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| author | Ian Abbott <abbotti@mev.co.uk> | 2019-04-17 15:35:31 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-19 14:33:33 +0200 |
| commit | f439696c81fcfe70ad46554fbec1c851bab9345a (patch) | |
| tree | 638ea57d98baad0fa8efd60b8212680cf80104f9 /drivers/staging/comedi | |
| parent | 2e299cc96952ab5709e809947a6a4ac66f60fdaf (diff) | |
| download | lwn-f439696c81fcfe70ad46554fbec1c851bab9345a.tar.gz lwn-f439696c81fcfe70ad46554fbec1c851bab9345a.zip | |
staging: comedi: don't release mutex too early in comedi_auto_config()
`comedi_auto_config()` uses `dev->class_dev` for logging a kernel
message after releasing `dev->mutex`. There is an unlikely possibility
that the Comedi device `dev` will have been removed by the
`COMEDI_DEVCONFIG` ioctl() command. Keep hold of the mutex until the
kernel message has been sent to prevent that. The function can call
`comedi_release_hardware_device()` on error. In that case, the mutex
must be unlocked before that.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/comedi')
| -rw-r--r-- | drivers/staging/comedi/drivers.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c index 5a32b8fc000e..b7b9e48d4303 100644 --- a/drivers/staging/comedi/drivers.c +++ b/drivers/staging/comedi/drivers.c @@ -1059,12 +1059,12 @@ int comedi_auto_config(struct device *hardware_device, ret = driver->auto_attach(dev, context); if (ret >= 0) ret = comedi_device_postconfig(dev); - mutex_unlock(&dev->mutex); if (ret < 0) { dev_warn(hardware_device, "driver '%s' failed to auto-configure device.\n", driver->driver_name); + mutex_unlock(&dev->mutex); comedi_release_hardware_device(hardware_device); } else { /* @@ -1074,6 +1074,7 @@ int comedi_auto_config(struct device *hardware_device, dev_info(dev->class_dev, "driver '%s' has successfully auto-configured '%s'.\n", driver->driver_name, dev->board_name); + mutex_unlock(&dev->mutex); } return ret; } |