Currently it's possible to iterate over the dangling pointer in case the device
suddenly disappears. This may happen becase callers put it at the end of a loop.
Instead, let's move that call inside acpi_dev_get_next_match_dev().
Fixes: 803abec64ef9 ("media: ipu3-cio2: Add cio2-bridge to ipu3-cio2 driver")
Fixes: bf263f64e804 ("media: ACPI / bus: Add acpi_dev_get_next_match_dev() and helper macro")
Cc: Daniel Scally <djrscally@xxxxxxxxx>
Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Signed-off-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
---
drivers/acpi/utils.c | 5 +----
drivers/media/pci/intel/ipu3/cio2-bridge.c | 8 +++-----
include/acpi/acpi_bus.h | 5 -----
3 files changed, 4 insertions(+), 14 deletions(-)
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index 3b54b8fd7396..ccfc484dbffd 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -846,10 +846,6 @@ EXPORT_SYMBOL(acpi_dev_present);
* Return the next match of ACPI device if another matching device was present
* at the moment of invocation, or NULL otherwise.
*
- * FIXME: The function does not tolerate the sudden disappearance of @adev, e.g.
- * in the case of a hotplug event. That said, the caller should ensure that
- * this will never happen.
- *
* The caller is responsible for invoking acpi_dev_put() on the returned device.
*
* See additional information in acpi_dev_present() as well.
@@ -866,6 +862,7 @@ acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const cha
match.hrv = hrv;
dev = bus_find_device(&acpi_bus_type, start, &match, acpi_dev_match_cb);
+ acpi_dev_put(adev);
return dev ? to_acpi_device(dev) : NULL;
}
EXPORT_SYMBOL(acpi_dev_get_next_match_dev);
diff --git a/drivers/media/pci/intel/ipu3/cio2-bridge.c b/drivers/media/pci/intel/ipu3/cio2-bridge.c
index e8511787c1e4..477417261b6e 100644
--- a/drivers/media/pci/intel/ipu3/cio2-bridge.c
+++ b/drivers/media/pci/intel/ipu3/cio2-bridge.c
@@ -178,13 +178,11 @@ static int cio2_bridge_connect_sensor(const struct cio2_sensor_config *cfg,
if (bridge->n_sensors >= CIO2_NUM_PORTS) {
dev_err(&cio2->dev, "Exceeded available CIO2 ports\n");
- cio2_bridge_unregister_sensors(bridge);
ret = -EINVAL;
- goto err_out;
+ goto err_put_adev;
}
sensor = &bridge->sensors[bridge->n_sensors];
- sensor->adev = adev;
strscpy(sensor->name, cfg->hid, sizeof(sensor->name));
ret = cio2_bridge_read_acpi_buffer(adev, "SSDB",
@@ -214,6 +212,7 @@ static int cio2_bridge_connect_sensor(const struct cio2_sensor_config *cfg,
goto err_free_swnodes;
}
+ sensor->adev = acpi_dev_get(adev);
adev->fwnode.secondary = fwnode;
dev_info(&cio2->dev, "Found supported sensor %s\n",
@@ -227,8 +226,7 @@ static int cio2_bridge_connect_sensor(const struct cio2_sensor_config *cfg,
err_free_swnodes:
software_node_unregister_nodes(sensor->swnodes);
err_put_adev:
- acpi_dev_put(sensor->adev);
-err_out:
+ acpi_dev_put(adev);
return ret;
}
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 3a82faac5767..bff6a11bb21f 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -698,11 +698,6 @@ acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv);
* @hrv: Hardware Revision of the device, pass -1 to not check _HRV
*
* The caller is responsible for invoking acpi_dev_put() on the returned device.
- *
- * FIXME: Due to above requirement there is a window that may invalidate @adev
- * and next iteration will use a dangling pointer, e.g. in the case of a
- * hotplug event. That said, the caller should ensure that this will never
- * happen.
*/
#define for_each_acpi_dev_match(adev, hid, uid, hrv) \
for (adev = acpi_dev_get_first_match_dev(hid, uid, hrv); \
--
2.31.1
