1 // SPDX-License-Identifier: GPL-2.0
3  * Copyright (C) 2002 - 2008 Jeff Dike (jdike@{addtoit,linux.intel}.com)
9 #include <poll.h>
15 #include <init.h>
24 static int write_sigio_pid = -1;
30  * On the UML side, they are changed under the sigio_lock.
32 #define SIGIO_FDS_INIT {-1, -1}
38 	struct pollfd *poll;  member
61 		n = poll(fds->poll, fds->used, -1);  in write_sigio_thread()
65 			printk(UM_KERN_ERR "write_sigio_thread : poll returned "  in write_sigio_thread()
68 		for (i = 0; i < fds->used; i++) {  in write_sigio_thread()
69 			p = &fds->poll[i];  in write_sigio_thread()
70 			if (p->revents == 0)  in write_sigio_thread()
72 			if (p->fd == sigio_private[1]) {  in write_sigio_thread()
78 					       "read on socket failed, "  in write_sigio_thread()
87 				fds->used--;  in write_sigio_thread()
88 				memmove(&fds->poll[i], &fds->poll[i + 1],  in write_sigio_thread()
89 					(fds->used - i) * sizeof(*fds->poll));  in write_sigio_thread()
95 				       "write on socket failed, err = %d\n",  in write_sigio_thread()
107 	if (n <= polls->size)  in need_poll()
114 		return -ENOMEM;  in need_poll()
117 	memcpy(new, polls->poll, polls->used * sizeof(struct pollfd));  in need_poll()
118 	kfree(polls->poll);  in need_poll()
120 	polls->poll = new;  in need_poll()
121 	polls->size = n;  in need_poll()
154 	if (write_sigio_pid != -1) {  in update_thread()
158 	write_sigio_pid = -1;  in update_thread()
173 		if (all_sigio_fds.poll[i].fd == fd)  in __add_sigio_fd()
177 		return -ENOSPC;  in __add_sigio_fd()
179 	p = &all_sigio_fds.poll[i];  in __add_sigio_fd()
182 		if (current_poll.poll[i].fd == fd)  in __add_sigio_fd()
191 	memcpy(next_poll.poll, current_poll.poll,  in __add_sigio_fd()
193 	next_poll.poll[n] = *p;  in __add_sigio_fd()
218 	 * This is called from exitcalls elsewhere in UML - if  in __ignore_sigio_fd()
220 	 * or fail because the thread is no longer running.  in __ignore_sigio_fd()
222 	if (write_sigio_pid == -1)  in __ignore_sigio_fd()
223 		return -EIO;  in __ignore_sigio_fd()
226 		if (current_poll.poll[i].fd == fd)  in __ignore_sigio_fd()
230 		return -ENOENT;  in __ignore_sigio_fd()
232 	err = need_poll(&next_poll, current_poll.used - 1);  in __ignore_sigio_fd()
237 		p = &current_poll.poll[i];  in __ignore_sigio_fd()
238 		if (p->fd != fd)  in __ignore_sigio_fd()
239 			next_poll.poll[n++] = *p;  in __ignore_sigio_fd()
241 	next_poll.used = current_poll.used - 1;  in __ignore_sigio_fd()
266 		       "poll\n");  in setup_initial_poll()
283 	/* We call this *tons* of times - and most ones we must just fail. */  in write_sigio_workaround()
288 	if (l_write_sigio_pid != -1)  in write_sigio_workaround()
293 		printk(UM_KERN_ERR "write_sigio_workaround - os_pipe 1 failed, "  in write_sigio_workaround()
294 		       "err = %d\n", -err);  in write_sigio_workaround()
299 		printk(UM_KERN_ERR "write_sigio_workaround - os_pipe 2 failed, "  in write_sigio_workaround()
300 		       "err = %d\n", -err);  in write_sigio_workaround()
312 	 * to happen, and no more than once at the boot.  in write_sigio_workaround()
314 	if (write_sigio_pid != -1)  in write_sigio_workaround()
317 	current_poll = ((struct pollfds) { .poll 	= p,  in write_sigio_workaround()
338 	write_sigio_pid = -1;  in write_sigio_workaround()
339 	write_sigio_fds[0] = -1;  in write_sigio_workaround()
340 	write_sigio_fds[1] = -1;  in write_sigio_workaround()
341 	sigio_private[0] = -1;  in write_sigio_workaround()
342 	sigio_private[1] = -1;  in write_sigio_workaround()
344 	current_poll = ((struct pollfds) { .poll	= NULL,  in write_sigio_workaround()
367 		printk(UM_KERN_ERR "maybe_sigio_broken - failed to add pollfd "  in sigio_broken()
372 	all_sigio_fds.poll[all_sigio_fds.used++] =  in sigio_broken()
396 	if (write_sigio_pid == -1)  in sigio_cleanup()
401 	write_sigio_pid = -1;  in sigio_cleanup()
424 	info->err = 0;  in openpty_cb()
425 	if (openpty(&info->master, &info->slave, NULL, NULL, NULL))  in openpty_cb()
426 		info->err = -errno;  in openpty_cb()
435 		return -errno;  in async_pty()
439 		return -errno;  in async_pty()
442 		return -errno;  in async_pty()
450 	struct openpty_arg pty = { .master = -1, .slave = -1 };  in check_one_sigio()
456 		       -pty.err);  in check_one_sigio()
463 	if ((master == -1) || (slave == -1)) {  in check_one_sigio()
473 		      -err);  in check_one_sigio()
480 		       "err = %d\n", -err);  in check_one_sigio()
529 	} else if (n == -EAGAIN)  in tty_output()
530 		printk(UM_KERN_CONT "No, enabling workaround\n");  in tty_output()
539 		printk(UM_KERN_WARNING "No pseudo-terminals available - "  in check_sigio()