#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <pty.h>
#include <sched.h>
#include <signal.h>
#include <string.h>
#include <sys/epoll.h>
#include <asm/unistd.h>
#include <kern_util.h>
#include <init.h>
#include <os.h>
#include <sigio.h>
#include <um_malloc.h>
static struct os_helper_thread *write_sigio_td;
static int epollfd = -1;
#define MAX_EPOLL_EVENTS 64
static struct epoll_event epoll_events[MAX_EPOLL_EVENTS];
static void *write_sigio_thread(void *unused)
{
int pid = getpid();
int r;
os_fix_helper_thread_signals();
while (1) {
r = epoll_wait(epollfd, epoll_events, MAX_EPOLL_EVENTS, -1);
if (r < 0) {
if (errno == EINTR)
continue;
printk(UM_KERN_ERR "%s: epoll_wait failed, errno = %d\n",
__func__, errno);
}
CATCH_EINTR(r = syscall(__NR_tgkill, pid, pid, SIGIO));
if (r < 0)
printk(UM_KERN_ERR "%s: tgkill failed, errno = %d\n",
__func__, errno);
}
return NULL;
}
int __add_sigio_fd(int fd)
{
struct epoll_event event = {
.data.fd = fd,
.events = EPOLLIN | EPOLLET,
};
int r;
CATCH_EINTR(r = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event));
return r < 0 ? -errno : 0;
}
int add_sigio_fd(int fd)
{
int err;
sigio_lock();
err = __add_sigio_fd(fd);
sigio_unlock();
return err;
}
int __ignore_sigio_fd(int fd)
{
struct epoll_event event;
int r;
CATCH_EINTR(r = epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, &event));
return r < 0 ? -errno : 0;
}
int ignore_sigio_fd(int fd)
{
int err;
sigio_lock();
err = __ignore_sigio_fd(fd);
sigio_unlock();
return err;
}
static void write_sigio_workaround(void)
{
int err;
sigio_lock();
if (write_sigio_td)
goto out;
epollfd = epoll_create(MAX_EPOLL_EVENTS);
if (epollfd < 0) {
printk(UM_KERN_ERR "%s: epoll_create failed, errno = %d\n",
__func__, errno);
goto out;
}
err = os_run_helper_thread(&write_sigio_td, write_sigio_thread, NULL);
if (err < 0) {
printk(UM_KERN_ERR "%s: os_run_helper_thread failed, errno = %d\n",
__func__, -err);
close(epollfd);
epollfd = -1;
goto out;
}
out:
sigio_unlock();
}
void sigio_broken(void)
{
write_sigio_workaround();
}
static int pty_output_sigio;
void maybe_sigio_broken(int fd)
{
if (!isatty(fd))
return;
if (pty_output_sigio)
return;
sigio_broken();
}
static void sigio_cleanup(void)
{
if (!write_sigio_td)
return;
os_kill_helper_thread(write_sigio_td);
write_sigio_td = NULL;
}
__uml_exitcall(sigio_cleanup);
static int got_sigio;
static void __init handler(int sig)
{
got_sigio = 1;
}
struct openpty_arg {
int master;
int slave;
int err;
};
static void openpty_cb(void *arg)
{
struct openpty_arg *info = arg;
info->err = 0;
if (openpty(&info->master, &info->slave, NULL, NULL, NULL))
info->err = -errno;
}
static int async_pty(int master, int slave)
{
int flags;
flags = fcntl(master, F_GETFL);
if (flags < 0)
return -errno;
if ((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||
(fcntl(master, F_SETOWN, os_getpid()) < 0))
return -errno;
if ((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0))
return -errno;
return 0;
}
static void __init check_one_sigio(void (*proc)(int, int))
{
struct sigaction old, new;
struct openpty_arg pty = { .master = -1, .slave = -1 };
int master, slave, err;
initial_thread_cb(openpty_cb, &pty);
if (pty.err) {
printk(UM_KERN_ERR "check_one_sigio failed, errno = %d\n",
-pty.err);
return;
}
master = pty.master;
slave = pty.slave;
if ((master == -1) || (slave == -1)) {
printk(UM_KERN_ERR "check_one_sigio failed to allocate a "
"pty\n");
return;
}
err = raw(master);
if (err < 0) {
printk(UM_KERN_ERR "check_one_sigio : raw failed, errno = %d\n",
-err);
return;
}
err = async_pty(master, slave);
if (err < 0) {
printk(UM_KERN_ERR "check_one_sigio : sigio_async failed, "
"err = %d\n", -err);
return;
}
if (sigaction(SIGIO, NULL, &old) < 0) {
printk(UM_KERN_ERR "check_one_sigio : sigaction 1 failed, "
"errno = %d\n", errno);
return;
}
new = old;
new.sa_handler = handler;
if (sigaction(SIGIO, &new, NULL) < 0) {
printk(UM_KERN_ERR "check_one_sigio : sigaction 2 failed, "
"errno = %d\n", errno);
return;
}
got_sigio = 0;
(*proc)(master, slave);
close(master);
close(slave);
if (sigaction(SIGIO, &old, NULL) < 0)
printk(UM_KERN_ERR "check_one_sigio : sigaction 3 failed, "
"errno = %d\n", errno);
}
static void tty_output(int master, int slave)
{
int n;
char buf[512];
printk(UM_KERN_INFO "Checking that host ptys support output SIGIO...");
memset(buf, 0, sizeof(buf));
while (write(master, buf, sizeof(buf)) > 0) ;
if (errno != EAGAIN)
printk(UM_KERN_ERR "tty_output : write failed, errno = %d\n",
errno);
while (((n = read(slave, buf, sizeof(buf))) > 0) &&
!({ barrier(); got_sigio; }))
;
if (got_sigio) {
printk(UM_KERN_CONT "Yes\n");
pty_output_sigio = 1;
} else if (n == -EAGAIN)
printk(UM_KERN_CONT "No, enabling workaround\n");
else
printk(UM_KERN_CONT "tty_output : read failed, err = %d\n", n);
}
static void __init check_sigio(void)
{
if ((access("/dev/ptmx", R_OK) < 0) &&
(access("/dev/ptyp0", R_OK) < 0)) {
printk(UM_KERN_WARNING "No pseudo-terminals available - "
"skipping pty SIGIO check\n");
return;
}
check_one_sigio(tty_output);
}
void __init os_check_bugs(void)
{
check_sigio();
}
