Subject: Re: linux-next: Tree for August 29

From: Bartlomiej Zolnierkiewicz <[email-masked]>
Date: Sun, 31 Aug 2008 14:32:30 +0200

Hi,

On Friday 29 August 2008, Stephen Rothwell wrote:
> Hi all,
> 
> Changes since next-20080828:

All block issuses have been fixed now (thanks guys!)
but the new warning emerged:

sysctl table check failed: /kernel/pty/nr .1.62.2 No data
Pid: 1, comm: swapper Not tainted 2.6.27-rc3-00458-g0ea12ec-dirty #196
 [<c012e004>] set_fail+0x30/0x39
 [<c012e436>] sysctl_check_table+0x429/0x467
 [<c012e44d>] sysctl_check_table+0x440/0x467
 [<c012e44d>] sysctl_check_table+0x440/0x467
 [<c01206d3>] __register_sysctl_paths+0xab/0x23c
 [<c02f8fb9>] mutex_lock+0x15/0x23
 [<c015f0ed>] exact_lock+0x0/0xd
 [<c012087e>] register_sysctl_paths+0x1a/0x1c
 [<c03d8106>] pty_init+0x215/0x293
 [<c0101122>] _stext+0x3a/0x12a
 [<c03d7ef1>] pty_init+0x0/0x293
 [<c018a1a8>] create_proc_entry+0x72/0x84
 [<c013ea0d>] register_irq_proc+0x6b/0x84
 [<c03c443b>] kernel_init+0x6d/0xb9
 [<c03c43ce>] kernel_init+0x0/0xb9
 [<c01037f3>] kernel_thread_helper+0x7/0x10
 =======================

git bisect points at:

commit 0ea12ecc2f11ab28478939a5902505bd47f9b765
Author: Alan Cox <[email-masked]>
Date:   Fri Aug 29 09:28:10 2008 +1000

    tty-driver-kref

and somehow the following chunk looks suspicious:

--- a/drivers/char/pty.c
+++ b/drivers/char/pty.c
@@ -571,8 +571,11 @@ static void __init unix98_pty_init(void)
        if (tty_register_driver(pts_driver))
                panic("Couldn't register Unix98 pts driver");

+       /* FIXME: WTF */
+#if 0
        pty_table[1].data = &ptm_driver->refcount;
-       register_sysctl_table(pty_root_table);
+#endif
+       register_sysctl_table(pty_root_table);

        /* Now create the /dev/ptmx special device */
        tty_default_fops(&ptmx_fops);

Unfortunately it cannot be simply reverted so it seems
like WTF part will need some work after all... ;)