On Saturday, March 14, 2015 05:58:11 PM Ian Lepore wrote: > On Sat, 2015-03-14 at 17:52 -0400, John Baldwin wrote: > > On Saturday, March 14, 2015 06:11:25 PM Ian Lepore wrote: > > > Author: ian > > > Date: Sat Mar 14 18:11:24 2015 > > > New Revision: 279997 > > > URL: https://svnweb.freebsd.org/changeset/base/279997 > > > > > > Log: > > > Use sbuf_new_for_sysctl() instead of plain sbuf_new() to ensure sysctl > > > string returned to userland is nulterminated. > > > > > > PR: 195668 > > > > This is not safe. sbuf_printf() is invoked with a lock held, so it isn't > > safe for the sbuf code to do a drain here. With sbuf_new_for_sysctl(), > > any call to an sbuf routine is a potential page fault, so the handler must > > either use sysctl_wire_old_buffer(), or the contents need to be output in > > one go. For this case I would prefer to use sbuf_len(sb) + 1 (or add > > INCLUDENUL to the args when creating it) and leave the sole SYSCTL_OUT() > > at the end. > > > > You will want to check the one or two other places you converted for this > > same issue as well. > > > > Doh! I was trying to keep an eye out for locks, but I missed that one. > Fixed in r280014. > > I'm at that point in a big maintenance task where I've looked at too > much code in too short a time, thanks for keeping a watchful eye on all > this.
No problem. I've replied to a few others that I think need a similar fix. However, fixing the larger bug is much appreciated. :) -- John Baldwin _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
