On Thu, Sep 24, 2020 at 3:08 AM Stefan Esser <s...@freebsd.org> wrote: > > Am 24.09.20 um 08:54 schrieb Warner Losh: > > > > > > On Thu, Sep 24, 2020 at 12:41 AM Stefan Esser <s...@freebsd.org > > <mailto:s...@freebsd.org>> wrote: > > > > Am 23.09.20 um 19:23 schrieb Warner Losh> But for this issue, we're not > > mounting devfs early enough. We should > > > fix that. Removing /dev/null from the boot process likely is > > never going > > > to happen because we use it all over the place to discard output... > > > There's ~200 instances of it in the boot rc scripts, so getting > > rid of > > > it there would also be quite the effort, with the same question. > > > > Removal of /dev/null from rc.d scripts should be quite simple, > > since most cases could just use ">-" (close file descriptor) > > instead. Other usage could be substituted with ":>" followed > > by chown. > > > > > > So closing fd1 and fd2 doesn't cause them to be available for these > > programs to get as an fd on open, causing other issues? > > > > But >- isn't documented in sh(1) as doing the close thing. On a whim I > > did the following: > > $ echo fred >- > > $ ls -last ./- > > 4 -rw-r--r-- 1 imp imp 5 Sep 24 00:50 ./- > > $ cat ./- > > fred > > $ > > which suggests maybe you now have a lot of files named - instead... > > Yes, sorry, please ignore what I wrote - I was thinking of ">&-" of > course, but that is not gracefully accepted by many commands (they > are aborted when trying to write to the closed file descriptor). > > I had thought about piping into a command that ignores STDIN, first, > e.g. "| :", but that generates a SIGPIPE when trying to flush the > FILE buffer (i.e. after 4 KB, which might be sufficient for most > cases, but it is not a general solution). > > A program that reads from STDIN and generates no output could be used, > though, e.g. "| sed d". > > But this would cause lots of extra forked processes and increase the > start-up time and is not acceptable. > > > but e.g. rc.d/syscons > > uses ${kbddev} (i.e. /dev/ttyv0) and rc.d/zvol performs swapon > > on /dev/zvol/${name}, rc.d/random uses /dev/random and so on. > > > > So those interactions should be disaled by rc variables... Or we should > > be failing the operation... > > Going multi-user should not be stopped by any of the rc scripts > failing due to lack of /dev. But since most developers will only > test with /dev available, there is a risk that changes to rc files > will not gracefully handle a missing /dev. >
I was under the impression from previous reading and kib's response that this is a complete non-issue, there's no way you can go multi-user without a mounted /dev and we go to somewhat great lengths to make sure we're good. I agree with the previous goal of ripping the /dev dependency out of the build, but this is also much, much easier said than done. _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
