From 3ea7f59af8ffa17ce5f5173d6f4bfbc73334187d Mon Sep 17 00:00:00 2001 From: Armin Wolf Date: Wed, 3 Jan 2024 20:27:06 +0100 Subject: platform/x86: wmi: Decouple legacy WMI notify handlers from wmi_block_list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Ilpo Järvinen Reviewed-by: Hans de Goede Link: https://lore.kernel.org/r/20240103192707.115512-4-W_Armin@gmx.de Signed-off-by: Hans de Goede --- drivers/platform/x86/wmi.c | 118 ++++++++++++++++++++++++++------------------- 1 file changed, 68 insertions(+), 50 deletions(-) (limited to 'drivers/platform/x86') diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index 4e2d0e15b155..699157ce347c 100644 --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c @@ -219,6 +219,17 @@ 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) @@ -238,6 +249,17 @@ 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); @@ -572,34 +594,30 @@ 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); @@ -613,34 +631,30 @@ 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); @@ -657,15 +671,19 @@ 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); -- cgit