Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #include <stdlib.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) #include <unistd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <termios.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <sys/ioctl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include "chan_user.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <os.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <um_malloc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) void generic_close(int fd, void *unused)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 	close(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) int generic_read(int fd, char *c_out, void *unused)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	int n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	n = read(fd, c_out, sizeof(*c_out));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	if (n > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 		return n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 	else if (n == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	else if (errno == EAGAIN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 	return -errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) /* XXX Trivial wrapper around write */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) int generic_write(int fd, const char *buf, int n, void *unused)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	err = write(fd, buf, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	if (err > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 		return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	else if (errno == EAGAIN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	else if (err == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	return -errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) int generic_window_size(int fd, void *unused, unsigned short *rows_out,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 			unsigned short *cols_out)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	struct winsize size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	if (ioctl(fd, TIOCGWINSZ, &size) < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 		return -errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	ret = ((*rows_out != size.ws_row) || (*cols_out != size.ws_col));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	*rows_out = size.ws_row;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	*cols_out = size.ws_col;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) void generic_free(void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	kfree(data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) int generic_console_write(int fd, const char *buf, int n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	sigset_t old, no_sigio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	struct termios save, new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	if (isatty(fd)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 		sigemptyset(&no_sigio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		sigaddset(&no_sigio, SIGIO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 		if (sigprocmask(SIG_BLOCK, &no_sigio, &old))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 			goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 		CATCH_EINTR(err = tcgetattr(fd, &save));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 		if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 			goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 		new = save;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 		 * The terminal becomes a bit less raw, to handle \n also as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 		 * "Carriage Return", not only as "New Line". Otherwise, the new
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		 * line won't start at the first column.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 		new.c_oflag |= OPOST;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &new));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 		if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 			goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	err = generic_write(fd, buf, n, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	 * Restore raw mode, in any case; we *must* ignore any error apart
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	 * EINTR, except for debug.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	if (isatty(fd)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		CATCH_EINTR(tcsetattr(fd, TCSAFLUSH, &save));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 		sigprocmask(SIG_SETMASK, &old, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	return -errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)  * UML SIGWINCH handling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)  * The point of this is to handle SIGWINCH on consoles which have host
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)  * ttys and relay them inside UML to whatever might be running on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)  * console and cares about the window size (since SIGWINCH notifies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)  * about terminal size changes).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)  * So, we have a separate thread for each host tty attached to a UML
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)  * device (side-issue - I'm annoyed that one thread can't have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)  * multiple controlling ttys for the purpose of handling SIGWINCH, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)  * I imagine there are other reasons that doesn't make any sense).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)  * SIGWINCH can't be received synchronously, so you have to set up to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)  * receive it as a signal.  That being the case, if you are going to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)  * wait for it, it is convenient to sit in sigsuspend() and wait for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)  * the signal to bounce you out of it (see below for how we make sure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)  * to exit only on SIGWINCH).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) static void winch_handler(int sig)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) struct winch_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	int pty_fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	int pipe_fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) static int winch_thread(void *arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	struct winch_data *data = arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	sigset_t sigs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	int pty_fd, pipe_fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	int count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	char c = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	pty_fd = data->pty_fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	pipe_fd = data->pipe_fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	count = write(pipe_fd, &c, sizeof(c));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	if (count != sizeof(c))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 		printk(UM_KERN_ERR "winch_thread : failed to write "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 		       "synchronization byte, err = %d\n", -count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	 * We are not using SIG_IGN on purpose, so don't fix it as I thought to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	 * do! If using SIG_IGN, the sigsuspend() call below would not stop on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	 * SIGWINCH.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	signal(SIGWINCH, winch_handler);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	sigfillset(&sigs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	/* Block all signals possible. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	if (sigprocmask(SIG_SETMASK, &sigs, NULL) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 		printk(UM_KERN_ERR "winch_thread : sigprocmask failed, "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 		       "errno = %d\n", errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 		exit(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	/* In sigsuspend(), block anything else than SIGWINCH. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	sigdelset(&sigs, SIGWINCH);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	if (setsid() < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 		printk(UM_KERN_ERR "winch_thread : setsid failed, errno = %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 		       errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 		exit(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	if (ioctl(pty_fd, TIOCSCTTY, 0) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		printk(UM_KERN_ERR "winch_thread : TIOCSCTTY failed on "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		       "fd %d err = %d\n", pty_fd, errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		exit(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	if (tcsetpgrp(pty_fd, os_getpid()) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 		printk(UM_KERN_ERR "winch_thread : tcsetpgrp failed on "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		       "fd %d err = %d\n", pty_fd, errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 		exit(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	 * These are synchronization calls between various UML threads on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	 * host - since they are not different kernel threads, we cannot use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	 * kernel semaphores. We don't use SysV semaphores because they are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	 * persistent.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	count = read(pipe_fd, &c, sizeof(c));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	if (count != sizeof(c))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 		printk(UM_KERN_ERR "winch_thread : failed to read "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 		       "synchronization byte, err = %d\n", errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	while(1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 		 * This will be interrupted by SIGWINCH only, since
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 		 * other signals are blocked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 		sigsuspend(&sigs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 		count = write(pipe_fd, &c, sizeof(c));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 		if (count != sizeof(c))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 			printk(UM_KERN_ERR "winch_thread : write failed, "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 			       "err = %d\n", errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) static int winch_tramp(int fd, struct tty_port *port, int *fd_out,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		       unsigned long *stack_out)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	struct winch_data data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	int fds[2], n, err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	char c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	err = os_pipe(fds, 1, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	if (err < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		printk(UM_KERN_ERR "winch_tramp : os_pipe failed, err = %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 		       -err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 	data = ((struct winch_data) { .pty_fd 		= fd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 				      .pipe_fd 		= fds[1] } );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	 * CLONE_FILES so this thread doesn't hold open files which are open
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	 * now, but later closed in a different thread.  This is a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	 * problem with /dev/net/tun, which if held open by this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	 * thread, prevents the TUN/TAP device from being reused.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	err = run_helper_thread(winch_thread, &data, CLONE_FILES, stack_out);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	if (err < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 		printk(UM_KERN_ERR "fork of winch_thread failed - errno = %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 		       -err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 		goto out_close;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	*fd_out = fds[0];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	n = read(fds[0], &c, sizeof(c));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 	if (n != sizeof(c)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 		printk(UM_KERN_ERR "winch_tramp : failed to read "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 		       "synchronization byte\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 		printk(UM_KERN_ERR "read failed, err = %d\n", errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 		printk(UM_KERN_ERR "fd %d will not support SIGWINCH\n", fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 		err = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 		goto out_close;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 	err = os_set_fd_block(*fd_out, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 		printk(UM_KERN_ERR "winch_tramp: failed to set thread_fd "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 		       "non-blocking.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 		goto out_close;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)  out_close:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 	close(fds[1]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	close(fds[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)  out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) void register_winch(int fd, struct tty_port *port)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 	unsigned long stack;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 	int pid, thread, count, thread_fd = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	char c = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	if (!isatty(fd))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 	pid = tcgetpgrp(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 	if (is_skas_winch(pid, fd, port)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 		register_winch_irq(-1, fd, -1, port, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 	if (pid == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 		thread = winch_tramp(fd, port, &thread_fd, &stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 		if (thread < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 			return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 		register_winch_irq(thread_fd, fd, thread, port, stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 		count = write(thread_fd, &c, sizeof(c));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 		if (count != sizeof(c))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 			printk(UM_KERN_ERR "register_winch : failed to write "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 			       "synchronization byte, err = %d\n", errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) }