev->power.wakeirq = wirq;
- return 0;
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+ return err;
}
/**
@@ -105,10 +103,10 @@ void dev_pm_clear_wake_irq(struct device *dev)
return;
spin_lock_irqsave(&dev->power.lock, flags);
+ device_wakeup_detach_irq(dev);
dev->power.wakeirq = NULL;
spin_unlock_irqrestore(&dev->power.lock, flags);
- device_wakeup_detach_irq(dev);
if (wirq->dedicated_irq)
free_irq(wirq->irq, wirq);
kfree(wirq);
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index 7332ebc..15d27d7 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -247,32 +247,25 @@ EXPORT_SYMBOL_GPL(device_wakeup_enable);
* Attach a device wakeirq to the wakeup source so the device
* wake IRQ can be configured automatically for suspend and
* resume.
+ *
+ * Call under the device's power.lock lock.
*/
int device_wakeup_attach_irq(struct device *dev,
struct wake_irq *wakeirq)
{
struct wakeup_source *ws;
- int ret = 0;
- spin_lock_irq(&dev->power.lock);
ws = dev->power.wakeup;
if (!ws) {
dev_err(dev, "forgot to call call device_init_wakeup?\n");
- ret = -EINVAL;
- goto unlock;
+ return -EINVAL;
}
- if (ws->wakeirq) {
- ret = -EEXIST;
- goto unlock;
- }
+ if (ws->wakeirq)
+ return -EEXIST;
ws->wakeirq = wakeirq;
-
-unlock:
- spin_unlock_irq(&dev->power.lock);
-
- return ret;
+ return 0;
}
/**
@@ -280,20 +273,16 @@ unlock:
* @dev: Device to handle
*
* Removes a device wakeirq from the wakeup source.
+ *
+ * Call under the device's power.lock lock.
*/
void device_wakeup_detach_irq(struct device *dev)
{
struct wakeup_source *ws;
- spin_lock_irq(&dev->power.lock);
ws = dev->power.wakeup;
- if (!ws)
- goto unlock;
-
- ws->wakeirq = NULL;
-
-unlock:
- spin_unlock_irq(&dev->power.lock);
+ if (ws)
+ ws->wakeirq = NULL;
}
/**
--
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