diff options
Diffstat (limited to 'fs/fcntl.c')
-rw-r--r-- | fs/fcntl.c | 166 |
1 files changed, 20 insertions, 146 deletions
@@ -26,124 +26,6 @@ #include <asm/siginfo.h> #include <asm/uaccess.h> -void set_close_on_exec(unsigned int fd, int flag) -{ - struct files_struct *files = current->files; - struct fdtable *fdt; - spin_lock(&files->file_lock); - fdt = files_fdtable(files); - if (flag) - __set_close_on_exec(fd, fdt); - else - __clear_close_on_exec(fd, fdt); - spin_unlock(&files->file_lock); -} - -static bool get_close_on_exec(unsigned int fd) -{ - struct files_struct *files = current->files; - struct fdtable *fdt; - bool res; - rcu_read_lock(); - fdt = files_fdtable(files); - res = close_on_exec(fd, fdt); - rcu_read_unlock(); - return res; -} - -SYSCALL_DEFINE3(dup3, unsigned int, oldfd, unsigned int, newfd, int, flags) -{ - int err = -EBADF; - struct file * file, *tofree; - struct files_struct * files = current->files; - struct fdtable *fdt; - - if ((flags & ~O_CLOEXEC) != 0) - return -EINVAL; - - if (unlikely(oldfd == newfd)) - return -EINVAL; - - spin_lock(&files->file_lock); - err = expand_files(files, newfd); - file = fcheck(oldfd); - if (unlikely(!file)) - goto Ebadf; - if (unlikely(err < 0)) { - if (err == -EMFILE) - goto Ebadf; - goto out_unlock; - } - /* - * We need to detect attempts to do dup2() over allocated but still - * not finished descriptor. NB: OpenBSD avoids that at the price of - * extra work in their equivalent of fget() - they insert struct - * file immediately after grabbing descriptor, mark it larval if - * more work (e.g. actual opening) is needed and make sure that - * fget() treats larval files as absent. Potentially interesting, - * but while extra work in fget() is trivial, locking implications - * and amount of surgery on open()-related paths in VFS are not. - * FreeBSD fails with -EBADF in the same situation, NetBSD "solution" - * deadlocks in rather amusing ways, AFAICS. All of that is out of - * scope of POSIX or SUS, since neither considers shared descriptor - * tables and this condition does not arise without those. - */ - err = -EBUSY; - fdt = files_fdtable(files); - tofree = fdt->fd[newfd]; - if (!tofree && fd_is_open(newfd, fdt)) - goto out_unlock; - get_file(file); - rcu_assign_pointer(fdt->fd[newfd], file); - __set_open_fd(newfd, fdt); - if (flags & O_CLOEXEC) - __set_close_on_exec(newfd, fdt); - else - __clear_close_on_exec(newfd, fdt); - spin_unlock(&files->file_lock); - - if (tofree) - filp_close(tofree, files); - - return newfd; - -Ebadf: - err = -EBADF; -out_unlock: - spin_unlock(&files->file_lock); - return err; -} - -SYSCALL_DEFINE2(dup2, unsigned int, oldfd, unsigned int, newfd) -{ - if (unlikely(newfd == oldfd)) { /* corner case */ - struct files_struct *files = current->files; - int retval = oldfd; - - rcu_read_lock(); - if (!fcheck_files(files, oldfd)) - retval = -EBADF; - rcu_read_unlock(); - return retval; - } - return sys_dup3(oldfd, newfd, 0); -} - -SYSCALL_DEFINE1(dup, unsigned int, fildes) -{ - int ret = -EBADF; - struct file *file = fget_raw(fildes); - - if (file) { - ret = get_unused_fd(); - if (ret >= 0) - fd_install(ret, file); - else - fput(file); - } - return ret; -} - #define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME) static int setfl(int fd, struct file * filp, unsigned long arg) @@ -267,7 +149,7 @@ pid_t f_getown(struct file *filp) static int f_setown_ex(struct file *filp, unsigned long arg) { - struct f_owner_ex * __user owner_p = (void * __user)arg; + struct f_owner_ex __user *owner_p = (void __user *)arg; struct f_owner_ex owner; struct pid *pid; int type; @@ -307,7 +189,7 @@ static int f_setown_ex(struct file *filp, unsigned long arg) static int f_getown_ex(struct file *filp, unsigned long arg) { - struct f_owner_ex * __user owner_p = (void * __user)arg; + struct f_owner_ex __user *owner_p = (void __user *)arg; struct f_owner_ex owner; int ret = 0; @@ -345,7 +227,7 @@ static int f_getown_ex(struct file *filp, unsigned long arg) static int f_getowner_uids(struct file *filp, unsigned long arg) { struct user_namespace *user_ns = current_user_ns(); - uid_t * __user dst = (void * __user)arg; + uid_t __user *dst = (void __user *)arg; uid_t src[2]; int err; @@ -373,14 +255,10 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, switch (cmd) { case F_DUPFD: + err = f_dupfd(arg, filp, 0); + break; case F_DUPFD_CLOEXEC: - if (arg >= rlimit(RLIMIT_NOFILE)) - break; - err = alloc_fd(arg, cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0); - if (err >= 0) { - get_file(filp); - fd_install(err, filp); - } + err = f_dupfd(arg, filp, O_CLOEXEC); break; case F_GETFD: err = get_close_on_exec(fd) ? FD_CLOEXEC : 0; @@ -470,25 +348,23 @@ static int check_fcntl_cmd(unsigned cmd) SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) { - struct file *filp; - int fput_needed; + struct fd f = fdget_raw(fd); long err = -EBADF; - filp = fget_raw_light(fd, &fput_needed); - if (!filp) + if (!f.file) goto out; - if (unlikely(filp->f_mode & FMODE_PATH)) { + if (unlikely(f.file->f_mode & FMODE_PATH)) { if (!check_fcntl_cmd(cmd)) goto out1; } - err = security_file_fcntl(filp, cmd, arg); + err = security_file_fcntl(f.file, cmd, arg); if (!err) - err = do_fcntl(fd, cmd, arg, filp); + err = do_fcntl(fd, cmd, arg, f.file); out1: - fput_light(filp, fput_needed); + fdput(f); out: return err; } @@ -497,38 +373,36 @@ out: SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, unsigned long, arg) { - struct file * filp; + struct fd f = fdget_raw(fd); long err = -EBADF; - int fput_needed; - filp = fget_raw_light(fd, &fput_needed); - if (!filp) + if (!f.file) goto out; - if (unlikely(filp->f_mode & FMODE_PATH)) { + if (unlikely(f.file->f_mode & FMODE_PATH)) { if (!check_fcntl_cmd(cmd)) goto out1; } - err = security_file_fcntl(filp, cmd, arg); + err = security_file_fcntl(f.file, cmd, arg); if (err) goto out1; switch (cmd) { case F_GETLK64: - err = fcntl_getlk64(filp, (struct flock64 __user *) arg); + err = fcntl_getlk64(f.file, (struct flock64 __user *) arg); break; case F_SETLK64: case F_SETLKW64: - err = fcntl_setlk64(fd, filp, cmd, + err = fcntl_setlk64(fd, f.file, cmd, (struct flock64 __user *) arg); break; default: - err = do_fcntl(fd, cmd, arg, filp); + err = do_fcntl(fd, cmd, arg, f.file); break; } out1: - fput_light(filp, fput_needed); + fdput(f); out: return err; } |