proc: pass env along with args to spawn()

src/init.rs

@@ -60,7 +60,7 @@ pub fn kinit() {
     let stderr = stdout.clone();
 
     {
-        let user_init = proc::exec::load_elf("init", file, &["/init", "xxx"]).unwrap();
+        let user_init = proc::exec::load_elf("init", file, &["/init", "xxx"], &[]).unwrap();
         let mut io = user_init.io.lock();
         io.set_ioctx(ioctx);
         io.set_file(RawFd::STDIN, stdin).unwrap();

src/proc/exec.rs

@@ -7,26 +7,78 @@ use vfs::FileRef;
 
 use crate::{
     mem::{
-        address::AsPhysicalAddress, phys, process::ProcessAddressSpace, table::MapAttributes,
-        ForeignPointer,
+        address::AsPhysicalAddress, phys, pointer::PhysicalRefMut, process::ProcessAddressSpace,
+        table::MapAttributes, ForeignPointer,
     },
     proc,
     task::{context::TaskContextImpl, process::Process, TaskContext},
 };
 
-fn setup_args(space: &ProcessAddressSpace, virt: usize, args: &[&str]) -> Result<(), Error> {
-    // arg data len
-    let args_size: usize = args.iter().map(|x| x.len()).sum();
-    // 1 + arg ptr:len count
-    let args_ptr_size = (1 + args.len() * 2) * size_of::<usize>();
+pub struct EnvWriter<'a> {
+    data: &'a mut [u8],
+    offset: usize,
+}
 
-    let total_size = args_size + args_ptr_size;
+impl<'a> EnvWriter<'a> {
+    pub fn new(data: &'a mut [u8]) -> Self {
+        Self { data, offset: 0 }
+    }
+
+    pub fn write_usize(&mut self, value: usize) -> Result<(), Error> {
+        self.write_bytes(&value.to_ne_bytes())
+    }
+
+    pub fn write_bytes(&mut self, value: &[u8]) -> Result<(), Error> {
+        if value.len() + self.offset > self.data.len() {
+            return Err(Error::InvalidArgument);
+        }
+        debugln!("write_bytes {:#x} {:x?}", self.offset, value);
+        self.data[self.offset..self.offset + value.len()].copy_from_slice(value);
+        self.offset += value.len();
+        Ok(())
+    }
+}
+
+fn write_2d_str_array(
+    space: &ProcessAddressSpace,
+    virt: usize,
+    array: &[&str],
+) -> Result<(), Error> {
+    todo!()
+}
+
+// TODO I hate this function, it's ugly
+fn setup_program_env(
+    space: &ProcessAddressSpace,
+    virt: usize,
+    args: &[&str],
+    envs: &[&str],
+) -> Result<(), Error> {
+    const fn str_array_size(n: usize) -> usize {
+        // length of the array itself (1 usize) + ptr:len pairs (2x usize * n)
+        (1 + n * 2) * size_of::<usize>()
+    }
+
+    const HEADER_SIZE: usize = 2 * size_of::<usize>();
+
+    // arg data len
+    let args_data_size: usize = args.iter().map(|x| x.len()).sum();
+    let envs_data_size: usize = envs.iter().map(|x| x.len()).sum();
+    let ptrs_size = str_array_size(args.len()) + str_array_size(envs.len());
+    let total_size = args_data_size + envs_data_size + ptrs_size + HEADER_SIZE;
+    // 1 + arg ptr:len count
+    // let args_ptr_size = (1 + args.len() * 2) * size_of::<usize>();
+    // let envs_ptr_size = (1 + envs.len() * 2) * size_of::<usize>();
+
+    // Total size: offset arrays + data + args/env split position
+    // let total_size = args_size + args_ptr_size + envs_size + envs_ptr_size + size_of::<usize>();
 
     if total_size > 0x1000 {
         todo!();
     }
 
-    debugln!("arg data size = {}", args_size);
+    // debugln!("arg data size = {}", args_size);
+    // debugln!("env data size = {}", envs_size);
 
     let phys_page = phys::alloc_page()?;
     space.map_single(
@@ -34,35 +86,44 @@ fn setup_args(space: &ProcessAddressSpace, virt: usize, args: &[&str]) -> Result
         phys_page,
         MapAttributes::USER_READ | MapAttributes::USER_WRITE | MapAttributes::NON_GLOBAL,
     )?;
-    let write = phys_page.virtualize_raw();
+    let mut slice = unsafe { PhysicalRefMut::map_slice(phys_page, 4096) };
+    let mut writer = EnvWriter::new(&mut *slice);
 
-    let mut offset = args_ptr_size;
+    let args_array_offset = HEADER_SIZE;
+    let envs_array_offset = args_array_offset + str_array_size(args.len());
+    let args_data_offset = envs_array_offset + str_array_size(envs.len());
+    let envs_data_offset = args_data_offset + args_data_size;
 
-    unsafe {
-        (write as *mut usize).write_volatile(args.len());
-    }
+    // Header
+    writer.write_usize(virt + args_array_offset);
+    writer.write_usize(virt + envs_array_offset);
 
-    for (i, arg) in args.iter().enumerate() {
-        // Place the argument pointer
-        let ptr_place = write + (i * 2 + 1) * size_of::<usize>();
-        let len_place = ptr_place + size_of::<usize>();
-        unsafe {
-            (ptr_place as *mut usize).write_volatile(virt + offset);
-            (len_place as *mut usize).write_volatile(arg.len());
-        }
+    // Args array
+    writer.write_usize(args.len());
+
+    let mut offset = args_data_offset;
+    for arg in args.iter() {
+        writer.write_usize(arg.len());
+        writer.write_usize(virt + offset);
         offset += arg.len();
     }
 
-    // Place the argument data
-    // TODO rewrite using write_foreign
-    unsafe {
-        let arg_data_slice =
-            core::slice::from_raw_parts_mut((write + args_ptr_size) as *mut u8, args_size);
-        let mut offset = 0;
-        for &s in args {
-            arg_data_slice[offset..offset + s.len()].copy_from_slice(s.as_bytes());
-            offset += s.len();
-        }
+    // Envs array
+    writer.write_usize(envs.len());
+
+    let mut offset = envs_data_offset;
+    for env in envs.iter() {
+        writer.write_usize(env.len());
+        writer.write_usize(virt + offset);
+        offset += env.len();
+    }
+
+    // String data
+    for arg in args.iter() {
+        writer.write_bytes(arg.as_bytes());
+    }
+    for env in envs.iter() {
+        writer.write_bytes(env.as_bytes());
     }
 
     Ok(())
@@ -73,6 +134,7 @@ fn setup_binary<S: Into<String>>(
     space: ProcessAddressSpace,
     entry: usize,
     args: &[&str],
+    envs: &[&str],
 ) -> Result<Arc<Process>, Error> {
     const USER_STACK_PAGES: usize = 16;
 
@@ -87,7 +149,7 @@ fn setup_binary<S: Into<String>>(
         MapAttributes::USER_WRITE | MapAttributes::USER_READ | MapAttributes::NON_GLOBAL,
     )?;
 
-    setup_args(&space, virt_args_base, args)?;
+    setup_program_env(&space, virt_args_base, args, envs)?;
 
     debugln!(
         "Entry: {:#x}, Stack: {:#x}..{:#x}, Args: {:#x}",
@@ -124,9 +186,10 @@ pub fn load_elf<S: Into<String>>(
     name: S,
     file: FileRef,
     args: &[&str],
+    envs: &[&str],
 ) -> Result<Arc<Process>, Error> {
     let space = ProcessAddressSpace::new()?;
     let elf_entry = proc::elf::load_elf_from_file(&space, file)?;
 
-    setup_binary(name, space, elf_entry, args)
+    setup_binary(name, space, elf_entry, args, envs)
 }

src/syscall/mod.rs

@@ -287,7 +287,12 @@ fn syscall_handler(func: SyscallFunction, args: &[u64]) -> Result<usize, Error>
 
                 // Setup a new process from the file
                 let file = node.open(OpenOptions::READ, FileMode::empty())?;
-                let child = proc::exec::load_elf(options.program, file, options.arguments)?;
+                let child = proc::exec::load_elf(
+                    options.program,
+                    file,
+                    options.arguments,
+                    options.environment,
+                )?;
                 let pid = child.id() as u32;
 
                 // Inherit group and session from the creator