Nathan Whitehorn wrote this message on Sun, Jan 13, 2013 at 10:14 -0800: > On 01/13/13 09:13, Konstantin Belousov wrote: > > On Sun, Jan 13, 2013 at 08:21:37AM -0800, Nathan Whitehorn wrote: > >> On 01/13/13 05:20, Konstantin Belousov wrote: > >>> On Sun, Jan 13, 2013 at 12:41:09PM +0100, Ed Schouten wrote: > >>>> Hi Kostik, > >>>> > >>>> 2013/1/7 Konstantin Belousov <kostik...@gmail.com>: > >>>>> I still do remember the buzz about the binary format 0xCAFEBABE, which > >>>>> AFAIR gained image activator support on several OSes, to be garbage > >>>>> collected. > >>>> > >>>> Maybe it would then be a good idea then to add some kind of general > >>>> purpose remapping imgact? Example: > >>>> > >>>> /etc/imgacttab: > >>>> > >>>> cafebabe /usr/local/bin/java > >>>> cffaedfe /usr/local/bin/osx_emulator > >>>> 4243c0de /usr/bin/lli > >>>> > >>>> That way we still give people the freedom to play around with mapping > >>>> their own executable formats, but don't need to maintain a bunch of > >>>> imgacts. > >>> > >>> A generic module that could be somewhat customized at runtime to map > >>> offset+signature into the shebang path could be a possibility indeed. > >>> I strongly prefer to have it as module and not enabled by default. > >>> > >>> Asking Nathan for writing the thing is too much, IMHO, esp. in > >>> the response to the 50-lines hack. > >>> > >> > >> I think this is a good idea, since it both prevents a profusion of > >> similar activators and works nicely in jails and similar environments. I > >> probably won't write it quickly, but it should not take more than about > >> 50 lines, so I can't imagine it will be that bad. There are some > >> complications with this kind of design from the things in the XXX > >> comment in imgact_llvm.c about handling argv[0] that I need to think > >> some more about. > > Great. I do not believe in the 50 lines, but I am happy that you want > > to work this out. > > > >> > >> Why are you opposed to having it there by default? I think it's actually > >> quite important that it be there by default. Having it not "standard" > >> would be fine, but it should at least be in GENERIC. There are minimal > >> security risks since it just munges begin_argv and doesn't even load the > >> executable and it's little enough code that there should not be any > >> kernel bloat to speak of. If things like this aren't enabled by default, > >> no one can depend on them being there, no one will use it, and the point > >> is entirely lost. > > All image activators demonstrated a constant stream of security holes. > > Even our ELF activator, and I was guilty there too. > > > > I definitely do not fight over the inclusion of the proposed activator > > into GENERIC, but do insist on the config option + module. > > > > OK, that sounds like a plan then. I'll try to code up something > configurable in the next couple weeks, unless someone else beats me to it.
I'll point out that file already has the magic (pun intended) that we are looking for, though I do realize that the code might be a bit much to import.. -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not." _______________________________________________ freebsd-toolchain@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-toolchain To unsubscribe, send any mail to "freebsd-toolchain-unsubscr...@freebsd.org"