| /* |
| * linux/fs/read_write.c |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| */ |
| |
| #include <linux/slab.h> |
| #include <linux/stat.h> |
| #include <linux/fcntl.h> |
| #include <linux/file.h> |
| #include <linux/uio.h> |
| #include <linux/fsnotify.h> |
| #include <linux/security.h> |
| #include <linux/export.h> |
| #include <linux/syscalls.h> |
| #include <linux/pagemap.h> |
| #include <linux/splice.h> |
| #include <linux/compat.h> |
| #include "internal.h" |
| |
| #include <asm/uaccess.h> |
| #include <asm/unistd.h> |
| |
| typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *); |
| typedef ssize_t (*iter_fn_t)(struct kiocb *, struct iov_iter *); |
| |
| const struct file_operations generic_ro_fops = { |
| .llseek = generic_file_llseek, |
| .read_iter = generic_file_read_iter, |
| .mmap = generic_file_readonly_mmap, |
| .splice_read = generic_file_splice_read, |
| }; |
| |
| EXPORT_SYMBOL(generic_ro_fops); |
| |
| static inline int unsigned_offsets(struct file *file) |
| { |
| return file->f_mode & FMODE_UNSIGNED_OFFSET; |
| } |
| |
| /** |
| * vfs_setpos - update the file offset for lseek |
| * @file: file structure in question |
| * @offset: file offset to seek to |
| * @maxsize: maximum file size |
| * |
| * This is a low-level filesystem helper for updating the file offset to |
| * the value specified by @offset if the given offset is valid and it is |
| * not equal to the current file offset. |
| * |
| * Return the specified offset on success and -EINVAL on invalid offset. |
| */ |
| loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) |
| { |
| if (offset < 0 && !unsigned_offsets(file)) |
| return -EINVAL; |
| if (offset > maxsize) |
| return -EINVAL; |
| |
| if (offset != file->f_pos) { |
| file->f_pos = offset; |
| file->f_version = 0; |
| } |
| return offset; |
| } |
| EXPORT_SYMBOL(vfs_setpos); |
| |
| /** |
| * generic_file_llseek_size - generic llseek implementation for regular files |
| * @file: file structure to seek on |
| * @offset: file offset to seek to |
| * @whence: type of seek |
| * @size: max size of this file in file system |
| * @eof: offset used for SEEK_END position |
| * |
| * This is a variant of generic_file_llseek that allows passing in a custom |
| * maximum file size and a custom EOF position, for e.g. hashed directories |
| * |
| * Synchronization: |
| * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) |
| * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. |
| * read/writes behave like SEEK_SET against seeks. |
| */ |
| loff_t |
| generic_file_llseek_size(struct file *file, loff_t offset, int whence, |
| loff_t maxsize, loff_t eof) |
| { |
| switch (whence) { |
| case SEEK_END: |
| offset += eof; |
| break; |
| case SEEK_CUR: |
| /* |
| * Here we special-case the lseek(fd, 0, SEEK_CUR) |
| * position-querying operation. Avoid rewriting the "same" |
| * f_pos value back to the file because a concurrent read(), |
| * write() or lseek() might have altered it |
| */ |
| if (offset == 0) |
| return file->f_pos; |
| /* |
| * f_lock protects against read/modify/write race with other |
| * SEEK_CURs. Note that parallel writes and reads behave |
| * like SEEK_SET. |
| */ |
| spin_lock(&file->f_lock); |
| offset = vfs_setpos(file, file->f_pos + offset, maxsize); |
| spin_unlock(&file->f_lock); |
| return offset; |
| case SEEK_DATA: |
| /* |
| * In the generic case the entire file is data, so as long as |
| * offset isn't at the end of the file then the offset is data. |
| */ |
| if ((unsigned long long)offset >= eof) |
| return -ENXIO; |
| break; |
| case SEEK_HOLE: |
| /* |
| * There is a virtual hole at the end of the file, so as long as |
| * offset isn't i_size or larger, return i_size. |
| */ |
| if ((unsigned long long)offset >= eof) |
| return -ENXIO; |
| offset = eof; |
| break; |
| } |
| |
| return vfs_setpos(file, offset, maxsize); |
| } |
| EXPORT_SYMBOL(generic_file_llseek_size); |
| |
| /** |
| * generic_file_llseek - generic llseek implementation for regular files |
| * @file: file structure to seek on |
| * @offset: file offset to seek to |
| * @whence: type of seek |
| * |
| * This is a generic implemenation of ->llseek useable for all normal local |
| * filesystems. It just updates the file offset to the value specified by |
| * @offset and @whence. |
| */ |
| loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) |
| { |
| struct inode *inode = file->f_mapping->host; |
| |
| return generic_file_llseek_size(file, offset, whence, |
| inode->i_sb->s_maxbytes, |
| i_size_read(inode)); |
| } |
| EXPORT_SYMBOL(generic_file_llseek); |
| |
| /** |
| * fixed_size_llseek - llseek implementation for fixed-sized devices |
| * @file: file structure to seek on |
| * @offset: file offset to seek to |
| * @whence: type of seek |
| * @size: size of the file |
| * |
| */ |
| loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) |
| { |
| switch (whence) { |
| case SEEK_SET: case SEEK_CUR: case SEEK_END: |
| return generic_file_llseek_size(file, offset, whence, |
| size, size); |
| default: |
| return -EINVAL; |
| } |
| } |
| EXPORT_SYMBOL(fixed_size_llseek); |
| |
| /** |
| * noop_llseek - No Operation Performed llseek implementation |
| * @file: file structure to seek on |
| * @offset: file offset to seek to |
| * @whence: type of seek |
| * |
| * This is an implementation of ->llseek useable for the rare special case when |
| * userspace expects the seek to succeed but the (device) file is actually not |
| * able to perform the seek. In this case you use noop_llseek() instead of |
| * falling back to the default implementation of ->llseek. |
| */ |
| loff_t noop_llseek(struct file *file, loff_t offset, int whence) |
| { |
| return file->f_pos; |
| } |
| EXPORT_SYMBOL(noop_llseek); |
| |
| loff_t no_llseek(struct file *file, loff_t offset, int whence) |
| { |
| return -ESPIPE; |
| } |
| EXPORT_SYMBOL(no_llseek); |
| |
| loff_t default_llseek(struct file *file, loff_t offset, int whence) |
| { |
| struct inode *inode = file_inode(file); |
| loff_t retval; |
| |
| mutex_lock(&inode->i_mutex); |
| switch (whence) { |
| case SEEK_END: |
| offset += i_size_read(inode); |
| break; |
| case SEEK_CUR: |
| if (offset == 0) { |
| retval = file->f_pos; |
| goto out; |
| } |
| offset += file->f_pos; |
| break; |
| case SEEK_DATA: |
| /* |
| * In the generic case the entire file is data, so as |
| * long as offset isn't at the end of the file then the |
| * offset is data. |
| */ |
| if (offset >= inode->i_size) { |
| retval = -ENXIO; |
| goto out; |
| } |
| break; |
| case SEEK_HOLE: |
| /* |
| * There is a virtual hole at the end of the file, so |
| * as long as offset isn't i_size or larger, return |
| * i_size. |
| */ |
| if (offset >= inode->i_size) { |
| retval = -ENXIO; |
| goto out; |
| } |
| offset = inode->i_size; |
| break; |
| } |
| retval = -EINVAL; |
| if (offset >= 0 || unsigned_offsets(file)) { |
| if (offset != file->f_pos) { |
| file->f_pos = offset; |
| file->f_version = 0; |
| } |
| retval = offset; |
| } |
| out: |
| mutex_unlock(&inode->i_mutex); |
| return retval; |
| } |
| EXPORT_SYMBOL(default_llseek); |
| |
| loff_t vfs_llseek(struct file *file, loff_t offset, int whence) |
| { |
| loff_t (*fn)(struct file *, loff_t, int); |
| |
| fn = no_llseek; |
| if (file->f_mode & FMODE_LSEEK) { |
| if (file->f_op->llseek) |
| fn = file->f_op->llseek; |
| } |
| return fn(file, offset, whence); |
| } |
| EXPORT_SYMBOL(vfs_llseek); |
| |
| static inline struct fd fdget_pos(int fd) |
| { |
| return __to_fd(__fdget_pos(fd)); |
| } |
| |
| static inline void fdput_pos(struct fd f) |
| { |
| if (f.flags & FDPUT_POS_UNLOCK) |
| mutex_unlock(&f.file->f_pos_lock); |
| fdput(f); |
| } |
| |
| SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) |
| { |
| off_t retval; |
| struct fd f = fdget_pos(fd); |
| if (!f.file) |
| return -EBADF; |
| |
| retval = -EINVAL; |
| if (whence <= SEEK_MAX) { |
| loff_t res = vfs_llseek(f.file, offset, whence); |
| retval = res; |
| if (res != (loff_t)retval) |
| retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ |
| } |
| fdput_pos(f); |
| return retval; |
| } |
| |
| #ifdef CONFIG_COMPAT |
| COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) |
| { |
| return sys_lseek(fd, offset, whence); |
| } |
| #endif |
| |
| #ifdef __ARCH_WANT_SYS_LLSEEK |
| SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
| unsigned long, offset_low, loff_t __user *, result, |
| unsigned int, whence) |
| { |
| int retval; |
| struct fd f = fdget_pos(fd); |
| loff_t offset; |
| |
| if (!f.file) |
| return -EBADF; |
| |
| retval = -EINVAL; |
| if (whence > SEEK_MAX) |
| goto out_putf; |
| |
| offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, |
| whence); |
| |
| retval = (int)offset; |
| if (offset >= 0) { |
| retval = -EFAULT; |
| if (!copy_to_user(result, &offset, sizeof(offset))) |
| retval = 0; |
| } |
| out_putf: |
| fdput_pos(f); |
| return retval; |
| } |
| #endif |
| |
| ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos) |
| { |
| struct kiocb kiocb; |
| ssize_t ret; |
| |
| if (!file->f_op->read_iter) |
| return -EINVAL; |
| |
| init_sync_kiocb(&kiocb, file); |
| kiocb.ki_pos = *ppos; |
| |
| iter->type |= READ; |
| ret = file->f_op->read_iter(&kiocb, iter); |
| BUG_ON(ret == -EIOCBQUEUED); |
| if (ret > 0) |
| *ppos = kiocb.ki_pos; |
| return ret; |
| } |
| EXPORT_SYMBOL(vfs_iter_read); |
| |
| ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos) |
| { |
| struct kiocb kiocb; |
| ssize_t ret; |
| |
| if (!file->f_op->write_iter) |
| return -EINVAL; |
| |
| init_sync_kiocb(&kiocb, file); |
| kiocb.ki_pos = *ppos; |
| |
| iter->type |= WRITE; |
| ret = file->f_op->write_iter(&kiocb, iter); |
| BUG_ON(ret == -EIOCBQUEUED); |
| if (ret > 0) { |
| *ppos = kiocb.ki_pos; |
| fsnotify_modify(file); |
| } |
| return ret; |
| } |
| EXPORT_SYMBOL(vfs_iter_write); |
| |
| /* |
| * rw_verify_area doesn't like huge counts. We limit |
| * them to something that fits in "int" so that others |
| * won't have to do range checks all the time. |
| */ |
| int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) |
| { |
| struct inode *inode; |
| loff_t pos; |
| int retval = -EINVAL; |
| |
| inode = file_inode(file); |
| if (unlikely((ssize_t) count < 0)) |
| return retval; |
| pos = *ppos; |
| if (unlikely(pos < 0)) { |
| if (!unsigned_offsets(file)) |
| return retval; |
| if (count >= -pos) /* both values are in 0..LLONG_MAX */ |
| return -EOVERFLOW; |
| } else if (unlikely((loff_t) (pos + count) < 0)) { |
| if (!unsigned_offsets(file)) |
| return retval; |
| } |
| |
| if (unlikely(inode->i_flctx && mandatory_lock(inode))) { |
| retval = locks_mandatory_area( |
| read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, |
| inode, file, pos, count); |
| if (retval < 0) |
| return retval; |
| } |
| retval = security_file_permission(file, |
| read_write == READ ? MAY_READ : MAY_WRITE); |
| if (retval) |
| return retval; |
| return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
| } |
| |
| static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
| { |
| struct iovec iov = { .iov_base = buf, .iov_len = len }; |
| struct kiocb kiocb; |
| struct iov_iter iter; |
| ssize_t ret; |
| |
| init_sync_kiocb(&kiocb, filp); |
| kiocb.ki_pos = *ppos; |
| iov_iter_init(&iter, READ, &iov, 1, len); |
| |
| ret = filp->f_op->read_iter(&kiocb, &iter); |
| BUG_ON(ret == -EIOCBQUEUED); |
| *ppos = kiocb.ki_pos; |
| return ret; |
| } |
| |
| ssize_t __vfs_read(struct file *file, char __user *buf, size_t count, |
| loff_t *pos) |
| { |
| if (file->f_op->read) |
| return file->f_op->read(file, buf, count, pos); |
| else if (file->f_op->read_iter) |
| return new_sync_read(file, buf, count, pos); |
| else |
| return -EINVAL; |
| } |
| EXPORT_SYMBOL(__vfs_read); |
| |
| ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) |
| { |
| ssize_t ret; |
| |
| if (!(file->f_mode & FMODE_READ)) |
| return -EBADF; |
| if (!(file->f_mode & FMODE_CAN_READ)) |
| return -EINVAL; |
| if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) |
| return -EFAULT; |
| |
| ret = rw_verify_area(READ, file, pos, count); |
| if (ret >= 0) { |
| count = ret; |
| ret = __vfs_read(file, buf, count, pos); |
| if (ret > 0) { |
| fsnotify_access(file); |
| add_rchar(current, ret); |
| } |
| inc_syscr(current); |
| } |
| |
| return ret; |
| } |
| |
| EXPORT_SYMBOL(vfs_read); |
| |
| static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) |
| { |
| struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
| struct kiocb kiocb; |
| struct iov_iter iter; |
| ssize_t ret; |
| |
| init_sync_kiocb(&kiocb, filp); |
| kiocb.ki_pos = *ppos; |
| iov_iter_init(&iter, WRITE, &iov, 1, len); |
| |
| ret = filp->f_op->write_iter(&kiocb, &iter); |
| BUG_ON(ret == -EIOCBQUEUED); |
| if (ret > 0) |
| *ppos = kiocb.ki_pos; |
| return ret; |
| } |
| |
| ssize_t __vfs_write(struct file *file, const char __user *p, size_t count, |
| loff_t *pos) |
| { |
| if (file->f_op->write) |
| return file->f_op->write(file, p, count, pos); |
| else if (file->f_op->write_iter) |
| return new_sync_write(file, p, count, pos); |
| else |
| return -EINVAL; |
| } |
| EXPORT_SYMBOL(__vfs_write); |
| |
| ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos) |
| { |
| mm_segment_t old_fs; |
| const char __user *p; |
| ssize_t ret; |
| |
| if (!(file->f_mode & FMODE_CAN_WRITE)) |
| return -EINVAL; |
| |
| old_fs = get_fs(); |
| set_fs(get_ds()); |
| p = (__force const char __user *)buf; |
| if (count > MAX_RW_COUNT) |
| count = MAX_RW_COUNT; |
| ret = __vfs_write(file, p, count, pos); |
| set_fs(old_fs); |
| if (ret > 0) { |
| fsnotify_modify(file); |
| add_wchar(current, ret); |
| } |
| inc_syscw(current); |
| return ret; |
| } |
| |
| EXPORT_SYMBOL(__kernel_write); |
| |
| ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
| { |
| ssize_t ret; |
| |
| if (!(file->f_mode & FMODE_WRITE)) |
| return -EBADF; |
| if (!(file->f_mode & FMODE_CAN_WRITE)) |
| return -EINVAL; |
| if (unlikely(!access_ok(VERIFY_READ, buf, count))) |
| return -EFAULT; |
| |
| ret = rw_verify_area(WRITE, file, pos, count); |
| if (ret >= 0) { |
| count = ret; |
| file_start_write(file); |
| ret = __vfs_write(file, buf, count, pos); |
| if (ret > 0) { |
| fsnotify_modify(file); |
| add_wchar(current, ret); |
| } |
| inc_syscw(current); |
| file_end_write(file); |
| } |
| |
| return ret; |
| } |
| |
| EXPORT_SYMBOL(vfs_write); |
| |
| static inline loff_t file_pos_read(struct file *file) |
| { |
| return file->f_pos; |
| } |
| |
| static inline void file_pos_write(struct file *file, loff_t pos) |
| { |
| file->f_pos = pos; |
| } |
| |
| SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
| { |
| struct fd f = fdget_pos(fd); |
| ssize_t ret = -EBADF; |
| |
| if (f.file) { |
| loff_t pos = file_pos_read(f.file); |
| ret = vfs_read(f.file, buf, count, &pos); |
| if (ret >= 0) |
| file_pos_write(f.file, pos); |
| fdput_pos(f); |
| } |
| return ret; |
| } |
| |
| SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
| size_t, count) |
| { |
| struct fd f = fdget_pos(fd); |
| ssize_t ret = -EBADF; |
| |
| if (f.file) { |
| loff_t pos = file_pos_read(f.file); |
| ret = vfs_write(f.file, buf, count, &pos); |
| if (ret >= 0) |
| file_pos_write(f.file, pos); |
| fdput_pos(f); |
| } |
| |
| return ret; |
| } |
| |
| SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
| size_t, count, loff_t, pos) |
| { |
| struct fd f; |
| ssize_t ret = -EBADF; |
| |
| if (pos < 0) |
| return -EINVAL; |
| |
| f = fdget(fd); |
| if (f.file) { |
| ret = -ESPIPE; |
| if (f.file->f_mode & FMODE_PREAD) |
| ret = vfs_read(f.file, buf, count, &pos); |
| fdput(f); |
| } |
| |
| return ret; |
| } |
| |
| SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
| size_t, count, loff_t, pos) |
| { |
| struct fd f; |
| ssize_t ret = -EBADF; |
| |
| if (pos < 0) |
| return -EINVAL; |
| |
| f = fdget(fd); |
| if (f.file) { |
| ret = -ESPIPE; |
| if (f.file->f_mode & FMODE_PWRITE) |
| ret = vfs_write(f.file, buf, count, &pos); |
| fdput(f); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Reduce an iovec's length in-place. Return the resulting number of segments |
| */ |
| unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) |
| { |
| unsigned long seg = 0; |
| size_t len = 0; |
| |
| while (seg < nr_segs) { |
| seg++; |
| if (len + iov->iov_len >= to) { |
| iov->iov_len = to - len; |
| break; |
| } |
| len += iov->iov_len; |
| iov++; |
| } |
| return seg; |
| } |
| EXPORT_SYMBOL(iov_shorten); |
| |
| static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, |
| loff_t *ppos, iter_fn_t fn) |
| { |
| struct kiocb kiocb; |
| ssize_t ret; |
| |
| init_sync_kiocb(&kiocb, filp); |
| kiocb.ki_pos = *ppos; |
| |
| ret = fn(&kiocb, iter); |
| BUG_ON(ret == -EIOCBQUEUED); |
| *ppos = kiocb.ki_pos; |
| return ret; |
| } |
| |
| /* Do it by hand, with file-ops */ |
| static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, |
| loff_t *ppos, io_fn_t fn) |
| { |
| ssize_t ret = 0; |
| |
| while (iov_iter_count(iter)) { |
| struct iovec iovec = iov_iter_iovec(iter); |
| ssize_t nr; |
| |
| nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos); |
| |
| if (nr < 0) { |
| if (!ret) |
| ret = nr; |
| break; |
| } |
| ret += nr; |
| if (nr != iovec.iov_len) |
| break; |
| iov_iter_advance(iter, nr); |
| } |
| |
| return ret; |
| } |
| |
| /* A write operation does a read from user space and vice versa */ |
| #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) |
| |
| ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
| unsigned long nr_segs, unsigned long fast_segs, |
| struct iovec *fast_pointer, |
| struct iovec **ret_pointer) |
| { |
| unsigned long seg; |
| ssize_t ret; |
| struct iovec *iov = fast_pointer; |
| |
| /* |
| * SuS says "The readv() function *may* fail if the iovcnt argument |
| * was less than or equal to 0, or greater than {IOV_MAX}. Linux has |
| * traditionally returned zero for zero segments, so... |
| */ |
| if (nr_segs == 0) { |
| ret = 0; |
| goto out; |
| } |
| |
| /* |
| * First get the "struct iovec" from user memory and |
| * verify all the pointers |
| */ |
| if (nr_segs > UIO_MAXIOV) { |
| ret = -EINVAL; |
| goto out; |
| } |
| if (nr_segs > fast_segs) { |
| iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
| if (iov == NULL) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| } |
| if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { |
| ret = -EFAULT; |
| goto out; |
| } |
| |
| /* |
| * According to the Single Unix Specification we should return EINVAL |
| * if an element length is < 0 when cast to ssize_t or if the |
| * total length would overflow the ssize_t return value of the |
| * system call. |
| * |
| * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the |
| * overflow case. |
| */ |
| ret = 0; |
| for (seg = 0; seg < nr_segs; seg++) { |
| void __user *buf = iov[seg].iov_base; |
| ssize_t len = (ssize_t)iov[seg].iov_len; |
| |
| /* see if we we're about to use an invalid len or if |
| * it's about to overflow ssize_t */ |
| if (len < 0) { |
| ret = -EINVAL; |
| goto out; |
| } |
| if (type >= 0 |
| && unlikely(!access_ok(vrfy_dir(type), buf, len))) { |
| ret = -EFAULT; |
| goto out; |
| } |
| if (len > MAX_RW_COUNT - ret) { |
| len = MAX_RW_COUNT - ret; |
| iov[seg].iov_len = len; |
| } |
| ret += len; |
| } |
| out: |
| *ret_pointer = iov; |
| return ret; |
| } |
| |
| static ssize_t do_readv_writev(int type, struct file *file, |
| const struct iovec __user * uvector, |
| unsigned long nr_segs, loff_t *pos) |
| { |
| size_t tot_len; |
| struct iovec iovstack[UIO_FASTIOV]; |
| struct iovec *iov = iovstack; |
| struct iov_iter iter; |
| ssize_t ret; |
| io_fn_t fn; |
| iter_fn_t iter_fn; |
| |
| ret = import_iovec(type, uvector, nr_segs, |
| ARRAY_SIZE(iovstack), &iov, &iter); |
| if (ret < 0) |
| return ret; |
| |
| tot_len = iov_iter_count(&iter); |
| if (!tot_len) |
| goto out; |
| ret = rw_verify_area(type, file, pos, tot_len); |
| if (ret < 0) |
| goto out; |
| |
| if (type == READ) { |
| fn = file->f_op->read; |
| iter_fn = file->f_op->read_iter; |
| } else { |
| fn = (io_fn_t)file->f_op->write; |
| iter_fn = file->f_op->write_iter; |
| file_start_write(file); |
| } |
| |
| if (iter_fn) |
| ret = do_iter_readv_writev(file, &iter, pos, iter_fn); |
| else |
| ret = do_loop_readv_writev(file, &iter, pos, fn); |
| |
| if (type != READ) |
| file_end_write(file); |
| |
| out: |
| kfree(iov); |
| if ((ret + (type == READ)) > 0) { |
| if (type == READ) |
| fsnotify_access(file); |
| else |
| fsnotify_modify(file); |
| } |
| return ret; |
| } |
| |
| ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, |
| unsigned long vlen, loff_t *pos) |
| { |
| if (!(file->f_mode & FMODE_READ)) |
| return -EBADF; |
| if (!(file->f_mode & FMODE_CAN_READ)) |
| return -EINVAL; |
| |
| return do_readv_writev(READ, file, vec, vlen, pos); |
| } |
| |
| EXPORT_SYMBOL(vfs_readv); |
| |
| ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, |
| unsigned long vlen, loff_t *pos) |
| { |
| if (!(file->f_mode & FMODE_WRITE)) |
| return -EBADF; |
| if (!(file->f_mode & FMODE_CAN_WRITE)) |
| return -EINVAL; |
| |
| return do_readv_writev(WRITE, file, vec, vlen, pos); |
| } |
| |
| EXPORT_SYMBOL(vfs_writev); |
| |
| SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
| unsigned long, vlen) |
| { |
| struct fd f = fdget_pos(fd); |
| ssize_t ret = -EBADF; |
| |
| if (f.file) { |
| loff_t pos = file_pos_read(f.file); |
| ret = vfs_readv(f.file, vec, vlen, &pos); |
| if (ret >= 0) |
| file_pos_write(f.file, pos); |
| fdput_pos(f); |
| } |
| |
| if (ret > 0) |
| add_rchar(current, ret); |
| inc_syscr(current); |
| return ret; |
| } |
| |
| SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, |
| unsigned long, vlen) |
| { |
| struct fd f = fdget_pos(fd); |
| ssize_t ret = -EBADF; |
| |
| if (f.file) { |
| loff_t pos = file_pos_read(f.file); |
| ret = vfs_writev(f.file, vec, vlen, &pos); |
| if (ret >= 0) |
| file_pos_write(f.file, pos); |
| fdput_pos(f); |
| } |
| |
| if (ret > 0) |
| add_wchar(current, ret); |
| inc_syscw(current); |
| return ret; |
| } |
| |
| static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
| { |
| #define HALF_LONG_BITS (BITS_PER_LONG / 2) |
| return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; |
| } |
| |
| SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
| unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
| { |
| loff_t pos = pos_from_hilo(pos_h, pos_l); |
| struct fd f; |
| ssize_t ret = -EBADF; |
| |
| if (pos < 0) |
| return -EINVAL; |
| |
| f = fdget(fd); |
| if (f.file) { |
| ret = -ESPIPE; |
| if (f.file->f_mode & FMODE_PREAD) |
| ret = vfs_readv(f.file, vec, vlen, &pos); |
| fdput(f); |
| } |
| |
| if (ret > 0) |
| add_rchar(current, ret); |
| inc_syscr(current); |
| return ret; |
| } |
| |
| SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, |
| unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
| { |
| loff_t pos = pos_from_hilo(pos_h, pos_l); |
| struct fd f; |
| ssize_t ret = -EBADF; |
| |
| if (pos < 0) |
| return -EINVAL; |
| |
| f = fdget(fd); |
| if (f.file) { |
| ret = -ESPIPE; |
| if (f.file->f_mode & FMODE_PWRITE) |
| ret = vfs_writev(f.file, vec, vlen, &pos); |
| fdput(f); |
| } |
| |
| if (ret > 0) |
| add_wchar(current, ret); |
| inc_syscw(current); |
| return ret; |
| } |
| |
| #ifdef CONFIG_COMPAT |
| |
| static ssize_t compat_do_readv_writev(int type, struct file *file, |
| const struct compat_iovec __user *uvector, |
| unsigned long nr_segs, loff_t *pos) |
| { |
| compat_ssize_t tot_len; |
| struct iovec iovstack[UIO_FASTIOV]; |
| struct iovec *iov = iovstack; |
| struct iov_iter iter; |
| ssize_t ret; |
| io_fn_t fn; |
| iter_fn_t iter_fn; |
| |
| ret = compat_import_iovec(type, uvector, nr_segs, |
| UIO_FASTIOV, &iov, &iter); |
| if (ret < 0) |
| return ret; |
| |
| tot_len = iov_iter_count(&iter); |
| if (!tot_len) |
| goto out; |
| ret = rw_verify_area(type, file, pos, tot_len); |
| if (ret < 0) |
| goto out; |
| |
| if (type == READ) { |
| fn = file->f_op->read; |
| iter_fn = file->f_op->read_iter; |
| } else { |
| fn = (io_fn_t)file->f_op->write; |
| iter_fn = file->f_op->write_iter; |
| file_start_write(file); |
| } |
| |
| if (iter_fn) |
| ret = do_iter_readv_writev(file, &iter, pos, iter_fn); |
| else |
| ret = do_loop_readv_writev(file, &iter, pos, fn); |
| |
| if (type != READ) |
| file_end_write(file); |
| |
| out: |
| kfree(iov); |
| if ((ret + (type == READ)) > 0) { |
| if (type == READ) |
| fsnotify_access(file); |
| else |
| fsnotify_modify(file); |
| } |
| return ret; |
| } |
| |
| static size_t compat_readv(struct file *file, |
| const struct compat_iovec __user *vec, |
| unsigned long vlen, loff_t *pos) |
| { |
| ssize_t ret = -EBADF; |
| |
| if (!(file->f_mode & FMODE_READ)) |
| goto out; |
| |
| ret = -EINVAL; |
| if (!(file->f_mode & FMODE_CAN_READ)) |
| goto out; |
| |
| ret = compat_do_readv_writev(READ, file, vec, vlen, pos); |
| |
| out: |
| if (ret > 0) |
| add_rchar(current, ret); |
| inc_syscr(current); |
| return ret; |
| } |
| |
| COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, |
| const struct compat_iovec __user *,vec, |
| compat_ulong_t, vlen) |
| { |
| struct fd f = fdget_pos(fd); |
| ssize_t ret; |
| loff_t pos; |
| |
| if (!f.file) |
| return -EBADF; |
| pos = f.file->f_pos; |
| ret = compat_readv(f.file, vec, vlen, &pos); |
| if (ret >= 0) |
| f.file->f_pos = pos; |
| fdput_pos(f); |
| return ret; |
| } |
| |
| static long __compat_sys_preadv64(unsigned long fd, |
| const struct compat_iovec __user *vec, |
| unsigned long vlen, loff_t pos) |
| { |
| struct fd f; |
| ssize_t ret; |
| |
| if (pos < 0) |
| return -EINVAL; |
| f = fdget(fd); |
| if (!f.file) |
| return -EBADF; |
| ret = -ESPIPE; |
| if (f.file->f_mode & FMODE_PREAD) |
| ret = compat_readv(f.file, vec, vlen, &pos); |
| fdput(f); |
| return ret; |
| } |
| |
| #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
| COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, |
| const struct compat_iovec __user *,vec, |
| unsigned long, vlen, loff_t, pos) |
| { |
| return __compat_sys_preadv64(fd, vec, vlen, pos); |
| } |
| #endif |
| |
| COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
| const struct compat_iovec __user *,vec, |
| compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
| { |
| loff_t pos = ((loff_t)pos_high << 32) | pos_low; |
| |
| return __compat_sys_preadv64(fd, vec, vlen, pos); |
| } |
| |
| static size_t compat_writev(struct file *file, |
| const struct compat_iovec __user *vec, |
| unsigned long vlen, loff_t *pos) |
| { |
| ssize_t ret = -EBADF; |
| |
| if (!(file->f_mode & FMODE_WRITE)) |
| goto out; |
| |
| ret = -EINVAL; |
| if (!(file->f_mode & FMODE_CAN_WRITE)) |
| goto out; |
| |
| ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); |
| |
| out: |
| if (ret > 0) |
| add_wchar(current, ret); |
| inc_syscw(current); |
| return ret; |
| } |
| |
| COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, |
| const struct compat_iovec __user *, vec, |
| compat_ulong_t, vlen) |
| { |
| struct fd f = fdget_pos(fd); |
| ssize_t ret; |
| loff_t pos; |
| |
| if (!f.file) |
| return -EBADF; |
| pos = f.file->f_pos; |
| ret = compat_writev(f.file, vec, vlen, &pos); |
| if (ret >= 0) |
| f.file->f_pos = pos; |
| fdput_pos(f); |
| return ret; |
| } |
| |
| static long __compat_sys_pwritev64(unsigned long fd, |
| const struct compat_iovec __user *vec, |
| unsigned long vlen, loff_t pos) |
| { |
| struct fd f; |
| ssize_t ret; |
| |
| if (pos < 0) |
| return -EINVAL; |
| f = fdget(fd); |
| if (!f.file) |
| return -EBADF; |
| ret = -ESPIPE; |
| if (f.file->f_mode & FMODE_PWRITE) |
| ret = compat_writev(f.file, vec, vlen, &pos); |
| fdput(f); |
| return ret; |
| } |
| |
| #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
| COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, |
| const struct compat_iovec __user *,vec, |
| unsigned long, vlen, loff_t, pos) |
| { |
| return __compat_sys_pwritev64(fd, vec, vlen, pos); |
| } |
| #endif |
| |
| COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
| const struct compat_iovec __user *,vec, |
| compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
| { |
| loff_t pos = ((loff_t)pos_high << 32) | pos_low; |
| |
| return __compat_sys_pwritev64(fd, vec, vlen, pos); |
| } |
| #endif |
| |
| static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
| size_t count, loff_t max) |
| { |
| struct fd in, out; |
| struct inode *in_inode, *out_inode; |
| loff_t pos; |
| loff_t out_pos; |
| ssize_t retval; |
| int fl; |
| |
| /* |
| * Get input file, and verify that it is ok.. |
| */ |
| retval = -EBADF; |
| in = fdget(in_fd); |
| if (!in.file) |
| goto out; |
| if (!(in.file->f_mode & FMODE_READ)) |
| goto fput_in; |
| retval = -ESPIPE; |
| if (!ppos) { |
| pos = in.file->f_pos; |
| } else { |
| pos = *ppos; |
| if (!(in.file->f_mode & FMODE_PREAD)) |
| goto fput_in; |
| } |
| retval = rw_verify_area(READ, in.file, &pos, count); |
| if (retval < 0) |
| goto fput_in; |
| count = retval; |
| |
| /* |
| * Get output file, and verify that it is ok.. |
| */ |
| retval = -EBADF; |
| out = fdget(out_fd); |
| if (!out.file) |
| goto fput_in; |
| if (!(out.file->f_mode & FMODE_WRITE)) |
| goto fput_out; |
| retval = -EINVAL; |
| in_inode = file_inode(in.file); |
| out_inode = file_inode(out.file); |
| out_pos = out.file->f_pos; |
| retval = rw_verify_area(WRITE, out.file, &out_pos, count); |
| if (retval < 0) |
| goto fput_out; |
| count = retval; |
| |
| if (!max) |
| max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); |
| |
| if (unlikely(pos + count > max)) { |
| retval = -EOVERFLOW; |
| if (pos >= max) |
| goto fput_out; |
| count = max - pos; |
| } |
| |
| fl = 0; |
| #if 0 |
| /* |
| * We need to debate whether we can enable this or not. The |
| * man page documents EAGAIN return for the output at least, |
| * and the application is arguably buggy if it doesn't expect |
| * EAGAIN on a non-blocking file descriptor. |
| */ |
| if (in.file->f_flags & O_NONBLOCK) |
| fl = SPLICE_F_NONBLOCK; |
| #endif |
| file_start_write(out.file); |
| retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); |
| file_end_write(out.file); |
| |
| if (retval > 0) { |
| add_rchar(current, retval); |
| add_wchar(current, retval); |
| fsnotify_access(in.file); |
| fsnotify_modify(out.file); |
| out.file->f_pos = out_pos; |
| if (ppos) |
| *ppos = pos; |
| else |
| in.file->f_pos = pos; |
| } |
| |
| inc_syscr(current); |
| inc_syscw(current); |
| if (pos > max) |
| retval = -EOVERFLOW; |
| |
| fput_out: |
| fdput(out); |
| fput_in: |
| fdput(in); |
| out: |
| return retval; |
| } |
| |
| SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
| { |
| loff_t pos; |
| off_t off; |
| ssize_t ret; |
| |
| if (offset) { |
| if (unlikely(get_user(off, offset))) |
| return -EFAULT; |
| pos = off; |
| ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); |
| if (unlikely(put_user(pos, offset))) |
| return -EFAULT; |
| return ret; |
| } |
| |
| return do_sendfile(out_fd, in_fd, NULL, count, 0); |
| } |
| |
| SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
| { |
| loff_t pos; |
| ssize_t ret; |
| |
| if (offset) { |
| if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) |
| return -EFAULT; |
| ret = do_sendfile(out_fd, in_fd, &pos, count, 0); |
| if (unlikely(put_user(pos, offset))) |
| return -EFAULT; |
| return ret; |
| } |
| |
| return do_sendfile(out_fd, in_fd, NULL, count, 0); |
| } |
| |
| #ifdef CONFIG_COMPAT |
| COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, |
| compat_off_t __user *, offset, compat_size_t, count) |
| { |
| loff_t pos; |
| off_t off; |
| ssize_t ret; |
| |
| if (offset) { |
| if (unlikely(get_user(off, offset))) |
| return -EFAULT; |
| pos = off; |
| ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); |
| if (unlikely(put_user(pos, offset))) |
| return -EFAULT; |
| return ret; |
| } |
| |
| return do_sendfile(out_fd, in_fd, NULL, count, 0); |
| } |
| |
| COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, |
| compat_loff_t __user *, offset, compat_size_t, count) |
| { |
| loff_t pos; |
| ssize_t ret; |
| |
| if (offset) { |
| if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) |
| return -EFAULT; |
| ret = do_sendfile(out_fd, in_fd, &pos, count, 0); |
| if (unlikely(put_user(pos, offset))) |
| return -EFAULT; |
| return ret; |
| } |
| |
| return do_sendfile(out_fd, in_fd, NULL, count, 0); |
| } |
| #endif |