fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / arch / um / drivers / chan_user.c

diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c
index 583b8e1..0cad354 100644 (file)
--- a/arch/um/drivers/chan_user.c
+++ b/arch/um/drivers/chan_user.c
@@ -9,6 +9,7 @@
 #include <termios.h>
 #include <string.h>
 #include <signal.h>
+#include <sched.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
@@ -16,12 +17,11 @@
 #include "user_util.h"
 #include "chan_user.h"
 #include "user.h"
-#include "helper.h"
 #include "os.h"
 #include "choose-mode.h"
 #include "mode.h"
 
-int generic_console_write(int fd, const char *buf, int n, void *unused)
+int generic_console_write(int fd, const char *buf, int n)
 {
        struct termios save, new;
        int err;
@@ -63,7 +63,7 @@ error:
  *
  * 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 a pause() and wait for the signal to bounce you out of
+ * 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).
  */
 
@@ -74,7 +74,6 @@ static void winch_handler(int sig)
 struct winch_data {
        int pty_fd;
        int pipe_fd;
-       int close_me;
 };
 
 static int winch_thread(void *arg)
@@ -85,7 +84,6 @@ static int winch_thread(void *arg)
        int count, err;
        char c = 1;
 
-       os_close_file(data->close_me);
        pty_fd = data->pty_fd;
        pipe_fd = data->pipe_fd;
        count = os_write_file(pipe_fd, &c, sizeof(c));
@@ -94,18 +92,19 @@ static int winch_thread(void *arg)
                       "byte, err = %d\n", -count);
 
        /* We are not using SIG_IGN on purpose, so don't fix it as I thought to
-        * do! If using SIG_IGN, the pause() call below would not stop on
+        * do! If using SIG_IGN, the sigsuspend() call below would not stop on
         * SIGWINCH. */
 
        signal(SIGWINCH, winch_handler);
        sigfillset(&sigs);
-       sigdelset(&sigs, SIGWINCH);
-       /* Block anything else than SIGWINCH. */
+       /* Block all signals possible. */
        if(sigprocmask(SIG_SETMASK, &sigs, NULL) < 0){
                printk("winch_thread : sigprocmask failed, errno = %d\n", 
                       errno);
                exit(1);
        }
+       /* In sigsuspend(), block anything else than SIGWINCH. */
+       sigdelset(&sigs, SIGWINCH);
 
        if(setsid() < 0){
                printk("winch_thread : setsid failed, errno = %d\n", errno);
@@ -121,7 +120,7 @@ static int winch_thread(void *arg)
        /* These are synchronization calls between various UML threads on the
         * host - since they are not different kernel threads, we cannot use
         * kernel semaphores. We don't use SysV semaphores because they are
-        * persistant. */
+        * persistent. */
        count = os_read_file(pipe_fd, &c, sizeof(c));
        if(count != sizeof(c))
                printk("winch_thread : failed to read synchronization byte, "
@@ -130,7 +129,7 @@ static int winch_thread(void *arg)
        while(1){
                /* This will be interrupted by SIGWINCH only, since other signals
                 * are blocked.*/
-               pause();
+               sigsuspend(&sigs);
 
                count = os_write_file(pipe_fd, &c, sizeof(c));
                if(count != sizeof(c))
@@ -143,39 +142,47 @@ static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out)
 {
        struct winch_data data;
        unsigned long stack;
-       int fds[2], pid, n, err;
+       int fds[2], n, err;
        char c;
 
        err = os_pipe(fds, 1, 1);
        if(err < 0){
                printk("winch_tramp : os_pipe failed, err = %d\n", -err);
-               return(err);
+               goto out;
        }
 
        data = ((struct winch_data) { .pty_fd           = fd,
-                                     .pipe_fd          = fds[1],
-                                     .close_me         = fds[0] } );
-       pid = run_helper_thread(winch_thread, &data, 0, &stack, 0);
-       if(pid < 0){
+                                     .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.
+        */
+       err = run_helper_thread(winch_thread, &data, CLONE_FILES, &stack, 0);
+       if(err < 0){
                printk("fork of winch_thread failed - errno = %d\n", errno);
-               return(pid);
+               goto out_close;
        }
 
-       os_close_file(fds[1]);
        *fd_out = fds[0];
        n = os_read_file(fds[0], &c, sizeof(c));
        if(n != sizeof(c)){
                printk("winch_tramp : failed to read synchronization byte\n");
                printk("read failed, err = %d\n", -n);
                printk("fd %d will not support SIGWINCH\n", fd);
-               *fd_out = -1;
+                err = -EINVAL;
+               goto out_close;
        }
-       return(pid);
+       return err ;
+
+ out_close:
+       os_close_file(fds[1]);
+       os_close_file(fds[0]);
+ out:
+       return err;
 }
 
 void register_winch(int fd, struct tty_struct *tty)
 {
-       int pid, thread, thread_fd;
+       int pid, thread, thread_fd = -1;
        int count;
        char c = 1;
 
@@ -186,7 +193,7 @@ void register_winch(int fd, struct tty_struct *tty)
        if(!CHOOSE_MODE_PROC(is_tracer_winch, is_skas_winch, pid, fd,
                             tty) && (pid == -1)){
                thread = winch_tramp(fd, tty, &thread_fd);
-               if(fd != -1){
+               if(thread > 0){
                        register_winch_irq(thread_fd, fd, thread, tty);
 
                        count = os_write_file(thread_fd, &c, sizeof(c));