16:49:51 <Guest51> hello
16:53:54 <gitomat> [illumos-gate] 16096 want proc_get_lwpstatus(3PROC) -- Robert Mustacchi <rm⊙fo>
20:28:12 <gitomat> [illumos-gate] 16107 asy VERIFY too strong in face of polledio -- Patrick Mooney <pmooney⊙pc>
20:36:01 <alanc> Happy new CPU bug! https://www.vusec.net/projects/slam/ (though it only affects Intel & ARM CPUs that haven't shipped to the public yet, but some AMD ones that have)
20:38:47 <richlowe> my complete slacking on ARM paging pays off again!
21:20:46 <danmcd> Storing information in pointers... sheesh, Macintosh System 1 did that, for crying out loud!
21:32:59 <alanc> heh, I remember the 24-bit -> 32-bit pointer change in the old Mac Systems back when I had a Mac II
21:34:21 <alanc> of course, we do that on recent SPARC systems for pointer checking with ADI, but that's more like ARM's Memory Tagging than ARM's Top-Byte Ignore
21:39:50 <richlowe> (I haven't looked at memory tagging either!)
21:39:59 <richlowe> I looked at pointer auth tho
21:40:05 <richlowe> didn't do anything, but I looked
21:42:57 <richlowe> danmcd: I mean, that's why OI force an /etc/system tweak to leave some bits free for javascript runtimes etc.
21:43:28 <richlowe> TBI is basically doing that, but without having to mask them off constantly
21:43:48 <richlowe> (at the expense of what alan's link talks about, re: address canonicity.)
21:44:14 <richlowe> (to be clear, the /etc/system tweak is so we don't put runtimes at an address that _requires a bit they use for type tagging_)
21:44:14 <danmcd> @alanc gets it.  :)  And thank you richlowe for the clarification.
21:44:45 <richlowe> and I remember the mac brouhaha, but thankfully only second hand
21:45:03 <richlowe> and I was impressed with amd64 making the VA hole checked and very cautious
21:45:12 <richlowe> so it's impossible to try to steal those bits, and get screwed the same way
21:45:29 <alanc> right, we have to do that with javascript runtimes as well, many of which assume only 48 bits of pointers matter, and won't be happy with 53-bit address busses
21:45:58 <alanc> though we do it via linker flags instead of /etc/system
21:46:22 <richlowe> actual flags, or something like map.above4G etc?
21:46:24 <alanc> (well, linker flags to load a special mapfile)
21:46:59 <richlowe> that makes more sense
21:47:22 <alanc> https://github.com/oracle/solaris-userland/blob/acfe23025ffac8c2f600ebc4f259df46a3b84820/components/desktop/firefox/patches/sparc-47bit-VA-space.patch
21:48:50 <alanc> https://github.com/search?q=repo%3Aoracle%2Fsolaris-userland+reserve_segment&type=code
21:50:17 <richlowe> maybe shipping that in /usr/lib/ld would make sense?
21:51:10 <richlowe> and dare I ask about https://github.com/oracle/solaris-userland/blob/acfe23025ffac8c2f600ebc4f259df46a3b84820/components/gnome/gnome-shell/mapfile.js#L3? :)
21:51:22 <alanc> we don't want to encourage it, but I suppose it's too late to pretend no one should ever need it
21:52:07 <richlowe> my logic was "It's probably better to ship one, that does it properly, then keep adding them to solaris-userland and also not helping 3rd parties"
21:52:26 <richlowe> than*
21:52:32 <alanc> yeah
21:52:35 <richlowe> but it's not like I did that for us :)
21:55:21 <alanc> what about that line did you want to ask?
21:56:32 <alanc> it sets the p_vaddr in the Program Header to the start of the range that overlaps with the bits set in the pointers
21:56:40 <alanc> Program Header[5]:  spidermonkey_reserve
21:56:40 <alanc>     p_vaddr:      0x800000000000      p_flags:    0
21:56:40 <alanc>     p_paddr:      0                   p_type:     [ PT_SUNW_RESERVE ]
21:56:40 <alanc>     p_filesz:     0                   p_memsz:    0xffff7fffffff0000
21:56:40 <alanc>     p_offset:     0                   p_align:    0x100000
22:00:21 <richlowe> alanc: sorry, the line-link was an accent.  I meant `mapfile.js`
22:00:25 <richlowe> accident, even
22:01:08 <alanc> gnome-shell uses libmozjs to run javascript code - that's what gnome-shell extensions are written in
22:02:02 <richlowe> ah, so it's a mapfile for javascript
22:02:09 <alanc> so same javascript engine as firefox, same problem with addresses
22:02:11 <richlowe> named so as to piss off editor syntax selection
22:02:18 <alanc> ah, yes, hehe
22:03:07 <alanc> not a new syntax for mapfiles, just following the convention of mapfile.<whats-it-for>
22:03:40 <alanc> though I guess /usr/lib/ld just uses map.<whats-it-for> as a naming convention instead