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Message-Id: <20240103192707.115512-4-W_Armin@gmx.de>
Date: Wed, 3 Jan 2024 20:27:06 +0100
From: Armin Wolf <W_Armin@....de>
To: hdegoede@...hat.com,
ilpo.jarvinen@...ux.intel.com
Cc: platform-driver-x86@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH 3/4] platform/x86: wmi: Decouple legacy WMI notify handlers from wmi_block_list
Until now, legacy WMI notify handler functions where using the
wmi_block_list, which did no refcounting on the returned WMI device.
This meant that the WMI device could disappear at any moment,
potentially leading to various errors.
Fix this by using bus_find_device() which returns an actual
reference to the found WMI device.
Tested on a Dell Inspiron 3505 and a Acer Aspire E1-731.
Signed-off-by: Armin Wolf <W_Armin@....de>
---
drivers/platform/x86/wmi.c | 118 +++++++++++++++++++++----------------
1 file changed, 68 insertions(+), 50 deletions(-)
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 7470a149b254..6a886635689a 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -218,6 +218,17 @@ static int wmidev_match_guid(struct device *dev, const void *data)
return 0;
}
+static int wmidev_match_notify_id(struct device *dev, const void *data)
+{
+ struct wmi_block *wblock = dev_to_wblock(dev);
+ const u32 *notify_id = data;
+
+ if (wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *notify_id)
+ return 1;
+
+ return 0;
+}
+
static struct bus_type wmi_bus_type;
static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
@@ -237,6 +248,17 @@ static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
return dev_to_wdev(dev);
}
+static struct wmi_device *wmi_find_event_by_notify_id(const u32 notify_id)
+{
+ struct device *dev;
+
+ dev = bus_find_device(&wmi_bus_type, NULL, ¬ify_id, wmidev_match_notify_id);
+ if (!dev)
+ return ERR_PTR(-ENODEV);
+
+ return to_wmi_device(dev);
+}
+
static void wmi_device_put(struct wmi_device *wdev)
{
put_device(&wdev->dev);
@@ -571,34 +593,30 @@ acpi_status wmi_install_notify_handler(const char *guid,
wmi_notify_handler handler,
void *data)
{
- struct wmi_block *block;
- guid_t guid_input;
-
- if (!guid || !handler)
- return AE_BAD_PARAMETER;
-
- if (guid_parse(guid, &guid_input))
- return AE_BAD_PARAMETER;
-
- list_for_each_entry(block, &wmi_block_list, list) {
- acpi_status wmi_status;
+ struct wmi_block *wblock;
+ struct wmi_device *wdev;
+ acpi_status status;
- if (guid_equal(&block->gblock.guid, &guid_input)) {
- if (block->handler)
- return AE_ALREADY_ACQUIRED;
+ wdev = wmi_find_device_by_guid(guid);
+ if (IS_ERR(wdev))
+ return AE_ERROR;
- block->handler = handler;
- block->handler_data = data;
+ wblock = container_of(wdev, struct wmi_block, dev);
+ if (wblock->handler) {
+ status = AE_ALREADY_ACQUIRED;
+ } else {
+ wblock->handler = handler;
+ wblock->handler_data = data;
- wmi_status = wmi_method_enable(block, true);
- if (ACPI_FAILURE(wmi_status))
- dev_warn(&block->dev.dev, "Failed to enable device\n");
+ if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
+ dev_warn(&wblock->dev.dev, "Failed to enable device\n");
- return AE_OK;
- }
+ status = AE_OK;
}
- return AE_NOT_EXIST;
+ wmi_device_put(wdev);
+
+ return status;
}
EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
@@ -612,34 +630,30 @@ EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
*/
acpi_status wmi_remove_notify_handler(const char *guid)
{
- struct wmi_block *block;
- guid_t guid_input;
-
- if (!guid)
- return AE_BAD_PARAMETER;
-
- if (guid_parse(guid, &guid_input))
- return AE_BAD_PARAMETER;
-
- list_for_each_entry(block, &wmi_block_list, list) {
- acpi_status wmi_status;
+ struct wmi_block *wblock;
+ struct wmi_device *wdev;
+ acpi_status status;
- if (guid_equal(&block->gblock.guid, &guid_input)) {
- if (!block->handler)
- return AE_NULL_ENTRY;
+ wdev = wmi_find_device_by_guid(guid);
+ if (IS_ERR(wdev))
+ return AE_ERROR;
- wmi_status = wmi_method_enable(block, false);
- if (ACPI_FAILURE(wmi_status))
- dev_warn(&block->dev.dev, "Failed to disable device\n");
+ wblock = container_of(wdev, struct wmi_block, dev);
+ if (!wblock->handler) {
+ status = AE_NULL_ENTRY;
+ } else {
+ if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
+ dev_warn(&wblock->dev.dev, "Failed to disable device\n");
- block->handler = NULL;
- block->handler_data = NULL;
+ wblock->handler = NULL;
+ wblock->handler_data = NULL;
- return AE_OK;
- }
+ status = AE_OK;
}
- return AE_NOT_EXIST;
+ wmi_device_put(wdev);
+
+ return status;
}
EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
@@ -656,15 +670,19 @@ EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
{
struct wmi_block *wblock;
+ struct wmi_device *wdev;
+ acpi_status status;
- list_for_each_entry(wblock, &wmi_block_list, list) {
- struct guid_block *gblock = &wblock->gblock;
+ wdev = wmi_find_event_by_notify_id(event);
+ if (IS_ERR(wdev))
+ return AE_NOT_FOUND;
- if ((gblock->flags & ACPI_WMI_EVENT) && gblock->notify_id == event)
- return get_event_data(wblock, out);
- }
+ wblock = container_of(wdev, struct wmi_block, dev);
+ status = get_event_data(wblock, out);
- return AE_NOT_FOUND;
+ wmi_device_put(wdev);
+
+ return status;
}
EXPORT_SYMBOL_GPL(wmi_get_event_data);
--
2.39.2
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