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fs/open.c
26.3 KB
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/* * linux/fs/open.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/string.h> #include <linux/mm.h> |
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#include <linux/file.h> |
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#include <linux/fdtable.h> |
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#include <linux/quotaops.h> |
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#include <linux/fsnotify.h> |
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#include <linux/module.h> #include <linux/slab.h> #include <linux/tty.h> #include <linux/namei.h> #include <linux/backing-dev.h> |
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#include <linux/capability.h> |
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#include <linux/securebits.h> |
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#include <linux/security.h> #include <linux/mount.h> #include <linux/vfs.h> |
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#include <linux/fcntl.h> |
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#include <asm/uaccess.h> #include <linux/fs.h> |
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#include <linux/personality.h> |
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#include <linux/pagemap.h> #include <linux/syscalls.h> |
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#include <linux/rcupdate.h> |
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#include <linux/audit.h> |
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#include <linux/falloc.h> |
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int vfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
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{ int retval = -ENODEV; |
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if (dentry) { |
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retval = -ENOSYS; |
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if (dentry->d_sb->s_op->statfs) { |
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memset(buf, 0, sizeof(*buf)); |
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retval = security_sb_statfs(dentry); |
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if (retval) return retval; |
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retval = dentry->d_sb->s_op->statfs(dentry, buf); |
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if (retval == 0 && buf->f_frsize == 0) buf->f_frsize = buf->f_bsize; } } return retval; } EXPORT_SYMBOL(vfs_statfs); |
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static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf) |
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{ struct kstatfs st; int retval; |
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retval = vfs_statfs(dentry, &st); |
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if (retval) return retval; if (sizeof(*buf) == sizeof(st)) memcpy(buf, &st, sizeof(st)); else { if (sizeof buf->f_blocks == 4) { |
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if ((st.f_blocks | st.f_bfree | st.f_bavail | st.f_bsize | st.f_frsize) & |
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0xffffffff00000000ULL) return -EOVERFLOW; /* * f_files and f_ffree may be -1; it's okay to stuff * that into 32 bits */ if (st.f_files != -1 && (st.f_files & 0xffffffff00000000ULL)) return -EOVERFLOW; if (st.f_ffree != -1 && (st.f_ffree & 0xffffffff00000000ULL)) return -EOVERFLOW; } buf->f_type = st.f_type; buf->f_bsize = st.f_bsize; buf->f_blocks = st.f_blocks; buf->f_bfree = st.f_bfree; buf->f_bavail = st.f_bavail; buf->f_files = st.f_files; buf->f_ffree = st.f_ffree; buf->f_fsid = st.f_fsid; buf->f_namelen = st.f_namelen; buf->f_frsize = st.f_frsize; memset(buf->f_spare, 0, sizeof(buf->f_spare)); } return 0; } |
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static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf) |
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{ struct kstatfs st; int retval; |
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retval = vfs_statfs(dentry, &st); |
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if (retval) return retval; if (sizeof(*buf) == sizeof(st)) memcpy(buf, &st, sizeof(st)); else { buf->f_type = st.f_type; buf->f_bsize = st.f_bsize; buf->f_blocks = st.f_blocks; buf->f_bfree = st.f_bfree; buf->f_bavail = st.f_bavail; buf->f_files = st.f_files; buf->f_ffree = st.f_ffree; buf->f_fsid = st.f_fsid; buf->f_namelen = st.f_namelen; buf->f_frsize = st.f_frsize; memset(buf->f_spare, 0, sizeof(buf->f_spare)); } return 0; } |
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asmlinkage long sys_statfs(const char __user *pathname, struct statfs __user * buf) |
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{ |
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struct path path; |
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int error; |
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error = user_path(pathname, &path); |
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if (!error) { struct statfs tmp; |
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error = vfs_statfs_native(path.dentry, &tmp); |
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if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) error = -EFAULT; |
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path_put(&path); |
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} return error; } |
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asmlinkage long sys_statfs64(const char __user *pathname, size_t sz, struct statfs64 __user *buf) |
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{ |
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struct path path; |
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long error; if (sz != sizeof(*buf)) return -EINVAL; |
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error = user_path(pathname, &path); |
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if (!error) { struct statfs64 tmp; |
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error = vfs_statfs64(path.dentry, &tmp); |
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if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) error = -EFAULT; |
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path_put(&path); |
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} return error; } asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf) { struct file * file; struct statfs tmp; int error; error = -EBADF; file = fget(fd); if (!file) goto out; |
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error = vfs_statfs_native(file->f_path.dentry, &tmp); |
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if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) error = -EFAULT; fput(file); out: return error; } asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf) { struct file * file; struct statfs64 tmp; int error; if (sz != sizeof(*buf)) return -EINVAL; error = -EBADF; file = fget(fd); if (!file) goto out; |
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error = vfs_statfs64(file->f_path.dentry, &tmp); |
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if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) error = -EFAULT; fput(file); out: return error; } |
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int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, struct file *filp) |
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{ int err; struct iattr newattrs; /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ if (length < 0) return -EINVAL; newattrs.ia_size = length; |
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newattrs.ia_valid = ATTR_SIZE | time_attrs; |
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if (filp) { newattrs.ia_file = filp; newattrs.ia_valid |= ATTR_FILE; } |
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/* Remove suid/sgid on truncate too */ newattrs.ia_valid |= should_remove_suid(dentry); |
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mutex_lock(&dentry->d_inode->i_mutex); |
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err = notify_change(dentry, &newattrs); |
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mutex_unlock(&dentry->d_inode->i_mutex); |
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return err; } |
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static long do_sys_truncate(const char __user *pathname, loff_t length) |
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{ |
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struct path path; struct inode *inode; |
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int error; error = -EINVAL; if (length < 0) /* sorry, but loff_t says... */ goto out; |
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error = user_path(pathname, &path); |
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if (error) goto out; |
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inode = path.dentry->d_inode; |
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/* For directories it's -EISDIR, for other non-regulars - -EINVAL */ error = -EISDIR; if (S_ISDIR(inode->i_mode)) goto dput_and_out; error = -EINVAL; if (!S_ISREG(inode->i_mode)) goto dput_and_out; |
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error = mnt_want_write(path.mnt); |
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if (error) goto dput_and_out; |
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error = inode_permission(inode, MAY_WRITE); |
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if (error) goto mnt_drop_write_and_out; |
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error = -EPERM; |
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if (IS_APPEND(inode)) |
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goto mnt_drop_write_and_out; |
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error = get_write_access(inode); |
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if (error) |
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goto mnt_drop_write_and_out; |
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/* * Make sure that there are no leases. get_write_access() protects * against the truncate racing with a lease-granting setlease(). */ error = break_lease(inode, FMODE_WRITE); |
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if (error) |
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goto put_write_and_out; |
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error = locks_verify_truncate(inode, NULL, length); |
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if (!error) error = security_path_truncate(&path, length, 0); |
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if (!error) { DQUOT_INIT(inode); |
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error = do_truncate(path.dentry, length, 0, NULL); |
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} |
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put_write_and_out: put_write_access(inode); |
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mnt_drop_write_and_out: |
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mnt_drop_write(path.mnt); |
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dput_and_out: |
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path_put(&path); |
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out: return error; } asmlinkage long sys_truncate(const char __user * path, unsigned long length) { /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */ return do_sys_truncate(path, (long)length); } |
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static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
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{ struct inode * inode; struct dentry *dentry; struct file * file; int error; error = -EINVAL; if (length < 0) goto out; error = -EBADF; file = fget(fd); if (!file) goto out; /* explicitly opened as large or we are on 64-bit box */ if (file->f_flags & O_LARGEFILE) small = 0; |
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dentry = file->f_path.dentry; |
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inode = dentry->d_inode; error = -EINVAL; if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) goto out_putf; error = -EINVAL; /* Cannot ftruncate over 2^31 bytes without large file support */ if (small && length > MAX_NON_LFS) goto out_putf; error = -EPERM; if (IS_APPEND(inode)) goto out_putf; error = locks_verify_truncate(inode, file, length); if (!error) |
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error = security_path_truncate(&file->f_path, length, ATTR_MTIME|ATTR_CTIME); if (!error) |
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error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file); |
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out_putf: fput(file); out: return error; } asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length) { |
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long ret = do_sys_ftruncate(fd, length, 1); |
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/* avoid REGPARM breakage on x86: */ |
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asmlinkage_protect(2, ret, fd, length); |
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return ret; |
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} /* LFS versions of truncate are only needed on 32 bit machines */ #if BITS_PER_LONG == 32 asmlinkage long sys_truncate64(const char __user * path, loff_t length) { return do_sys_truncate(path, length); } asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length) { |
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long ret = do_sys_ftruncate(fd, length, 0); |
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/* avoid REGPARM breakage on x86: */ |
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asmlinkage_protect(2, ret, fd, length); |
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return ret; |
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} #endif |
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asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len) { struct file *file; struct inode *inode; long ret = -EINVAL; if (offset < 0 || len <= 0) goto out; /* Return error if mode is not supported */ ret = -EOPNOTSUPP; if (mode && !(mode & FALLOC_FL_KEEP_SIZE)) goto out; ret = -EBADF; file = fget(fd); if (!file) goto out; if (!(file->f_mode & FMODE_WRITE)) goto out_fput; /* * Revalidate the write permissions, in case security policy has * changed since the files were opened. */ ret = security_file_permission(file, MAY_WRITE); if (ret) goto out_fput; inode = file->f_path.dentry->d_inode; ret = -ESPIPE; if (S_ISFIFO(inode->i_mode)) goto out_fput; ret = -ENODEV; /* * Let individual file system decide if it supports preallocation * for directories or not. */ if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) goto out_fput; ret = -EFBIG; /* Check for wrap through zero too */ if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) goto out_fput; |
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if (inode->i_op->fallocate) |
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ret = inode->i_op->fallocate(inode, mode, offset, len); else |
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ret = -EOPNOTSUPP; |
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out_fput: fput(file); out: return ret; } |
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/* * access() needs to use the real uid/gid, not the effective uid/gid. * We do this by temporarily clearing all FS-related capabilities and * switching the fsuid/fsgid around to the real ones. */ |
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asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) |
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{ |
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const struct cred *old_cred; struct cred *override_cred; |
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struct path path; |
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struct inode *inode; |
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int res; if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ return -EINVAL; |
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override_cred = prepare_creds(); if (!override_cred) return -ENOMEM; |
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override_cred->fsuid = override_cred->uid; override_cred->fsgid = override_cred->gid; |
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|
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if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
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/* Clear the capabilities if we switch to a non-root user */ |
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if (override_cred->uid) cap_clear(override_cred->cap_effective); |
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else |
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override_cred->cap_effective = override_cred->cap_permitted; |
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} |
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old_cred = override_creds(override_cred); |
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res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
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if (res) goto out; |
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inode = path.dentry->d_inode; |
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if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { |
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/* * MAY_EXEC on regular files is denied if the fs is mounted * with the "noexec" flag. */ res = -EACCES; |
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if (path.mnt->mnt_flags & MNT_NOEXEC) |
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goto out_path_release; } |
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res = inode_permission(inode, mode | MAY_ACCESS); |
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/* SuS v2 requires we report a read only fs too */ |
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if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) |
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goto out_path_release; |
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/* * This is a rare case where using __mnt_is_readonly() * is OK without a mnt_want/drop_write() pair. Since * no actual write to the fs is performed here, we do * not need to telegraph to that to anyone. * * By doing this, we accept that this access is * inherently racy and know that the fs may change * state before we even see this result. */ |
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if (__mnt_is_readonly(path.mnt)) |
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res = -EROFS; |
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|
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out_path_release: |
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path_put(&path); |
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out: |
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revert_creds(old_cred); put_cred(override_cred); |
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return res; } |
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asmlinkage long sys_access(const char __user *filename, int mode) { return sys_faccessat(AT_FDCWD, filename, mode); } |
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asmlinkage long sys_chdir(const char __user * filename) { |
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struct path path; |
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int error; |
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error = user_path_dir(filename, &path); |
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if (error) goto out; |
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error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS); |
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if (error) goto dput_and_out; |
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set_fs_pwd(current->fs, &path); |
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dput_and_out: |
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path_put(&path); |
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out: return error; } asmlinkage long sys_fchdir(unsigned int fd) { struct file *file; |
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struct inode *inode; |
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int error; error = -EBADF; file = fget(fd); if (!file) goto out; |
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inode = file->f_path.dentry->d_inode; |
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error = -ENOTDIR; if (!S_ISDIR(inode->i_mode)) goto out_putf; |
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error = inode_permission(inode, MAY_EXEC | MAY_ACCESS); |
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if (!error) |
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set_fs_pwd(current->fs, &file->f_path); |
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out_putf: fput(file); out: return error; } asmlinkage long sys_chroot(const char __user * filename) { |
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struct path path; |
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int error; |
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error = user_path_dir(filename, &path); |
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if (error) goto out; |
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error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS); |
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if (error) goto dput_and_out; error = -EPERM; if (!capable(CAP_SYS_CHROOT)) goto dput_and_out; |
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set_fs_root(current->fs, &path); |
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error = 0; dput_and_out: |
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path_put(&path); |
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out: return error; } asmlinkage long sys_fchmod(unsigned int fd, mode_t mode) { struct inode * inode; struct dentry * dentry; struct file * file; int err = -EBADF; struct iattr newattrs; file = fget(fd); if (!file) goto out; |
0f7fc9e4d
|
555 |
dentry = file->f_path.dentry; |
1da177e4c
|
556 |
inode = dentry->d_inode; |
5a190ae69
|
557 |
audit_inode(NULL, dentry); |
73241ccca
|
558 |
|
2af482a7e
|
559 560 |
err = mnt_want_write(file->f_path.mnt); if (err) |
1da177e4c
|
561 |
goto out_putf; |
1b1dcc1b5
|
562 |
mutex_lock(&inode->i_mutex); |
1da177e4c
|
563 564 565 566 567 |
if (mode == (mode_t) -1) mode = inode->i_mode; newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; err = notify_change(dentry, &newattrs); |
1b1dcc1b5
|
568 |
mutex_unlock(&inode->i_mutex); |
2af482a7e
|
569 |
mnt_drop_write(file->f_path.mnt); |
1da177e4c
|
570 571 572 573 574 |
out_putf: fput(file); out: return err; } |
5590ff0d5
|
575 576 |
asmlinkage long sys_fchmodat(int dfd, const char __user *filename, mode_t mode) |
1da177e4c
|
577 |
{ |
2d8f30380
|
578 579 |
struct path path; struct inode *inode; |
1da177e4c
|
580 581 |
int error; struct iattr newattrs; |
2d8f30380
|
582 |
error = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
1da177e4c
|
583 584 |
if (error) goto out; |
2d8f30380
|
585 |
inode = path.dentry->d_inode; |
1da177e4c
|
586 |
|
2d8f30380
|
587 |
error = mnt_want_write(path.mnt); |
2af482a7e
|
588 |
if (error) |
1da177e4c
|
589 |
goto dput_and_out; |
1b1dcc1b5
|
590 |
mutex_lock(&inode->i_mutex); |
1da177e4c
|
591 592 593 594 |
if (mode == (mode_t) -1) mode = inode->i_mode; newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; |
2d8f30380
|
595 |
error = notify_change(path.dentry, &newattrs); |
1b1dcc1b5
|
596 |
mutex_unlock(&inode->i_mutex); |
2d8f30380
|
597 |
mnt_drop_write(path.mnt); |
1da177e4c
|
598 |
dput_and_out: |
2d8f30380
|
599 |
path_put(&path); |
1da177e4c
|
600 601 602 |
out: return error; } |
5590ff0d5
|
603 604 605 606 |
asmlinkage long sys_chmod(const char __user *filename, mode_t mode) { return sys_fchmodat(AT_FDCWD, filename, mode); } |
1da177e4c
|
607 608 |
static int chown_common(struct dentry * dentry, uid_t user, gid_t group) { |
beb29e058
|
609 |
struct inode *inode = dentry->d_inode; |
1da177e4c
|
610 611 |
int error; struct iattr newattrs; |
1da177e4c
|
612 613 614 615 616 617 618 619 620 621 |
newattrs.ia_valid = ATTR_CTIME; if (user != (uid_t) -1) { newattrs.ia_valid |= ATTR_UID; newattrs.ia_uid = user; } if (group != (gid_t) -1) { newattrs.ia_valid |= ATTR_GID; newattrs.ia_gid = group; } if (!S_ISDIR(inode->i_mode)) |
b53767719
|
622 623 |
newattrs.ia_valid |= ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; |
1b1dcc1b5
|
624 |
mutex_lock(&inode->i_mutex); |
1da177e4c
|
625 |
error = notify_change(dentry, &newattrs); |
1b1dcc1b5
|
626 |
mutex_unlock(&inode->i_mutex); |
beb29e058
|
627 |
|
1da177e4c
|
628 629 630 631 632 |
return error; } asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group) { |
2d8f30380
|
633 |
struct path path; |
1da177e4c
|
634 |
int error; |
2d8f30380
|
635 |
error = user_path(filename, &path); |
6902d925d
|
636 637 |
if (error) goto out; |
2d8f30380
|
638 |
error = mnt_want_write(path.mnt); |
2af482a7e
|
639 640 |
if (error) goto out_release; |
2d8f30380
|
641 642 |
error = chown_common(path.dentry, user, group); mnt_drop_write(path.mnt); |
2af482a7e
|
643 |
out_release: |
2d8f30380
|
644 |
path_put(&path); |
6902d925d
|
645 |
out: |
1da177e4c
|
646 647 |
return error; } |
5590ff0d5
|
648 649 650 |
asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, int flag) { |
2d8f30380
|
651 |
struct path path; |
5590ff0d5
|
652 653 654 655 656 657 658 |
int error = -EINVAL; int follow; if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) goto out; follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; |
2d8f30380
|
659 |
error = user_path_at(dfd, filename, follow, &path); |
6902d925d
|
660 661 |
if (error) goto out; |
2d8f30380
|
662 |
error = mnt_want_write(path.mnt); |
2af482a7e
|
663 664 |
if (error) goto out_release; |
2d8f30380
|
665 666 |
error = chown_common(path.dentry, user, group); mnt_drop_write(path.mnt); |
2af482a7e
|
667 |
out_release: |
2d8f30380
|
668 |
path_put(&path); |
5590ff0d5
|
669 670 671 |
out: return error; } |
1da177e4c
|
672 673 |
asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group) { |
2d8f30380
|
674 |
struct path path; |
1da177e4c
|
675 |
int error; |
2d8f30380
|
676 |
error = user_lpath(filename, &path); |
6902d925d
|
677 678 |
if (error) goto out; |
2d8f30380
|
679 |
error = mnt_want_write(path.mnt); |
2af482a7e
|
680 681 |
if (error) goto out_release; |
2d8f30380
|
682 683 |
error = chown_common(path.dentry, user, group); mnt_drop_write(path.mnt); |
2af482a7e
|
684 |
out_release: |
2d8f30380
|
685 |
path_put(&path); |
6902d925d
|
686 |
out: |
1da177e4c
|
687 688 689 690 691 692 693 694 |
return error; } asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group) { struct file * file; int error = -EBADF; |
6902d925d
|
695 |
struct dentry * dentry; |
1da177e4c
|
696 697 |
file = fget(fd); |
6902d925d
|
698 699 |
if (!file) goto out; |
2af482a7e
|
700 701 702 |
error = mnt_want_write(file->f_path.mnt); if (error) goto out_fput; |
0f7fc9e4d
|
703 |
dentry = file->f_path.dentry; |
5a190ae69
|
704 |
audit_inode(NULL, dentry); |
6902d925d
|
705 |
error = chown_common(dentry, user, group); |
2af482a7e
|
706 707 |
mnt_drop_write(file->f_path.mnt); out_fput: |
6902d925d
|
708 709 |
fput(file); out: |
1da177e4c
|
710 711 |
return error; } |
4a3fd211c
|
712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 |
/* * You have to be very careful that these write * counts get cleaned up in error cases and * upon __fput(). This should probably never * be called outside of __dentry_open(). */ static inline int __get_file_write_access(struct inode *inode, struct vfsmount *mnt) { int error; error = get_write_access(inode); if (error) return error; /* * Do not take mount writer counts on * special files since no writes to * the mount itself will occur. */ if (!special_file(inode->i_mode)) { /* * Balanced in __fput() */ error = mnt_want_write(mnt); if (error) put_write_access(inode); } return error; } |
a1a5b3d93
|
740 |
static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
834f2a4a1
|
741 |
int flags, struct file *f, |
745ca2475
|
742 743 |
int (*open)(struct inode *, struct file *), const struct cred *cred) |
1da177e4c
|
744 |
{ |
1da177e4c
|
745 746 |
struct inode *inode; int error; |
1da177e4c
|
747 |
f->f_flags = flags; |
aeb5d7270
|
748 |
f->f_mode = (__force fmode_t)((flags+1) & O_ACCMODE) | FMODE_LSEEK | |
a1a5b3d93
|
749 |
FMODE_PREAD | FMODE_PWRITE; |
1da177e4c
|
750 751 |
inode = dentry->d_inode; if (f->f_mode & FMODE_WRITE) { |
4a3fd211c
|
752 |
error = __get_file_write_access(inode, mnt); |
1da177e4c
|
753 754 |
if (error) goto cleanup_file; |
ad775f5a8
|
755 756 |
if (!special_file(inode->i_mode)) file_take_write(f); |
1da177e4c
|
757 758 759 |
} f->f_mapping = inode->i_mapping; |
0f7fc9e4d
|
760 761 |
f->f_path.dentry = dentry; f->f_path.mnt = mnt; |
1da177e4c
|
762 763 764 |
f->f_pos = 0; f->f_op = fops_get(inode->i_fop); file_move(f, &inode->i_sb->s_files); |
745ca2475
|
765 |
error = security_dentry_open(f, cred); |
788e7dd4c
|
766 767 |
if (error) goto cleanup_all; |
834f2a4a1
|
768 769 770 771 |
if (!open && f->f_op) open = f->f_op->open; if (open) { error = open(inode, f); |
1da177e4c
|
772 773 774 |
if (error) goto cleanup_all; } |
834f2a4a1
|
775 |
|
1da177e4c
|
776 777 778 779 780 781 |
f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); /* NB: we're sure to have correct a_ops only after f_op->open */ if (f->f_flags & O_DIRECT) { |
ceffc0785
|
782 783 |
if (!f->f_mapping->a_ops || ((!f->f_mapping->a_ops->direct_IO) && |
70688e4dd
|
784 |
(!f->f_mapping->a_ops->get_xip_mem))) { |
1da177e4c
|
785 786 787 788 789 790 791 792 793 |
fput(f); f = ERR_PTR(-EINVAL); } } return f; cleanup_all: fops_put(f->f_op); |
4a3fd211c
|
794 |
if (f->f_mode & FMODE_WRITE) { |
1da177e4c
|
795 |
put_write_access(inode); |
ad775f5a8
|
796 797 798 799 800 801 802 803 |
if (!special_file(inode->i_mode)) { /* * We don't consider this a real * mnt_want/drop_write() pair * because it all happenend right * here, so just reset the state. */ file_reset_write(f); |
4a3fd211c
|
804 |
mnt_drop_write(mnt); |
ad775f5a8
|
805 |
} |
4a3fd211c
|
806 |
} |
1da177e4c
|
807 |
file_kill(f); |
0f7fc9e4d
|
808 809 |
f->f_path.dentry = NULL; f->f_path.mnt = NULL; |
1da177e4c
|
810 811 |
cleanup_file: put_filp(f); |
1da177e4c
|
812 813 814 815 |
dput(dentry); mntput(mnt); return ERR_PTR(error); } |
834f2a4a1
|
816 817 818 819 820 821 822 823 824 825 |
/** * lookup_instantiate_filp - instantiates the open intent filp * @nd: pointer to nameidata * @dentry: pointer to dentry * @open: open callback * * Helper for filesystems that want to use lookup open intents and pass back * a fully instantiated struct file to the caller. * This function is meant to be called from within a filesystem's * lookup method. |
9a56c2139
|
826 827 828 829 |
* Beware of calling it for non-regular files! Those ->open methods might block * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, * leading to a deadlock, as nobody can open that fifo anymore, because * another process to open fifo will block on locked parent when doing lookup). |
834f2a4a1
|
830 831 832 833 834 835 836 837 |
* Note that in case of error, nd->intent.open.file is destroyed, but the * path information remains valid. * If the open callback is set to NULL, then the standard f_op->open() * filesystem callback is substituted. */ struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, int (*open)(struct inode *, struct file *)) { |
745ca2475
|
838 |
const struct cred *cred = current_cred(); |
834f2a4a1
|
839 840 841 842 |
if (IS_ERR(nd->intent.open.file)) goto out; if (IS_ERR(dentry)) goto out_err; |
4ac913785
|
843 |
nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt), |
834f2a4a1
|
844 845 |
nd->intent.open.flags - 1, nd->intent.open.file, |
745ca2475
|
846 |
open, cred); |
834f2a4a1
|
847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 |
out: return nd->intent.open.file; out_err: release_open_intent(nd); nd->intent.open.file = (struct file *)dentry; goto out; } EXPORT_SYMBOL_GPL(lookup_instantiate_filp); /** * nameidata_to_filp - convert a nameidata to an open filp. * @nd: pointer to nameidata * @flags: open flags * * Note that this function destroys the original nameidata */ struct file *nameidata_to_filp(struct nameidata *nd, int flags) { |
745ca2475
|
865 |
const struct cred *cred = current_cred(); |
834f2a4a1
|
866 867 868 869 870 |
struct file *filp; /* Pick up the filp from the open intent */ filp = nd->intent.open.file; /* Has the filesystem initialised the file for us? */ |
0f7fc9e4d
|
871 |
if (filp->f_path.dentry == NULL) |
4ac913785
|
872 |
filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp, |
745ca2475
|
873 |
NULL, cred); |
834f2a4a1
|
874 |
else |
1d957f9bf
|
875 |
path_put(&nd->path); |
834f2a4a1
|
876 877 |
return filp; } |
6fdcc2162
|
878 879 880 881 |
/* * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an * error. */ |
745ca2475
|
882 883 |
struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, const struct cred *cred) |
a1a5b3d93
|
884 885 886 |
{ int error; struct file *f; |
322ee5b36
|
887 888 889 890 891 892 893 894 895 896 897 898 |
/* * We must always pass in a valid mount pointer. Historically * callers got away with not passing it, but we must enforce this at * the earliest possible point now to avoid strange problems deep in the * filesystem stack. */ if (!mnt) { printk(KERN_WARNING "%s called with NULL vfsmount ", __func__); dump_stack(); return ERR_PTR(-EINVAL); } |
a1a5b3d93
|
899 900 |
error = -ENFILE; f = get_empty_filp(); |
6fdcc2162
|
901 902 903 |
if (f == NULL) { dput(dentry); mntput(mnt); |
a1a5b3d93
|
904 |
return ERR_PTR(error); |
6fdcc2162
|
905 |
} |
a1a5b3d93
|
906 |
|
745ca2475
|
907 |
return __dentry_open(dentry, mnt, flags, f, NULL, cred); |
a1a5b3d93
|
908 |
} |
1da177e4c
|
909 |
EXPORT_SYMBOL(dentry_open); |
b01ec0ef6
|
910 |
static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
1da177e4c
|
911 |
{ |
badf16621
|
912 913 |
struct fdtable *fdt = files_fdtable(files); __FD_CLR(fd, fdt->open_fds); |
0c9e63fd3
|
914 915 |
if (fd < files->next_fd) files->next_fd = fd; |
1da177e4c
|
916 |
} |
fc9b52cd8
|
917 |
void put_unused_fd(unsigned int fd) |
1da177e4c
|
918 919 920 921 922 923 924 925 926 927 |
{ struct files_struct *files = current->files; spin_lock(&files->file_lock); __put_unused_fd(files, fd); spin_unlock(&files->file_lock); } EXPORT_SYMBOL(put_unused_fd); /* |
5590ff0d5
|
928 |
* Install a file pointer in the fd array. |
1da177e4c
|
929 930 931 932 933 934 935 936 937 938 |
* * The VFS is full of places where we drop the files lock between * setting the open_fds bitmap and installing the file in the file * array. At any such point, we are vulnerable to a dup2() race * installing a file in the array before us. We need to detect this and * fput() the struct file we are about to overwrite in this case. * * It should never happen - if we allow dup2() do it, _really_ bad things * will follow. */ |
fc9b52cd8
|
939 |
void fd_install(unsigned int fd, struct file *file) |
1da177e4c
|
940 941 |
{ struct files_struct *files = current->files; |
badf16621
|
942 |
struct fdtable *fdt; |
1da177e4c
|
943 |
spin_lock(&files->file_lock); |
badf16621
|
944 |
fdt = files_fdtable(files); |
ab2af1f50
|
945 946 |
BUG_ON(fdt->fd[fd] != NULL); rcu_assign_pointer(fdt->fd[fd], file); |
1da177e4c
|
947 948 949 950 |
spin_unlock(&files->file_lock); } EXPORT_SYMBOL(fd_install); |
5590ff0d5
|
951 |
long do_sys_open(int dfd, const char __user *filename, int flags, int mode) |
1da177e4c
|
952 |
{ |
e922efc34
|
953 954 |
char *tmp = getname(filename); int fd = PTR_ERR(tmp); |
1da177e4c
|
955 |
|
1da177e4c
|
956 |
if (!IS_ERR(tmp)) { |
f23513e8d
|
957 |
fd = get_unused_fd_flags(flags); |
1da177e4c
|
958 |
if (fd >= 0) { |
5590ff0d5
|
959 |
struct file *f = do_filp_open(dfd, tmp, flags, mode); |
fed2fc18a
|
960 961 962 963 |
if (IS_ERR(f)) { put_unused_fd(fd); fd = PTR_ERR(f); } else { |
0f7fc9e4d
|
964 |
fsnotify_open(f->f_path.dentry); |
fed2fc18a
|
965 966 |
fd_install(fd, f); } |
1da177e4c
|
967 |
} |
1da177e4c
|
968 969 970 |
putname(tmp); } return fd; |
1da177e4c
|
971 |
} |
e922efc34
|
972 973 974 |
asmlinkage long sys_open(const char __user *filename, int flags, int mode) { |
385910f2b
|
975 |
long ret; |
e922efc34
|
976 977 |
if (force_o_largefile()) flags |= O_LARGEFILE; |
385910f2b
|
978 979 |
ret = do_sys_open(AT_FDCWD, filename, flags, mode); /* avoid REGPARM breakage on x86: */ |
54a015104
|
980 |
asmlinkage_protect(3, ret, filename, flags, mode); |
385910f2b
|
981 |
return ret; |
e922efc34
|
982 |
} |
1da177e4c
|
983 |
|
5590ff0d5
|
984 985 986 |
asmlinkage long sys_openat(int dfd, const char __user *filename, int flags, int mode) { |
385910f2b
|
987 |
long ret; |
5590ff0d5
|
988 989 |
if (force_o_largefile()) flags |= O_LARGEFILE; |
385910f2b
|
990 991 |
ret = do_sys_open(dfd, filename, flags, mode); /* avoid REGPARM breakage on x86: */ |
54a015104
|
992 |
asmlinkage_protect(4, ret, dfd, filename, flags, mode); |
385910f2b
|
993 |
return ret; |
5590ff0d5
|
994 |
} |
5590ff0d5
|
995 |
|
1da177e4c
|
996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 |
#ifndef __alpha__ /* * For backward compatibility? Maybe this should be moved * into arch/i386 instead? */ asmlinkage long sys_creat(const char __user * pathname, int mode) { return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); } #endif /* * "id" is the POSIX thread ID. We use the * files pointer for this.. */ int filp_close(struct file *filp, fl_owner_t id) { |
45778ca81
|
1015 |
int retval = 0; |
1da177e4c
|
1016 1017 1018 1019 |
if (!file_count(filp)) { printk(KERN_ERR "VFS: Close: file count is 0 "); |
45778ca81
|
1020 |
return 0; |
1da177e4c
|
1021 |
} |
45778ca81
|
1022 |
if (filp->f_op && filp->f_op->flush) |
75e1fcc0b
|
1023 |
retval = filp->f_op->flush(filp, id); |
1da177e4c
|
1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 |
dnotify_flush(filp, id); locks_remove_posix(filp, id); fput(filp); return retval; } EXPORT_SYMBOL(filp_close); /* * Careful here! We test whether the file pointer is NULL before * releasing the fd. This ensures that one clone task can't release * an fd while another clone is opening it. */ asmlinkage long sys_close(unsigned int fd) { struct file * filp; struct files_struct *files = current->files; |
badf16621
|
1042 |
struct fdtable *fdt; |
ee731f4f7
|
1043 |
int retval; |
1da177e4c
|
1044 1045 |
spin_lock(&files->file_lock); |
badf16621
|
1046 1047 |
fdt = files_fdtable(files); if (fd >= fdt->max_fds) |
1da177e4c
|
1048 |
goto out_unlock; |
badf16621
|
1049 |
filp = fdt->fd[fd]; |
1da177e4c
|
1050 1051 |
if (!filp) goto out_unlock; |
ab2af1f50
|
1052 |
rcu_assign_pointer(fdt->fd[fd], NULL); |
badf16621
|
1053 |
FD_CLR(fd, fdt->close_on_exec); |
1da177e4c
|
1054 1055 |
__put_unused_fd(files, fd); spin_unlock(&files->file_lock); |
ee731f4f7
|
1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 |
retval = filp_close(filp, files); /* can't restart close syscall because file table entry was cleared */ if (unlikely(retval == -ERESTARTSYS || retval == -ERESTARTNOINTR || retval == -ERESTARTNOHAND || retval == -ERESTART_RESTARTBLOCK)) retval = -EINTR; return retval; |
1da177e4c
|
1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 |
out_unlock: spin_unlock(&files->file_lock); return -EBADF; } EXPORT_SYMBOL(sys_close); /* * This routine simulates a hangup on the tty, to arrange that users * are given clean terminals at login time. */ asmlinkage long sys_vhangup(void) { if (capable(CAP_SYS_TTY_CONFIG)) { |
2cb5998b5
|
1081 |
tty_vhangup_self(); |
1da177e4c
|
1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 |
return 0; } return -EPERM; } /* * Called when an inode is about to be open. * We use this to disallow opening large files on 32bit systems if * the caller didn't specify O_LARGEFILE. On 64bit systems we force * on this flag in sys_open. */ int generic_file_open(struct inode * inode, struct file * filp) { if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) |
a9c62a18a
|
1096 |
return -EOVERFLOW; |
1da177e4c
|
1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 |
return 0; } EXPORT_SYMBOL(generic_file_open); /* * This is used by subsystems that don't want seekable * file descriptors */ int nonseekable_open(struct inode *inode, struct file *filp) { filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); return 0; } EXPORT_SYMBOL(nonseekable_open); |