From dc90cb5a8d97c537ffd0df97a0845fc8bb57f354 Mon Sep 17 00:00:00 2001
From: Yuhao Zhou <miskcoo@gmail.com>
Date: Mon, 15 Apr 2019 18:09:48 +0800
Subject: [PATCH] Fix pgfault, fstat syscall convention. biscuit/ls works!

---
 kernel/src/arch/mipsel/interrupt.rs | 16 +++++++
 kernel/src/syscall/fs.rs            | 67 ++++++++++++++++++++++++++++-
 kernel/src/syscall/mem.rs           | 15 +++++++
 kernel/src/syscall/mod.rs           |  6 +++
 4 files changed, 102 insertions(+), 2 deletions(-)

diff --git a/kernel/src/arch/mipsel/interrupt.rs b/kernel/src/arch/mipsel/interrupt.rs
index 5ae84dd..1c45132 100644
--- a/kernel/src/arch/mipsel/interrupt.rs
+++ b/kernel/src/arch/mipsel/interrupt.rs
@@ -78,6 +78,9 @@ pub extern "C" fn rust_trap(tf: &mut TrapFrame) {
                 tf.epc = tf.epc + 4;
             }
         }
+        E::CoprocessorUnusable => {
+            tf.epc = tf.epc + 4;
+        }
         _ => {
             error!("Unhandled Exception @ CPU{}: {:?} ", 0, tf.cause.cause());
             crate::trap::error(tf)
@@ -244,6 +247,19 @@ fn page_fault(tf: &mut TrapFrame) {
                 tlb_entry.entry_lo0.get_pfn() << 12,
                 tlb_entry.entry_lo1.get_pfn() << 12
             );
+
+            let tlb_valid = if virt_addr.page_number() & 1 == 0 {
+                tlb_entry.entry_lo0.valid()
+            } else {
+                tlb_entry.entry_lo1.valid()
+            };
+
+            if !tlb_valid {
+                if !crate::memory::handle_page_fault(addr) {
+                    crate::trap::error(tf);
+                }
+            }
+
             tlb::write_tlb_random(tlb_entry)
         }
         Err(()) => {
diff --git a/kernel/src/syscall/fs.rs b/kernel/src/syscall/fs.rs
index d94e8b5..7035b31 100644
--- a/kernel/src/syscall/fs.rs
+++ b/kernel/src/syscall/fs.rs
@@ -913,7 +913,48 @@ pub struct Stat {
     ctime: Timespec,
 }
 
-#[cfg(not(target_arch = "x86_64"))]
+#[cfg(target_arch = "mips")]
+#[repr(C)]
+#[derive(Debug)]
+pub struct Stat {
+    /// ID of device containing file
+    dev: u64,
+    /// padding
+    __pad1: u64,
+    /// inode number
+    ino: u64,
+    /// file type and mode
+    mode: StatMode,
+    /// number of hard links
+    nlink: u32,
+
+    /// user ID of owner
+    uid: u32,
+    /// group ID of owner
+    gid: u32,
+    /// device ID (if special file)
+    rdev: u64,
+    /// padding
+    __pad2: u64,
+    /// total size, in bytes
+    size: u64,
+
+    /// last access time
+    atime: Timespec,
+    /// last modification time
+    mtime: Timespec,
+    /// last status change time
+    ctime: Timespec,
+
+    /// blocksize for filesystem I/O
+    blksize: u32,
+    /// padding
+    __pad3: u32,
+    /// number of 512B blocks allocated
+    blocks: u64,
+}
+
+#[cfg(not(any(target_arch = "x86_64", target_arch = "mips"))]
 #[repr(C)]
 #[derive(Debug)]
 pub struct Stat {
@@ -1042,7 +1083,29 @@ impl From<Metadata> for Stat {
         }
     }
 
-    #[cfg(not(target_arch = "x86_64"))]
+    #[cfg(target_arch = "mips")]
+    fn from(info: Metadata) -> Self {
+        Stat {
+            dev: info.dev as u64,
+            ino: info.inode as u64,
+            mode: StatMode::from_type_mode(info.type_, info.mode as u16),
+            nlink: info.nlinks as u32,
+            uid: info.uid as u32,
+            gid: info.gid as u32,
+            rdev: 0,
+            size: info.size as u64,
+            blksize: info.blk_size as u32,
+            blocks: info.blocks as u64,
+            atime: info.atime,
+            mtime: info.mtime,
+            ctime: info.ctime,
+            __pad1: 0,
+            __pad2: 0,
+            __pad3: 0,
+        }
+    }
+
+    #[cfg(not(any(target_arch = "x86_64", target_arch="mips")))]
     fn from(info: Metadata) -> Self {
         Stat {
             dev: info.dev as u64,
diff --git a/kernel/src/syscall/mem.rs b/kernel/src/syscall/mem.rs
index 1c5bee9..0b471c2 100644
--- a/kernel/src/syscall/mem.rs
+++ b/kernel/src/syscall/mem.rs
@@ -123,6 +123,21 @@ bitflags! {
     }
 }
 
+#[cfg(target_arch = "mips")]
+bitflags! {
+    pub struct MmapFlags: usize {
+        /// Changes are shared.
+        const SHARED = 1 << 0;
+        /// Changes are private.
+        const PRIVATE = 1 << 1;
+        /// Place the mapping at the exact address
+        const FIXED = 1 << 4;
+        /// The mapping is not backed by any file. (non-POSIX)
+        const ANONYMOUS = 0x800;
+    }
+}
+
+#[cfg(not(target_arch = "mips"))]
 bitflags! {
     pub struct MmapFlags: usize {
         /// Changes are shared.
diff --git a/kernel/src/syscall/mod.rs b/kernel/src/syscall/mod.rs
index 961f794..efc5c0f 100644
--- a/kernel/src/syscall/mod.rs
+++ b/kernel/src/syscall/mod.rs
@@ -322,6 +322,12 @@ fn mips_syscall(id: usize, args: [usize; 6], tf: &mut TrapFrame) -> Option<SysRe
         SYS_OPEN => sys_open(args[0] as *const u8, args[1], args[2]),
         SYS_DUP2 => sys_dup2(args[0], args[1]),
         SYS_MMAP2 => sys_mmap(args[0], args[1], args[2], args[3], args[4], args[5] * 4096),
+        SYS_FSTAT64 => sys_fstat(args[0], args[1] as *mut Stat),
+        SYS_STAT64 => sys_stat(args[0] as *const u8, args[1] as *mut Stat),
+        SYS_FCNTL64 => {
+            warn!("sys_fcntl64 is unimplemented");
+            Ok(0)
+        }
         SYS_SET_THREAD_AREA => {
             extern "C" {
                 fn _cur_tls();