Created student weenix repository

1 files changed, 83 insertions, 0 deletions

diff --git a/kernel/vm/mmap.c b/kernel/vm/mmap.c
new file mode 100644
index 0000000..7eb2d89
--- /dev/null
+++ b/kernel/vm/mmap.c
@@ -0,0 +1,83 @@
+#include "vm/mmap.h"
+#include "errno.h"
+#include "fs/file.h"
+#include "fs/vfs.h"
+#include "fs/vnode.h"
+#include "globals.h"
+#include "mm/mm.h"
+#include "mm/mman.h"
+#include "mm/tlb.h"
+#include "util/debug.h"
+
+/*
+ * This function implements the mmap(2) syscall: Add a mapping to the current
+ * process's address space. Supports the following flags: MAP_SHARED,
+ * MAP_PRIVATE, MAP_FIXED, and MAP_ANON.
+ *
+ *  ret - If provided, on success, *ret must point to the start of the mapped area
+ *
+ * Return 0 on success, or:
+ *  - EACCES: 
+ *     - a file mapping was requested, but fd is not open for reading. 
+ *     - MAP_SHARED was requested and PROT_WRITE is set, but fd is
+ *       not open in read/write (O_RDWR) mode.
+ *     - PROT_WRITE is set, but the file has FMODE_APPEND specified.
+ *  - EBADF:
+ *     - fd is not a valid file descriptor and MAP_ANON was
+ *       not set
+ *  - EINVAL:
+ *     - addr is not page aligned and MAP_FIXED is specified 
+ *     - addr is out of range of the user address space and MAP_FIXED is specified
+ *     - off is not page aligned
+ *     - len is <= 0 or off < 0
+ *     - flags do not contain MAP_PRIVATE or MAP_SHARED
+ *  - ENODEV:
+ *     - The underlying filesystem of the specified file does not
+ *       support memory mapping or in other words, the file's vnode's mmap
+ *       operation doesn't exist
+ *  - Propagate errors from vmmap_map()
+ * 
+ *  See the errors section of the mmap(2) man page for more details
+ * 
+ * Hints:
+ *  1) A lot of error checking.
+ *  2) Call vmmap_map() to create the mapping.
+ *     a) Use VMMAP_DIR_HILO as default, which will make other stencil code in
+ *        Weenix happy.
+ *  3) Call tlb_flush_range() on the newly-mapped region. This is because the
+ *     newly-mapped region could have been used by someone else, and you don't
+ *     want to get stale mappings.
+ *  4) Don't forget to set ret if it was provided.
+ * 
+ *  If you are mapping less than a page, make sure that you are still allocating 
+ *  a full page.
+ */
+long do_mmap(void *addr, size_t len, int prot, int flags, int fd, off_t off,
+             void **ret)
+{
+    NOT_YET_IMPLEMENTED("VM: ***none***");
+    return -1;
+}
+
+/*
+ * This function implements the munmap(2) syscall.
+ *
+ * Return 0 on success, or:
+ *  - EINVAL:
+ *     - addr is not aligned on a page boundary
+ *     - the region to unmap is out of range of the user address space
+ *     - len is 0
+ *  - Propagate errors from vmmap_remove()
+ * 
+ *  See the errors section of the munmap(2) man page for more details
+ *
+ * Hints:
+ *  - Similar to do_mmap():
+ *  1) Perform error checking.
+ *  2) Call vmmap_remove().
+ */
+long do_munmap(void *addr, size_t len)
+{
+    NOT_YET_IMPLEMENTED("VM: ***none***");
+    return -1;
+}
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