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Diffstat (limited to 'open_issues/mondriaan_memory_protection.mdwn')
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diff --git a/open_issues/mondriaan_memory_protection.mdwn b/open_issues/mondriaan_memory_protection.mdwn deleted file mode 100644 index 2c7b9ba1..00000000 --- a/open_issues/mondriaan_memory_protection.mdwn +++ /dev/null @@ -1,85 +0,0 @@ -[[!meta copyright="Copyright © 2013 Free Software Foundation, Inc."]] - -[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable -id="license" text="Permission is granted to copy, distribute and/or modify this -document under the terms of the GNU Free Documentation License, Version 1.2 or -any later version published by the Free Software Foundation; with no Invariant -Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license -is included in the section entitled [[GNU Free Documentation -License|/fdl]]."]]"""]] - -<http://scale.eecs.berkeley.edu/mondriaan/>. - - -# IRC, freenode, #hurd, 2013-07-02 - - <xscript> in any case, what I wanted to check is if current hurd support - PIE - <xscript`> I just saw samuel posted some fixes to have PIE working in hurd - <xscript`> are those included in the official image? - <youpi> sure - <youpi> it's just a trivial fixup in some address calculation code - <xscript> youpi: nice - <xscript> and does anyone know how complex would it be to implement some - hackish support to have non-overlapping virtual addresses for - applications supporting PIE? - <braunr> not too difficult - <xscript> really? I didn't expect such an answer XD - <xscript> I'd like to have something similar to a SASOS - <xscript> (single address space os) - <braunr> ? - <braunr> you mean an sasos on top of mach ? - <xscript> yes, but only for a few apps I want to evaluate - <braunr> i see - <xscript> the optimal would be to have all of hurd's servers on that mode - <braunr> you'l probably need to implement a small allocator but other than - that it shouldn't be too hard, yes - <braunr> uh ?? - <xscript> but running on 32 bits can be a problem here - <braunr> and not hurdish at all - <xscript> what's not hurdish? - <braunr> we do want address space separation - <xscript> well, you can have multiple address spaces (page tables), but - without overlapping addresses between them - <xscript> that's exactly what I'm looking for - <braunr> sorry i don't see what you mean - <braunr> if you run several servers in the same address space, they can - corrupt each other - <braunr> we don't want that - <braunr> it's that simple - <xscript> yes, sorry, I didn't explain myself - <xscript> I want a separate address space on each server - <xscript> but I want all memory allocations to be on addresses unique to - the whole OS - <braunr> that still doesn't make sense - <xscript> well, it will still be secure - <xscript> but I know it does not make sense per se - <xscript> I want to do some experiments with a simulator - <braunr> why do you want them non overlapping if they're separate ? - <xscript> well, in my simulator I wouldn't need to change the page tables, - protection is provided through other means - <braunr> segmentation ? - <xscript> that's one possibility - <xscript> (small address spaces) - <braunr> what do you have in mind ? - <braunr> it wouldn't be on top of mach anyway then - <braunr> mach implements paging - <xscript> what I'm simulating is something of the likes of Mondriaan - (http://www.cs.utexas.edu/~witchel/pubs/mmp-asplos2002.pdf) - <xscript> paging is ok for me - <braunr> 19:06 < xscript> well, in my simulator I wouldn't need to change - the page tables, protection is provided through other means - <braunr> it didn't sound so - <xscript> I meant switching page tables (cr3, etc) - <braunr> mach does that - <xscript> I know, I know, I can just ignore that part for the moment - <braunr> ok - <xscript> for now, I'd like to morph hurd into a SASOS using one page table - per process - <xscript> I just wanted to know how hard that would be, without starting - with a full dive into the code - <xscript> there are other options (OSes, microkernels), but none of them - provides as many readily-available applications as hurd - <xscript> I suppose MINIX would also be easy to modify, but there's less - apps there, and I also would like to tamper with MIG - <xscript> I just wonder how hard it would be to modify MIG |