It's better to let kernel thread skip the duplication of caller's file handler, here is the patch: https://github.com/apache/incubator-nuttx/pull/5379 Michael, could you try it?
On Mon, Jan 31, 2022 at 12:59 AM Michael Jung <mij...@gmx.net> wrote: > Hi Xiang, Hi Matthew, > > Thanks for your responses. > > Matthew wrote: > > Creating a kernel thread in an ioctl "lower-half" would probably cause > the file descriptors from the calling task to get copied. > > Yes, that is exactly what is happening. The started kernel thread actively > polls for an event to happen and terminates afterwards, calling close on > all the copied file descriptors (which includes the one the ioctl was > called on). Currently I made my device driver more robust via reference > counting, but I tend to agree with the referenced issues that kernel > threads should not maintain file descriptors. > > Thanks! > Michael > > Am Fr., 28. Jan. 2022 um 23:38 Uhr schrieb Matthew Trescott < > matthewtresc...@gmail.com>: > > > On Fri, Jan 28, 2022 at 7:43 PM Michael Jung <mij...@gmx.net> wrote: > > > specific ioctl command implementation > > > > Creating a kernel thread in an ioctl "lower-half" would probably cause > > the file descriptors from the calling task to get copied. Might this > > be another case of > > https://github.com/apache/incubator-nuttx/issues/1108 and > > https://github.com/apache/incubator-nuttx/issues/2663 ? > > >
