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Diffstat (limited to 'kernel/vm/mmap.c')
| -rw-r--r-- | kernel/vm/mmap.c | 83 |
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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