[GSoC] Questions about emulating missing linux system calls project

[Jamgadepatil Shivraj Shashikant <shivrajj%iisc.ac.in@localhost>]

Hello,

For the past few days, I have been trying to assess support for Linux 

system calls on a NetBSD system. I am using Linux Test Project 

for identifying system calls that are yet to be emulated on NetBSD.

I have setup QEMU with GENERIC kernel for testing purpose

(Thanks iMil for helping me out!) with COMPAT_LINUX option

enabled. 

I have following particular questions:

1. I wish to emulate support for pidfd_* family of system calls,
   open_tree, openat2, clone3. I believe they still lack
   emulation support. Where should I look to identify the
   possible mappings for these system calls in NetBSD
   kernel?
   
   
2. I found around 40 system calls that currently lack
   emulation support. Most of them are the system calls

that aren't popular or are more relevant to Linux kernel. Only 

some of the newer system calls seem more likely to be able 

to be mapped directly to NetBSD system calls. Is it expected

to actually implement some of them in NetBSD kernel and

then add them to compat layer as part of this project?

Also, what's the state of splice and sendfile system calls? I 

can see that they have been implemented as part of 

GSoC 2022 but the test cases relating to them still can't

find these system calls.

3. With respect to system calls relating to scheduler, I get error
   relating to not finding some particular files in proc directory.
   I have set up proc as mentioned in documentation but I still
   get these errors when I run schedular related system calls.
   Does proc need to be configured in different way or do schedular
   related system calls actually lack emulation support?
   
   

I would also like to thank Theodore for helping me understand the work he did last year.

Thanking you,

Shivraj