[PATCH v2 0/2] Enable sysfs module symlink for more built-in drivers

[PATCH v2 0/2] Enable sysfs module symlink for more built-in drivers

[Shashank Balaji]

struct device_driver's mod_name is not set by a number of bus' driver registration
functions. Without that, built-in drivers don't have the module symlink in sysfs.
We want this to go from unbound driver name -> module name -> kernel config name.
This is useful on embedded platforms to minimize kernel config, reduce kernel size,
and reduce boot time.

In order to achieve this, mod_name has to be set to KBUILD_MODNAME, and this has
to be done for all buses which don't yet do this.

Here are some treewide stats:
- 110 registration functions across all bus types
- 20 of them set mod_name
- Remaining 90 do not set mod_name:
    1. 36 functions under pattern 1:
        They have a __register function + register macro. KBUILD_MODNAME needs to
        be passed and the function needs to take mod_name as input.
    2. 42 functions under pattern 2:
        These have no macro wrapper. They need a double-underscore rename + macro
        wrapper to make them similar to pattern 1.
    3. Remaining 12 do not have such a clean registration interface. More analysis
       is required.

We plan to start with pattern 1, since it's the easiest category of changes.
Within that, for now we're only sending the platform patch. If we get the go-ahead
on that, we'll send the remaining ones.

Patch 2 depends on patch 1, without which arm64 defconfig fails to boot with
patch 2.

Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
---
Changes in v2:
- Drop acpi patch, send platform instead (Rafael)
- Link to v1: https://patch.msgid.link/20260416-acpi_mod_name-v1-0-1a4d96fd86c9@sony.com

To: Kay Sievers <kay.sievers@vrfy.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
To: Danilo Krummrich <dakr@kernel.org>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
To: Mike Leach <mike.leach@linaro.org>
To: James Clark <james.clark@linaro.org>
To: Alexander Shishkin <alexander.shishkin@linux.intel.com>
To: Maxime Coquelin <mcoquelin.stm32@gmail.com>
To: Alexandre Torgue <alexandre.torgue@foss.st.com>
To: Miguel Ojeda <ojeda@kernel.org>
To: Boqun Feng <boqun@kernel.org>
To: Gary Guo <gary@garyguo.net>
To: Björn Roy Baron <bjorn3_gh@protonmail.com>
To: Benno Lossin <lossin@kernel.org>
To: Andreas Hindborg <a.hindborg@kernel.org>
To: Alice Ryhl <aliceryhl@google.com>
To: Trevor Gross <tmgross@umich.edu>
To: Richard Cochran <richardcochran@gmail.com>
To: Jonathan Corbet <corbet@lwn.net>
To: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: driver-core@lists.linux.dev
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: rust-for-linux@vger.kernel.org
Cc: linux-doc@vger.kernel.org

---
Shashank Balaji (2):
      kernel: param: handle NULL module_kset in lookup_or_create_module_kobject()
      driver core: platform: set mod_name in driver registration

 Documentation/driver-api/driver-model/platform.rst |  3 ++-
 drivers/base/platform.c                            | 21 ++++++++++++++-------
 drivers/hwtracing/coresight/coresight-catu.c       |  3 ++-
 drivers/hwtracing/coresight/coresight-core.c       |  5 +++--
 drivers/hwtracing/coresight/coresight-cpu-debug.c  |  2 +-
 drivers/hwtracing/coresight/coresight-funnel.c     |  2 +-
 drivers/hwtracing/coresight/coresight-replicator.c |  2 +-
 drivers/hwtracing/coresight/coresight-stm.c        |  3 ++-
 drivers/hwtracing/coresight/coresight-tmc-core.c   |  3 ++-
 drivers/hwtracing/coresight/coresight-tnoc.c       |  3 ++-
 drivers/hwtracing/coresight/coresight-tpdm.c       |  2 +-
 drivers/hwtracing/coresight/coresight-tpiu.c       |  3 ++-
 include/linux/coresight.h                          |  3 ++-
 include/linux/platform_device.h                    | 17 +++++++++--------
 kernel/params.c                                    |  3 +++
 rust/kernel/platform.rs                            |  4 +++-
 16 files changed, 50 insertions(+), 29 deletions(-)
---
base-commit: b4e07588e743c989499ca24d49e752c074924a9a
change-id: 20260416-acpi_mod_name-f645a76e337b

Best regards,
--  
Shashank Balaji <shashank.mahadasyam@sony.com>

[PATCH v2 1/2] kernel: param: handle NULL module_kset in lookup_or_create_module_kobject()

[Shashank Balaji]

module_kset is initialized in a subsys_initcall. If a built-in driver tries to
register before subsys_initcall with its struct device_driver's mod_name set,
then a null module_kset is dereferenced via this call trace:

     [    0.095865] Call trace:
     [    0.095999]  _raw_spin_lock+0x4c/0x6c (P)
     [    0.096150]  kset_find_obj+0x24/0x104
     [    0.096209]  lookup_or_create_module_kobject+0x2c/0xd8
     [    0.096274]  module_add_driver+0xd4/0x138
     [    0.096328]  bus_add_driver+0x16c/0x268
     [    0.096380]  driver_register+0x68/0x100
     [    0.096428]  __platform_driver_register+0x24/0x30
     [    0.096486]  tegra194_cbb_init+0x24/0x30
     [    0.096540]  do_one_initcall+0xdc/0x250
     [    0.096608]  do_initcall_level+0x9c/0xd0
     [    0.096660]  do_initcalls+0x54/0x94
     [    0.096706]  do_basic_setup+0x20/0x2c
     [    0.096753]  kernel_init_freeable+0xc8/0x154
     [    0.096807]  kernel_init+0x20/0x1a0
     [    0.096851]  ret_from_fork+0x10/0x20

So, return null in lookup_or_create_module_kobject() if module_kset is null.
Existing callers handle null already.

Fixes: f30c53a873d0 ("MODULES: add the module name for built in kernel drivers")
Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
---
This bug is triggered by the next patch on arm64 defconfig: tegra194-cbb tries
to register from a pure_initcall, and with the next patch adding mod_name, this
null deref is hit.
---
 kernel/params.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/params.c b/kernel/params.c
index 74d620bc2521..881c7328c059 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -752,6 +752,9 @@ lookup_or_create_module_kobject(const char *name)
 	struct kobject *kobj;
 	int err;
 
+	if (!module_kset)
+		return NULL;
+
 	kobj = kset_find_obj(module_kset, name);
 	if (kobj)
 		return to_module_kobject(kobj);

-- 
2.43.0

[PATCH v2 2/2] driver core: platform: set mod_name in driver registration

[Shashank Balaji]

Pass KBUILD_MODNAME through the driver registration macro so that
the driver core can create the module symlink in sysfs for built-in
drivers, and fixup all callers.

The Rust platform adapter is updated to pass the module name through to the new
parameter.

Tested on qemu with:
- x86 defconfig + CONFIG_RUST
- arm64 defconfig + CONFIG_RUST + CONFIG_CORESIGHT

Examples after this patch:

    /sys/bus/platform/drivers/...
        coresight-itnoc/module		-> coresight_tnoc
        coresight-static-tpdm/module	-> coresight_tpdm
        coresight-catu-platform/module	-> coresight_catu
        serial8250/module		-> 8250
        acpi-ged/module			-> acpi
        vmclock/module			-> ptp_vmclock

Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
---
Depends on the previous patch, without which the kernel fails to boot on arm64
defconfig.
---
 Documentation/driver-api/driver-model/platform.rst |  3 ++-
 drivers/base/platform.c                            | 21 ++++++++++++++-------
 drivers/hwtracing/coresight/coresight-catu.c       |  3 ++-
 drivers/hwtracing/coresight/coresight-core.c       |  5 +++--
 drivers/hwtracing/coresight/coresight-cpu-debug.c  |  2 +-
 drivers/hwtracing/coresight/coresight-funnel.c     |  2 +-
 drivers/hwtracing/coresight/coresight-replicator.c |  2 +-
 drivers/hwtracing/coresight/coresight-stm.c        |  3 ++-
 drivers/hwtracing/coresight/coresight-tmc-core.c   |  3 ++-
 drivers/hwtracing/coresight/coresight-tnoc.c       |  3 ++-
 drivers/hwtracing/coresight/coresight-tpdm.c       |  2 +-
 drivers/hwtracing/coresight/coresight-tpiu.c       |  3 ++-
 include/linux/coresight.h                          |  3 ++-
 include/linux/platform_device.h                    | 17 +++++++++--------
 rust/kernel/platform.rs                            |  4 +++-
 15 files changed, 47 insertions(+), 29 deletions(-)

diff --git a/Documentation/driver-api/driver-model/platform.rst b/Documentation/driver-api/driver-model/platform.rst
index cf5ff48d3115..9673470bded2 100644
--- a/Documentation/driver-api/driver-model/platform.rst
+++ b/Documentation/driver-api/driver-model/platform.rst
@@ -70,7 +70,8 @@ Kernel modules can be composed of several platform drivers. The platform core
 provides helpers to register and unregister an array of drivers::
 
 	int __platform_register_drivers(struct platform_driver * const *drivers,
-				      unsigned int count, struct module *owner);
+				      unsigned int count, struct module *owner,
+				      const char *mod_name);
 	void platform_unregister_drivers(struct platform_driver * const *drivers,
 					 unsigned int count);
 
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 75b4698d0e58..2b0cc0889386 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -901,11 +901,14 @@ EXPORT_SYMBOL_GPL(platform_device_register_full);
  * __platform_driver_register - register a driver for platform-level devices
  * @drv: platform driver structure
  * @owner: owning module/driver
+ * @mod_name: module name string
  */
-int __platform_driver_register(struct platform_driver *drv, struct module *owner)
+int __platform_driver_register(struct platform_driver *drv, struct module *owner,
+			       const char *mod_name)
 {
 	drv->driver.owner = owner;
 	drv->driver.bus = &platform_bus_type;
+	drv->driver.mod_name = mod_name;
 
 	return driver_register(&drv->driver);
 }
@@ -938,6 +941,7 @@ static int is_bound_to_driver(struct device *dev, void *driver)
  * @drv: platform driver structure
  * @probe: the driver probe routine, probably from an __init section
  * @module: module which will be the owner of the driver
+ * @mod_name: module name string
  *
  * Use this instead of platform_driver_register() when you know the device
  * is not hotpluggable and has already been registered, and you want to
@@ -955,7 +959,8 @@ static int is_bound_to_driver(struct device *dev, void *driver)
  */
 int __init_or_module __platform_driver_probe(struct platform_driver *drv,
 					     int (*probe)(struct platform_device *),
-					     struct module *module)
+					     struct module *module,
+					     const char *mod_name)
 {
 	int retval;
 
@@ -983,7 +988,7 @@ int __init_or_module __platform_driver_probe(struct platform_driver *drv,
 
 	/* temporary section violation during probe() */
 	drv->probe = probe;
-	retval = __platform_driver_register(drv, module);
+	retval = __platform_driver_register(drv, module, mod_name);
 	if (retval)
 		return retval;
 
@@ -1011,6 +1016,7 @@ EXPORT_SYMBOL_GPL(__platform_driver_probe);
  * @data: platform specific data for this platform device
  * @size: size of platform specific data
  * @module: module which will be the owner of the driver
+ * @mod_name: module name string
  *
  * Use this in legacy-style modules that probe hardware directly and
  * register a single platform device and corresponding platform driver.
@@ -1021,7 +1027,7 @@ struct platform_device * __init_or_module
 __platform_create_bundle(struct platform_driver *driver,
 			 int (*probe)(struct platform_device *),
 			 struct resource *res, unsigned int n_res,
-			 const void *data, size_t size, struct module *module)
+			 const void *data, size_t size, struct module *module, const char *mod_name)
 {
 	struct platform_device *pdev;
 	int error;
@@ -1044,7 +1050,7 @@ __platform_create_bundle(struct platform_driver *driver,
 	if (error)
 		goto err_pdev_put;
 
-	error = __platform_driver_probe(driver, probe, module);
+	error = __platform_driver_probe(driver, probe, module, mod_name);
 	if (error)
 		goto err_pdev_del;
 
@@ -1064,6 +1070,7 @@ EXPORT_SYMBOL_GPL(__platform_create_bundle);
  * @drivers: an array of drivers to register
  * @count: the number of drivers to register
  * @owner: module owning the drivers
+ * @mod_name: module name string
  *
  * Registers platform drivers specified by an array. On failure to register a
  * driver, all previously registered drivers will be unregistered. Callers of
@@ -1073,7 +1080,7 @@ EXPORT_SYMBOL_GPL(__platform_create_bundle);
  * Returns: 0 on success or a negative error code on failure.
  */
 int __platform_register_drivers(struct platform_driver * const *drivers,
-				unsigned int count, struct module *owner)
+				unsigned int count, struct module *owner, const char *mod_name)
 {
 	unsigned int i;
 	int err;
@@ -1081,7 +1088,7 @@ int __platform_register_drivers(struct platform_driver * const *drivers,
 	for (i = 0; i < count; i++) {
 		pr_debug("registering platform driver %ps\n", drivers[i]);
 
-		err = __platform_driver_register(drivers[i], owner);
+		err = __platform_driver_register(drivers[i], owner, mod_name);
 		if (err < 0) {
 			pr_err("failed to register platform driver %ps: %d\n",
 			       drivers[i], err);
diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
index dfd035852b12..3e4df832f02a 100644
--- a/drivers/hwtracing/coresight/coresight-catu.c
+++ b/drivers/hwtracing/coresight/coresight-catu.c
@@ -708,7 +708,8 @@ static int __init catu_init(void)
 {
 	int ret;
 
-	ret = coresight_init_driver("catu", &catu_driver, &catu_platform_driver, THIS_MODULE);
+	ret = coresight_init_driver("catu", &catu_driver, &catu_platform_driver,
+				    THIS_MODULE, KBUILD_MODNAME);
 	tmc_etr_set_catu_ops(&etr_catu_buf_ops);
 	return ret;
 }
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 80e26396ad0a..b88bc053ab58 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1645,7 +1645,8 @@ module_init(coresight_init);
 module_exit(coresight_exit);
 
 int coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
-			  struct platform_driver *pdev_drv, struct module *owner)
+			  struct platform_driver *pdev_drv, struct module *owner,
+			  const char *mod_name)
 {
 	int ret;
 
@@ -1655,7 +1656,7 @@ int coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
 		return ret;
 	}
 
-	ret = __platform_driver_register(pdev_drv, owner);
+	ret = __platform_driver_register(pdev_drv, owner, mod_name);
 	if (!ret)
 		return 0;
 
diff --git a/drivers/hwtracing/coresight/coresight-cpu-debug.c b/drivers/hwtracing/coresight/coresight-cpu-debug.c
index 629614278e46..00b7c52d3ab9 100644
--- a/drivers/hwtracing/coresight/coresight-cpu-debug.c
+++ b/drivers/hwtracing/coresight/coresight-cpu-debug.c
@@ -758,7 +758,7 @@ static struct platform_driver debug_platform_driver = {
 static int __init debug_init(void)
 {
 	return coresight_init_driver("debug", &debug_driver, &debug_platform_driver,
-				     THIS_MODULE);
+				     THIS_MODULE, KBUILD_MODNAME);
 }
 
 static void __exit debug_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
index 3b248e54471a..8ee5b42bb475 100644
--- a/drivers/hwtracing/coresight/coresight-funnel.c
+++ b/drivers/hwtracing/coresight/coresight-funnel.c
@@ -415,7 +415,7 @@ static struct amba_driver dynamic_funnel_driver = {
 static int __init funnel_init(void)
 {
 	return coresight_init_driver("funnel", &dynamic_funnel_driver, &funnel_driver,
-				     THIS_MODULE);
+				     THIS_MODULE, KBUILD_MODNAME);
 }
 
 static void __exit funnel_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
index e6472658235d..9af67100f1fd 100644
--- a/drivers/hwtracing/coresight/coresight-replicator.c
+++ b/drivers/hwtracing/coresight/coresight-replicator.c
@@ -421,7 +421,7 @@ static struct amba_driver dynamic_replicator_driver = {
 static int __init replicator_init(void)
 {
 	return coresight_init_driver("replicator", &dynamic_replicator_driver, &replicator_driver,
-				     THIS_MODULE);
+				     THIS_MODULE, KBUILD_MODNAME);
 }
 
 static void __exit replicator_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
index e68529bf89c9..b140069e07b5 100644
--- a/drivers/hwtracing/coresight/coresight-stm.c
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -1052,7 +1052,8 @@ static struct platform_driver stm_platform_driver = {
 
 static int __init stm_init(void)
 {
-	return coresight_init_driver("stm", &stm_driver, &stm_platform_driver, THIS_MODULE);
+	return coresight_init_driver("stm", &stm_driver, &stm_platform_driver,
+				     THIS_MODULE, KBUILD_MODNAME);
 }
 
 static void __exit stm_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
index 36599c431be6..bef0a9d1fa1b 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-core.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
@@ -1051,7 +1051,8 @@ static struct platform_driver tmc_platform_driver = {
 
 static int __init tmc_init(void)
 {
-	return coresight_init_driver("tmc", &tmc_driver, &tmc_platform_driver, THIS_MODULE);
+	return coresight_init_driver("tmc", &tmc_driver, &tmc_platform_driver,
+				     THIS_MODULE, KBUILD_MODNAME);
 }
 
 static void __exit tmc_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-tnoc.c b/drivers/hwtracing/coresight/coresight-tnoc.c
index 1128612e70a7..1c7c7a062600 100644
--- a/drivers/hwtracing/coresight/coresight-tnoc.c
+++ b/drivers/hwtracing/coresight/coresight-tnoc.c
@@ -346,7 +346,8 @@ static struct platform_driver itnoc_driver = {
 
 static int __init tnoc_init(void)
 {
-	return coresight_init_driver("tnoc", &trace_noc_driver, &itnoc_driver, THIS_MODULE);
+	return coresight_init_driver("tnoc", &trace_noc_driver, &itnoc_driver,
+				     THIS_MODULE, KBUILD_MODNAME);
 }
 
 static void __exit tnoc_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 06e0a905a67d..2a735f797c8e 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -1534,7 +1534,7 @@ static struct platform_driver static_tpdm_driver = {
 static int __init tpdm_init(void)
 {
 	return coresight_init_driver("tpdm", &dynamic_tpdm_driver, &static_tpdm_driver,
-				     THIS_MODULE);
+				     THIS_MODULE, KBUILD_MODNAME);
 }
 
 static void __exit tpdm_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c
index aaa44bc521c3..3ddabb81b946 100644
--- a/drivers/hwtracing/coresight/coresight-tpiu.c
+++ b/drivers/hwtracing/coresight/coresight-tpiu.c
@@ -312,7 +312,8 @@ static struct platform_driver tpiu_platform_driver = {
 
 static int __init tpiu_init(void)
 {
-	return coresight_init_driver("tpiu", &tpiu_driver, &tpiu_platform_driver, THIS_MODULE);
+	return coresight_init_driver("tpiu", &tpiu_driver, &tpiu_platform_driver,
+				     THIS_MODULE, KBUILD_MODNAME);
 }
 
 static void __exit tpiu_exit(void)
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 2b48be97fcd0..382341f587d0 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -698,7 +698,8 @@ coresight_find_output_type(struct coresight_platform_data *pdata,
 			   union coresight_dev_subtype subtype);
 
 int coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
-			  struct platform_driver *pdev_drv, struct module *owner);
+			  struct platform_driver *pdev_drv, struct module *owner,
+			  const char *mod_name);
 
 void coresight_remove_driver(struct amba_driver *amba_drv,
 			     struct platform_driver *pdev_drv);
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 975400a472e3..26e6a43358e2 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -293,18 +293,19 @@ struct platform_driver {
  * use a macro to avoid include chaining to get THIS_MODULE
  */
 #define platform_driver_register(drv) \
-	__platform_driver_register(drv, THIS_MODULE)
+	__platform_driver_register(drv, THIS_MODULE, KBUILD_MODNAME)
 extern int __platform_driver_register(struct platform_driver *,
-					struct module *);
+					struct module *, const char *mod_name);
 extern void platform_driver_unregister(struct platform_driver *);
 
 /* non-hotpluggable platform devices may use this so that probe() and
  * its support may live in __init sections, conserving runtime memory.
  */
 #define platform_driver_probe(drv, probe) \
-	__platform_driver_probe(drv, probe, THIS_MODULE)
+	__platform_driver_probe(drv, probe, THIS_MODULE, KBUILD_MODNAME)
 extern int __platform_driver_probe(struct platform_driver *driver,
-		int (*probe)(struct platform_device *), struct module *module);
+		int (*probe)(struct platform_device *), struct module *module,
+		const char *mod_name);
 
 static inline void *platform_get_drvdata(const struct platform_device *pdev)
 {
@@ -368,19 +369,19 @@ static int __init __platform_driver##_init(void) \
 device_initcall(__platform_driver##_init); \
 
 #define platform_create_bundle(driver, probe, res, n_res, data, size) \
-	__platform_create_bundle(driver, probe, res, n_res, data, size, THIS_MODULE)
+	__platform_create_bundle(driver, probe, res, n_res, data, size, THIS_MODULE, KBUILD_MODNAME)
 extern struct platform_device *__platform_create_bundle(
 	struct platform_driver *driver, int (*probe)(struct platform_device *),
 	struct resource *res, unsigned int n_res,
-	const void *data, size_t size, struct module *module);
+	const void *data, size_t size, struct module *module, const char *mod_name);
 
 int __platform_register_drivers(struct platform_driver * const *drivers,
-				unsigned int count, struct module *owner);
+				unsigned int count, struct module *owner, const char *mod_name);
 void platform_unregister_drivers(struct platform_driver * const *drivers,
 				 unsigned int count);
 
 #define platform_register_drivers(drivers, count) \
-	__platform_register_drivers(drivers, count, THIS_MODULE)
+	__platform_register_drivers(drivers, count, THIS_MODULE, KBUILD_MODNAME)
 
 #ifdef CONFIG_SUSPEND
 extern int platform_pm_suspend(struct device *dev);
diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index 8917d4ee499f..2d626eecc450 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -82,7 +82,9 @@ unsafe fn register(
         }
 
         // SAFETY: `pdrv` is guaranteed to be a valid `DriverType`.
-        to_result(unsafe { bindings::__platform_driver_register(pdrv.get(), module.0) })
+        to_result(unsafe {
+            bindings::__platform_driver_register(pdrv.get(), module.0, name.as_char_ptr())
+        })
     }
 
     unsafe fn unregister(pdrv: &Opaque<Self::DriverType>) {

-- 
2.43.0

Re: [PATCH v2 2/2] driver core: platform: set mod_name in driver registration

[Greg Kroah-Hartman]

On Tue, Apr 21, 2026 at 03:02:35PM +0900, Shashank Balaji wrote:
> Pass KBUILD_MODNAME through the driver registration macro so that
> the driver core can create the module symlink in sysfs for built-in
> drivers, and fixup all callers.
> 
> The Rust platform adapter is updated to pass the module name through to the new
> parameter.
> 
> Tested on qemu with:
> - x86 defconfig + CONFIG_RUST
> - arm64 defconfig + CONFIG_RUST + CONFIG_CORESIGHT
> 
> Examples after this patch:
> 
>     /sys/bus/platform/drivers/...
>         coresight-itnoc/module		-> coresight_tnoc
>         coresight-static-tpdm/module	-> coresight_tpdm
>         coresight-catu-platform/module	-> coresight_catu
>         serial8250/module		-> 8250
>         acpi-ged/module			-> acpi
>         vmclock/module			-> ptp_vmclock
> 
> Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
> Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
> Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
> ---
> Depends on the previous patch, without which the kernel fails to boot on arm64
> defconfig.
> ---
>  Documentation/driver-api/driver-model/platform.rst |  3 ++-
>  drivers/base/platform.c                            | 21 ++++++++++++++-------
>  drivers/hwtracing/coresight/coresight-catu.c       |  3 ++-
>  drivers/hwtracing/coresight/coresight-core.c       |  5 +++--
>  drivers/hwtracing/coresight/coresight-cpu-debug.c  |  2 +-
>  drivers/hwtracing/coresight/coresight-funnel.c     |  2 +-
>  drivers/hwtracing/coresight/coresight-replicator.c |  2 +-
>  drivers/hwtracing/coresight/coresight-stm.c        |  3 ++-
>  drivers/hwtracing/coresight/coresight-tmc-core.c   |  3 ++-
>  drivers/hwtracing/coresight/coresight-tnoc.c       |  3 ++-
>  drivers/hwtracing/coresight/coresight-tpdm.c       |  2 +-
>  drivers/hwtracing/coresight/coresight-tpiu.c       |  3 ++-
>  include/linux/coresight.h                          |  3 ++-
>  include/linux/platform_device.h                    | 17 +++++++++--------
>  rust/kernel/platform.rs                            |  4 +++-
>  15 files changed, 47 insertions(+), 29 deletions(-)

That's a lot of different things all in one change, please break this up
into smaller bits, this is not going to work.

Especially as the coresight changes are incorrect, no individual module
should EVER have to list THIS_MODULE or KBUILD_MODNAME in a function, it
should happen automatically by the compiler using a helper #define, like
is done for other busses.

Please fix that up first, then you can worry about the other ones.

thanks,

greg k-h

Re: [PATCH v2 1/2] kernel: param: handle NULL module_kset in lookup_or_create_module_kobject()

[Greg Kroah-Hartman]

On Tue, Apr 21, 2026 at 03:02:34PM +0900, Shashank Balaji wrote:
> module_kset is initialized in a subsys_initcall. If a built-in driver tries to
> register before subsys_initcall with its struct device_driver's mod_name set,
> then a null module_kset is dereferenced via this call trace:
> 
>      [    0.095865] Call trace:
>      [    0.095999]  _raw_spin_lock+0x4c/0x6c (P)
>      [    0.096150]  kset_find_obj+0x24/0x104
>      [    0.096209]  lookup_or_create_module_kobject+0x2c/0xd8
>      [    0.096274]  module_add_driver+0xd4/0x138
>      [    0.096328]  bus_add_driver+0x16c/0x268
>      [    0.096380]  driver_register+0x68/0x100
>      [    0.096428]  __platform_driver_register+0x24/0x30
>      [    0.096486]  tegra194_cbb_init+0x24/0x30
>      [    0.096540]  do_one_initcall+0xdc/0x250
>      [    0.096608]  do_initcall_level+0x9c/0xd0
>      [    0.096660]  do_initcalls+0x54/0x94
>      [    0.096706]  do_basic_setup+0x20/0x2c
>      [    0.096753]  kernel_init_freeable+0xc8/0x154
>      [    0.096807]  kernel_init+0x20/0x1a0
>      [    0.096851]  ret_from_fork+0x10/0x20
> 
> So, return null in lookup_or_create_module_kobject() if module_kset is null.
> Existing callers handle null already.
> 
> Fixes: f30c53a873d0 ("MODULES: add the module name for built in kernel drivers")

This isn't a bugfix.

> Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
> Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
> Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
> ---
> This bug is triggered by the next patch on arm64 defconfig: tegra194-cbb tries
> to register from a pure_initcall, and with the next patch adding mod_name, this
> null deref is hit.

So this isn't a bug, it's a "don't do that" type of thing :)

> ---
>  kernel/params.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/kernel/params.c b/kernel/params.c
> index 74d620bc2521..881c7328c059 100644
> --- a/kernel/params.c
> +++ b/kernel/params.c
> @@ -752,6 +752,9 @@ lookup_or_create_module_kobject(const char *name)
>  	struct kobject *kobj;
>  	int err;
>  
> +	if (!module_kset)
> +		return NULL;

Are you sure that making this change is going to be ok?
mod_sysfs_init() should have been called first as the module has to be
created before it can be looked up.

As you are wanting "built in" drivers to show up here, you are going to
beat the call to param_sysfs_init(), so don't do that.  Make sure that
the drivers are NOT called before then.

thanks,

greg k-h

Re: [PATCH v2 1/2] kernel: param: handle NULL module_kset in lookup_or_create_module_kobject()

[Shashank Balaji]

Hi Greg,

Thanks for the quick feedback!

On Tue, Apr 21, 2026 at 08:27:10AM +0200, Greg Kroah-Hartman wrote:
> On Tue, Apr 21, 2026 at 03:02:34PM +0900, Shashank Balaji wrote:
> > module_kset is initialized in a subsys_initcall. If a built-in driver tries to
> > register before subsys_initcall with its struct device_driver's mod_name set,
> > then a null module_kset is dereferenced via this call trace:
> > 
> >      [    0.095865] Call trace:
> >      [    0.095999]  _raw_spin_lock+0x4c/0x6c (P)
> >      [    0.096150]  kset_find_obj+0x24/0x104
> >      [    0.096209]  lookup_or_create_module_kobject+0x2c/0xd8
> >      [    0.096274]  module_add_driver+0xd4/0x138
> >      [    0.096328]  bus_add_driver+0x16c/0x268
> >      [    0.096380]  driver_register+0x68/0x100
> >      [    0.096428]  __platform_driver_register+0x24/0x30
> >      [    0.096486]  tegra194_cbb_init+0x24/0x30
> >      [    0.096540]  do_one_initcall+0xdc/0x250
> >      [    0.096608]  do_initcall_level+0x9c/0xd0
> >      [    0.096660]  do_initcalls+0x54/0x94
> >      [    0.096706]  do_basic_setup+0x20/0x2c
> >      [    0.096753]  kernel_init_freeable+0xc8/0x154
> >      [    0.096807]  kernel_init+0x20/0x1a0
> >      [    0.096851]  ret_from_fork+0x10/0x20
> > 
> > So, return null in lookup_or_create_module_kobject() if module_kset is null.
> > Existing callers handle null already.
> > 
> > Fixes: f30c53a873d0 ("MODULES: add the module name for built in kernel drivers")
> 
> This isn't a bugfix.

I'll drop it in the next version.

> > Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
> > Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
> > Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
> > ---
> > This bug is triggered by the next patch on arm64 defconfig: tegra194-cbb tries
> > to register from a pure_initcall, and with the next patch adding mod_name, this
> > null deref is hit.
> 
> So this isn't a bug, it's a "don't do that" type of thing :)
> 
> > ---
> >  kernel/params.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/kernel/params.c b/kernel/params.c
> > index 74d620bc2521..881c7328c059 100644
> > --- a/kernel/params.c
> > +++ b/kernel/params.c
> > @@ -752,6 +752,9 @@ lookup_or_create_module_kobject(const char *name)
> >  	struct kobject *kobj;
> >  	int err;
> >  
> > +	if (!module_kset)
> > +		return NULL;
> 
> Are you sure that making this change is going to be ok?
> mod_sysfs_init() should have been called first as the module has to be
> created before it can be looked up.
> 
> As you are wanting "built in" drivers to show up here, you are going to
> beat the call to param_sysfs_init(), so don't do that.  Make sure that
> the drivers are NOT called before then.

The reason lookup_or_create_module_kobject() can be reached with module_kset == NULL
is that some platform drivers register before subsys_initcall: tegra194_cbb and
tegra234_cbb at pure_initcall, plus roughly 375 others at core_initcall/arch_initcall
(208 arch, 154 core, plus 2 pure and 13 _sync variants). These are dominated by
pinctrl, clk, interconnect, gpio, and mailbox drivers across six SoC vendor trees
(Qualcomm, MediaTek, Freescale, Samsung, Tegra, HiSilicon).

Given that, three ways forward:

  1. Move module_kset creation out of param_sysfs_init() (currently
     subsys_initcall) and call it directly from do_basic_setup()
     before do_initcalls(). This is the cleanest fix from a
     correctness angle: every initcall level sees a live
     module_kset. But it touches init/main.c and kernel/params.c,
     crosses two subsystem trees. I haven't fully audited
     dependencies at do_basic_setup() time.

  2. Demote the ~377 early-initcall platform drivers to
     subsys_initcall or later. Impractical at scale given coordination
     across six vendor trees, and many of these levels seem to be
     architecturally required.

  3. (This patch) Guard lookup_or_create_module_kobject() against
     NULL module_kset. Drivers registered before subsys_initcall
     don't get the /sys/.../module symlink, but they don't get it
     today either (drv->mod_name is NULL pre-patch, so the
     else-if (drv->mod_name) branch in module_add_driver() isn't
     taken). Verified on arm64: /sys/module/tegra194_cbb/ does not
     exist on a booted defconfig with or without my series. The
     guard preserves that exact state while letting the
     device_initcall majority get their symlinks as designed.

I went with option 3 because it preserves observable behaviour
everywhere and keeps the series scoped to driver-core. If you'd
rather I do option 1 instead, I'm happy to.

Thanks,
Shashank

Re: [PATCH v2 1/2] kernel: param: handle NULL module_kset in lookup_or_create_module_kobject()

[Greg Kroah-Hartman]

On Tue, Apr 21, 2026 at 11:59:51PM +0900, Shashank Balaji wrote:
> Hi Greg,
> 
> Thanks for the quick feedback!
> 
> On Tue, Apr 21, 2026 at 08:27:10AM +0200, Greg Kroah-Hartman wrote:
> > On Tue, Apr 21, 2026 at 03:02:34PM +0900, Shashank Balaji wrote:
> > > module_kset is initialized in a subsys_initcall. If a built-in driver tries to
> > > register before subsys_initcall with its struct device_driver's mod_name set,
> > > then a null module_kset is dereferenced via this call trace:
> > > 
> > >      [    0.095865] Call trace:
> > >      [    0.095999]  _raw_spin_lock+0x4c/0x6c (P)
> > >      [    0.096150]  kset_find_obj+0x24/0x104
> > >      [    0.096209]  lookup_or_create_module_kobject+0x2c/0xd8
> > >      [    0.096274]  module_add_driver+0xd4/0x138
> > >      [    0.096328]  bus_add_driver+0x16c/0x268
> > >      [    0.096380]  driver_register+0x68/0x100
> > >      [    0.096428]  __platform_driver_register+0x24/0x30
> > >      [    0.096486]  tegra194_cbb_init+0x24/0x30
> > >      [    0.096540]  do_one_initcall+0xdc/0x250
> > >      [    0.096608]  do_initcall_level+0x9c/0xd0
> > >      [    0.096660]  do_initcalls+0x54/0x94
> > >      [    0.096706]  do_basic_setup+0x20/0x2c
> > >      [    0.096753]  kernel_init_freeable+0xc8/0x154
> > >      [    0.096807]  kernel_init+0x20/0x1a0
> > >      [    0.096851]  ret_from_fork+0x10/0x20
> > > 
> > > So, return null in lookup_or_create_module_kobject() if module_kset is null.
> > > Existing callers handle null already.
> > > 
> > > Fixes: f30c53a873d0 ("MODULES: add the module name for built in kernel drivers")
> > 
> > This isn't a bugfix.
> 
> I'll drop it in the next version.
> 
> > > Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
> > > Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
> > > Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
> > > ---
> > > This bug is triggered by the next patch on arm64 defconfig: tegra194-cbb tries
> > > to register from a pure_initcall, and with the next patch adding mod_name, this
> > > null deref is hit.
> > 
> > So this isn't a bug, it's a "don't do that" type of thing :)
> > 
> > > ---
> > >  kernel/params.c | 3 +++
> > >  1 file changed, 3 insertions(+)
> > > 
> > > diff --git a/kernel/params.c b/kernel/params.c
> > > index 74d620bc2521..881c7328c059 100644
> > > --- a/kernel/params.c
> > > +++ b/kernel/params.c
> > > @@ -752,6 +752,9 @@ lookup_or_create_module_kobject(const char *name)
> > >  	struct kobject *kobj;
> > >  	int err;
> > >  
> > > +	if (!module_kset)
> > > +		return NULL;
> > 
> > Are you sure that making this change is going to be ok?
> > mod_sysfs_init() should have been called first as the module has to be
> > created before it can be looked up.
> > 
> > As you are wanting "built in" drivers to show up here, you are going to
> > beat the call to param_sysfs_init(), so don't do that.  Make sure that
> > the drivers are NOT called before then.
> 
> The reason lookup_or_create_module_kobject() can be reached with module_kset == NULL
> is that some platform drivers register before subsys_initcall: tegra194_cbb and
> tegra234_cbb at pure_initcall, plus roughly 375 others at core_initcall/arch_initcall
> (208 arch, 154 core, plus 2 pure and 13 _sync variants). These are dominated by
> pinctrl, clk, interconnect, gpio, and mailbox drivers across six SoC vendor trees
> (Qualcomm, MediaTek, Freescale, Samsung, Tegra, HiSilicon).

That's not good, everyone wants to be first.  It's amazing it works at
all sometimes...

> Given that, three ways forward:
> 
>   1. Move module_kset creation out of param_sysfs_init() (currently
>      subsys_initcall) and call it directly from do_basic_setup()
>      before do_initcalls(). This is the cleanest fix from a
>      correctness angle: every initcall level sees a live
>      module_kset. But it touches init/main.c and kernel/params.c,
>      crosses two subsystem trees. I haven't fully audited
>      dependencies at do_basic_setup() time.

That's one way, OR dynamically create the kset the first time it is
asked for.

>   2. Demote the ~377 early-initcall platform drivers to
>      subsys_initcall or later. Impractical at scale given coordination
>      across six vendor trees, and many of these levels seem to be
>      architecturally required.

Ick, yeah, that is sure to be a nightmare as there will be regressions.

>   3. (This patch) Guard lookup_or_create_module_kobject() against
>      NULL module_kset. Drivers registered before subsys_initcall
>      don't get the /sys/.../module symlink, but they don't get it
>      today either (drv->mod_name is NULL pre-patch, so the
>      else-if (drv->mod_name) branch in module_add_driver() isn't
>      taken). Verified on arm64: /sys/module/tegra194_cbb/ does not
>      exist on a booted defconfig with or without my series. The
>      guard preserves that exact state while letting the
>      device_initcall majority get their symlinks as designed.

THat's going to confuse people as to why some have the link and others
do not.  How about moving it earlier OR creating it dynamically when
first needed?

thanks,

greg k-h

[PATCH v3 0/4] Enable sysfs module symlink for more built-in drivers

[Shashank Balaji]

struct device_driver's mod_name is not set by a number of bus' driver registration
functions. Without that, built-in drivers don't have the module symlink in sysfs.
We want this to go from unbound driver name -> module name -> kernel config name.
This is useful on embedded platforms to minimize kernel config, reduce kernel size,
and reduce boot time.

In order to achieve this, mod_name has to be set to KBUILD_MODNAME, and this has
to be done for all buses which don't yet do this.

Here are some treewide stats:
- 110 registration functions across all bus types
- 20 of them set mod_name
- Remaining 90 do not set mod_name:
    1. 36 functions under pattern 1:
        They have a __register function + register macro. KBUILD_MODNAME needs to
        be passed and the function needs to take mod_name as input.
    2. 42 functions under pattern 2:
        These have no macro wrapper. They need a double-underscore rename + macro
        wrapper to make them similar to pattern 1.
    3. Remaining 12 do not have such a clean registration interface. More analysis
       is required.

We plan to start with pattern 1, since it's the easiest category of changes.
Within that, for now we're only sending the platform patch. If we get the go-ahead
on that, we'll send the remaining ones.

Patch 3 depends on patches 1 and 2.

Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
---
Changes in v3:
- Initialize module_kset on-demand (Greg)
- Make coresight driver registration happen through a macro (Greg)
- Split up the patch adding mod_name to platform driver registrations (Greg)
- Link to v2: https://patch.msgid.link/20260421-acpi_mod_name-v2-0-e73f9310dad3@sony.com

Changes in v2:
- Drop acpi patch, send platform instead (Rafael)
- Link to v1: https://patch.msgid.link/20260416-acpi_mod_name-v1-0-1a4d96fd86c9@sony.com

To: Suzuki K Poulose <suzuki.poulose@arm.com>
To: Mike Leach <mike.leach@linaro.org>
To: James Clark <james.clark@linaro.org>
To: Alexander Shishkin <alexander.shishkin@linux.intel.com>
To: Maxime Coquelin <mcoquelin.stm32@gmail.com>
To: Alexandre Torgue <alexandre.torgue@foss.st.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
To: Danilo Krummrich <dakr@kernel.org>
To: Miguel Ojeda <ojeda@kernel.org>
To: Boqun Feng <boqun@kernel.org>
To: Gary Guo <gary@garyguo.net>
To: Björn Roy Baron <bjorn3_gh@protonmail.com>
To: Benno Lossin <lossin@kernel.org>
To: Andreas Hindborg <a.hindborg@kernel.org>
To: Alice Ryhl <aliceryhl@google.com>
To: Trevor Gross <tmgross@umich.edu>
To: Richard Cochran <richardcochran@gmail.com>
To: Jonathan Corbet <corbet@lwn.net>
To: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: driver-core@lists.linux.dev
Cc: rust-for-linux@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: Shashank Balaji <shashank.mahadasyam@sony.com>
Cc: Rahul Bukte <rahul.bukte@sony.com>
Cc: Daniel Palmer <daniel.palmer@sony.com>
Cc: Tim Bird <tim.bird@sony.com>

---
Shashank Balaji (4):
      kernel: param: initialize module_kset on-demand
      coresight: pass THIS_MODULE implicitly through a macro
      driver core: platform: set mod_name in driver registration
      docs: driver-api: add mod_name argument to __platform_register_drivers()

 Documentation/driver-api/driver-model/platform.rst |  3 +-
 drivers/base/platform.c                            | 21 +++++++----
 drivers/hwtracing/coresight/coresight-catu.c       |  2 +-
 drivers/hwtracing/coresight/coresight-core.c       |  9 ++---
 drivers/hwtracing/coresight/coresight-cpu-debug.c  |  3 +-
 drivers/hwtracing/coresight/coresight-funnel.c     |  3 +-
 drivers/hwtracing/coresight/coresight-replicator.c |  3 +-
 drivers/hwtracing/coresight/coresight-stm.c        |  2 +-
 drivers/hwtracing/coresight/coresight-tmc-core.c   |  2 +-
 drivers/hwtracing/coresight/coresight-tnoc.c       |  2 +-
 drivers/hwtracing/coresight/coresight-tpdm.c       |  3 +-
 drivers/hwtracing/coresight/coresight-tpiu.c       |  2 +-
 include/linux/coresight.h                          |  7 ++--
 include/linux/platform_device.h                    | 17 ++++-----
 kernel/params.c                                    | 41 +++++++++++++---------
 rust/kernel/platform.rs                            |  4 ++-
 16 files changed, 72 insertions(+), 52 deletions(-)
---
base-commit: 6596a02b207886e9e00bb0161c7fd59fea53c081
change-id: 20260416-acpi_mod_name-f645a76e337b

Best regards,
--  
Shashank Balaji <shashank.mahadasyam@sony.com>

[PATCH v3 1/4] kernel: param: initialize module_kset on-demand

[Shashank Balaji]

module_kset is initialized in param_sysfs_init(), a subsys_initcall. A number
of platform drivers register themselves prior to subsys_initcalls. With an
upcoming patch ("driver core: platform: set mod_name in driver registration")
that sets their mod_name in struct device_driver, lookup_or_create_module()
will be called for those drivers, which calls kset_find_object(module_kset, mod_name).
This fails because module_kset isn't alive yet.

Fix this by initializing module_kset on-demand in lookup_or_create_module().
Retain the param_sysfs_init() subsys_initcall to ensure that module_kset is
live after subsys_initcalls (assuming no OOM) for any users who may need it,
on the off chance that it wasn't init'd on-demand because of no
pre-subsys_initcall drivers.

This on-demand path can trigger before subsys_initcall. kset_create_and_add()
be should safe in those contexts because the allocator is up and running by then,
no userspace to start uevent helper or listen to a uevent socket.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>

---

Patch 3 depends on this patch.
---
 kernel/params.c | 41 +++++++++++++++++++++++++----------------
 1 file changed, 25 insertions(+), 16 deletions(-)

diff --git a/kernel/params.c b/kernel/params.c
index 74d620bc2521..f25d6fda159c 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -745,6 +745,26 @@ void module_param_sysfs_remove(struct module *mod)
 }
 #endif
 
+static int uevent_filter(const struct kobject *kobj)
+{
+	const struct kobj_type *ktype = get_ktype(kobj);
+
+	if (ktype == &module_ktype)
+		return 1;
+	return 0;
+}
+
+static const struct kset_uevent_ops module_uevent_ops = {
+	.filter = uevent_filter,
+};
+
+static struct kset *__init_or_module ensure_module_kset(void)
+{
+	if (!module_kset)
+		module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
+	return module_kset;
+}
+
 struct module_kobject * __init_or_module
 lookup_or_create_module_kobject(const char *name)
 {
@@ -752,6 +772,9 @@ lookup_or_create_module_kobject(const char *name)
 	struct kobject *kobj;
 	int err;
 
+	if (!ensure_module_kset())
+		return NULL;
+
 	kobj = kset_find_obj(module_kset, name);
 	if (kobj)
 		return to_module_kobject(kobj);
@@ -911,19 +934,6 @@ static const struct sysfs_ops module_sysfs_ops = {
 	.store = module_attr_store,
 };
 
-static int uevent_filter(const struct kobject *kobj)
-{
-	const struct kobj_type *ktype = get_ktype(kobj);
-
-	if (ktype == &module_ktype)
-		return 1;
-	return 0;
-}
-
-static const struct kset_uevent_ops module_uevent_ops = {
-	.filter = uevent_filter,
-};
-
 struct kset *module_kset;
 
 static void module_kobj_release(struct kobject *kobj)
@@ -940,7 +950,7 @@ const struct kobj_type module_ktype = {
 };
 
 /*
- * param_sysfs_init - create "module" kset
+ * param_sysfs_init - create module_kset if not already done
  *
  * This must be done before the initramfs is unpacked and
  * request_module() thus becomes possible, because otherwise the
@@ -948,8 +958,7 @@ const struct kobj_type module_ktype = {
  */
 static int __init param_sysfs_init(void)
 {
-	module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
-	if (!module_kset) {
+	if (!ensure_module_kset()) {
 		printk(KERN_WARNING "%s (%d): error creating kset\n",
 			__FILE__, __LINE__);
 		return -ENOMEM;

-- 
2.43.0

[PATCH v3 2/4] coresight: pass THIS_MODULE implicitly through a macro

[Shashank Balaji]

Rename coresight_init_driver() to __coresight_init_driver() and replace
it with a macro wrapper that passes THIS_MODULE implicitly. This is in line with
what other buses do.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>

---

Patch 3 depends on this patch.
---
 drivers/hwtracing/coresight/coresight-catu.c       | 2 +-
 drivers/hwtracing/coresight/coresight-core.c       | 4 ++--
 drivers/hwtracing/coresight/coresight-cpu-debug.c  | 3 +--
 drivers/hwtracing/coresight/coresight-funnel.c     | 3 +--
 drivers/hwtracing/coresight/coresight-replicator.c | 3 +--
 drivers/hwtracing/coresight/coresight-stm.c        | 2 +-
 drivers/hwtracing/coresight/coresight-tmc-core.c   | 2 +-
 drivers/hwtracing/coresight/coresight-tnoc.c       | 2 +-
 drivers/hwtracing/coresight/coresight-tpdm.c       | 3 +--
 drivers/hwtracing/coresight/coresight-tpiu.c       | 2 +-
 include/linux/coresight.h                          | 4 +++-
 11 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
index dfd035852b12..1bace64eca73 100644
--- a/drivers/hwtracing/coresight/coresight-catu.c
+++ b/drivers/hwtracing/coresight/coresight-catu.c
@@ -708,7 +708,7 @@ static int __init catu_init(void)
 {
 	int ret;
 
-	ret = coresight_init_driver("catu", &catu_driver, &catu_platform_driver, THIS_MODULE);
+	ret = coresight_init_driver("catu", &catu_driver, &catu_platform_driver);
 	tmc_etr_set_catu_ops(&etr_catu_buf_ops);
 	return ret;
 }
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 80e26396ad0a..9e93b22cb056 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1644,7 +1644,7 @@ static void __exit coresight_exit(void)
 module_init(coresight_init);
 module_exit(coresight_exit);
 
-int coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
+int __coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
 			  struct platform_driver *pdev_drv, struct module *owner)
 {
 	int ret;
@@ -1663,7 +1663,7 @@ int coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
 	amba_driver_unregister(amba_drv);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(coresight_init_driver);
+EXPORT_SYMBOL_GPL(__coresight_init_driver);
 
 void coresight_remove_driver(struct amba_driver *amba_drv,
 			     struct platform_driver *pdev_drv)
diff --git a/drivers/hwtracing/coresight/coresight-cpu-debug.c b/drivers/hwtracing/coresight/coresight-cpu-debug.c
index 629614278e46..3a806c1d50ea 100644
--- a/drivers/hwtracing/coresight/coresight-cpu-debug.c
+++ b/drivers/hwtracing/coresight/coresight-cpu-debug.c
@@ -757,8 +757,7 @@ static struct platform_driver debug_platform_driver = {
 
 static int __init debug_init(void)
 {
-	return coresight_init_driver("debug", &debug_driver, &debug_platform_driver,
-				     THIS_MODULE);
+	return coresight_init_driver("debug", &debug_driver, &debug_platform_driver);
 }
 
 static void __exit debug_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
index 3b248e54471a..b9929f0d13ec 100644
--- a/drivers/hwtracing/coresight/coresight-funnel.c
+++ b/drivers/hwtracing/coresight/coresight-funnel.c
@@ -414,8 +414,7 @@ static struct amba_driver dynamic_funnel_driver = {
 
 static int __init funnel_init(void)
 {
-	return coresight_init_driver("funnel", &dynamic_funnel_driver, &funnel_driver,
-				     THIS_MODULE);
+	return coresight_init_driver("funnel", &dynamic_funnel_driver, &funnel_driver);
 }
 
 static void __exit funnel_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
index e6472658235d..02fbca334667 100644
--- a/drivers/hwtracing/coresight/coresight-replicator.c
+++ b/drivers/hwtracing/coresight/coresight-replicator.c
@@ -420,8 +420,7 @@ static struct amba_driver dynamic_replicator_driver = {
 
 static int __init replicator_init(void)
 {
-	return coresight_init_driver("replicator", &dynamic_replicator_driver, &replicator_driver,
-				     THIS_MODULE);
+	return coresight_init_driver("replicator", &dynamic_replicator_driver, &replicator_driver);
 }
 
 static void __exit replicator_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
index e68529bf89c9..d4fceb52a5cd 100644
--- a/drivers/hwtracing/coresight/coresight-stm.c
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -1052,7 +1052,7 @@ static struct platform_driver stm_platform_driver = {
 
 static int __init stm_init(void)
 {
-	return coresight_init_driver("stm", &stm_driver, &stm_platform_driver, THIS_MODULE);
+	return coresight_init_driver("stm", &stm_driver, &stm_platform_driver);
 }
 
 static void __exit stm_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
index 36599c431be6..0e0caa600270 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-core.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
@@ -1051,7 +1051,7 @@ static struct platform_driver tmc_platform_driver = {
 
 static int __init tmc_init(void)
 {
-	return coresight_init_driver("tmc", &tmc_driver, &tmc_platform_driver, THIS_MODULE);
+	return coresight_init_driver("tmc", &tmc_driver, &tmc_platform_driver);
 }
 
 static void __exit tmc_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-tnoc.c b/drivers/hwtracing/coresight/coresight-tnoc.c
index 1128612e70a7..e3f54d215414 100644
--- a/drivers/hwtracing/coresight/coresight-tnoc.c
+++ b/drivers/hwtracing/coresight/coresight-tnoc.c
@@ -346,7 +346,7 @@ static struct platform_driver itnoc_driver = {
 
 static int __init tnoc_init(void)
 {
-	return coresight_init_driver("tnoc", &trace_noc_driver, &itnoc_driver, THIS_MODULE);
+	return coresight_init_driver("tnoc", &trace_noc_driver, &itnoc_driver);
 }
 
 static void __exit tnoc_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 06e0a905a67d..ca2add2af581 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -1533,8 +1533,7 @@ static struct platform_driver static_tpdm_driver = {
 
 static int __init tpdm_init(void)
 {
-	return coresight_init_driver("tpdm", &dynamic_tpdm_driver, &static_tpdm_driver,
-				     THIS_MODULE);
+	return coresight_init_driver("tpdm", &dynamic_tpdm_driver, &static_tpdm_driver);
 }
 
 static void __exit tpdm_exit(void)
diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c
index aaa44bc521c3..401da2958f7f 100644
--- a/drivers/hwtracing/coresight/coresight-tpiu.c
+++ b/drivers/hwtracing/coresight/coresight-tpiu.c
@@ -312,7 +312,7 @@ static struct platform_driver tpiu_platform_driver = {
 
 static int __init tpiu_init(void)
 {
-	return coresight_init_driver("tpiu", &tpiu_driver, &tpiu_platform_driver, THIS_MODULE);
+	return coresight_init_driver("tpiu", &tpiu_driver, &tpiu_platform_driver);
 }
 
 static void __exit tpiu_exit(void)
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 2b48be97fcd0..4f58bfc59080 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -697,7 +697,9 @@ coresight_find_output_type(struct coresight_platform_data *pdata,
 			   enum coresight_dev_type type,
 			   union coresight_dev_subtype subtype);
 
-int coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
+#define coresight_init_driver(drv, amba_drv, pdev_drv) \
+	__coresight_init_driver(drv, amba_drv, pdev_drv, THIS_MODULE)
+int __coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
 			  struct platform_driver *pdev_drv, struct module *owner);
 
 void coresight_remove_driver(struct amba_driver *amba_drv,

-- 
2.43.0

[PATCH v3 3/4] driver core: platform: set mod_name in driver registration

[Shashank Balaji]

Pass KBUILD_MODNAME through the driver registration macro so that
the driver core can create the module symlink in sysfs for built-in
drivers, and fixup all callers.

The Rust platform adapter is updated to pass the module name through to the new
parameter.

Tested on qemu with:
- x86 defconfig + CONFIG_RUST
- arm64 defconfig + CONFIG_RUST + CONFIG_CORESIGHT stuff

Examples after this patch:

    /sys/bus/platform/drivers/...
        coresight-itnoc/module		-> coresight_tnoc
        coresight-static-tpdm/module	-> coresight_tpdm
        coresight-catu-platform/module	-> coresight_catu
        serial8250/module		-> 8250
        acpi-ged/module			-> acpi
        vmclock/module			-> ptp_vmclock

Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>

---

This patch depends on patches 1 and 2.
---
 drivers/base/platform.c                      | 21 ++++++++++++++-------
 drivers/hwtracing/coresight/coresight-core.c |  5 +++--
 include/linux/coresight.h                    |  5 +++--
 include/linux/platform_device.h              | 17 +++++++++--------
 rust/kernel/platform.rs                      |  4 +++-
 5 files changed, 32 insertions(+), 20 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 75b4698d0e58..2b0cc0889386 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -901,11 +901,14 @@ EXPORT_SYMBOL_GPL(platform_device_register_full);
  * __platform_driver_register - register a driver for platform-level devices
  * @drv: platform driver structure
  * @owner: owning module/driver
+ * @mod_name: module name string
  */
-int __platform_driver_register(struct platform_driver *drv, struct module *owner)
+int __platform_driver_register(struct platform_driver *drv, struct module *owner,
+			       const char *mod_name)
 {
 	drv->driver.owner = owner;
 	drv->driver.bus = &platform_bus_type;
+	drv->driver.mod_name = mod_name;
 
 	return driver_register(&drv->driver);
 }
@@ -938,6 +941,7 @@ static int is_bound_to_driver(struct device *dev, void *driver)
  * @drv: platform driver structure
  * @probe: the driver probe routine, probably from an __init section
  * @module: module which will be the owner of the driver
+ * @mod_name: module name string
  *
  * Use this instead of platform_driver_register() when you know the device
  * is not hotpluggable and has already been registered, and you want to
@@ -955,7 +959,8 @@ static int is_bound_to_driver(struct device *dev, void *driver)
  */
 int __init_or_module __platform_driver_probe(struct platform_driver *drv,
 					     int (*probe)(struct platform_device *),
-					     struct module *module)
+					     struct module *module,
+					     const char *mod_name)
 {
 	int retval;
 
@@ -983,7 +988,7 @@ int __init_or_module __platform_driver_probe(struct platform_driver *drv,
 
 	/* temporary section violation during probe() */
 	drv->probe = probe;
-	retval = __platform_driver_register(drv, module);
+	retval = __platform_driver_register(drv, module, mod_name);
 	if (retval)
 		return retval;
 
@@ -1011,6 +1016,7 @@ EXPORT_SYMBOL_GPL(__platform_driver_probe);
  * @data: platform specific data for this platform device
  * @size: size of platform specific data
  * @module: module which will be the owner of the driver
+ * @mod_name: module name string
  *
  * Use this in legacy-style modules that probe hardware directly and
  * register a single platform device and corresponding platform driver.
@@ -1021,7 +1027,7 @@ struct platform_device * __init_or_module
 __platform_create_bundle(struct platform_driver *driver,
 			 int (*probe)(struct platform_device *),
 			 struct resource *res, unsigned int n_res,
-			 const void *data, size_t size, struct module *module)
+			 const void *data, size_t size, struct module *module, const char *mod_name)
 {
 	struct platform_device *pdev;
 	int error;
@@ -1044,7 +1050,7 @@ __platform_create_bundle(struct platform_driver *driver,
 	if (error)
 		goto err_pdev_put;
 
-	error = __platform_driver_probe(driver, probe, module);
+	error = __platform_driver_probe(driver, probe, module, mod_name);
 	if (error)
 		goto err_pdev_del;
 
@@ -1064,6 +1070,7 @@ EXPORT_SYMBOL_GPL(__platform_create_bundle);
  * @drivers: an array of drivers to register
  * @count: the number of drivers to register
  * @owner: module owning the drivers
+ * @mod_name: module name string
  *
  * Registers platform drivers specified by an array. On failure to register a
  * driver, all previously registered drivers will be unregistered. Callers of
@@ -1073,7 +1080,7 @@ EXPORT_SYMBOL_GPL(__platform_create_bundle);
  * Returns: 0 on success or a negative error code on failure.
  */
 int __platform_register_drivers(struct platform_driver * const *drivers,
-				unsigned int count, struct module *owner)
+				unsigned int count, struct module *owner, const char *mod_name)
 {
 	unsigned int i;
 	int err;
@@ -1081,7 +1088,7 @@ int __platform_register_drivers(struct platform_driver * const *drivers,
 	for (i = 0; i < count; i++) {
 		pr_debug("registering platform driver %ps\n", drivers[i]);
 
-		err = __platform_driver_register(drivers[i], owner);
+		err = __platform_driver_register(drivers[i], owner, mod_name);
 		if (err < 0) {
 			pr_err("failed to register platform driver %ps: %d\n",
 			       drivers[i], err);
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 9e93b22cb056..a9ff0b3d8717 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1645,7 +1645,8 @@ module_init(coresight_init);
 module_exit(coresight_exit);
 
 int __coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
-			  struct platform_driver *pdev_drv, struct module *owner)
+			  struct platform_driver *pdev_drv, struct module *owner,
+			  const char *mod_name)
 {
 	int ret;
 
@@ -1655,7 +1656,7 @@ int __coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
 		return ret;
 	}
 
-	ret = __platform_driver_register(pdev_drv, owner);
+	ret = __platform_driver_register(pdev_drv, owner, mod_name);
 	if (!ret)
 		return 0;
 
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 4f58bfc59080..bcc6c1754dba 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -698,9 +698,10 @@ coresight_find_output_type(struct coresight_platform_data *pdata,
 			   union coresight_dev_subtype subtype);
 
 #define coresight_init_driver(drv, amba_drv, pdev_drv) \
-	__coresight_init_driver(drv, amba_drv, pdev_drv, THIS_MODULE)
+	__coresight_init_driver(drv, amba_drv, pdev_drv, THIS_MODULE, KBUILD_MODNAME)
 int __coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
-			  struct platform_driver *pdev_drv, struct module *owner);
+			  struct platform_driver *pdev_drv, struct module *owner,
+			  const char *mod_name);
 
 void coresight_remove_driver(struct amba_driver *amba_drv,
 			     struct platform_driver *pdev_drv);
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 975400a472e3..26e6a43358e2 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -293,18 +293,19 @@ struct platform_driver {
  * use a macro to avoid include chaining to get THIS_MODULE
  */
 #define platform_driver_register(drv) \
-	__platform_driver_register(drv, THIS_MODULE)
+	__platform_driver_register(drv, THIS_MODULE, KBUILD_MODNAME)
 extern int __platform_driver_register(struct platform_driver *,
-					struct module *);
+					struct module *, const char *mod_name);
 extern void platform_driver_unregister(struct platform_driver *);
 
 /* non-hotpluggable platform devices may use this so that probe() and
  * its support may live in __init sections, conserving runtime memory.
  */
 #define platform_driver_probe(drv, probe) \
-	__platform_driver_probe(drv, probe, THIS_MODULE)
+	__platform_driver_probe(drv, probe, THIS_MODULE, KBUILD_MODNAME)
 extern int __platform_driver_probe(struct platform_driver *driver,
-		int (*probe)(struct platform_device *), struct module *module);
+		int (*probe)(struct platform_device *), struct module *module,
+		const char *mod_name);
 
 static inline void *platform_get_drvdata(const struct platform_device *pdev)
 {
@@ -368,19 +369,19 @@ static int __init __platform_driver##_init(void) \
 device_initcall(__platform_driver##_init); \
 
 #define platform_create_bundle(driver, probe, res, n_res, data, size) \
-	__platform_create_bundle(driver, probe, res, n_res, data, size, THIS_MODULE)
+	__platform_create_bundle(driver, probe, res, n_res, data, size, THIS_MODULE, KBUILD_MODNAME)
 extern struct platform_device *__platform_create_bundle(
 	struct platform_driver *driver, int (*probe)(struct platform_device *),
 	struct resource *res, unsigned int n_res,
-	const void *data, size_t size, struct module *module);
+	const void *data, size_t size, struct module *module, const char *mod_name);
 
 int __platform_register_drivers(struct platform_driver * const *drivers,
-				unsigned int count, struct module *owner);
+				unsigned int count, struct module *owner, const char *mod_name);
 void platform_unregister_drivers(struct platform_driver * const *drivers,
 				 unsigned int count);
 
 #define platform_register_drivers(drivers, count) \
-	__platform_register_drivers(drivers, count, THIS_MODULE)
+	__platform_register_drivers(drivers, count, THIS_MODULE, KBUILD_MODNAME)
 
 #ifdef CONFIG_SUSPEND
 extern int platform_pm_suspend(struct device *dev);
diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index 8917d4ee499f..2d626eecc450 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -82,7 +82,9 @@ unsafe fn register(
         }
 
         // SAFETY: `pdrv` is guaranteed to be a valid `DriverType`.
-        to_result(unsafe { bindings::__platform_driver_register(pdrv.get(), module.0) })
+        to_result(unsafe {
+            bindings::__platform_driver_register(pdrv.get(), module.0, name.as_char_ptr())
+        })
     }
 
     unsafe fn unregister(pdrv: &Opaque<Self::DriverType>) {

-- 
2.43.0

[PATCH v3 4/4] docs: driver-api: add mod_name argument to __platform_register_drivers()

[Shashank Balaji]

Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
---
 Documentation/driver-api/driver-model/platform.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/driver-api/driver-model/platform.rst b/Documentation/driver-api/driver-model/platform.rst
index cf5ff48d3115..9673470bded2 100644
--- a/Documentation/driver-api/driver-model/platform.rst
+++ b/Documentation/driver-api/driver-model/platform.rst
@@ -70,7 +70,8 @@ Kernel modules can be composed of several platform drivers. The platform core
 provides helpers to register and unregister an array of drivers::
 
 	int __platform_register_drivers(struct platform_driver * const *drivers,
-				      unsigned int count, struct module *owner);
+				      unsigned int count, struct module *owner,
+				      const char *mod_name);
 	void platform_unregister_drivers(struct platform_driver * const *drivers,
 					 unsigned int count);
 

-- 
2.43.0

Re: [PATCH v3 4/4] docs: driver-api: add mod_name argument to __platform_register_drivers()

[Greg Kroah-Hartman]

On Wed, Apr 22, 2026 at 06:49:06PM +0900, Shashank Balaji wrote:
> Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
> Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
> Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
> ---
>  Documentation/driver-api/driver-model/platform.rst | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

For obvious reasons we can't take patches without any changelog text at
all (and neither should you want us to...)

thanks,

greg k-h