Messages in this thread | | | Date | Fri, 19 Sep 2014 15:02:54 -0700 | Subject | Re: [PATCH] x86/vdso: Add prctl to set per-process VDSO load | From | Filipe Brandenburger <> |
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Hi Andy,
On Fri, Sep 19, 2014 at 12:27 PM, Andy Lutomirski <luto@amacapital.net> wrote: > I have this (special mapping tracking) 3/4 implemented. I'm planning > on making it fully functional for 64-bit programs and almost correct > for 32-bit. (You'll still crash if you have multiple threads, you use > sysenter, and you remap the vdso, but I think that this is essentially > unavoidable until someone lets mremap work on multiple vmas at once.)
In case that's useful, I was looking at swapping the vvar page by changing the vm_special_mapping to change the pages array between the actual vvar page and the zero page and using zap_page_range to force the next access to go through a page fault that would remap it.
I didn't have all the details figured out (I was closer to 1/4 of it implemented) but I didn't see any issues on 32-bit programs.
Let me know if you'd like to see some of my patches or if you think I should keep working on them.
Cheers, Filipe
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