20 messages in org.freebsd.freebsd-archTime to make the stack non-executable?| From | Sent On | Attachments |
|---|---|---|
| Terry Lambert | Jun 29, 2002 3:13 pm | |
| Jake Burkholder | Jun 29, 2002 3:55 pm | |
| Alfred Perlstein | Jun 29, 2002 4:08 pm | |
| Julian Elischer | Jun 29, 2002 4:14 pm | |
| Jake Burkholder | Jun 29, 2002 4:24 pm | |
| Bill Huey | Jun 29, 2002 4:25 pm | |
| Terry Lambert | Jun 29, 2002 5:50 pm | |
| Bill Huey | Jun 29, 2002 6:18 pm | |
| David O'Brien | Jun 29, 2002 7:39 pm | |
| Bakul Shah | Jun 29, 2002 10:40 pm | |
| Arun Sharma | Jun 29, 2002 11:31 pm | |
| Peter Wemm | Jun 29, 2002 11:59 pm | |
| Igor Sysoev | Jun 30, 2002 2:49 am | |
| Terry Lambert | Jun 30, 2002 3:24 am | |
| Terry Lambert | Jun 30, 2002 3:38 am | |
| Eivind Eklund | Jun 30, 2002 3:44 am | |
| Terry Lambert | Jun 30, 2002 4:39 am | |
| Cedric Berger | Jun 30, 2002 5:14 am | |
| Terry Lambert | Jun 30, 2002 5:24 am | |
| Peter Wemm | Jun 30, 2002 1:42 pm |
| Subject: | Time to make the stack non-executable? | |
|---|---|---|
| From: | Terry Lambert (tlam...@mindspring.com) | |
| Date: | Jun 29, 2002 3:13:36 pm | |
| List: | org.freebsd.freebsd-arch | |
Doug Barton wrote:
Subject: We're famous http://story.news.yahoo.com/news?tmpl=story&ncid=70&e=2&cid=70&u=/cn/20020629/tc_cn/940585
Sean Eric Fagan and I discussed this several years ago, and we discussed it again the other day, before this attack hit. It looks like it's an idea whose time has come.
We've identified a number of issues that might make doing this problematic, and on which there needs to be feedback:
o Java; specifically, JITs may rely on an executable stack. Neither of us knows if this is true, for sure.
o FORTH? Same question.
o Signals
o Julian's new threads patches
o Multiple architecture support
Right now, SEF points out (and I concur) that the only portion of the system that seems to care about having an executable stack is the signal trampoline. I would imagine that the trampoline for the user space threads scheduler for KSE based threading will (does) have the same problem.
For signals, this is easy: copy SVR4, and modify the signal functions to pass in a return address, then disable the execute bits on stack pages and see whose head blows up.
Frankly, I'm very surprised to discover that OpenBSD has not already done this.
Opinions? Patches from people who know and love the signals facility on Alpha, SPARC64, PPC, etc.?
-- Terry
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