Porting VMMAP to RawPOSIX

[ChinmayShringi]

Please note this is taken from RawPosix: (Lind-Project/RawPOSIX#87)

Description

Issue # 45

Type of change

Porting pranav-bhatt and ruchjoshi-nyu implementation of VMMAP to RawPOSIX. Request review for porting location and if more comments are needed.

I also added few comments to make things more clear. That would be great if ruchjoshi-nyu could review their correctness.

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Checklist:

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• Any dependent changes have been added to a pull request and/or merged in other modules (native-client, lind-glibc, lind-project)

[Yaxuan-w]

Awesome! Minor changes requested.

Would it make more sense to move LIND_ROOT in fs_calls.rs and net_calls.rs to corresponding constant files as well?

[rennergade]

@ChinmayShringi add address checking and conversion:

1. create function in mem.rs called check_and_convert_addr(user_addr: u64)
   That function calls check_addr_mapping() in vmmap.rs and checks if address is valid, if not return Error type of result
   If valid return Result(vmmap.base_addr + user_addr)
2. in dispatcher, if returns error, return EFAULT error
3. if succesful, unwrap Result and send that value to syscall like usual

[rennergade]

@ChinmayShringi additional tasks

• read through all of this, add additional comments on understanding
• add additional tests as needed

[Yaxuan-w]

I met this error while compiling the newest vmmap:

error[E0308]: `match` arms have incompatible types
    --> src/safeposix/dispatcher.rs:312:13
     |
204  |       let ret = match call_number {
     |  _______________-
205  | |         WRITE_SYSCALL => {
206  | |             // Handles writing data from user buffer to file descriptor
...    |
233  | |             cage.write_syscall(fd, buf, count)
     | |             ---------------------------------- this is found to be of type `i32`
...    |
269  | |             cage.writev_syscall(fd, iov_base, iovcnt)
     | |             ----------------------------------------- this is found to be of type `i32`
...    |
286  | |             interface::munmap_handler(cageid, addr, length)
     | |             ----------------------------------------------- this is found to be of type `i32`
...    |
312  | |             interface::mmap_handler(cageid, addr, len, prot, flags, fd, off)
     | |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `i32`, found `u32`
...    |
1624 | |         _ => -1, // Return -1 for unknown syscalls
1625 | |     };
     | |_____- `match` arms have incompatible types
     |
help: you can convert a `u32` to an `i32` and panic if the converted value doesn't fit

[rennergade]

Added a few notes.

Also Im not sure but think the vmmap branch needs to be updated against main because I think there's stuff showing up thats already been merged?

[rennergade]

I think this is ready to merge once the tests are straightened out.

[ChinmayShringi]

The test cases are fixed and it builds and runs, test cases do fail but now they run without errors.

[qianxichen233]

The test cases are fixed and it builds and runs, test cases do fail but now they run without errors.

Which test cases are you refering to? RawPOSIX testsuite or lind-wasm unit test?

[ChinmayShringi]

The test cases are fixed and it builds and runs, test cases do fail but now they run without errors.

Which test cases are you refering to? RawPOSIX testsuite or lind-wasm unit test?

Rawposix test suite

[qianxichen233]

The test cases are fixed and it builds and runs, test cases do fail but now they run without errors.

Which test cases are you refering to? RawPOSIX testsuite or lind-wasm unit test?

Rawposix test suite

Can you also test the lind-wasm test cases? Especially those mmap tests. They are under lind-wasm/tests/unit-test/memory-test/