weenix

1 files changed, 161 insertions, 4 deletions

diff --git a/kernel/vm/mmap.c b/kernel/vm/mmap.c
index 082149b..78aa3b5 100644
--- a/kernel/vm/mmap.c
+++ b/kernel/vm/mmap.c
@@ -55,8 +55,134 @@
 long do_mmap(void *addr, size_t len, int prot, int flags, int fd, off_t off,
              void **ret)
 {
-    NOT_YET_IMPLEMENTED("VM: do_mmap");
-    return -1;
+    // NOT_YET_IMPLEMENTED("VM: do_mmap");
+
+    // check if addr is page aligned when MAP_FIXED is specified
+    if (PAGE_ALIGNED(addr) == 0 && (flags & MAP_FIXED))
+    {
+        return -EINVAL;
+    }
+
+    // check if MAP_FIXED is specified and addr is out of range of the user address space
+    if ((flags & MAP_FIXED) && ((uintptr_t)addr < USER_MEM_LOW || (uintptr_t)addr + len > USER_MEM_HIGH))
+    {
+        return -EINVAL;
+    }
+
+    // check if len is not zero (len is an unsigned value, so it is always positive)
+    if (len == 0)
+    {
+        return -EINVAL;
+    }
+
+    // check if offset is positive and aligned
+    if (off < 0 || PAGE_ALIGNED(off) == 0)
+    {
+        return -EINVAL;
+    }
+
+    // check if flags do not contain MAP_PRIVATE or MAP_SHARED
+    if ((flags & MAP_PRIVATE) == 0 && (flags & MAP_SHARED) == 0)
+    {
+        return -EINVAL;
+    }
+
+    // check if fd is not a valid file descriptor and MAP_ANON was not set
+    if (fd < 0 && (flags & MAP_ANON) == 0)
+    {
+        return -EBADF;
+    }
+
+    // check if a file mapping was requested, but fd is not open for reading
+    // file error checking is done in if statement below
+    file_t *file = NULL;
+    if (fd >= 0 && (flags & MAP_ANON) == 0)
+    {
+        // get the file and check if it is valid
+        file = fget(fd);
+        if (file == NULL)
+        {
+            return -EBADF;
+        }
+
+        // ENODEV CHECKS
+
+        // check if the file's vnode's mmap operation doesn't exist
+        if (file->f_vnode->vn_ops == NULL || file->f_vnode->vn_ops->mmap == NULL)
+        {
+            fput(&file);
+            return -ENODEV;
+        }
+
+        // ACCESS CHECKS
+
+        // check if thef FMODE_READ flag is not set
+        if ((file->f_mode & FMODE_READ) == 0)
+        {
+            fput(&file);
+            return -EACCES;
+        }
+        
+        // check if append mode is set and PROT_WRITE is set
+        if ((prot & PROT_WRITE) && (file->f_mode & FMODE_APPEND))
+        {
+            fput(&file);
+            return -EACCES;
+        }
+
+        // check if MAP_SHARED was requested and PROT_WRITE is set, but fd is not open in read/write (O_RDWR) mode
+        if ((flags & MAP_SHARED) && (prot & PROT_WRITE) && (file->f_mode & FMODE_READ) == 0)
+        {
+            fput(&file);
+            return -EACCES;
+        }
+
+        // check if PROT_WRITE is set, but the file has FMODE_APPEND specified
+        if ((prot & PROT_WRITE) && (file->f_mode & FMODE_APPEND))
+        {
+            fput(&file);
+            return -EACCES;
+        }
+
+        fput(&file);
+    }
+
+
+    // Now that error checking is done, we can proceed with the mapping
+    vmarea_t *vma = NULL;
+    long err = vmmap_map(
+        curproc->p_vmmap, 
+        file ? file->f_vnode : NULL,
+        ADDR_TO_PN(PAGE_ALIGN_DOWN(addr)),
+        ADDR_TO_PN(PAGE_ALIGN_UP((uintptr_t)addr + len)) - ADDR_TO_PN(PAGE_ALIGN_DOWN(addr)), 
+        prot, 
+        flags, 
+        off, 
+        VMMAP_DIR_HILO,
+        &vma
+    );
+
+    // check if vmmap_map() failed
+    if (err < 0)
+    {
+        return err;
+    }
+
+    // set ret if it was provided
+    void *start = PN_TO_ADDR(vma->vma_start);
+    if (ret)
+    {
+        *ret = start;
+    }
+
+    // flush the TLB
+    tlb_flush_range(
+        (uintptr_t) start,
+        PAGE_SIZE * (vma->vma_end - vma->vma_start)
+    );
+
+    // return 0 on success
+    return 0;
 }
 
 /*
@@ -78,6 +204,37 @@ long do_mmap(void *addr, size_t len, int prot, int flags, int fd, off_t off,
  */
 long do_munmap(void *addr, size_t len)
 {
-    NOT_YET_IMPLEMENTED("VM: do_munmap");
-    return -1;
+    // NOT_YET_IMPLEMENTED("VM: do_munmap");
+
+    // Check if addr is page aligned
+    if (PAGE_ALIGNED(addr) == 0)
+    {
+        return -EINVAL;
+    }
+
+    // Check if len is in bounds
+    if (len > USER_MEM_HIGH)
+    {
+        return -EINVAL;
+    }
+
+    // Check if the addr is out of range of the user address space
+    if ((uintptr_t)addr < USER_MEM_LOW || (uintptr_t)addr + len > USER_MEM_HIGH)
+    {
+        return -EINVAL;
+    }
+
+    // Check if len is 0
+    if (len == 0)
+    {
+        return -EINVAL;
+    }
+
+    // Remove the mapping
+    long ret = vmmap_remove(
+        curproc->p_vmmap, 
+        ADDR_TO_PN(addr), 
+        ADDR_TO_PN(PAGE_ALIGN_UP((uintptr_t)addr + len))
+    );
+    return ret;
 }
\ No newline at end of file