feat(kernel): per-process budgets (pages, endpoints, notifs, regions) carved from creator, returned on death; init owns pool

crates/init/src/lib.rs

@@ -7,6 +7,7 @@ mod selftest;
 
 use types::address::{EntryPoint, StackPointer, VirtualAddress};
 use types::bounded::{CapSlot, PageCount};
+use types::budget::Limits;
 use types::permission::{Permission, PermissionSet};
 use libkos::fs::Storage;
 use libkos::syscall;
@@ -42,7 +43,12 @@ pub(crate) struct LoadedProcess {
     pub(crate) entry_point: EntryPoint,
 }
 
-pub(crate) fn load_binary(storage: &mut Storage, scratch: &mut [u8], filename: &[u8]) -> Option<LoadedProcess> {
+pub(crate) fn load_binary(
+    storage: &mut Storage,
+    scratch: &mut [u8],
+    filename: &[u8],
+    limits: Limits,
+) -> Option<LoadedProcess> {
     let file_size = read_file(storage, scratch, filename)?;
     let elf_data = &scratch[..file_size];
     let elf_info = match elf::parse(elf_data) {
@@ -50,7 +56,7 @@ pub(crate) fn load_binary(storage: &mut Storage, scratch: &mut [u8], filename: &
         Err(_) => return None,
     };
 
-    let process_cap = syscall::create_process(CREATE_CAP)?;
+    let process_cap = syscall::create_process(CREATE_CAP, limits)?;
 
     for segment in elf_info.segments() {
         let page_start = segment.vaddr & !0xFFF;
@@ -102,14 +108,25 @@ pub(crate) fn load_binary(storage: &mut Storage, scratch: &mut [u8], filename: &
 struct ServerInfo {
     filename: &'static [u8],
     name: &'static str,
+    limits: Limits,
 }
 
+/// Enough for a small program: its image, stack and a little heap.
+pub(crate) const SMALL: Limits = Limits {
+    pages: 64,
+    endpoints: 2,
+    notifications: 2,
+    regions: 2,
+};
+
 const SERVERS: &[ServerInfo] = &[
-    ServerInfo { filename: b"log.elf", name: "log" },
-    ServerInfo { filename: b"permis.elf", name: "permis" },
-    ServerInfo { filename: b"session.elf", name: "session" },
+    ServerInfo { filename: b"log.elf", name: "log", limits: SMALL },
+    ServerInfo { filename: b"permis.elf", name: "permis", limits: SMALL },
+    ServerInfo { filename: b"session.elf", name: "session", limits: SMALL },
 ];
 
+const SNAKE: Limits = Limits { pages: 128, ..SMALL };
+
 pub fn run() -> ! {
     libkos::start::set_console(devices::console());
     libkos::println!("init: started (pid={:#x})", syscall::get_process_id().raw());
@@ -142,7 +159,7 @@ pub fn run() -> ! {
     for server in SERVERS {
         libkos::print!("init: loading {}... ", server.name);
 
-        let loaded = match load_binary(&mut storage, scratch, server.filename) {
+        let loaded = match load_binary(&mut storage, scratch, server.filename, server.limits) {
             Some(l) => l,
             None => {
                 libkos::println!("SKIP");
@@ -166,7 +183,7 @@ pub fn run() -> ! {
     }
 
     libkos::print!("init: loading snake... ");
-    if let Some(snake) = load_binary(&mut storage, scratch, b"snake.elf") {
+    if let Some(snake) = load_binary(&mut storage, scratch, b"snake.elf", SNAKE) {
         // A client only calls: Execute, never Read, so it cannot pose as
         // the server and take other clients' requests.
         let client = PermissionSet::empty().with(Permission::Execute);

crates/init/src/selftest.rs

@@ -40,7 +40,7 @@ fn start_spinner(storage: &mut Storage, scratch: &mut [u8], page: CapSlot) -> Re
     for i in 0..=THREADS {
         word(i).store(0, Ordering::SeqCst);
     }
-    let spinner = crate::load_binary(storage, scratch, b"smptest.elf").ok_or("cannot load smptest.elf")?;
+    let spinner = crate::load_binary(storage, scratch, b"smptest.elf", crate::SMALL).ok_or("cannot load smptest.elf")?;
     let rw = PermissionSet::empty()
         .with(Permission::Read)
         .with(Permission::Write)