Fix some incorrect memory region initialization

ostd/src/arch/x86/boot/linux_boot/mod.rs

@@ -12,7 +12,10 @@ use crate::{
         memory_region::{MemoryRegion, MemoryRegionArray, MemoryRegionType},
         BootloaderAcpiArg, BootloaderFramebufferArg,
     },
-    mm::kspace::{paddr_to_vaddr, LINEAR_MAPPING_BASE_VADDR},
+    mm::{
+        kspace::{paddr_to_vaddr, LINEAR_MAPPING_BASE_VADDR},
+        Paddr,
+    },
 };
 
 fn parse_bootloader_name(boot_params: &BootParams) -> &str {
@@ -44,8 +47,9 @@ fn parse_bootloader_name(boot_params: &BootParams) -> &str {
 }
 
 fn parse_kernel_commandline(boot_params: &BootParams) -> &str {
+    let ptr = paddr_to_vaddr(boot_params.hdr.cmd_line_ptr as usize) as *const i8;
     // SAFETY: The pointer in the header points to a valid C string.
-    let cmdline_c_str: &CStr = unsafe { CStr::from_ptr(boot_params.hdr.cmd_line_ptr as *const i8) };
+    let cmdline_c_str: &CStr = unsafe { CStr::from_ptr(ptr) };
     let cmdline_str = cmdline_c_str.to_str().unwrap();
     cmdline_str
 }
@@ -140,6 +144,16 @@ fn parse_memory_regions(boot_params: &BootParams) -> MemoryRegionArray {
         ))
         .unwrap();
 
+    // Add the region of the kernel cmdline since some bootloaders do not provide it.
+    let kcmdline_str = parse_kernel_commandline(boot_params);
+    regions
+        .push(MemoryRegion::new(
+            kcmdline_str.as_ptr() as Paddr - LINEAR_MAPPING_BASE_VADDR,
+            kcmdline_str.len(),
+            MemoryRegionType::Reclaimable,
+        ))
+        .unwrap();
+
     regions.into_non_overlapping()
 }
 

ostd/src/arch/x86/boot/multiboot/mod.rs

@@ -20,16 +20,11 @@ pub(super) const MULTIBOOT_ENTRY_MAGIC: u32 = 0x2BADB002;
 fn parse_bootloader_name(mb1_info: &MultibootLegacyInfo) -> &str {
     let mut name = "Unknown Multiboot loader";
     if mb1_info.boot_loader_name != 0 {
+        let ptr = paddr_to_vaddr(mb1_info.boot_loader_name as usize) as *const i8;
         // SAFETY: the bootloader name is C-style zero-terminated string.
-        unsafe {
-            let cstr = paddr_to_vaddr(mb1_info.boot_loader_name as usize) as *const u8;
-            let mut len = 0;
-            while cstr.add(len).read() != 0 {
-                len += 1;
-            }
-
-            name = core::str::from_utf8(core::slice::from_raw_parts(cstr, len))
-                .expect("cmdline is not a utf-8 string");
+        let cstr = unsafe { core::ffi::CStr::from_ptr(ptr) };
+        if let Ok(s) = cstr.to_str() {
+            name = s;
         }
     }
     name
@@ -148,6 +143,24 @@ fn parse_memory_regions(mb1_info: &MultibootLegacyInfo) -> MemoryRegionArray {
         ))
         .unwrap();
 
+    // Add the kernel cmdline and boot loader name region since Grub does not specify it.
+    let kcmdline = parse_kernel_commandline(mb1_info);
+    regions
+        .push(MemoryRegion::new(
+            kcmdline.as_ptr() as Paddr - LINEAR_MAPPING_BASE_VADDR,
+            kcmdline.len(),
+            MemoryRegionType::Reclaimable,
+        ))
+        .unwrap();
+    let bootloader_name = parse_bootloader_name(mb1_info);
+    regions
+        .push(MemoryRegion::new(
+            bootloader_name.as_ptr() as Paddr - LINEAR_MAPPING_BASE_VADDR,
+            bootloader_name.len(),
+            MemoryRegionType::Reclaimable,
+        ))
+        .unwrap();
+
     regions.into_non_overlapping()
 }
 

ostd/src/arch/x86/boot/multiboot2/mod.rs

@@ -10,7 +10,10 @@ use crate::{
         memory_region::{MemoryRegion, MemoryRegionArray, MemoryRegionType},
         BootloaderAcpiArg, BootloaderFramebufferArg,
     },
-    mm::kspace::paddr_to_vaddr,
+    mm::{
+        kspace::{paddr_to_vaddr, LINEAR_MAPPING_BASE_VADDR},
+        Paddr,
+    },
 };
 
 global_asm!(include_str!("header.S"));
@@ -20,23 +23,41 @@ pub(super) const MULTIBOOT2_ENTRY_MAGIC: u32 = 0x36d76289;
 static MB2_INFO: Once<BootInformation> = Once::new();
 
 fn parse_bootloader_name() -> &'static str {
-    MB2_INFO
+    let s = MB2_INFO
         .get()
         .unwrap()
         .boot_loader_name_tag()
         .expect("Bootloader name not found from the Multiboot2 header!")
         .name()
-        .expect("UTF-8 error: failed to parse bootloader name!")
+        .expect("UTF-8 error: failed to parse bootloader name!");
+    let pa = s.as_ptr() as Paddr;
+    // SAFETY: We just convert this to virtual address.
+    unsafe {
+        core::str::from_utf8(core::slice::from_raw_parts(
+            paddr_to_vaddr(pa) as *const u8,
+            s.len(),
+        ))
+        .unwrap()
+    }
 }
 
 fn parse_kernel_commandline() -> &'static str {
-    MB2_INFO
+    let s = MB2_INFO
         .get()
         .unwrap()
         .command_line_tag()
         .expect("Kernel command-line not found from the Multiboot2 header!")
         .cmdline()
-        .expect("UTF-8 error: failed to parse kernel command-line!")
+        .expect("UTF-8 error: failed to parse kernel command-line!");
+    let pa = s.as_ptr() as Paddr;
+    // SAFETY: We just convert this to virtual address.
+    unsafe {
+        core::str::from_utf8(core::slice::from_raw_parts(
+            paddr_to_vaddr(pa) as *const u8,
+            s.len(),
+        ))
+        .unwrap()
+    }
 }
 
 fn parse_initramfs() -> Option<&'static [u8]> {
@@ -146,6 +167,24 @@ fn parse_memory_regions() -> MemoryRegionArray {
         ))
         .unwrap();
 
+    // Add the kernel cmdline and boot loader name region since Grub does not specify it.
+    let kcmdline = parse_kernel_commandline();
+    regions
+        .push(MemoryRegion::new(
+            kcmdline.as_ptr() as Paddr - LINEAR_MAPPING_BASE_VADDR,
+            kcmdline.len(),
+            MemoryRegionType::Reclaimable,
+        ))
+        .unwrap();
+    let bootloader_name = parse_bootloader_name();
+    regions
+        .push(MemoryRegion::new(
+            bootloader_name.as_ptr() as Paddr - LINEAR_MAPPING_BASE_VADDR,
+            bootloader_name.len(),
+            MemoryRegionType::Reclaimable,
+        ))
+        .unwrap();
+
     regions.into_non_overlapping()
 }