From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- fs/fcntl.c | 601 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 601 insertions(+) create mode 100644 fs/fcntl.c (limited to 'fs/fcntl.c') diff --git a/fs/fcntl.c b/fs/fcntl.c new file mode 100644 index 000000000000..c1708066bf55 --- /dev/null +++ b/fs/fcntl.c @@ -0,0 +1,601 @@ +/* + * linux/fs/fcntl.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +void fastcall set_close_on_exec(unsigned int fd, int flag) +{ + struct files_struct *files = current->files; + spin_lock(&files->file_lock); + if (flag) + FD_SET(fd, files->close_on_exec); + else + FD_CLR(fd, files->close_on_exec); + spin_unlock(&files->file_lock); +} + +static inline int get_close_on_exec(unsigned int fd) +{ + struct files_struct *files = current->files; + int res; + spin_lock(&files->file_lock); + res = FD_ISSET(fd, files->close_on_exec); + spin_unlock(&files->file_lock); + return res; +} + +/* + * locate_fd finds a free file descriptor in the open_fds fdset, + * expanding the fd arrays if necessary. Must be called with the + * file_lock held for write. + */ + +static int locate_fd(struct files_struct *files, + struct file *file, unsigned int orig_start) +{ + unsigned int newfd; + unsigned int start; + int error; + + error = -EINVAL; + if (orig_start >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) + goto out; + +repeat: + /* + * Someone might have closed fd's in the range + * orig_start..files->next_fd + */ + start = orig_start; + if (start < files->next_fd) + start = files->next_fd; + + newfd = start; + if (start < files->max_fdset) { + newfd = find_next_zero_bit(files->open_fds->fds_bits, + files->max_fdset, start); + } + + error = -EMFILE; + if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) + goto out; + + error = expand_files(files, newfd); + if (error < 0) + goto out; + + /* + * If we needed to expand the fs array we + * might have blocked - try again. + */ + if (error) + goto repeat; + + if (start <= files->next_fd) + files->next_fd = newfd + 1; + + error = newfd; + +out: + return error; +} + +static int dupfd(struct file *file, unsigned int start) +{ + struct files_struct * files = current->files; + int fd; + + spin_lock(&files->file_lock); + fd = locate_fd(files, file, start); + if (fd >= 0) { + FD_SET(fd, files->open_fds); + FD_CLR(fd, files->close_on_exec); + spin_unlock(&files->file_lock); + fd_install(fd, file); + } else { + spin_unlock(&files->file_lock); + fput(file); + } + + return fd; +} + +asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd) +{ + int err = -EBADF; + struct file * file, *tofree; + struct files_struct * files = current->files; + + spin_lock(&files->file_lock); + if (!(file = fcheck(oldfd))) + goto out_unlock; + err = newfd; + if (newfd == oldfd) + goto out_unlock; + err = -EBADF; + if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) + goto out_unlock; + get_file(file); /* We are now finished with oldfd */ + + err = expand_files(files, newfd); + if (err < 0) + goto out_fput; + + /* To avoid races with open() and dup(), we will mark the fd as + * in-use in the open-file bitmap throughout the entire dup2() + * process. This is quite safe: do_close() uses the fd array + * entry, not the bitmap, to decide what work needs to be + * done. --sct */ + /* Doesn't work. open() might be there first. --AV */ + + /* Yes. It's a race. In user space. Nothing sane to do */ + err = -EBUSY; + tofree = files->fd[newfd]; + if (!tofree && FD_ISSET(newfd, files->open_fds)) + goto out_fput; + + files->fd[newfd] = file; + FD_SET(newfd, files->open_fds); + FD_CLR(newfd, files->close_on_exec); + spin_unlock(&files->file_lock); + + if (tofree) + filp_close(tofree, files); + err = newfd; +out: + return err; +out_unlock: + spin_unlock(&files->file_lock); + goto out; + +out_fput: + spin_unlock(&files->file_lock); + fput(file); + goto out; +} + +asmlinkage long sys_dup(unsigned int fildes) +{ + int ret = -EBADF; + struct file * file = fget(fildes); + + if (file) + ret = dupfd(file, 0); + return ret; +} + +#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | FASYNC | O_DIRECT | O_NOATIME) + +static int setfl(int fd, struct file * filp, unsigned long arg) +{ + struct inode * inode = filp->f_dentry->d_inode; + int error = 0; + + /* O_APPEND cannot be cleared if the file is marked as append-only */ + if (!(arg & O_APPEND) && IS_APPEND(inode)) + return -EPERM; + + /* O_NOATIME can only be set by the owner or superuser */ + if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME)) + if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER)) + return -EPERM; + + /* required for strict SunOS emulation */ + if (O_NONBLOCK != O_NDELAY) + if (arg & O_NDELAY) + arg |= O_NONBLOCK; + + if (arg & O_DIRECT) { + if (!filp->f_mapping || !filp->f_mapping->a_ops || + !filp->f_mapping->a_ops->direct_IO) + return -EINVAL; + } + + if (filp->f_op && filp->f_op->check_flags) + error = filp->f_op->check_flags(arg); + if (error) + return error; + + lock_kernel(); + if ((arg ^ filp->f_flags) & FASYNC) { + if (filp->f_op && filp->f_op->fasync) { + error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0); + if (error < 0) + goto out; + } + } + + filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK); + out: + unlock_kernel(); + return error; +} + +static void f_modown(struct file *filp, unsigned long pid, + uid_t uid, uid_t euid, int force) +{ + write_lock_irq(&filp->f_owner.lock); + if (force || !filp->f_owner.pid) { + filp->f_owner.pid = pid; + filp->f_owner.uid = uid; + filp->f_owner.euid = euid; + } + write_unlock_irq(&filp->f_owner.lock); +} + +int f_setown(struct file *filp, unsigned long arg, int force) +{ + int err; + + err = security_file_set_fowner(filp); + if (err) + return err; + + f_modown(filp, arg, current->uid, current->euid, force); + return 0; +} + +EXPORT_SYMBOL(f_setown); + +void f_delown(struct file *filp) +{ + f_modown(filp, 0, 0, 0, 1); +} + +static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, + struct file *filp) +{ + long err = -EINVAL; + + switch (cmd) { + case F_DUPFD: + get_file(filp); + err = dupfd(filp, arg); + break; + case F_GETFD: + err = get_close_on_exec(fd) ? FD_CLOEXEC : 0; + break; + case F_SETFD: + err = 0; + set_close_on_exec(fd, arg & FD_CLOEXEC); + break; + case F_GETFL: + err = filp->f_flags; + break; + case F_SETFL: + err = setfl(fd, filp, arg); + break; + case F_GETLK: + err = fcntl_getlk(filp, (struct flock __user *) arg); + break; + case F_SETLK: + case F_SETLKW: + err = fcntl_setlk(filp, cmd, (struct flock __user *) arg); + break; + case F_GETOWN: + /* + * XXX If f_owner is a process group, the + * negative return value will get converted + * into an error. Oops. If we keep the + * current syscall conventions, the only way + * to fix this will be in libc. + */ + err = filp->f_owner.pid; + force_successful_syscall_return(); + break; + case F_SETOWN: + err = f_setown(filp, arg, 1); + break; + case F_GETSIG: + err = filp->f_owner.signum; + break; + case F_SETSIG: + /* arg == 0 restores default behaviour. */ + if (arg < 0 || arg > _NSIG) { + break; + } + err = 0; + filp->f_owner.signum = arg; + break; + case F_GETLEASE: + err = fcntl_getlease(filp); + break; + case F_SETLEASE: + err = fcntl_setlease(fd, filp, arg); + break; + case F_NOTIFY: + err = fcntl_dirnotify(fd, filp, arg); + break; + default: + break; + } + return err; +} + +asmlinkage long sys_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg) +{ + struct file *filp; + long err = -EBADF; + + filp = fget(fd); + if (!filp) + goto out; + + err = security_file_fcntl(filp, cmd, arg); + if (err) { + fput(filp); + return err; + } + + err = do_fcntl(fd, cmd, arg, filp); + + fput(filp); +out: + return err; +} + +#if BITS_PER_LONG == 32 +asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg) +{ + struct file * filp; + long err; + + err = -EBADF; + filp = fget(fd); + if (!filp) + goto out; + + err = security_file_fcntl(filp, cmd, arg); + if (err) { + fput(filp); + return err; + } + err = -EBADF; + + switch (cmd) { + case F_GETLK64: + err = fcntl_getlk64(filp, (struct flock64 __user *) arg); + break; + case F_SETLK64: + case F_SETLKW64: + err = fcntl_setlk64(filp, cmd, (struct flock64 __user *) arg); + break; + default: + err = do_fcntl(fd, cmd, arg, filp); + break; + } + fput(filp); +out: + return err; +} +#endif + +/* Table to convert sigio signal codes into poll band bitmaps */ + +static long band_table[NSIGPOLL] = { + POLLIN | POLLRDNORM, /* POLL_IN */ + POLLOUT | POLLWRNORM | POLLWRBAND, /* POLL_OUT */ + POLLIN | POLLRDNORM | POLLMSG, /* POLL_MSG */ + POLLERR, /* POLL_ERR */ + POLLPRI | POLLRDBAND, /* POLL_PRI */ + POLLHUP | POLLERR /* POLL_HUP */ +}; + +static inline int sigio_perm(struct task_struct *p, + struct fown_struct *fown, int sig) +{ + return (((fown->euid == 0) || + (fown->euid == p->suid) || (fown->euid == p->uid) || + (fown->uid == p->suid) || (fown->uid == p->uid)) && + !security_file_send_sigiotask(p, fown, sig)); +} + +static void send_sigio_to_task(struct task_struct *p, + struct fown_struct *fown, + int fd, + int reason) +{ + if (!sigio_perm(p, fown, fown->signum)) + return; + + switch (fown->signum) { + siginfo_t si; + default: + /* Queue a rt signal with the appropriate fd as its + value. We use SI_SIGIO as the source, not + SI_KERNEL, since kernel signals always get + delivered even if we can't queue. Failure to + queue in this case _should_ be reported; we fall + back to SIGIO in that case. --sct */ + si.si_signo = fown->signum; + si.si_errno = 0; + si.si_code = reason; + /* Make sure we are called with one of the POLL_* + reasons, otherwise we could leak kernel stack into + userspace. */ + if ((reason & __SI_MASK) != __SI_POLL) + BUG(); + if (reason - POLL_IN >= NSIGPOLL) + si.si_band = ~0L; + else + si.si_band = band_table[reason - POLL_IN]; + si.si_fd = fd; + if (!send_sig_info(fown->signum, &si, p)) + break; + /* fall-through: fall back on the old plain SIGIO signal */ + case 0: + send_group_sig_info(SIGIO, SEND_SIG_PRIV, p); + } +} + +void send_sigio(struct fown_struct *fown, int fd, int band) +{ + struct task_struct *p; + int pid; + + read_lock(&fown->lock); + pid = fown->pid; + if (!pid) + goto out_unlock_fown; + + read_lock(&tasklist_lock); + if (pid > 0) { + p = find_task_by_pid(pid); + if (p) { + send_sigio_to_task(p, fown, fd, band); + } + } else { + do_each_task_pid(-pid, PIDTYPE_PGID, p) { + send_sigio_to_task(p, fown, fd, band); + } while_each_task_pid(-pid, PIDTYPE_PGID, p); + } + read_unlock(&tasklist_lock); + out_unlock_fown: + read_unlock(&fown->lock); +} + +static void send_sigurg_to_task(struct task_struct *p, + struct fown_struct *fown) +{ + if (sigio_perm(p, fown, SIGURG)) + send_group_sig_info(SIGURG, SEND_SIG_PRIV, p); +} + +int send_sigurg(struct fown_struct *fown) +{ + struct task_struct *p; + int pid, ret = 0; + + read_lock(&fown->lock); + pid = fown->pid; + if (!pid) + goto out_unlock_fown; + + ret = 1; + + read_lock(&tasklist_lock); + if (pid > 0) { + p = find_task_by_pid(pid); + if (p) { + send_sigurg_to_task(p, fown); + } + } else { + do_each_task_pid(-pid, PIDTYPE_PGID, p) { + send_sigurg_to_task(p, fown); + } while_each_task_pid(-pid, PIDTYPE_PGID, p); + } + read_unlock(&tasklist_lock); + out_unlock_fown: + read_unlock(&fown->lock); + return ret; +} + +static DEFINE_RWLOCK(fasync_lock); +static kmem_cache_t *fasync_cache; + +/* + * fasync_helper() is used by some character device drivers (mainly mice) + * to set up the fasync queue. It returns negative on error, 0 if it did + * no changes and positive if it added/deleted the entry. + */ +int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp) +{ + struct fasync_struct *fa, **fp; + struct fasync_struct *new = NULL; + int result = 0; + + if (on) { + new = kmem_cache_alloc(fasync_cache, SLAB_KERNEL); + if (!new) + return -ENOMEM; + } + write_lock_irq(&fasync_lock); + for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { + if (fa->fa_file == filp) { + if(on) { + fa->fa_fd = fd; + kmem_cache_free(fasync_cache, new); + } else { + *fp = fa->fa_next; + kmem_cache_free(fasync_cache, fa); + result = 1; + } + goto out; + } + } + + if (on) { + new->magic = FASYNC_MAGIC; + new->fa_file = filp; + new->fa_fd = fd; + new->fa_next = *fapp; + *fapp = new; + result = 1; + } +out: + write_unlock_irq(&fasync_lock); + return result; +} + +EXPORT_SYMBOL(fasync_helper); + +void __kill_fasync(struct fasync_struct *fa, int sig, int band) +{ + while (fa) { + struct fown_struct * fown; + if (fa->magic != FASYNC_MAGIC) { + printk(KERN_ERR "kill_fasync: bad magic number in " + "fasync_struct!\n"); + return; + } + fown = &fa->fa_file->f_owner; + /* Don't send SIGURG to processes which have not set a + queued signum: SIGURG has its own default signalling + mechanism. */ + if (!(sig == SIGURG && fown->signum == 0)) + send_sigio(fown, fa->fa_fd, band); + fa = fa->fa_next; + } +} + +EXPORT_SYMBOL(__kill_fasync); + +void kill_fasync(struct fasync_struct **fp, int sig, int band) +{ + /* First a quick test without locking: usually + * the list is empty. + */ + if (*fp) { + read_lock(&fasync_lock); + /* reread *fp after obtaining the lock */ + __kill_fasync(*fp, sig, band); + read_unlock(&fasync_lock); + } +} +EXPORT_SYMBOL(kill_fasync); + +static int __init fasync_init(void) +{ + fasync_cache = kmem_cache_create("fasync_cache", + sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL, NULL); + return 0; +} + +module_init(fasync_init) -- cgit v1.2.3