Messages in this thread Patch in this message | | | Subject | Re: PATCH: tty locking for 2.6.9rc2 | From | Paul Fulghum <> | Date | 15 Sep 2004 15:23:19 -0500 |
| |
Alan:
Here is a patch against your last patch that clears up both the per tty refcount initialization and the remove_dev() global refcount leak.
I've tested it and it seems to work.
The patch is not meant to be applied and is just for your information in deciding how you want the final code to look.
--- linux-2.6.9/drivers/char/tty_io.c 2004-09-15 15:19:58.044611590 -0500 +++ linux-2.6.9-mg/drivers/char/tty_io.c 2004-09-15 15:19:34.690680997 -0500 @@ -288,6 +288,7 @@ } else ld = NULL; + if (ld) printk("tty_ldisc_get ld=%p refcount=%d\n", ld, ld->refcount); spin_unlock_irqrestore(&tty_ldisc_lock, flags); return ld; } @@ -307,6 +308,7 @@ if(ld->refcount == 0) BUG(); ld->refcount --; + printk("tty_ldisc_put ld=%p refcount=%d\n", ld, ld->refcount); module_put(ld->owner); spin_unlock_irqrestore(&tty_ldisc_lock, flags); } @@ -497,6 +499,7 @@ /* Now set up the new line discipline. */ tty->ldisc = *ld; + tty->ldisc.refcount = 0; tty->termios->c_line = ldisc; if (tty->ldisc.open) retval = (tty->ldisc.open)(tty); @@ -504,11 +507,13 @@ tty_ldisc_put(ldisc); /* There is an outstanding reference here so this is safe */ tty->ldisc = *tty_ldisc_get(o_ldisc.num); + tty->ldisc.refcount = 0; tty->termios->c_line = tty->ldisc.num; if (tty->ldisc.open && (tty->ldisc.open(tty) < 0)) { tty_ldisc_put(o_ldisc.num); /* This driver is always present */ tty->ldisc = *tty_ldisc_get(N_TTY); + tty->ldisc.refcount = 0; tty->termios->c_line = N_TTY; if (tty->ldisc.open) { int r = tty->ldisc.open(tty); @@ -1567,15 +1572,15 @@ /* * Switch the line discipline back */ - tty->ldisc = *tty_ldisc_get(N_TTY); - tty->termios->c_line = N_TTY; +// tty->ldisc = *tty_ldisc_get(N_TTY); +// tty->termios->c_line = N_TTY; if (o_tty) { /* FIXME: could o_tty be in setldisc here ? */ clear_bit(TTY_LDISC, &o_tty->flags); if (o_tty->ldisc.close) (o_tty->ldisc.close)(o_tty); tty_ldisc_put(o_tty->ldisc.num); - o_tty->ldisc = *tty_ldisc_get(N_TTY); +// o_tty->ldisc = *tty_ldisc_get(N_TTY); } /* @@ -2466,6 +2471,7 @@ memset(tty, 0, sizeof(struct tty_struct)); tty->magic = TTY_MAGIC; tty->ldisc = *tty_ldisc_get(N_TTY); + tty->ldisc.refcount = 0; tty->pgrp = -1; tty->flip.char_buf_ptr = tty->flip.char_buf; tty->flip.flag_buf_ptr = tty->flip.flag_buf; Thanks, Paul
-- Paul Fulghum paulkf@microgate.com
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |