https://github.com/lmangani/vmemfd

memfd_create elf execution in v
https://github.com/lmangani/vmemfd

elf memfd v vlang

Last synced: 11 days ago
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memfd_create elf execution in v

• Host: GitHub
• URL: https://github.com/lmangani/vmemfd
• Owner: lmangani
• License: mit
• Created: 2022-09-13T10:55:03.000Z (about 2 years ago)
• Default Branch: main
• Last Pushed: 2022-10-07T13:16:15.000Z (about 2 years ago)
• Last Synced: 2024-10-04T13:22:01.181Z (about 1 month ago)
• Topics: elf, memfd, v, vlang
• Language: C
• Homepage:
• Size: 232 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        

#  vmemfd

Experimental [`memfd_create`](https://man7.org/linux/man-pages/man2/memfd_create.2.html) ELF execution prototype in [`vlang`](https://vlang.io)

#### [`memfd_create`](https://man7.org/linux/man-pages/man2/memfd_create.2.html)

> memfd_create() creates an anonymous file and returns a file

       descriptor that refers to it.  The file behaves like a regular

       file, and so can be modified, truncated, memory-mapped, and so

       on.  However, unlike a regular file, it lives in RAM and has a

       volatile backing storage.  Once all references to the file are

       dropped, it is automatically released.  Anonymous memory is used

       for all backing pages of the file. 

## Goals

- [x] memfd based ELF execution in v

  - [x] c module exporting [`memfd_create`](https://man7.org/linux/man-pages/man2/memfd_create.2.html)

- [ ] use `$embed_file` _for files < 20Mb_

- [ ] self-extracting binary decompressing to `memfd` pointer

## Gist

```c

import lmangani.memfd

// Read binary ELF

data := os.read_file(filename) or {

  panic('error reading elf $filename')

  return

}

// Allocate a memfd MFD_CLOEXEC and write ELF

fd_id := memfd.vmemfd_new('myapp')

os.fd_write(fd_id, data)	

// Execute w/ arguments from memfd

pointer := '/proc/self/fd/$fd_id'

os.execve(pointer, args, []) or {

  panic('error executing $pointer')

  return

}

```

## Test

Compile an ELF binary expecting args _(or bring your own)_

```bash

v -o app -prod app.v

```

Load and execute ELF using `memdfd` 

```bash

v run vload.v test me

```