[PATCH v3 0/3] drivers: base: Don't match device with NULL of_node/fwnode/etc + tests

[PATCH v3 0/3] drivers: base: Don't match device with NULL of_node/fwnode/etc + tests

[Brian Norris]

This series:
1. makes the behavior of_find_device_by_node(),
   bus_find_device_by_of_node(), bus_find_device_by_fwnode(), etc., more
   consistent when provided with a NULL node/handle;
2. adds kunit tests to validate the new NULL-argument behavior; and
3. makes some related improvements and refactoring for the drivers/base/
   kunit tests.

This series aims to prevent problems like the ones resolved in commit
5c8418cf4025 ("PCI/pwrctrl: Unregister platform device only if one
actually exists").

Changes in v3:
 * Fix potential leak in test error case

Changes in v2:
 * CC LKML (oops!)
 * Keep "devm" and "match" tests in separate suites

Brian Norris (3):
  drivers: base: Don't match devices with NULL of_node/fwnode/etc
  drivers: base: test: Enable device model tests with KUNIT_ALL_TESTS
  drivers: base: test: Add ...find_device_by...(... NULL) tests

 drivers/base/core.c                      |  8 ++---
 drivers/base/test/Kconfig                |  1 +
 drivers/base/test/platform-device-test.c | 41 +++++++++++++++++++++++-
 3 files changed, 45 insertions(+), 5 deletions(-)

-- 
2.47.1.613.gc27f4b7a9f-goog

[PATCH v3 1/3] drivers: base: Don't match devices with NULL of_node/fwnode/etc

[Brian Norris]

of_find_device_by_node(), bus_find_device_by_of_node(),
bus_find_device_by_fwnode(), ..., all produce arbitrary results when
provided with a NULL of_node, fwnode, ACPI handle, etc. This is
counterintuitive, and the source of a few bugs, such as the one fixed by
commit 5c8418cf4025 ("PCI/pwrctrl: Unregister platform device only if
one actually exists").

It's hard to imagine a good reason that these device_match_*() APIs
should return 'true' for a NULL argument. Augment these to return 0
(false).

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Brian Norris <briannorris@chromium.org>
---

Changes in v3:
 * Add Rafael's Acked-by

Changes in v2:
 * Add Rob's Reviewed-by

 drivers/base/core.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 94865c9d8adc..2b7b13fc36d7 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -5246,13 +5246,13 @@ EXPORT_SYMBOL_GPL(device_match_name);
 
 int device_match_of_node(struct device *dev, const void *np)
 {
-	return dev->of_node == np;
+	return np && dev->of_node == np;
 }
 EXPORT_SYMBOL_GPL(device_match_of_node);
 
 int device_match_fwnode(struct device *dev, const void *fwnode)
 {
-	return dev_fwnode(dev) == fwnode;
+	return fwnode && dev_fwnode(dev) == fwnode;
 }
 EXPORT_SYMBOL_GPL(device_match_fwnode);
 
@@ -5264,13 +5264,13 @@ EXPORT_SYMBOL_GPL(device_match_devt);
 
 int device_match_acpi_dev(struct device *dev, const void *adev)
 {
-	return ACPI_COMPANION(dev) == adev;
+	return adev && ACPI_COMPANION(dev) == adev;
 }
 EXPORT_SYMBOL(device_match_acpi_dev);
 
 int device_match_acpi_handle(struct device *dev, const void *handle)
 {
-	return ACPI_HANDLE(dev) == handle;
+	return handle && ACPI_HANDLE(dev) == handle;
 }
 EXPORT_SYMBOL(device_match_acpi_handle);
 
-- 
2.47.1.613.gc27f4b7a9f-goog

[PATCH v3 2/3] drivers: base: test: Enable device model tests with KUNIT_ALL_TESTS

[Brian Norris]

Per commit bebe94b53eb7 ("drivers: base: default KUNIT_* fragments to
KUNIT_ALL_TESTS"), it seems like we should default to KUNIT_ALL_TESTS.

This enables these platform_device tests for common configurations, such
as with:
  ./tools/testing/kunit/kunit.py run

Signed-off-by: Brian Norris <briannorris@chromium.org>
---

(no changes since v1)

 drivers/base/test/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/base/test/Kconfig b/drivers/base/test/Kconfig
index 5c7fac80611c..2756870615cc 100644
--- a/drivers/base/test/Kconfig
+++ b/drivers/base/test/Kconfig
@@ -12,6 +12,7 @@ config TEST_ASYNC_DRIVER_PROBE
 config DM_KUNIT_TEST
 	tristate "KUnit Tests for the device model" if !KUNIT_ALL_TESTS
 	depends on KUNIT
+	default KUNIT_ALL_TESTS
 
 config DRIVER_PE_KUNIT_TEST
 	tristate "KUnit Tests for property entry API" if !KUNIT_ALL_TESTS
-- 
2.47.1.613.gc27f4b7a9f-goog

[PATCH v3 3/3] drivers: base: test: Add ...find_device_by...(... NULL) tests

[Brian Norris]

We recently updated these device_match*() (and therefore, various
*find_device_by*()) functions to return a consistent 'false' value when
trying to match a NULL handle. Add tests for this.

This provides regression-testing coverage for the sorts of bugs that
underly commit 5c8418cf4025 ("PCI/pwrctrl: Unregister platform device
only if one actually exists").

Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
---

Changes in v3:
 * Fix potential leak in test error case
 * Add Maxime's Reviewed-by

Changes in v2:
 * Keep "devm" and "match" tests in separate suites

 drivers/base/test/platform-device-test.c | 41 +++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/drivers/base/test/platform-device-test.c b/drivers/base/test/platform-device-test.c
index ea05b8785743..6355a2231b74 100644
--- a/drivers/base/test/platform-device-test.c
+++ b/drivers/base/test/platform-device-test.c
@@ -1,8 +1,11 @@
 // SPDX-License-Identifier: GPL-2.0
 
+#include <kunit/platform_device.h>
 #include <kunit/resource.h>
 
 #include <linux/device.h>
+#include <linux/device/bus.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 
 #define DEVICE_NAME "test"
@@ -217,7 +220,43 @@ static struct kunit_suite platform_device_devm_test_suite = {
 	.test_cases = platform_device_devm_tests,
 };
 
-kunit_test_suite(platform_device_devm_test_suite);
+static void platform_device_find_by_null_test(struct kunit *test)
+{
+	struct platform_device *pdev;
+	int ret;
+
+	pdev = kunit_platform_device_alloc(test, DEVICE_NAME, PLATFORM_DEVID_NONE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	ret = kunit_platform_device_add(test, pdev);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_PTR_EQ(test, of_find_device_by_node(NULL), NULL);
+
+	KUNIT_EXPECT_PTR_EQ(test, bus_find_device_by_of_node(&platform_bus_type, NULL), NULL);
+	KUNIT_EXPECT_PTR_EQ(test, bus_find_device_by_fwnode(&platform_bus_type, NULL), NULL);
+	KUNIT_EXPECT_PTR_EQ(test, bus_find_device_by_acpi_dev(&platform_bus_type, NULL), NULL);
+
+	KUNIT_EXPECT_FALSE(test, device_match_of_node(&pdev->dev, NULL));
+	KUNIT_EXPECT_FALSE(test, device_match_fwnode(&pdev->dev, NULL));
+	KUNIT_EXPECT_FALSE(test, device_match_acpi_dev(&pdev->dev, NULL));
+	KUNIT_EXPECT_FALSE(test, device_match_acpi_handle(&pdev->dev, NULL));
+}
+
+static struct kunit_case platform_device_match_tests[] = {
+	KUNIT_CASE(platform_device_find_by_null_test),
+	{}
+};
+
+static struct kunit_suite platform_device_match_test_suite = {
+	.name = "platform-device-match",
+	.test_cases = platform_device_match_tests,
+};
+
+kunit_test_suites(
+	&platform_device_devm_test_suite,
+	&platform_device_match_test_suite,
+);
 
 MODULE_DESCRIPTION("Test module for platform devices");
 MODULE_AUTHOR("Maxime Ripard <mripard@kernel.org>");
-- 
2.47.1.613.gc27f4b7a9f-goog

Re: [PATCH v3 2/3] drivers: base: test: Enable device model tests with KUNIT_ALL_TESTS

[Maxime Ripard]

On Mon, 16 Dec 2024 12:11:43 -0800, Brian Norris wrote:
> Per commit bebe94b53eb7 ("drivers: base: default KUNIT_* fragments to
> KUNIT_ALL_TESTS"), it seems like we should default to KUNIT_ALL_TESTS.
> 
> This enables these platform_device tests for common configurations, such
> as with:
> 
> [ ... ]

Reviewed-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime

Re: [PATCH v3 1/3] drivers: base: Don't match devices with NULL of_node/fwnode/etc

[David Gow]

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On Tue, 17 Dec 2024 at 04:12, Brian Norris <briannorris@chromium.org> wrote:
>
> of_find_device_by_node(), bus_find_device_by_of_node(),
> bus_find_device_by_fwnode(), ..., all produce arbitrary results when
> provided with a NULL of_node, fwnode, ACPI handle, etc. This is
> counterintuitive, and the source of a few bugs, such as the one fixed by
> commit 5c8418cf4025 ("PCI/pwrctrl: Unregister platform device only if
> one actually exists").
>
> It's hard to imagine a good reason that these device_match_*() APIs
> should return 'true' for a NULL argument. Augment these to return 0
> (false).
>
> Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> ---

Seems sensible enough to me.

Acked-by: David Gow <davidgow@google.com>

I assume this series (including the KUnit test changes) will go in via Greg.

Cheers,
-- David

>
> Changes in v3:
>  * Add Rafael's Acked-by
>
> Changes in v2:
>  * Add Rob's Reviewed-by
>
>  drivers/base/core.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 94865c9d8adc..2b7b13fc36d7 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -5246,13 +5246,13 @@ EXPORT_SYMBOL_GPL(device_match_name);
>
>  int device_match_of_node(struct device *dev, const void *np)
>  {
> -       return dev->of_node == np;
> +       return np && dev->of_node == np;
>  }
>  EXPORT_SYMBOL_GPL(device_match_of_node);
>
>  int device_match_fwnode(struct device *dev, const void *fwnode)
>  {
> -       return dev_fwnode(dev) == fwnode;
> +       return fwnode && dev_fwnode(dev) == fwnode;
>  }
>  EXPORT_SYMBOL_GPL(device_match_fwnode);
>
> @@ -5264,13 +5264,13 @@ EXPORT_SYMBOL_GPL(device_match_devt);
>
>  int device_match_acpi_dev(struct device *dev, const void *adev)
>  {
> -       return ACPI_COMPANION(dev) == adev;
> +       return adev && ACPI_COMPANION(dev) == adev;
>  }
>  EXPORT_SYMBOL(device_match_acpi_dev);
>
>  int device_match_acpi_handle(struct device *dev, const void *handle)
>  {
> -       return ACPI_HANDLE(dev) == handle;
> +       return handle && ACPI_HANDLE(dev) == handle;
>  }
>  EXPORT_SYMBOL(device_match_acpi_handle);
>
> --
> 2.47.1.613.gc27f4b7a9f-goog
>

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Re: [PATCH v3 2/3] drivers: base: test: Enable device model tests with KUNIT_ALL_TESTS

[David Gow]

[-- Attachment #1: Type: text/plain, Size: 1128 bytes --]

On Tue, 17 Dec 2024 at 04:12, Brian Norris <briannorris@chromium.org> wrote:
>
> Per commit bebe94b53eb7 ("drivers: base: default KUNIT_* fragments to
> KUNIT_ALL_TESTS"), it seems like we should default to KUNIT_ALL_TESTS.
>
> This enables these platform_device tests for common configurations, such
> as with:
>   ./tools/testing/kunit/kunit.py run
>
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> ---

Excellent!

Reviewed-by: David Gow <davidgow@google.com>

Cheers,
-- David


>
> (no changes since v1)
>
>  drivers/base/test/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/base/test/Kconfig b/drivers/base/test/Kconfig
> index 5c7fac80611c..2756870615cc 100644
> --- a/drivers/base/test/Kconfig
> +++ b/drivers/base/test/Kconfig
> @@ -12,6 +12,7 @@ config TEST_ASYNC_DRIVER_PROBE
>  config DM_KUNIT_TEST
>         tristate "KUnit Tests for the device model" if !KUNIT_ALL_TESTS
>         depends on KUNIT
> +       default KUNIT_ALL_TESTS
>
>  config DRIVER_PE_KUNIT_TEST
>         tristate "KUnit Tests for property entry API" if !KUNIT_ALL_TESTS
> --
> 2.47.1.613.gc27f4b7a9f-goog
>

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Re: [PATCH v3 3/3] drivers: base: test: Add ...find_device_by...(... NULL) tests

[David Gow]

[-- Attachment #1: Type: text/plain, Size: 3339 bytes --]

On Tue, 17 Dec 2024 at 04:12, Brian Norris <briannorris@chromium.org> wrote:
>
> We recently updated these device_match*() (and therefore, various
> *find_device_by*()) functions to return a consistent 'false' value when
> trying to match a NULL handle. Add tests for this.
>
> This provides regression-testing coverage for the sorts of bugs that
> underly commit 5c8418cf4025 ("PCI/pwrctrl: Unregister platform device
> only if one actually exists").
>
> Reviewed-by: Maxime Ripard <mripard@kernel.org>
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> ---
>

Thanks. This looks good to me.

Reviewed-by: David Gow <davidgow@google.com>


-- David

> Changes in v3:
>  * Fix potential leak in test error case
>  * Add Maxime's Reviewed-by
>
> Changes in v2:
>  * Keep "devm" and "match" tests in separate suites
>
>  drivers/base/test/platform-device-test.c | 41 +++++++++++++++++++++++-
>  1 file changed, 40 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/test/platform-device-test.c b/drivers/base/test/platform-device-test.c
> index ea05b8785743..6355a2231b74 100644
> --- a/drivers/base/test/platform-device-test.c
> +++ b/drivers/base/test/platform-device-test.c
> @@ -1,8 +1,11 @@
>  // SPDX-License-Identifier: GPL-2.0
>
> +#include <kunit/platform_device.h>
>  #include <kunit/resource.h>
>
>  #include <linux/device.h>
> +#include <linux/device/bus.h>
> +#include <linux/of_platform.h>
>  #include <linux/platform_device.h>
>
>  #define DEVICE_NAME "test"
> @@ -217,7 +220,43 @@ static struct kunit_suite platform_device_devm_test_suite = {
>         .test_cases = platform_device_devm_tests,
>  };
>
> -kunit_test_suite(platform_device_devm_test_suite);
> +static void platform_device_find_by_null_test(struct kunit *test)
> +{
> +       struct platform_device *pdev;
> +       int ret;
> +
> +       pdev = kunit_platform_device_alloc(test, DEVICE_NAME, PLATFORM_DEVID_NONE);
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
> +
> +       ret = kunit_platform_device_add(test, pdev);
> +       KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +       KUNIT_EXPECT_PTR_EQ(test, of_find_device_by_node(NULL), NULL);
> +
> +       KUNIT_EXPECT_PTR_EQ(test, bus_find_device_by_of_node(&platform_bus_type, NULL), NULL);
> +       KUNIT_EXPECT_PTR_EQ(test, bus_find_device_by_fwnode(&platform_bus_type, NULL), NULL);
> +       KUNIT_EXPECT_PTR_EQ(test, bus_find_device_by_acpi_dev(&platform_bus_type, NULL), NULL);
> +
> +       KUNIT_EXPECT_FALSE(test, device_match_of_node(&pdev->dev, NULL));
> +       KUNIT_EXPECT_FALSE(test, device_match_fwnode(&pdev->dev, NULL));
> +       KUNIT_EXPECT_FALSE(test, device_match_acpi_dev(&pdev->dev, NULL));
> +       KUNIT_EXPECT_FALSE(test, device_match_acpi_handle(&pdev->dev, NULL));
> +}
> +
> +static struct kunit_case platform_device_match_tests[] = {
> +       KUNIT_CASE(platform_device_find_by_null_test),
> +       {}
> +};
> +
> +static struct kunit_suite platform_device_match_test_suite = {
> +       .name = "platform-device-match",
> +       .test_cases = platform_device_match_tests,
> +};
> +
> +kunit_test_suites(
> +       &platform_device_devm_test_suite,
> +       &platform_device_match_test_suite,
> +);
>
>  MODULE_DESCRIPTION("Test module for platform devices");
>  MODULE_AUTHOR("Maxime Ripard <mripard@kernel.org>");
> --
> 2.47.1.613.gc27f4b7a9f-goog
>

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Re: [PATCH v3 1/3] drivers: base: Don't match devices with NULL of_node/fwnode/etc

[Shuah Khan]

On 12/18/24 22:45, David Gow wrote:
> On Tue, 17 Dec 2024 at 04:12, Brian Norris <briannorris@chromium.org> wrote:
>>
>> of_find_device_by_node(), bus_find_device_by_of_node(),
>> bus_find_device_by_fwnode(), ..., all produce arbitrary results when
>> provided with a NULL of_node, fwnode, ACPI handle, etc. This is
>> counterintuitive, and the source of a few bugs, such as the one fixed by
>> commit 5c8418cf4025 ("PCI/pwrctrl: Unregister platform device only if
>> one actually exists").
>>
>> It's hard to imagine a good reason that these device_match_*() APIs
>> should return 'true' for a NULL argument. Augment these to return 0
>> (false).
>>
>> Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
>> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>> Signed-off-by: Brian Norris <briannorris@chromium.org>
>> ---
> 
> Seems sensible enough to me.
> 
> Acked-by: David Gow <davidgow@google.com>
> 
> I assume this series (including the KUnit test changes) will go in via Greg.
> 

Works for me.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>

thanks,
-- Shuah

Re: [PATCH v3 3/3] drivers: base: test: Add ...find_device_by...(... NULL) tests

[Shuah Khan]

On 12/18/24 22:45, David Gow wrote:
> On Tue, 17 Dec 2024 at 04:12, Brian Norris <briannorris@chromium.org> wrote:
>>
>> We recently updated these device_match*() (and therefore, various
>> *find_device_by*()) functions to return a consistent 'false' value when
>> trying to match a NULL handle. Add tests for this.
>>
>> This provides regression-testing coverage for the sorts of bugs that
>> underly commit 5c8418cf4025 ("PCI/pwrctrl: Unregister platform device
>> only if one actually exists").
>>
>> Reviewed-by: Maxime Ripard <mripard@kernel.org>
>> Signed-off-by: Brian Norris <briannorris@chromium.org>
>> ---
>>
> 
> Thanks. This looks good to me.
> 
> Reviewed-by: David Gow <davidgow@google.com>
> 
> 
>

This one also can go through Greg's drivers tree:

Acked-by: Shuah Khan <skhan@linuxfoundation.org>

thanks,
-- Shuah

Re: [PATCH v3 1/3] drivers: base: Don't match devices with NULL of_node/fwnode/etc

[Greg Kroah-Hartman]

On Fri, Dec 20, 2024 at 10:33:51AM -0700, Shuah Khan wrote:
> On 12/18/24 22:45, David Gow wrote:
> > On Tue, 17 Dec 2024 at 04:12, Brian Norris <briannorris@chromium.org> wrote:
> > > 
> > > of_find_device_by_node(), bus_find_device_by_of_node(),
> > > bus_find_device_by_fwnode(), ..., all produce arbitrary results when
> > > provided with a NULL of_node, fwnode, ACPI handle, etc. This is
> > > counterintuitive, and the source of a few bugs, such as the one fixed by
> > > commit 5c8418cf4025 ("PCI/pwrctrl: Unregister platform device only if
> > > one actually exists").
> > > 
> > > It's hard to imagine a good reason that these device_match_*() APIs
> > > should return 'true' for a NULL argument. Augment these to return 0
> > > (false).
> > > 
> > > Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> > > Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > > Signed-off-by: Brian Norris <briannorris@chromium.org>
> > > ---
> > 
> > Seems sensible enough to me.
> > 
> > Acked-by: David Gow <davidgow@google.com>
> > 
> > I assume this series (including the KUnit test changes) will go in via Greg.
> > 
> 
> Works for me.
> 
> Acked-by: Shuah Khan <skhan@linuxfoundation.org>

Thanks, I'll take these in a few days.

greg k-h