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ISAPNP: don't unlock isapnp_cfg_mutex unless we've locked it first

PATCH In review Bjorn Helgaas 2 participants 2 messages Mar 2, 2010 – Mar 3, 2010

Subsystems (3)
ACPI Pnp support Isapnp
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Bjorn Helgaas

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#0 lore raw

PATCH 1/1 ISAPNP: don't unlock isapnp_cfg_mutex unless we've locked it first

If isapnp_cfg_begin() fails, it returns without locking isapnp_cfg_mutex. Previously, we always unlocked the mutex, even if we haven't locked it first.

This patch checks the isapnp_cfg_begin() return value so we can just exit and avoid this locking error.

Found by the Linux Device Drivers Verification Project and reported by Alexander Strakh <[email protected]>.

Signed-off-by Bjorn Helgaas <[email protected]>

---

 drivers/pnp/isapnp/core.c |   18 ++++++++++++++----
 1 files changed, 14 insertions(+), 4 deletions(-)
drivers/pnp/isapnp/core.c +14 -4
index e851160..93e95ad 100644
@@ -903,7 +903,10 @@ static int isapnp_get_resources(struct pnp_dev *dev)
 
 	pnp_dbg(&dev->dev, "get resources\n");
 	pnp_init_resources(dev);
-	isapnp_cfg_begin(dev->card->number, dev->number);
+	ret = isapnp_cfg_begin(dev->card->number, dev->number);
+	if (ret)
+		return ret;
+
 	dev->active = isapnp_read_byte(ISAPNP_CFG_ACTIVATE);
 	if (!dev->active)
 		goto __end;

@@ -937,10 +940,13 @@ __end:
 static int isapnp_set_resources(struct pnp_dev *dev)
 {
 	struct resource *res;
-	int tmp;
+	int tmp, ret;
 
 	pnp_dbg(&dev->dev, "set resources\n");
-	isapnp_cfg_begin(dev->card->number, dev->number);
+	ret = isapnp_cfg_begin(dev->card->number, dev->number);
+	if (ret)
+		return ret;
+
 	dev->active = 1;
 	for (tmp = 0; tmp < ISAPNP_MAX_PORT; tmp++) {
 		res = pnp_get_resource(dev, IORESOURCE_IO, tmp);

@@ -986,9 +992,13 @@ static int isapnp_set_resources(struct pnp_dev *dev)
 
 static int isapnp_disable_resources(struct pnp_dev *dev)
 {
+	int ret;
+
 	if (!dev->active)
 		return -EINVAL;
-	isapnp_cfg_begin(dev->card->number, dev->number);
+	ret = isapnp_cfg_begin(dev->card->number, dev->number);
+	if (ret)
+		return ret;
 	isapnp_deactivate(dev->number);
 	dev->active = 0;
 	isapnp_cfg_end();
maintainer Acked-by on v1 1/1
#1 lore raw
Quoted 5 lines · Bjorn Helgaas

If isapnp_cfg_begin() fails, it returns without locking isapnp_cfg_mutex. Previously, we always unlocked the mutex, even if we haven't locked it first.

Quoted 7 lines

This patch checks the isapnp_cfg_begin() return value so we can just exit and avoid this locking error.

Found by the Linux Device Drivers Verification Project and reported by Alexander Strakh <[email protected]>.

Signed-off-by Bjorn Helgaas <[email protected]>
Acked-by Jaroslav Kysela <[email protected]>

Jaroslav

-----
Jaroslav Kysela <[email protected]>
Linux Kernel Sound Maintainer
ALSA Project, Red Hat, Inc.