Merge branch 'merge_bootstrap_into_initfs' into 'master'

Support embedding bootstrap blob into the initfs

See merge request redox-os/bootstrap!8

Cargo.lock

@@ -104,7 +104,7 @@ dependencies = [
 [[package]]
 name = "redox-initfs"
 version = "0.1.0"
-source = "git+https://gitlab.redox-os.org/redox-os/redox-initfs.git#89b8fb8984cf96c418880b7dcd9ce3d6afc3f71c"
+source = "git+https://gitlab.redox-os.org/redox-os/redox-initfs.git#7dd9b2e84d983a444518218f3ec74d3e9ac900b3"
 dependencies = [
  "plain",
 ]

Cargo.toml

@@ -12,7 +12,7 @@ crate-type = ["staticlib"]
 [dependencies]
 hashbrown = { version = "0.14", default-features = false, features = ["inline-more"] }
 linked_list_allocator = "0.10"
-redox-initfs = { git = "https://gitlab.redox-os.org/redox-os/redox-initfs.git", features = ["kernel"], default-features = false }
+redox-initfs = { git = "https://gitlab.redox-os.org/redox-os/redox-initfs.git", default-features = false }
 redox-exec = { git = "https://gitlab.redox-os.org/redox-os/relibc.git" }
 redox_syscall = "0.4"
 

src/aarch64.ld

@@ -2,7 +2,8 @@ ENTRY(_start)
 OUTPUT_FORMAT("elf64-littleaarch64", "elf64-littleaarch64", "elf64-littleaarch64")
 
 SECTIONS {
-  . = 0;
+  . = 4096 + 4096; /* Reserved for the null page and the initfs header prepended by redox-initfs-ar */
+  __initfs_header = . - 4096;
   . += SIZEOF_HEADERS;
   . = ALIGN(4096);
 

src/exec.rs

@@ -7,8 +7,6 @@ use syscall::flag::{O_CLOEXEC, O_RDONLY};
 use redox_exec::*;
 
 pub fn main() -> ! {
-    let (initfs_offset, initfs_length);
-
     let envs = {
         let mut env = [0_u8; 4096];
 
@@ -23,30 +21,22 @@ pub fn main() -> ! {
 
         let raw_iter = || env.split(|c| *c == b'\n').filter(|var| !var.is_empty());
 
-        let mut initfs_offset_opt = None;
-        let mut initfs_length_opt = None;
-
-        for var in raw_iter() {
-            let equal_sign = var.iter().position(|c| *c == b'=').expect("malformed environment variable");
-            let name = &var[..equal_sign];
-            let value = &var[equal_sign + 1..];
-
-            match name {
-                b"INITFS_OFFSET" => initfs_offset_opt = core::str::from_utf8(value).ok().and_then(|s| usize::from_str_radix(s, 16).ok()),
-                b"INITFS_LENGTH" => initfs_length_opt = core::str::from_utf8(value).ok().and_then(|s| usize::from_str_radix(s, 16).ok()),
-
-                _ => continue,
-            }
-        }
-        initfs_offset = initfs_offset_opt.expect("missing INITFS_OFFSET");
-        initfs_length = initfs_length_opt.expect("missing INITFS_LENGTH");
-
         let iter = || raw_iter().filter(|var| !var.starts_with(b"INITFS_"));
 
         iter().map(|var| var.to_owned()).collect::<Vec<_>>()
     };
+
+    extern {
+        // The linker script will define this as the location of the initfs header.
+        static __initfs_header: u8;
+    }
+
+    let initfs_length = unsafe { (*(core::ptr::addr_of!(__initfs_header) as *const redox_initfs::types::Header)).initfs_size };
+
     unsafe {
-        spawn_initfs(initfs_offset, initfs_length);
+        // Creating a reference to NULL is UB. Mask the UB for now using black_box.
+        // FIXME use a raw pointer and inline asm for reading instead for the initfs header.
+        spawn_initfs(core::ptr::addr_of!(__initfs_header), initfs_length.get() as usize);
     }
     const CWD: &[u8] = b"/scheme/initfs";
     let extrainfo = redox_exec::ExtraInfo {
@@ -65,7 +55,7 @@ pub fn main() -> ! {
     unreachable!()
 }
 
-unsafe fn spawn_initfs(initfs_start: usize, initfs_length: usize) {
+unsafe fn spawn_initfs(initfs_start: *const u8, initfs_length: usize) {
     let read = syscall::open("pipe:", O_CLOEXEC).expect("failed to open sync read pipe");
 
     // The write pipe will not inherit O_CLOEXEC, but is closed by the daemon later.
@@ -92,5 +82,5 @@ unsafe fn spawn_initfs(initfs_start: usize, initfs_length: usize) {
             return;
         }
     }
-    crate::initfs::run(core::slice::from_raw_parts(initfs_start as *const u8, initfs_length), write);
+    crate::initfs::run(core::slice::from_raw_parts(initfs_start, initfs_length), write);
 }

src/i686.ld

@@ -2,7 +2,8 @@ ENTRY(_start)
 OUTPUT_FORMAT(elf32-i386)
 
 SECTIONS {
-  . = 0;
+  . = 4096 + 4096; /* Reserved for the null page and the initfs header prepended by redox-initfs-ar */
+  __initfs_header = . - 4096;
   . += SIZEOF_HEADERS;
   . = ALIGN(4096);
 

src/start.rs

@@ -35,13 +35,14 @@ pub unsafe extern "C" fn start() -> ! {
     let _ = syscall::open("debug:", syscall::O_WRONLY); // stdout
     let _ = syscall::open("debug:", syscall::O_WRONLY); // stderr
 
-    // TODO: PROT_NONE
-    let _ = syscall::mprotect(0, 4096, MapFlags::PROT_READ | MapFlags::MAP_PRIVATE).expect("mprotect failed for NULL page");
+    let _ = syscall::mprotect(4096, 4096, MapFlags::PROT_READ | MapFlags::MAP_PRIVATE).expect("mprotect failed for initfs header page");
 
     let _ = syscall::mprotect(text_start, text_end - text_start, MapFlags::PROT_READ | MapFlags::PROT_EXEC | MapFlags::MAP_PRIVATE).expect("mprotect failed for .text");
     let _ = syscall::mprotect(rodata_start, rodata_end - rodata_start, MapFlags::PROT_READ | MapFlags::MAP_PRIVATE).expect("mprotect failed for .rodata");
     let _ = syscall::mprotect(data_start, data_end - data_start, MapFlags::PROT_READ | MapFlags::PROT_WRITE | MapFlags::MAP_PRIVATE).expect("mprotect failed for .data/.bss");
     let _ = syscall::mprotect(data_end, crate::arch::STACK_START - data_end, MapFlags::PROT_READ | MapFlags::MAP_PRIVATE).expect("mprotect failed for rest of memory");
 
+    // FIXME make the initfs read-only
+
     crate::exec::main();
 }

src/x86_64.ld

@@ -2,7 +2,8 @@ ENTRY(_start)
 OUTPUT_FORMAT(elf64-x86-64)
 
 SECTIONS {
-  . = 0;
+  . = 4096 + 4096; /* Reserved for the null page and the initfs header prepended by redox-initfs-ar */
+  __initfs_header = . - 4096;
   . += SIZEOF_HEADERS;
   . = ALIGN(4096);