CVS commit: src/sys

["Jaromir Dolecek" <jdolecek%netbsd.org@localhost>]

Module Name:    src
Committed By:   jdolecek
Date:           Sun May  2 19:13:43 UTC 2021

Modified Files:
        src/sys/kern: kern_event.c
        src/sys/sys: eventvar.h

Log Message:
implement fo_restart hook for kqueue descriptors, so that close(2)
on the descriptor won't block indefinitely if other thread is currently
blocked on the same kqueue in kevent(2)

done similarily to pipes and sockets, i.e. using flag on the potentially
shared kqueue structure hooked off file_t - this is somewhat suboptimal
if the application dup(2)ped the descriptor, but this should be rare
enough to not really matter

usually this causes the kevent(2) to end up returning EBADF since
on the syscall restart the descriptor is not there anymore; if
dup(2)ped the kevent(2) call can continue successfully if the closed
kqueue descriptor was other than the one used for the kevent(2)
call

PR kern/46248 by Julian Fagir


To generate a diff of this commit:
cvs rdiff -u -r1.117 -r1.118 src/sys/kern/kern_event.c
cvs rdiff -u -r1.8 -r1.9 src/sys/sys/eventvar.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.