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| author |   Hans de Goede <hdegoede@redhat.com> | 2019-04-04 15:51:32 +0200 |
|---|---|---|
| committer |   Benjamin Tissoires <benjamin.tissoires@redhat.com> | 2019-04-05 17:35:02 +0200 |
| commit | 4ceabaf7909d109db6afbffc4ed182741fc32043 (patch) | |
| tree | b64def112a3fbfe3bb135ac35b5fddc9e459464a /drivers/hid | |
| parent | HID: core: Call request_module before doing device_add (diff) | |
| download | linux-dev-4ceabaf7909d109db6afbffc4ed182741fc32043.tar.xz linux-dev-4ceabaf7909d109db6afbffc4ed182741fc32043.zip | |
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 <v-lide@microsoft.com>
Reported-by: Lili Deng <v-lide@microsoft.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Diffstat (limited to 'drivers/hid')
| -rw-r--r-- | drivers/hid/hid-core.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 2f843b84811e..59e95768142d 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -30,6 +30,7 @@ #include <linux/vmalloc.h> #include <linux/sched.h> #include <linux/semaphore.h> +#include <linux/async.h> #include <linux/hid.h> #include <linux/hiddev.h> @@ -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); |