From: Hans de Goede Date: Thu, 4 Apr 2019 13:51:32 +0000 (+0200) Subject: HID: core: Do not call request_module() in async context X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4ceabaf79;p=linux.git HID: core: Do not call request_module() in async context request_module() may not be called form async context and in some cases hid devices may be added from an async context. One example of this happening is under hyperv, where this was triggering a WARN_ON in request_module(): [ 11.174497] hid_add_device+0xee/0x2b0 [hid] [ 11.174499] mousevsc_probe+0x223/0x2eb [hid_hyperv] [ 11.174501] vmbus_probe+0x3a/0x90 [ 11.174504] really_probe+0x229/0x420 [ 11.174506] driver_probe_device+0x115/0x130 [ 11.174507] __driver_attach_async_helper+0x87/0x90 [ 11.174509] async_run_entry_fn+0x37/0x150 This commit skips the request_module(), falling back to the old behavior of letting userspace deal with this, in case we are called from an async context. Cc: Lili Deng Reported-by: Lili Deng Signed-off-by: Hans de Goede Signed-off-by: Benjamin Tissoires --- diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 2f843b84811e0..59e95768142dc 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -2366,8 +2367,9 @@ int hid_add_device(struct hid_device *hdev) * not first have hid-generic binding only to have it replaced * immediately afterwards with a specialized driver. */ - request_module("hid:b%04Xg%04Xv%08Xp%08X", - hdev->bus, hdev->group, hdev->vendor, hdev->product); + if (!current_is_async()) + request_module("hid:b%04Xg%04Xv%08Xp%08X", hdev->bus, + hdev->group, hdev->vendor, hdev->product); hid_debug_register(hdev, dev_name(&hdev->dev)); ret = device_add(&hdev->dev);