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Commit cd2ee4a3 authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
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[PATCH] uml: Fix SIGWINCH relaying 



This makes SIGWINCH work again, and fixes a couple of SIGWINCH-associated
crashes.  First, the sigio thread disables SIGWINCH because all hell breaks
loose if it ever gets one and tries to call the signal handling code.  Second,
there was a problem with deferencing tty structs after they were freed.  The
SIGWINCH support for a tty wasn't being turned off or freed after the tty went
away.

Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent c578455a

arch/um/drivers/line.c

+39 −2
Original line number Diff line number Diff line
@@ -462,12 +462,15 @@ int line_open(struct line *lines, struct tty_struct *tty, 
	return err;

}



static void unregister_winch(struct tty_struct *tty);



void line_close(struct tty_struct *tty, struct file * filp)

{

	struct line *line = tty->driver_data;



	/* XXX: I assume this should be called in process context, not with interrupt

	 * disabled!*/

	/* XXX: I assume this should be called in process context, not with

         *  interrupts disabled!

         */

	spin_lock_irq(&line->lock);



	/* We ignore the error anyway! */
@@ -478,6 +481,12 @@ void line_close(struct tty_struct *tty, struct file * filp) 
		line_disable(tty, -1);

		tty->driver_data = NULL;

	}



        if((line->count == 0) && line->sigio){

                unregister_winch(tty);

                line->sigio = 0;

        }



	spin_unlock_irq(&line->lock);

}
@@ -729,6 +738,34 @@ void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty) 
	up(&winch_handler_sem);

}



static void unregister_winch(struct tty_struct *tty)

{

	struct list_head *ele;

	struct winch *winch, *found = NULL;



	down(&winch_handler_sem);

	list_for_each(ele, &winch_handlers){

		winch = list_entry(ele, struct winch, list);

                if(winch->tty == tty){

                        found = winch;

                        break;

                }

        }



        if(found == NULL)

                goto out;



        if(winch->pid != -1)

                os_kill_process(winch->pid, 1);



        free_irq_by_irq_and_dev(WINCH_IRQ, winch);

        free_irq(WINCH_IRQ, winch);

        list_del(&winch->list);

        kfree(winch);

 out:

	up(&winch_handler_sem);

}



static void winch_cleanup(void)

{

	struct list_head *ele;

arch/um/include/os.h

+1 −0
Original line number Diff line number Diff line
@@ -160,6 +160,7 @@ extern void os_kill_process(int pid, int reap_child); 
extern void os_kill_ptraced_process(int pid, int reap_child);

extern void os_usr1_process(int pid);

extern int os_getpid(void);

extern int os_getpgrp(void);



extern int os_map_memory(void *virt, int fd, unsigned long long off,

			 unsigned long len, int r, int w, int x);

arch/um/kernel/irq.c

+0 −1
Original line number Diff line number Diff line
@@ -163,7 +163,6 @@ void __init init_IRQ(void) 
		irq_desc[i].handler = &SIGIO_irq_type;

		enable_irq(i);

	}

	init_irq_signals(0);

}



/*

arch/um/kernel/process.c

+0 −2
Original line number Diff line number Diff line
@@ -65,8 +65,6 @@ void init_new_thread_signals(int altstack) 
		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);

	set_handler(SIGBUS, (__sighandler_t) sig_handler, flags, 

		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);

	set_handler(SIGWINCH, (__sighandler_t) sig_handler, flags, 

		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);

	set_handler(SIGUSR2, (__sighandler_t) sig_handler, 

		    flags, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);

	signal(SIGHUP, SIG_IGN);

arch/um/kernel/sigio_user.c

+1 −0
Original line number Diff line number Diff line
@@ -182,6 +182,7 @@ static int write_sigio_thread(void *unused) 
	int i, n, respond_fd;

	char c;



        signal(SIGWINCH, SIG_IGN);

	fds = &current_poll;

	while(1){

		n = poll(fds->poll, fds->used, -1);