Re: kern/54541: kernel panic using "zfs diff"

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

The following reply was made to PR kern/54541; it has been noted by GNATS.

From: Patrick Welche <prlw1%cam.ac.uk@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/54541: kernel panic using "zfs diff"
Date: Mon, 14 Oct 2019 14:14:08 +0100

 On the rump front, I'm pretty sure that select() ends up calling fd_getfile.
 
 A quick test doesn't uncover any clues:
 - take the example program from select(2)
 - replace fd = 1 with fd = open("/dev/zero", O_RDONLY);
 
 $ rump/fdscan
 Data received on 1 file descriptor(s)
 Data on file descriptor 5
 $ export  RUMPHIJACK=blanket=/dev/zero
 $ rump/fdscan
 Data received on 1 file descriptor(s)
 Data on file descriptor 131
 
 so no panic, but in the latter run fd_getfile gets called with 3, not 3+128=131.