Fix problems in lab 7 (#48)

Author: tiger2005

docs/labs/0x07/tasks.md

@@ -18,6 +18,8 @@
 
     合并后的代码并不能直接运行，你需要基于合并后的代码、按照文档进行修改补充，才能逐步实现本次实验的功能。
 
+    需要注意，本次实验对内存分配器的实现从 `pkg/lib/src/allocator.rs` 文件变为 `pkg/lib/src/allocator` 文件夹，其中包含你需要实现的部分。请在合并代码后**手动删除 `pkg/lib/src/allocator.rs` 文件**，以保证编译能够正常进行。
+
 本次实验代码量较小，给出的代码集中于 `pkg/kernel/src/proc/vm` 目录下。
 
 - `heap.rs`：添加了 `Heap` 结构体，用于管理堆内存。

src/0x01/pkg/elf/src/lib.rs

@@ -88,17 +88,15 @@ pub fn load_elf(
     page_table: &mut impl Mapper<Size4KiB>,
     frame_allocator: &mut impl FrameAllocator<Size4KiB>,
 ) -> Result<(), MapToError<Size4KiB>> {
-    let file_buf = elf.input.as_ptr();
-
-    info!("Loading ELF file... @ {:#x}", file_buf as u64);
+    trace!("Loading ELF file...{:?}", elf.input.as_ptr());
 
     for segment in elf.program_iter() {
         if segment.get_type().unwrap() != program::Type::Load {
             continue;
         }
 
         load_segment(
-            file_buf,
+            elf,
             physical_offset,
             &segment,
             page_table,
@@ -113,7 +111,7 @@ pub fn load_elf(
 ///
 /// load segment to new frame and set page table
 fn load_segment(
-    file_buf: *const u8,
+    elf: &ElfFile,
     physical_offset: u64,
     segment: &program::ProgramHeader,
     page_table: &mut impl Mapper<Size4KiB>,
@@ -137,7 +135,7 @@ fn load_segment(
     let end_page = Page::containing_address(virt_start_addr + file_size - 1u64);
     let pages = Page::range_inclusive(start_page, end_page);
 
-    let data = unsafe { file_buf.add(file_offset as usize) };
+    let data = unsafe { elf.input.as_ptr().add(file_offset as usize) };
 
     for (idx, page) in pages.enumerate() {
         let frame = frame_allocator

src/0x07/pkg/kernel/src/proc/vm/heap.rs

@@ -64,7 +64,7 @@ impl Heap {
 
         // FIXME: update the end address
 
-        Some(new_end)
+        new_end
     }
 
     pub(super) fn clean_up(

src/0x07/pkg/kernel/src/proc/vm/mod.rs

@@ -71,6 +71,12 @@ impl ProcessVm {
     //     self
     // }
 
+    pub fn init_kernel_vm(mut self) -> Self {
+        // TODO: record kernel code usage
+        self.stack = Stack::kstack();
+        self
+    }
+
     pub fn brk(&self, addr: Option<VirtAddr>) -> Option<VirtAddr> {
         self.heap.brk(
             addr,

src/0x07/pkg/lib/src/macros.rs

@@ -25,12 +25,12 @@ fn panic(info: &core::panic::PanicInfo) -> ! {
     } else {
         "Unknown location".to_string()
     };
-    let msg = if let Some(msg) = info.message() {
-        alloc::format!("{}", msg)
-    } else {
-        "No more message...".to_string()
-    };
-    errln!("\n\n\rERROR: panicked at {}\n\n\r{}", location, msg);
+
+    errln!(
+        "\n\n\rERROR: panicked at {}\n\n\r{}",
+        location,
+        info.message()
+    );
 
     crate::sys_exit(1);
 }