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* [PATCH v2] nubus: Call bus_register unconditionally
@ 2018-05-09  1:04 Finn Thain
  0 siblings, 0 replies; 3+ messages in thread
From: Finn Thain @ 2018-05-09  1:04 UTC (permalink / raw)
  To: Geert Uytterhoeven; +Cc: Greg Kroah-Hartman, linux-m68k, linux-kernel

Loading a NuBus driver module on a non-NuBus machine triggers the
BUG_ON(!drv->bus->p) in driver_register(), because bus_register() was
not called, because it is conditional on MACH_IS_MAC.

Fix the crash by calling bus_register() unconditionally. Call it from
a postcore_initcall(), like other busses do.

Hence, the bus type is available for device_register(), which happens
in a subsys initcall, and for driver_register(), which happens in a
device or module initcall.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Stan Johnson <userm57@yahoo.com>
Fixes: 7f86c765a6a2 ("nubus: Add support for the driver model")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
Changed since v1:
- Improved commit log entry.
- The device_register(&nubus_parent) stays in the subsys initcall.
---
 drivers/nubus/bus.c   | 19 +++++++------------
 drivers/nubus/nubus.c |  2 +-
 include/linux/nubus.h |  2 +-
 3 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/nubus/bus.c b/drivers/nubus/bus.c
index d306c348c857..a59b6c4bb5b8 100644
--- a/drivers/nubus/bus.c
+++ b/drivers/nubus/bus.c
@@ -63,20 +63,15 @@ static struct device nubus_parent = {
 	.init_name	= "nubus",
 };
 
-int __init nubus_bus_register(void)
+static int __init nubus_bus_register(void)
 {
-	int err;
-
-	err = device_register(&nubus_parent);
-	if (err)
-		return err;
-
-	err = bus_register(&nubus_bus_type);
-	if (!err)
-		return 0;
+	return bus_register(&nubus_bus_type);
+}
+postcore_initcall(nubus_bus_register);
 
-	device_unregister(&nubus_parent);
-	return err;
+int __init nubus_parent_device_register(void)
+{
+	return device_register(&nubus_parent);
 }
 
 static void nubus_device_release(struct device *dev)
diff --git a/drivers/nubus/nubus.c b/drivers/nubus/nubus.c
index 4621ff98138c..bb0d63a44f41 100644
--- a/drivers/nubus/nubus.c
+++ b/drivers/nubus/nubus.c
@@ -875,7 +875,7 @@ static int __init nubus_init(void)
 		return 0;
 
 	nubus_proc_init();
-	err = nubus_bus_register();
+	err = nubus_parent_device_register();
 	if (err)
 		return err;
 	nubus_scan_bus();
diff --git a/include/linux/nubus.h b/include/linux/nubus.h
index 6e8200215321..eba50b057f6f 100644
--- a/include/linux/nubus.h
+++ b/include/linux/nubus.h
@@ -163,7 +163,7 @@ void nubus_seq_write_rsrc_mem(struct seq_file *m,
 unsigned char *nubus_dirptr(const struct nubus_dirent *nd);
 
 /* Declarations relating to driver model objects */
-int nubus_bus_register(void);
+int nubus_parent_device_register(void);
 int nubus_device_register(struct nubus_board *board);
 int nubus_driver_register(struct nubus_driver *ndrv);
 void nubus_driver_unregister(struct nubus_driver *ndrv);
-- 
2.16.1

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] nubus: Call bus_register unconditionally
       [not found] <5af2492f.1c69fb81.a0c3b.4ef6SMTPIN_ADDED_MISSING@mx.google.com>
@ 2018-05-09  7:31 ` Geert Uytterhoeven
  0 siblings, 0 replies; 3+ messages in thread
From: Geert Uytterhoeven @ 2018-05-09  7:31 UTC (permalink / raw)
  To: Finn Thain; +Cc: Greg Kroah-Hartman, linux-m68k, Linux Kernel Mailing List

On Wed, May 9, 2018 at 3:04 AM, Finn Thain <fthain@telegraphics.com.au> wrote:
> Loading a NuBus driver module on a non-NuBus machine triggers the
> BUG_ON(!drv->bus->p) in driver_register(), because bus_register() was
> not called, because it is conditional on MACH_IS_MAC.
>
> Fix the crash by calling bus_register() unconditionally. Call it from
> a postcore_initcall(), like other busses do.
>
> Hence, the bus type is available for device_register(), which happens
> in a subsys initcall, and for driver_register(), which happens in a
> device or module initcall.
>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Reported-by: Michael Schmitz <schmitzmic@gmail.com>
> Tested-by: Stan Johnson <userm57@yahoo.com>
> Fixes: 7f86c765a6a2 ("nubus: Add support for the driver model")
> Signed-off-by: Finn Thain <fthain@telegraphics.com.au>

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [PATCH v2] nubus: Call bus_register unconditionally
@ 2018-05-09  1:04 Finn Thain
  0 siblings, 0 replies; 3+ messages in thread
From: Finn Thain @ 2018-05-09  1:04 UTC (permalink / raw)
  To: Geert Uytterhoeven; +Cc: Greg Kroah-Hartman, linux-m68k, linux-kernel

Loading a NuBus driver module on a non-NuBus machine triggers the
BUG_ON(!drv->bus->p) in driver_register(), because bus_register() was
not called, because it is conditional on MACH_IS_MAC.

Fix the crash by calling bus_register() unconditionally. Call it from
a postcore_initcall(), like other busses do.

Hence, the bus type is available for device_register(), which happens
in a subsys initcall, and for driver_register(), which happens in a
device or module initcall.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Stan Johnson <userm57@yahoo.com>
Fixes: 7f86c765a6a2 ("nubus: Add support for the driver model")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
---
Changed since v1:
- Improved commit log entry.
- The device_register(&nubus_parent) stays in the subsys initcall.
---
 drivers/nubus/bus.c   | 19 +++++++------------
 drivers/nubus/nubus.c |  2 +-
 include/linux/nubus.h |  2 +-
 3 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/nubus/bus.c b/drivers/nubus/bus.c
index d306c348c857..a59b6c4bb5b8 100644
--- a/drivers/nubus/bus.c
+++ b/drivers/nubus/bus.c
@@ -63,20 +63,15 @@ static struct device nubus_parent = {
 	.init_name	= "nubus",
 };
 
-int __init nubus_bus_register(void)
+static int __init nubus_bus_register(void)
 {
-	int err;
-
-	err = device_register(&nubus_parent);
-	if (err)
-		return err;
-
-	err = bus_register(&nubus_bus_type);
-	if (!err)
-		return 0;
+	return bus_register(&nubus_bus_type);
+}
+postcore_initcall(nubus_bus_register);
 
-	device_unregister(&nubus_parent);
-	return err;
+int __init nubus_parent_device_register(void)
+{
+	return device_register(&nubus_parent);
 }
 
 static void nubus_device_release(struct device *dev)
diff --git a/drivers/nubus/nubus.c b/drivers/nubus/nubus.c
index 4621ff98138c..bb0d63a44f41 100644
--- a/drivers/nubus/nubus.c
+++ b/drivers/nubus/nubus.c
@@ -875,7 +875,7 @@ static int __init nubus_init(void)
 		return 0;
 
 	nubus_proc_init();
-	err = nubus_bus_register();
+	err = nubus_parent_device_register();
 	if (err)
 		return err;
 	nubus_scan_bus();
diff --git a/include/linux/nubus.h b/include/linux/nubus.h
index 6e8200215321..eba50b057f6f 100644
--- a/include/linux/nubus.h
+++ b/include/linux/nubus.h
@@ -163,7 +163,7 @@ void nubus_seq_write_rsrc_mem(struct seq_file *m,
 unsigned char *nubus_dirptr(const struct nubus_dirent *nd);
 
 /* Declarations relating to driver model objects */
-int nubus_bus_register(void);
+int nubus_parent_device_register(void);
 int nubus_device_register(struct nubus_board *board);
 int nubus_driver_register(struct nubus_driver *ndrv);
 void nubus_driver_unregister(struct nubus_driver *ndrv);
-- 
2.16.1

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2018-05-09  7:31 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2018-05-09  1:04 [PATCH v2] nubus: Call bus_register unconditionally Finn Thain
2018-05-09  1:04 Finn Thain
     [not found] <5af2492f.1c69fb81.a0c3b.4ef6SMTPIN_ADDED_MISSING@mx.google.com>
2018-05-09  7:31 ` Geert Uytterhoeven

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