diff options
| -rw-r--r-- | fs/file.c | 64 | ||||
| -rw-r--r-- | fs/open.c | 20 | ||||
| -rw-r--r-- | include/linux/fdtable.h | 2 | ||||
| -rw-r--r-- | include/linux/syscalls.h | 2 |
4 files changed, 80 insertions, 8 deletions
diff --git a/fs/file.c b/fs/file.c index abb8b7081d7a..1b8ff05e8311 100644 --- a/fs/file.c +++ b/fs/file.c @@ -10,6 +10,7 @@ #include <linux/syscalls.h> #include <linux/export.h> #include <linux/fs.h> +#include <linux/kernel.h> #include <linux/mm.h> #include <linux/sched/signal.h> #include <linux/slab.h> @@ -620,12 +621,9 @@ void fd_install(unsigned int fd, struct file *file) EXPORT_SYMBOL(fd_install); -/* - * The same warnings as for __alloc_fd()/__fd_install() apply here... - */ -int __close_fd(struct files_struct *files, unsigned fd) +static struct file *pick_file(struct files_struct *files, unsigned fd) { - struct file *file; + struct file *file = NULL; struct fdtable *fdt; spin_lock(&files->file_lock); @@ -637,15 +635,65 @@ int __close_fd(struct files_struct *files, unsigned fd) goto out_unlock; rcu_assign_pointer(fdt->fd[fd], NULL); __put_unused_fd(files, fd); - spin_unlock(&files->file_lock); - return filp_close(file, files); out_unlock: spin_unlock(&files->file_lock); - return -EBADF; + return file; +} + +/* + * The same warnings as for __alloc_fd()/__fd_install() apply here... + */ +int __close_fd(struct files_struct *files, unsigned fd) +{ + struct file *file; + + file = pick_file(files, fd); + if (!file) + return -EBADF; + + return filp_close(file, files); } EXPORT_SYMBOL(__close_fd); /* for ksys_close() */ +/** + * __close_range() - Close all file descriptors in a given range. + * + * @fd: starting file descriptor to close + * @max_fd: last file descriptor to close + * + * This closes a range of file descriptors. All file descriptors + * from @fd up to and including @max_fd are closed. + */ +int __close_range(struct files_struct *files, unsigned fd, unsigned max_fd) +{ + unsigned int cur_max; + + if (fd > max_fd) + return -EINVAL; + + rcu_read_lock(); + cur_max = files_fdtable(files)->max_fds; + rcu_read_unlock(); + + /* cap to last valid index into fdtable */ + cur_max--; + + max_fd = min(max_fd, cur_max); + while (fd <= max_fd) { + struct file *file; + + file = pick_file(files, fd++); + if (!file) + continue; + + filp_close(file, files); + cond_resched(); + } + + return 0; +} + /* * variant of __close_fd that gets a ref on the file for later fput. * The caller must ensure that filp_close() called on the file, and then diff --git a/fs/open.c b/fs/open.c index 6cd48a61cda3..073ea3c45347 100644 --- a/fs/open.c +++ b/fs/open.c @@ -1310,6 +1310,26 @@ SYSCALL_DEFINE1(close, unsigned int, fd) return retval; } +/** + * close_range() - Close all file descriptors in a given range. + * + * @fd: starting file descriptor to close + * @max_fd: last file descriptor to close + * @flags: reserved for future extensions + * + * This closes a range of file descriptors. All file descriptors + * from @fd up to and including @max_fd are closed. + * Currently, errors to close a given file descriptor are ignored. + */ +SYSCALL_DEFINE3(close_range, unsigned int, fd, unsigned int, max_fd, + unsigned int, flags) +{ + if (flags) + return -EINVAL; + + return __close_range(current->files, fd, max_fd); +} + /* * This routine simulates a hangup on the tty, to arrange that users * are given clean terminals at login time. diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index f07c55ea0c22..fcd07181a365 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -121,6 +121,8 @@ extern void __fd_install(struct files_struct *files, unsigned int fd, struct file *file); extern int __close_fd(struct files_struct *files, unsigned int fd); +extern int __close_range(struct files_struct *files, unsigned int fd, + unsigned int max_fd); extern int __close_fd_get_file(unsigned int fd, struct file **res); extern struct kmem_cache *files_cachep; diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 7c354c2955f5..b22382db89cf 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -444,6 +444,8 @@ asmlinkage long sys_openat(int dfd, const char __user *filename, int flags, asmlinkage long sys_openat2(int dfd, const char __user *filename, struct open_how *how, size_t size); asmlinkage long sys_close(unsigned int fd); +asmlinkage long sys_close_range(unsigned int fd, unsigned int max_fd, + unsigned int flags); asmlinkage long sys_vhangup(void); /* fs/pipe.c */ |