Port NaCl VMMap as a Rust Library

[rennergade]

We need an efficient memory map to be able to manage malloc and mmap effectively. It seems like a good start would be to port NaCl's memory map to Rust as a library.

[pranav-bhatt]

Document covering Vmmap APIs in NaCl

[pranav-bhatt]

@rennergade @yzhang71 @JustinCappos I've finished a bulk of the implementation of the Vmmap library, but there is still a ton of polishing and testing that needs to be done. Here is the repo link

I started out initially by trying to use BTreeMaps myself, but I had to sit and implement a ton of boilerplate operations for that. Eventually I decided to go library hunting cause I figured surely someone would have needed a non-overlapping interval tree map, and explored several options such as rangemap and rust-bio.

I ran into nodit three days ago, which performed quite well and was just what we needed. So I went ahead and redid the library using it. It provides a ton of useful abstractions, which makes working with intervals a piece of cake, and in future we can expose more of those if needed.

There are a few places where I've deviated from NaCl (mainly for the better), and I've roughly covered those in the above documentation. You can also find which of the functions are done, and which are still left (most are done, or don't need to be implement) in the docs as well.

I would love your feedback and reviews on the code if you feel something needs to be changed. I'm very unclear about the map alignment stuff so any inputs on that would be much appreciated!

[JustinCappos]

I don't see much documentation or testing. I also don't see benchmarking, which I think would be really useful here. Without these things I can't really make sense of this to know what is missing...

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On Fri, Sep 27, 2024 at 4:19 AM Pranav Bhatt ***@***.***> wrote: @rennergade <https://github.com/rennergade> @yzhang71 <https://github.com/yzhang71> @JustinCappos <https://github.com/JustinCappos> I've finished a bulk of the implementation of the Vmmap library, but there is still a ton of polishing and testing that needs to be done. Here is the repo link <https://github.com/pranav-bhatt/rust_vmmap> I started out initially by trying to use BTreeMaps myself, but I had to sit and implement a ton of boilerplate operations for that. Eventually I decided to go library hunting cause I figured surely someone would have needed a non-overlapping interval tree map, and explored several options such as rangemap and rust-bio. I ran into nodit <https://crates.io/crates/nodit> three days ago, which performed quite well and was just what we needed. So I went ahead and redid the library using it. It provides a ton of useful abstractions, which makes working with intervals a piece of cake, and in future we can expose more of those if needed. There are a few places where I've deviated from NaCl (mainly for the better), and I've roughly covered those in the above documentation. You can also find which of the functions are done, and which are still left (most are done, or don't need to be implement) in the docs as well. I would love your feedback and reviews on the code if you feel something needs to be changed. I'm very unclear about the map alignment stuff so any inputs on that would be much appreciated! — Reply to this email directly, view it on GitHub <#7 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAGRODZLX2NUXCKJ44ACSULZYUIHTAVCNFSM6AAAAABLNPGXDCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGNZYG4YTQOJVGU> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[rennergade]

Yeah, I agree the next step here is adding testing. Dennis and I should be able to walk you through that if you have any questions.

[rennergade]

TODOs as of 11/18:

• Fix/add brk(), properly initialize first entry for heap @qianxichen233
• PR mmap/brk changes to main vmmap PR @qianxichen233
• Add MACRO for end of cage memory, test find map space functions @ruchjoshi-nyu
• Add comments across remaining functions in vmmap @ruchjoshi-nyu
• Fix constants @ChinmayShringi
• Fix file backed protection function @Yaxuan-w
• PR at this point to monorepo

Additional changes/PRs

• add address checking for functions with pointers as paramaters @ChinmayShringi
• add mprotect() @ChinmayShringi
• Test/add shared memory mapping - @ChinmayShringi