[PATCH 0/5] MIPS: ip22-gio: fix leaks and replace static root

[PATCH 0/5] MIPS: ip22-gio: fix leaks and replace static root

[Johan Hovold]

This series fixes some issues found through inspection when looking into
replacing the statically allocated gio bus root device.

Johan


Johan Hovold (5):
  MIPS: ip22-gio: fix kfree() of static object
  MIPS: ip22-gio: fix gio device memory leak
  MIPS: ip22-gio: fix device reference leak in probe
  MIPS: ip22-gio: switch to dynamic root device
  MIPS: ip22-gio: do not export device release function

 arch/mips/include/asm/gio_device.h |  6 ------
 arch/mips/sgi-ip22/ip22-gio.c      | 34 ++++++++++--------------------
 2 files changed, 11 insertions(+), 29 deletions(-)

-- 
2.53.0

[PATCH 1/5] MIPS: ip22-gio: fix kfree() of static object

[Johan Hovold]

The gio bus root device is a statically allocated object which must not
be freed by kfree() on failure to register the device or bus.

Fixes: 82242d28ff8b ("MIPS: IP22: Add missing put_device call")
Cc: stable@vger.kernel.org	# 3.17
Cc: Levente Kurusa <levex@linux.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 arch/mips/sgi-ip22/ip22-gio.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/mips/sgi-ip22/ip22-gio.c b/arch/mips/sgi-ip22/ip22-gio.c
index 9eec8842ffb7..a574441fa44b 100644
--- a/arch/mips/sgi-ip22/ip22-gio.c
+++ b/arch/mips/sgi-ip22/ip22-gio.c
@@ -30,7 +30,6 @@ static struct {
 
 static void gio_bus_release(struct device *dev)
 {
-	kfree(dev);
 }
 
 static struct device gio_bus = {
-- 
2.53.0

[PATCH 2/5] MIPS: ip22-gio: fix gio device memory leak

[Johan Hovold]

The gio device release callback was never wired up so gio devices are
not freed when the last reference is dropped.

Fixes: e84de0c61905 ("MIPS: GIO bus support for SGI IP22/28")
Cc: stable@vger.kernel.org	# 3.3
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 arch/mips/sgi-ip22/ip22-gio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/mips/sgi-ip22/ip22-gio.c b/arch/mips/sgi-ip22/ip22-gio.c
index a574441fa44b..2f5c6c6f8254 100644
--- a/arch/mips/sgi-ip22/ip22-gio.c
+++ b/arch/mips/sgi-ip22/ip22-gio.c
@@ -100,6 +100,8 @@ int gio_device_register(struct gio_device *giodev)
 {
 	giodev->dev.bus = &gio_bus_type;
 	giodev->dev.parent = &gio_bus;
+	giodev->dev.release = gio_release_dev;
+
 	return device_register(&giodev->dev);
 }
 EXPORT_SYMBOL_GPL(gio_device_register);
-- 
2.53.0

[PATCH 3/5] MIPS: ip22-gio: fix device reference leak in probe

[Johan Hovold]

The gio probe function needlessly takes a device reference which is
never released and therefore prevents unbound gio devices from being
freed.

Fixes: e84de0c61905 ("MIPS: GIO bus support for SGI IP22/28")
Cc: stable@vger.kernel.org	# 3.3
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 arch/mips/sgi-ip22/ip22-gio.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/arch/mips/sgi-ip22/ip22-gio.c b/arch/mips/sgi-ip22/ip22-gio.c
index 2f5c6c6f8254..7b7572d11250 100644
--- a/arch/mips/sgi-ip22/ip22-gio.c
+++ b/arch/mips/sgi-ip22/ip22-gio.c
@@ -133,13 +133,9 @@ static int gio_device_probe(struct device *dev)
 	if (!drv->probe)
 		return error;
 
-	gio_dev_get(gio_dev);
-
 	match = gio_match_device(drv->id_table, gio_dev);
 	if (match)
 		error = drv->probe(gio_dev, match);
-	if (error)
-		gio_dev_put(gio_dev);
 
 	return error;
 }
-- 
2.53.0

[PATCH 4/5] MIPS: ip22-gio: switch to dynamic root device

[Johan Hovold]

Driver core expects devices to be dynamically allocated and will, for
example, complain loudly when no release function has been provided.

Use root_device_register() to allocate and register the root device
instead of open coding using a static device.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 arch/mips/sgi-ip22/ip22-gio.c | 24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)

diff --git a/arch/mips/sgi-ip22/ip22-gio.c b/arch/mips/sgi-ip22/ip22-gio.c
index 7b7572d11250..d29067430b44 100644
--- a/arch/mips/sgi-ip22/ip22-gio.c
+++ b/arch/mips/sgi-ip22/ip22-gio.c
@@ -28,14 +28,7 @@ static struct {
 	{ .name = "SGI GR2/GR3", .id = 0x7f },
 };
 
-static void gio_bus_release(struct device *dev)
-{
-}
-
-static struct device gio_bus = {
-	.init_name = "gio",
-	.release = &gio_bus_release,
-};
+static struct device *gio_bus;
 
 /**
  * gio_match_device - Tell if an of_device structure has a matching
@@ -99,7 +92,7 @@ EXPORT_SYMBOL_GPL(gio_release_dev);
 int gio_device_register(struct gio_device *giodev)
 {
 	giodev->dev.bus = &gio_bus_type;
-	giodev->dev.parent = &gio_bus;
+	giodev->dev.parent = gio_bus;
 	giodev->dev.release = gio_release_dev;
 
 	return device_register(&giodev->dev);
@@ -397,11 +390,9 @@ static int __init ip22_gio_init(void)
 	unsigned int pbdma __maybe_unused;
 	int ret;
 
-	ret = device_register(&gio_bus);
-	if (ret) {
-		put_device(&gio_bus);
-		return ret;
-	}
+	gio_bus = root_device_register("gio");
+	if (IS_ERR(gio_bus))
+		return PTR_ERR(gio_bus);
 
 	ret = bus_register(&gio_bus_type);
 	if (!ret) {
@@ -420,8 +411,9 @@ static int __init ip22_gio_init(void)
 			ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIOEXP0_IRQ);
 			ip22_check_gio(2, GIO_SLOT_EXP1_BASE, SGI_GIOEXP1_IRQ);
 		}
-	} else
-		device_unregister(&gio_bus);
+	} else {
+		root_device_unregister(gio_bus);
+	}
 
 	return ret;
 }
-- 
2.53.0

[PATCH 5/5] MIPS: ip22-gio: do not export device release function

[Johan Hovold]

There is no need to export the gio device release function as the
devices are reference counted.

Drop the export along with the unused inline wrapper.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 arch/mips/include/asm/gio_device.h | 6 ------
 arch/mips/sgi-ip22/ip22-gio.c      | 3 +--
 2 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/arch/mips/include/asm/gio_device.h b/arch/mips/include/asm/gio_device.h
index 159087f5386e..f9c102f038d6 100644
--- a/arch/mips/include/asm/gio_device.h
+++ b/arch/mips/include/asm/gio_device.h
@@ -37,12 +37,6 @@ extern void gio_dev_put(struct gio_device *);
 
 extern int gio_device_register(struct gio_device *);
 extern void gio_device_unregister(struct gio_device *);
-extern void gio_release_dev(struct device *);
-
-static inline void gio_device_free(struct gio_device *dev)
-{
-	gio_release_dev(&dev->dev);
-}
 
 extern int gio_register_driver(struct gio_driver *);
 extern void gio_unregister_driver(struct gio_driver *);
diff --git a/arch/mips/sgi-ip22/ip22-gio.c b/arch/mips/sgi-ip22/ip22-gio.c
index d29067430b44..54e17c8693e2 100644
--- a/arch/mips/sgi-ip22/ip22-gio.c
+++ b/arch/mips/sgi-ip22/ip22-gio.c
@@ -80,14 +80,13 @@ EXPORT_SYMBOL_GPL(gio_dev_put);
  * Will be called only by the device core when all users of this gio device are
  * done.
  */
-void gio_release_dev(struct device *dev)
+static void gio_release_dev(struct device *dev)
 {
 	struct gio_device *giodev;
 
 	giodev = to_gio_device(dev);
 	kfree(giodev);
 }
-EXPORT_SYMBOL_GPL(gio_release_dev);
 
 int gio_device_register(struct gio_device *giodev)
 {
-- 
2.53.0

Re: [PATCH 0/5] MIPS: ip22-gio: fix leaks and replace static root

[Thomas Bogendoerfer]

On Fri, Apr 24, 2026 at 12:28:44PM +0200, Johan Hovold wrote:
> This series fixes some issues found through inspection when looking into
> replacing the statically allocated gio bus root device.
> 
> Johan
> 
> 
> Johan Hovold (5):
>   MIPS: ip22-gio: fix kfree() of static object
>   MIPS: ip22-gio: fix gio device memory leak
>   MIPS: ip22-gio: fix device reference leak in probe
>   MIPS: ip22-gio: switch to dynamic root device
>   MIPS: ip22-gio: do not export device release function
> 
>  arch/mips/include/asm/gio_device.h |  6 ------
>  arch/mips/sgi-ip22/ip22-gio.c      | 34 ++++++++++--------------------
>  2 files changed, 11 insertions(+), 29 deletions(-)

series applied to mips-next

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]