| Message ID | 20241212003201.2098123-2-briannorris@chromium.org |
|---|---|
| State | New |
| Headers | show |
| Series | drivers: base: Don't match device with NULL of_node/fwnode/etc + tests | expand |
On Thu, Dec 12, 2024 at 1:32 AM 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). > > Signed-off-by: Brian Norris <briannorris@chromium.org> > Reviewed-by: Rob Herring (Arm) <robh@kernel.org> For the ACPI part Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > > 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); > > -- > 2.47.0.338.g60cca15819-goog >
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);
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). Signed-off-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Rob Herring (Arm) <robh@kernel.org> --- Changes in v2: * Add Rob's Reviewed-by drivers/base/core.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)