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From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Date: Tue, 26 Mar 2024 21:23:31 +0100
Subject: [PATCH 01/19] amba: store owner from modules with
 amba_driver_register()
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Message-Id: <20240326-module-owner-amba-v1-1-4517b091385b@linaro.org>
References: <20240326-module-owner-amba-v1-0-4517b091385b@linaro.org>
In-Reply-To: <20240326-module-owner-amba-v1-0-4517b091385b@linaro.org>
To: Russell King <linux@armlinux.org.uk>, 
 Suzuki K Poulose <suzuki.poulose@arm.com>, 
 Mike Leach <mike.leach@linaro.org>, James Clark <james.clark@arm.com>, 
 Alexander Shishkin <alexander.shishkin@linux.intel.com>, 
 Maxime Coquelin <mcoquelin.stm32@gmail.com>, 
 Alexandre Torgue <alexandre.torgue@foss.st.com>, 
 Linus Walleij <linus.walleij@linaro.org>, 
 Andi Shyti <andi.shyti@kernel.org>, Olivia Mackall <olivia@selenic.com>, 
 Herbert Xu <herbert@gondor.apana.org.au>, Vinod Koul <vkoul@kernel.org>, 
 Dmitry Torokhov <dmitry.torokhov@gmail.com>, 
 Miquel Raynal <miquel.raynal@bootlin.com>, 
 Michal Simek <michal.simek@amd.com>, 
 Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>, 
 Eric Auger <eric.auger@redhat.com>, 
 Alex Williamson <alex.williamson@redhat.com>
Cc: linux-kernel@vger.kernel.org, coresight@lists.linaro.org, 
 linux-arm-kernel@lists.infradead.org, 
 linux-stm32@st-md-mailman.stormreply.com, linux-i2c@vger.kernel.org, 
 linux-crypto@vger.kernel.org, dmaengine@vger.kernel.org, 
 linux-input@vger.kernel.org, kvm@vger.kernel.org

Modules registering driver with amba_driver_register() often forget to
set .owner field.  The field is used by some of other kernel parts for
reference counting (try_module_get()), so it is expected that drivers
will set it.

Solve the problem by moving this task away from the drivers to the core
amba bus code, just like we did for platform_driver in
commit 9447057eaff8 ("platform_device: use a macro instead of
platform_driver_register").

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 drivers/amba/bus.c       | 11 +++++++----
 include/linux/amba/bus.h | 11 +++++++++--
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index a24c152bfaac..aba3aa95b224 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -488,28 +488,31 @@ static int __init amba_stub_drv_init(void)
 	 * waiting on amba_match(). So, register a stub driver to make sure
 	 * amba_match() is called even if no amba driver has been registered.
 	 */
-	return amba_driver_register(&amba_proxy_drv);
+	return __amba_driver_register(&amba_proxy_drv, NULL);
 }
 late_initcall_sync(amba_stub_drv_init);
 
 /**
- *	amba_driver_register - register an AMBA device driver
+ *	__amba_driver_register - register an AMBA device driver
  *	@drv: amba device driver structure
+ *	@owner: owning module/driver
  *
  *	Register an AMBA device driver with the Linux device model
  *	core.  If devices pre-exist, the drivers probe function will
  *	be called.
  */
-int amba_driver_register(struct amba_driver *drv)
+int __amba_driver_register(struct amba_driver *drv,
+			   struct module *owner)
 {
 	if (!drv->probe)
 		return -EINVAL;
 
+	drv->drv.owner = owner;
 	drv->drv.bus = &amba_bustype;
 
 	return driver_register(&drv->drv);
 }
-EXPORT_SYMBOL(amba_driver_register);
+EXPORT_SYMBOL(__amba_driver_register);
 
 /**
  *	amba_driver_unregister - remove an AMBA device driver
diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h
index c60a6a14638c..958a55bcc708 100644
--- a/include/linux/amba/bus.h
+++ b/include/linux/amba/bus.h
@@ -112,11 +112,18 @@ extern struct bus_type amba_bustype;
 #define amba_get_drvdata(d)	dev_get_drvdata(&d->dev)
 #define amba_set_drvdata(d,p)	dev_set_drvdata(&d->dev, p)
 
+/*
+ * use a macro to avoid include chaining to get THIS_MODULE
+ */
+#define amba_driver_register(drv) \
+	__amba_driver_register(drv, THIS_MODULE)
+
 #ifdef CONFIG_ARM_AMBA
-int amba_driver_register(struct amba_driver *);
+int __amba_driver_register(struct amba_driver *, struct module *);
 void amba_driver_unregister(struct amba_driver *);
 #else
-static inline int amba_driver_register(struct amba_driver *drv)
+static inline int __amba_driver_register(struct amba_driver *drv,
+					 struct module *owner)
 {
 	return -EINVAL;
 }

-- 
2.34.1