summaryrefslogtreecommitdiff
path: root/open_issues/mondriaan_memory_protection.mdwn
diff options
context:
space:
mode:
authorSamuel Thibault <samuel.thibault@ens-lyon.org>2015-02-18 00:58:35 +0100
committerSamuel Thibault <samuel.thibault@ens-lyon.org>2015-02-18 00:58:35 +0100
commit49a086299e047b18280457b654790ef4a2e5abfa (patch)
treec2b29e0734d560ce4f58c6945390650b5cac8a1b /open_issues/mondriaan_memory_protection.mdwn
parente2b3602ea241cd0f6bc3db88bf055bee459028b6 (diff)
Revert "rename open_issues.mdwn to service_solahart_jakarta_selatan__082122541663.mdwn"
This reverts commit 95878586ec7611791f4001a4ee17abf943fae3c1.
Diffstat (limited to 'open_issues/mondriaan_memory_protection.mdwn')
-rw-r--r--open_issues/mondriaan_memory_protection.mdwn85
1 files changed, 85 insertions, 0 deletions
diff --git a/open_issues/mondriaan_memory_protection.mdwn b/open_issues/mondriaan_memory_protection.mdwn
new file mode 100644
index 00000000..2c7b9ba1
--- /dev/null
+++ b/open_issues/mondriaan_memory_protection.mdwn
@@ -0,0 +1,85 @@
+[[!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