Messages in this thread Patch in this message | | | Date | Tue, 30 Mar 2004 18:26:27 -0800 | From | Andrew Morton <> | Subject | Re: 2.6.5-rc3-mm1 |
| |
Andrew Morton <akpm@osdl.org> wrote: > > I'm thinking that this can be fixed from the other direction: just before > release_dev() calls close (dropping BKL), if tty->count==1, make the > going-away tty ineligible for concurrent lookups. Do that by setting > tty->driver->ttys[idx] to NULL. Maybe.
Famous last word: Volia!
diff -puN drivers/char/tty_io.c~tty-race-fix-42 drivers/char/tty_io.c --- 25/drivers/char/tty_io.c~tty-race-fix-42 Tue Mar 30 16:30:55 2004 +++ 25-akpm/drivers/char/tty_io.c Tue Mar 30 16:35:21 2004 @@ -1142,6 +1142,17 @@ static void release_dev(struct file * fi } #endif + /* + * ->close can sleep, and drop the BKL. If this tty is about to + * be destroyed we need to prevent other threads from coming in and + * grabbing a new ref against the about-to-die tty. Those threads + * perform the lookup via tty->driver->ttys[], in init_dev(). + */ + if (tty->count == 1) { + if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) + tty->driver->ttys[idx] = NULL; + } + if (tty->driver->close) tty->driver->close(tty, filp);
- 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/
| |