#include <sys/ioctl.h>
#include <sys/socket.h>
#include "kern_util.h"
-#include "user_util.h"
#include "chan_user.h"
#include "user.h"
#include "os.h"
/*
* UML SIGWINCH handling
*
- * The point of this is to handle SIGWINCH on consoles which have host ttys and
- * relay them inside UML to whatever might be running on the console and cares
- * about the window size (since SIGWINCH notifies about terminal size changes).
+ * The point of this is to handle SIGWINCH on consoles which have host
+ * ttys and relay them inside UML to whatever might be running on the
+ * console and cares about the window size (since SIGWINCH notifies
+ * about terminal size changes).
*
- * So, we have a separate thread for each host tty attached to a UML device
- * (side-issue - I'm annoyed that one thread can't have multiple controlling
- * ttys for purposed of handling SIGWINCH, but I imagine there are other reasons
- * that doesn't make any sense).
+ * So, we have a separate thread for each host tty attached to a UML
+ * device (side-issue - I'm annoyed that one thread can't have
+ * multiple controlling ttys for the purpose of handling SIGWINCH, but
+ * I imagine there are other reasons that doesn't make any sense).
*
- * SIGWINCH can't be received synchronously, so you have to set up to receive it
- * as a signal. That being the case, if you are going to wait for it, it is
- * convenient to sit in sigsuspend() and wait for the signal to bounce you out of
- * it (see below for how we make sure to exit only on SIGWINCH).
+ * SIGWINCH can't be received synchronously, so you have to set up to
+ * receive it as a signal. That being the case, if you are going to
+ * wait for it, it is convenient to sit in sigsuspend() and wait for
+ * the signal to bounce you out of it (see below for how we make sure
+ * to exit only on SIGWINCH).
*/
static void winch_handler(int sig)
err = os_new_tty_pgrp(pty_fd, os_getpid());
if(err < 0){
- printk("winch_thread : new_tty_pgrp failed, err = %d\n", -err);
+ printk("winch_thread : new_tty_pgrp failed on fd %d, "
+ "err = %d\n", pty_fd, -err);
exit(1);
}
"err = %d\n", -count);
while(1){
- /* This will be interrupted by SIGWINCH only, since other signals
- * are blocked.*/
+ /* This will be interrupted by SIGWINCH only, since
+ * other signals are blocked.
+ */
sigsuspend(&sigs);
count = os_write_file(pipe_fd, &c, sizeof(c));
}
}
-static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out)
+static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out,
+ unsigned long *stack_out)
{
struct winch_data data;
- unsigned long stack;
int fds[2], n, err;
char c;
data = ((struct winch_data) { .pty_fd = fd,
.pipe_fd = fds[1] } );
/* CLONE_FILES so this thread doesn't hold open files which are open
- * now, but later closed. This is a problem with /dev/net/tun.
+ * now, but later closed in a different thread. This is a
+ * problem with /dev/net/tun, which if held open by this
+ * thread, prevents the TUN/TAP device from being reused.
*/
- err = run_helper_thread(winch_thread, &data, CLONE_FILES, &stack, 0);
+ err = run_helper_thread(winch_thread, &data, CLONE_FILES, stack_out);
if(err < 0){
- printk("fork of winch_thread failed - errno = %d\n", err);
+ printk("fork of winch_thread failed - errno = %d\n", -err);
goto out_close;
}
err = -EINVAL;
goto out_close;
}
- return err ;
+
+ if (os_set_fd_block(*fd_out, 0)) {
+ printk("winch_tramp: failed to set thread_fd non-blocking.\n");
+ goto out_close;
+ }
+
+ return err;
out_close:
os_close_file(fds[1]);
void register_winch(int fd, struct tty_struct *tty)
{
- int pid, thread, thread_fd = -1;
- int count;
+ unsigned long stack;
+ int pid, thread, count, thread_fd = -1;
char c = 1;
if(!isatty(fd))
return;
pid = tcgetpgrp(fd);
- if(!CHOOSE_MODE_PROC(is_tracer_winch, is_skas_winch, pid, fd,
- tty) && (pid == -1)){
- thread = winch_tramp(fd, tty, &thread_fd);
- if(thread > 0){
- register_winch_irq(thread_fd, fd, thread, tty);
-
- count = os_write_file(thread_fd, &c, sizeof(c));
- if(count != sizeof(c))
- printk("register_winch : failed to write "
- "synchronization byte, err = %d\n",
- -count);
- }
+ if (!CHOOSE_MODE_PROC(is_tracer_winch, is_skas_winch, pid, fd, tty) &&
+ (pid == -1)) {
+ thread = winch_tramp(fd, tty, &thread_fd, &stack);
+ if (thread < 0)
+ return;
+
+ register_winch_irq(thread_fd, fd, thread, tty, stack);
+
+ count = os_write_file(thread_fd, &c, sizeof(c));
+ if(count != sizeof(c))
+ printk("register_winch : failed to write "
+ "synchronization byte, err = %d\n", -count);
}
}
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only. This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
projects / linux-2.6 / blobdiff