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fs/read_write.c
21 KB
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/* * 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> |
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#include <linux/fsnotify.h> |
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#include <linux/security.h> #include <linux/module.h> #include <linux/syscalls.h> |
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#include <linux/pagemap.h> |
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#include <linux/splice.h> |
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#include "read_write.h" |
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#include <asm/uaccess.h> #include <asm/unistd.h> |
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const struct file_operations generic_ro_fops = { |
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.llseek = generic_file_llseek, |
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.read = do_sync_read, .aio_read = generic_file_aio_read, |
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.mmap = generic_file_readonly_mmap, |
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.splice_read = generic_file_splice_read, |
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}; EXPORT_SYMBOL(generic_ro_fops); |
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static int __negative_fpos_check(struct file *file, loff_t pos, size_t count) { /* * pos or pos+count is negative here, check overflow. * too big "count" will be caught in rw_verify_area(). */ if ((pos < 0) && (pos + count < pos)) return -EOVERFLOW; if (file->f_mode & FMODE_UNSIGNED_OFFSET) return 0; return -EINVAL; } |
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/** * generic_file_llseek_unlocked - lockless generic llseek implementation * @file: file structure to seek on * @offset: file offset to seek to * @origin: type of seek * * Updates the file offset to the value specified by @offset and @origin. * Locking must be provided by the caller. */ |
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loff_t generic_file_llseek_unlocked(struct file *file, loff_t offset, int origin) |
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{ |
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struct inode *inode = file->f_mapping->host; |
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switch (origin) { |
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case SEEK_END: offset += inode->i_size; break; case SEEK_CUR: |
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/* * 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; |
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offset += file->f_pos; break; |
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} |
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if (offset < 0 && __negative_fpos_check(file, offset, 0)) return -EINVAL; if (offset > inode->i_sb->s_maxbytes) |
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return -EINVAL; /* Special lock needed here? */ if (offset != file->f_pos) { file->f_pos = offset; file->f_version = 0; |
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} |
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return offset; |
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} |
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EXPORT_SYMBOL(generic_file_llseek_unlocked); |
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/** * generic_file_llseek - generic llseek implementation for regular files * @file: file structure to seek on * @offset: file offset to seek to * @origin: 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 @origin under i_mutex. */ |
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loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) |
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{ |
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loff_t rval; |
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mutex_lock(&file->f_dentry->d_inode->i_mutex); |
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rval = generic_file_llseek_unlocked(file, offset, origin); |
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mutex_unlock(&file->f_dentry->d_inode->i_mutex); |
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return rval; |
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} |
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EXPORT_SYMBOL(generic_file_llseek); |
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/** * noop_llseek - No Operation Performed llseek implementation * @file: file structure to seek on * @offset: file offset to seek to * @origin: 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 origin) { return file->f_pos; } EXPORT_SYMBOL(noop_llseek); |
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loff_t no_llseek(struct file *file, loff_t offset, int origin) { return -ESPIPE; } EXPORT_SYMBOL(no_llseek); loff_t default_llseek(struct file *file, loff_t offset, int origin) { |
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loff_t retval; |
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|
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mutex_lock(&file->f_dentry->d_inode->i_mutex); |
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switch (origin) { |
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case SEEK_END: |
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offset += i_size_read(file->f_path.dentry->d_inode); |
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break; |
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case SEEK_CUR: |
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if (offset == 0) { retval = file->f_pos; goto out; } |
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offset += file->f_pos; } retval = -EINVAL; |
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if (offset >= 0 || !__negative_fpos_check(file, offset, 0)) { |
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if (offset != file->f_pos) { file->f_pos = offset; file->f_version = 0; } retval = offset; } |
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out: |
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mutex_unlock(&file->f_dentry->d_inode->i_mutex); |
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return retval; } EXPORT_SYMBOL(default_llseek); loff_t vfs_llseek(struct file *file, loff_t offset, int origin) { loff_t (*fn)(struct file *, loff_t, int); fn = no_llseek; if (file->f_mode & FMODE_LSEEK) { |
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if (file->f_op && file->f_op->llseek) fn = file->f_op->llseek; } return fn(file, offset, origin); } EXPORT_SYMBOL(vfs_llseek); |
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SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, origin) |
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{ off_t retval; struct file * file; int fput_needed; retval = -EBADF; file = fget_light(fd, &fput_needed); if (!file) goto bad; retval = -EINVAL; |
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if (origin <= SEEK_MAX) { |
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loff_t res = vfs_llseek(file, offset, origin); retval = res; if (res != (loff_t)retval) retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ } fput_light(file, fput_needed); bad: return retval; } #ifdef __ARCH_WANT_SYS_LLSEEK |
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SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, unsigned long, offset_low, loff_t __user *, result, unsigned int, origin) |
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{ int retval; struct file * file; loff_t offset; int fput_needed; retval = -EBADF; file = fget_light(fd, &fput_needed); if (!file) goto bad; retval = -EINVAL; |
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if (origin > SEEK_MAX) |
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goto out_putf; offset = vfs_llseek(file, ((loff_t) offset_high << 32) | offset_low, origin); retval = (int)offset; if (offset >= 0) { retval = -EFAULT; if (!copy_to_user(result, &offset, sizeof(offset))) retval = 0; } out_putf: fput_light(file, fput_needed); bad: return retval; } #endif |
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/* * 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. */ |
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int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count) { struct inode *inode; loff_t pos; |
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int retval = -EINVAL; |
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|
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inode = file->f_path.dentry->d_inode; |
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if (unlikely((ssize_t) count < 0)) |
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return retval; |
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pos = *ppos; |
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if (unlikely((pos < 0) || (loff_t) (pos + count) < 0)) { retval = __negative_fpos_check(file, pos, count); if (retval) return retval; } |
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if (unlikely(inode->i_flock && mandatory_lock(inode))) { |
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retval = locks_mandatory_area( |
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read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, inode, file, pos, count); if (retval < 0) return retval; } |
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retval = security_file_permission(file, read_write == READ ? MAY_READ : MAY_WRITE); if (retval) return retval; |
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return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
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} |
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static void wait_on_retry_sync_kiocb(struct kiocb *iocb) { set_current_state(TASK_UNINTERRUPTIBLE); if (!kiocbIsKicked(iocb)) schedule(); else kiocbClearKicked(iocb); __set_current_state(TASK_RUNNING); } |
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ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) { |
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struct iovec iov = { .iov_base = buf, .iov_len = len }; |
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struct kiocb kiocb; ssize_t ret; init_sync_kiocb(&kiocb, filp); kiocb.ki_pos = *ppos; |
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kiocb.ki_left = len; |
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kiocb.ki_nbytes = len; |
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for (;;) { ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); if (ret != -EIOCBRETRY) break; |
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wait_on_retry_sync_kiocb(&kiocb); |
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} |
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if (-EIOCBQUEUED == ret) ret = wait_on_sync_kiocb(&kiocb); *ppos = kiocb.ki_pos; return ret; } EXPORT_SYMBOL(do_sync_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_op || (!file->f_op->read && !file->f_op->aio_read)) return -EINVAL; if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) return -EFAULT; ret = rw_verify_area(READ, file, pos, count); |
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if (ret >= 0) { count = ret; |
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if (file->f_op->read) ret = file->f_op->read(file, buf, count, pos); else ret = do_sync_read(file, buf, count, pos); if (ret > 0) { |
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fsnotify_access(file); |
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add_rchar(current, ret); |
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} |
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inc_syscr(current); |
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} return ret; } EXPORT_SYMBOL(vfs_read); ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) { |
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struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
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struct kiocb kiocb; ssize_t ret; init_sync_kiocb(&kiocb, filp); kiocb.ki_pos = *ppos; |
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kiocb.ki_left = len; |
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kiocb.ki_nbytes = len; |
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for (;;) { ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); if (ret != -EIOCBRETRY) break; |
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wait_on_retry_sync_kiocb(&kiocb); |
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} |
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if (-EIOCBQUEUED == ret) ret = wait_on_sync_kiocb(&kiocb); *ppos = kiocb.ki_pos; return ret; } EXPORT_SYMBOL(do_sync_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_op || (!file->f_op->write && !file->f_op->aio_write)) return -EINVAL; if (unlikely(!access_ok(VERIFY_READ, buf, count))) return -EFAULT; ret = rw_verify_area(WRITE, file, pos, count); |
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if (ret >= 0) { count = ret; |
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if (file->f_op->write) ret = file->f_op->write(file, buf, count, pos); else ret = do_sync_write(file, buf, count, pos); if (ret > 0) { |
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fsnotify_modify(file); |
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add_wchar(current, ret); |
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} |
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inc_syscw(current); |
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} 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; } |
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SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
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{ struct file *file; ssize_t ret = -EBADF; int fput_needed; file = fget_light(fd, &fput_needed); if (file) { loff_t pos = file_pos_read(file); ret = vfs_read(file, buf, count, &pos); file_pos_write(file, pos); fput_light(file, fput_needed); } return ret; } |
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SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, size_t, count) |
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{ struct file *file; ssize_t ret = -EBADF; int fput_needed; file = fget_light(fd, &fput_needed); if (file) { loff_t pos = file_pos_read(file); ret = vfs_write(file, buf, count, &pos); file_pos_write(file, pos); fput_light(file, fput_needed); } return ret; } |
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SYSCALL_DEFINE(pread64)(unsigned int fd, char __user *buf, size_t count, loff_t pos) |
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{ struct file *file; ssize_t ret = -EBADF; int fput_needed; if (pos < 0) return -EINVAL; file = fget_light(fd, &fput_needed); if (file) { ret = -ESPIPE; if (file->f_mode & FMODE_PREAD) ret = vfs_read(file, buf, count, &pos); fput_light(file, fput_needed); } return ret; } |
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#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS asmlinkage long SyS_pread64(long fd, long buf, long count, loff_t pos) { return SYSC_pread64((unsigned int) fd, (char __user *) buf, (size_t) count, pos); } SYSCALL_ALIAS(sys_pread64, SyS_pread64); #endif |
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SYSCALL_DEFINE(pwrite64)(unsigned int fd, const char __user *buf, size_t count, loff_t pos) |
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{ struct file *file; ssize_t ret = -EBADF; int fput_needed; if (pos < 0) return -EINVAL; file = fget_light(fd, &fput_needed); if (file) { ret = -ESPIPE; if (file->f_mode & FMODE_PWRITE) ret = vfs_write(file, buf, count, &pos); fput_light(file, fput_needed); } return ret; } |
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#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS asmlinkage long SyS_pwrite64(long fd, long buf, long count, loff_t pos) { return SYSC_pwrite64((unsigned int) fd, (const char __user *) buf, (size_t) count, pos); } SYSCALL_ALIAS(sys_pwrite64, SyS_pwrite64); #endif |
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/* * 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; } |
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EXPORT_SYMBOL(iov_shorten); |
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ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) { struct kiocb kiocb; ssize_t ret; init_sync_kiocb(&kiocb, filp); kiocb.ki_pos = *ppos; kiocb.ki_left = len; kiocb.ki_nbytes = len; for (;;) { ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); if (ret != -EIOCBRETRY) break; wait_on_retry_sync_kiocb(&kiocb); } if (ret == -EIOCBQUEUED) ret = wait_on_sync_kiocb(&kiocb); *ppos = kiocb.ki_pos; return ret; } /* Do it by hand, with file-ops */ ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, unsigned long nr_segs, loff_t *ppos, io_fn_t fn) { struct iovec *vector = iov; ssize_t ret = 0; while (nr_segs > 0) { void __user *base; size_t len; ssize_t nr; base = vector->iov_base; len = vector->iov_len; vector++; nr_segs--; nr = fn(filp, base, len, ppos); if (nr < 0) { if (!ret) ret = nr; break; } ret += nr; if (nr != len) break; } return ret; } |
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/* A write operation does a read from user space and vice versa */ #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) |
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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) |
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{ |
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unsigned long seg; |
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ssize_t ret; |
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struct iovec *iov = fast_pointer; |
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/* * 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... */ |
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if (nr_segs == 0) { ret = 0; |
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goto out; |
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} |
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/* * First get the "struct iovec" from user memory and * verify all the pointers */ |
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if (nr_segs > UIO_MAXIOV) { ret = -EINVAL; |
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goto out; |
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} if (nr_segs > fast_segs) { |
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iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
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if (iov == NULL) { ret = -ENOMEM; |
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goto out; |
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} |
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} |
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if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { ret = -EFAULT; |
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goto out; |
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} |
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/* |
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* 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. |
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* * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the * overflow case. */ |
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ret = 0; |
435f49a51
|
612 613 614 |
for (seg = 0; seg < nr_segs; seg++) { void __user *buf = iov[seg].iov_base; ssize_t len = (ssize_t)iov[seg].iov_len; |
eed4e51fb
|
615 616 617 |
/* see if we we're about to use an invalid len or if * it's about to overflow ssize_t */ |
435f49a51
|
618 |
if (len < 0) { |
eed4e51fb
|
619 |
ret = -EINVAL; |
435f49a51
|
620 |
goto out; |
eed4e51fb
|
621 622 623 |
} if (unlikely(!access_ok(vrfy_dir(type), buf, len))) { ret = -EFAULT; |
435f49a51
|
624 625 626 627 628 |
goto out; } if (len > MAX_RW_COUNT - ret) { len = MAX_RW_COUNT - ret; iov[seg].iov_len = len; |
eed4e51fb
|
629 |
} |
eed4e51fb
|
630 |
ret += len; |
435f49a51
|
631 |
} |
eed4e51fb
|
632 633 634 635 |
out: *ret_pointer = iov; return ret; } |
1da177e4c
|
636 637 638 639 |
static ssize_t do_readv_writev(int type, struct file *file, const struct iovec __user * uvector, unsigned long nr_segs, loff_t *pos) { |
1da177e4c
|
640 641 |
size_t tot_len; struct iovec iovstack[UIO_FASTIOV]; |
ee0b3e671
|
642 |
struct iovec *iov = iovstack; |
1da177e4c
|
643 |
ssize_t ret; |
1da177e4c
|
644 645 |
io_fn_t fn; iov_fn_t fnv; |
eed4e51fb
|
646 647 |
if (!file->f_op) { ret = -EINVAL; |
1da177e4c
|
648 |
goto out; |
1da177e4c
|
649 |
} |
1da177e4c
|
650 |
|
eed4e51fb
|
651 652 653 |
ret = rw_copy_check_uvector(type, uvector, nr_segs, ARRAY_SIZE(iovstack), iovstack, &iov); if (ret <= 0) |
1da177e4c
|
654 |
goto out; |
1da177e4c
|
655 |
|
eed4e51fb
|
656 |
tot_len = ret; |
1da177e4c
|
657 |
ret = rw_verify_area(type, file, pos, tot_len); |
e28cc7157
|
658 |
if (ret < 0) |
1da177e4c
|
659 660 661 662 663 |
goto out; fnv = NULL; if (type == READ) { fn = file->f_op->read; |
ee0b3e671
|
664 |
fnv = file->f_op->aio_read; |
1da177e4c
|
665 666 |
} else { fn = (io_fn_t)file->f_op->write; |
ee0b3e671
|
667 |
fnv = file->f_op->aio_write; |
1da177e4c
|
668 |
} |
ee0b3e671
|
669 670 671 672 673 |
if (fnv) ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, pos, fnv); else ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); |
1da177e4c
|
674 |
|
1da177e4c
|
675 676 677 |
out: if (iov != iovstack) kfree(iov); |
0eeca2830
|
678 679 |
if ((ret + (type == READ)) > 0) { if (type == READ) |
2a12a9d78
|
680 |
fsnotify_access(file); |
0eeca2830
|
681 |
else |
2a12a9d78
|
682 |
fsnotify_modify(file); |
0eeca2830
|
683 |
} |
1da177e4c
|
684 |
return ret; |
1da177e4c
|
685 686 687 688 689 690 691 |
} 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; |
ee0b3e671
|
692 |
if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) |
1da177e4c
|
693 694 695 696 697 698 699 700 701 702 703 704 |
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; |
ee0b3e671
|
705 |
if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) |
1da177e4c
|
706 707 708 709 710 711 |
return -EINVAL; return do_readv_writev(WRITE, file, vec, vlen, pos); } EXPORT_SYMBOL(vfs_writev); |
3cdad4288
|
712 713 |
SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen) |
1da177e4c
|
714 715 716 717 718 719 720 721 722 723 724 725 726 727 |
{ struct file *file; ssize_t ret = -EBADF; int fput_needed; file = fget_light(fd, &fput_needed); if (file) { loff_t pos = file_pos_read(file); ret = vfs_readv(file, vec, vlen, &pos); file_pos_write(file, pos); fput_light(file, fput_needed); } if (ret > 0) |
4b98d11b4
|
728 729 |
add_rchar(current, ret); inc_syscr(current); |
1da177e4c
|
730 731 |
return ret; } |
3cdad4288
|
732 733 |
SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen) |
1da177e4c
|
734 735 736 737 738 739 740 741 742 743 744 745 746 747 |
{ struct file *file; ssize_t ret = -EBADF; int fput_needed; file = fget_light(fd, &fput_needed); if (file) { loff_t pos = file_pos_read(file); ret = vfs_writev(file, vec, vlen, &pos); file_pos_write(file, pos); fput_light(file, fput_needed); } if (ret > 0) |
4b98d11b4
|
748 749 |
add_wchar(current, ret); inc_syscw(current); |
1da177e4c
|
750 751 |
return ret; } |
601cc11d0
|
752 753 754 755 756 |
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; } |
f3554f4bc
|
757 |
SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
601cc11d0
|
758 |
unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4bc
|
759 |
{ |
601cc11d0
|
760 |
loff_t pos = pos_from_hilo(pos_h, pos_l); |
f3554f4bc
|
761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 |
struct file *file; ssize_t ret = -EBADF; int fput_needed; if (pos < 0) return -EINVAL; file = fget_light(fd, &fput_needed); if (file) { ret = -ESPIPE; if (file->f_mode & FMODE_PREAD) ret = vfs_readv(file, vec, vlen, &pos); fput_light(file, fput_needed); } if (ret > 0) add_rchar(current, ret); inc_syscr(current); return ret; } SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, |
601cc11d0
|
783 |
unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4bc
|
784 |
{ |
601cc11d0
|
785 |
loff_t pos = pos_from_hilo(pos_h, pos_l); |
f3554f4bc
|
786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 |
struct file *file; ssize_t ret = -EBADF; int fput_needed; if (pos < 0) return -EINVAL; file = fget_light(fd, &fput_needed); if (file) { ret = -ESPIPE; if (file->f_mode & FMODE_PWRITE) ret = vfs_writev(file, vec, vlen, &pos); fput_light(file, fput_needed); } if (ret > 0) add_wchar(current, ret); inc_syscw(current); return ret; } |
1da177e4c
|
806 807 808 809 810 811 812 |
static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, size_t count, loff_t max) { struct file * in_file, * out_file; struct inode * in_inode, * out_inode; loff_t pos; ssize_t retval; |
534f2aaa6
|
813 |
int fput_needed_in, fput_needed_out, fl; |
1da177e4c
|
814 815 816 817 818 819 820 821 822 823 |
/* * Get input file, and verify that it is ok.. */ retval = -EBADF; in_file = fget_light(in_fd, &fput_needed_in); if (!in_file) goto out; if (!(in_file->f_mode & FMODE_READ)) goto fput_in; |
1da177e4c
|
824 825 826 827 828 829 830 |
retval = -ESPIPE; if (!ppos) ppos = &in_file->f_pos; else if (!(in_file->f_mode & FMODE_PREAD)) goto fput_in; retval = rw_verify_area(READ, in_file, ppos, count); |
e28cc7157
|
831 |
if (retval < 0) |
1da177e4c
|
832 |
goto fput_in; |
e28cc7157
|
833 |
count = retval; |
1da177e4c
|
834 |
|
1da177e4c
|
835 836 837 838 839 840 841 842 843 844 |
/* * Get output file, and verify that it is ok.. */ retval = -EBADF; out_file = fget_light(out_fd, &fput_needed_out); if (!out_file) goto fput_in; if (!(out_file->f_mode & FMODE_WRITE)) goto fput_out; retval = -EINVAL; |
6818173bd
|
845 |
in_inode = in_file->f_path.dentry->d_inode; |
0f7fc9e4d
|
846 |
out_inode = out_file->f_path.dentry->d_inode; |
1da177e4c
|
847 |
retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count); |
e28cc7157
|
848 |
if (retval < 0) |
1da177e4c
|
849 |
goto fput_out; |
e28cc7157
|
850 |
count = retval; |
1da177e4c
|
851 |
|
1da177e4c
|
852 853 854 855 |
if (!max) max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); pos = *ppos; |
1da177e4c
|
856 857 858 859 860 861 |
if (unlikely(pos + count > max)) { retval = -EOVERFLOW; if (pos >= max) goto fput_out; count = max - pos; } |
d96e6e716
|
862 |
fl = 0; |
534f2aaa6
|
863 |
#if 0 |
d96e6e716
|
864 865 866 867 868 869 870 871 |
/* * 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; |
534f2aaa6
|
872 |
#endif |
d96e6e716
|
873 |
retval = do_splice_direct(in_file, ppos, out_file, count, fl); |
1da177e4c
|
874 875 |
if (retval > 0) { |
4b98d11b4
|
876 877 |
add_rchar(current, retval); add_wchar(current, retval); |
1da177e4c
|
878 |
} |
1da177e4c
|
879 |
|
4b98d11b4
|
880 881 |
inc_syscr(current); inc_syscw(current); |
1da177e4c
|
882 883 884 885 886 887 888 889 890 891 |
if (*ppos > max) retval = -EOVERFLOW; fput_out: fput_light(out_file, fput_needed_out); fput_in: fput_light(in_file, fput_needed_in); out: return retval; } |
002c8976e
|
892 |
SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4c
|
893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 |
{ 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); } |
002c8976e
|
910 |
SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4c
|
911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 |
{ 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); } |