Re: [Bluez-devel] Oops involving RFCOMM and sysfs

Gabor Gombas
2008-01-07T14:13:16Z

Hi,

On Sat, Jan 05, 2008 at 07:50:39AM +0000, Al Viro wrote:

> Could you stick
> if (!parent->d_inode)
> printk(KERN_WARNING "sysfs locking blows: %s",
> parent->d_name.name);
> right before
> mutex_lock(&parent->d_inode->i_mutex);
> dentry = lookup_one_noperm(cur->s_name, parent);
> mutex_unlock(&parent->d_inode->i_mutex);
> in sysfs_get_dentry() (fs/sysfs/dir.c) and verify that it does, indeed,
> trigger?

Here it is:

Jan 7 14:35:43 twister kernel: sysfs locking blows: acl001BAFE1624D<1>Unable to handle kernel NULL pointer dereference at 00000000000000b8 RIP:
Jan 7 14:35:43 twister kernel: [<ffffffff80473835>] mutex_lock+0x10/0x1d
Jan 7 14:35:43 twister kernel: PGD b6031067 PUD b609c067 PMD 0
Jan 7 14:35:43 twister kernel: Oops: 0002 [1]
Jan 7 14:35:43 twister kernel: CPU 0
Jan 7 14:35:43 twister kernel: Modules linked in: binfmt_misc rfcomm l2cap nfsd auth_rpcgss exportfs ipt_REJECT xt_tcpudp ipt_LOG xt_limit iptable_filter ip_tables x_tables nfs lockd nfs_acl sunrpc fuse dm_crypt saa7134_alsa radeon hwmon_vid eeprom hci_usb bluetooth usb_storage tuner tea5767 tda8290 tuner_simple mt20xx tea5761 parport_pc parport floppy snd_intel8x0 snd_ac97_codec saa7134 ac97_bus firewire_ohci firewire_core videobuf_dma_sg videobuf_core ir_kbd_i2c sky2 ir_common crc_itu_t snd_pcm forcedeth snd_timer snd_page_alloc ehci_hcd ohci_hcd sg sr_mod cdrom
Jan 7 14:35:43 twister kernel: Pid: 3218, comm: cat Not tainted 2.6.24-rc6debug-dirty #5
Jan 7 14:35:43 twister kernel: RIP: 0010:[<ffffffff80473835>] [<ffffffff80473835>] mutex_lock+0x10/0x1d
Jan 7 14:35:43 twister kernel: RSP: 0018:ffff8100b5733d08 EFLAGS: 00010246
Jan 7 14:35:43 twister kernel: RAX: 0000000000000000 RBX: 00000000000000b8 RCX: 0000000000000001
Jan 7 14:35:43 twister kernel: RDX: ffff8100b5733fd8 RSI: ffff8100bfab6000 RDI: 00000000000000b8
Jan 7 14:35:43 twister kernel: RBP: ffffffff80593db0 R08: ffffffff8057b118 R09: ffffffff806093d0
Jan 7 14:35:43 twister kernel: R10: ffff8100b6074aa0 R11: ffff81000101b100 R12: ffff8100b6074aa0
Jan 7 14:35:43 twister kernel: R13: 00000000fffffff4 R14: ffff8100b571fb80 R15: ffff8100b573e000
Jan 7 14:35:43 twister kernel: FS: 00002aead9fc56e0(0000) GS:ffffffff805ba000(0000) knlGS:0000000000000000
Jan 7 14:35:43 twister kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
Jan 7 14:35:43 twister kernel: CR2: 00000000000000b8 CR3: 00000000b60b2000 CR4: 00000000000006e0
Jan 7 14:35:43 twister kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
Jan 7 14:35:43 twister kernel: DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Jan 7 14:35:43 twister kernel: Process cat (pid: 3218, threadinfo ffff8100b5732000, task ffff8100bfa70830)
Jan 7 14:35:43 twister kernel: Stack: ffffe2000007e310 ffffffff8028560d ffff8100b202a7d0 ffffffff802af076
Jan 7 14:35:43 twister kernel: ffff8100bfa52f00 ffff8100b6074aa0 ffff8100b618c720 ffffffff802af28b
Jan 7 14:35:43 twister kernel: ffff8100b61308d0 ffff8100b61308d0 ffff8100bfa1a800 ffff8100b618c720
Jan 7 14:35:43 twister kernel: Call Trace:
Jan 7 14:35:43 twister kernel: [<ffffffff8028560d>] dput+0x26/0x103
Jan 7 14:35:43 twister kernel: [<ffffffff802af076>] sysfs_get_dentry+0x5e/0xa8
Jan 7 14:35:43 twister kernel: [<ffffffff802af28b>] sysfs_move_dir+0x63/0x204
Jan 7 14:35:43 twister kernel: [<ffffffff803007c5>] kobject_move+0xba/0x110
Jan 7 14:35:43 twister kernel: [<ffffffff803698ec>] device_move+0x59/0x111
Jan 7 14:35:43 twister kernel: [<ffffffff8827c433>] :rfcomm:rfcomm_tty_close+0x2f/0x74
Jan 7 14:35:43 twister kernel: [<ffffffff803447af>] release_dev+0x212/0x5e2
Jan 7 14:35:43 twister kernel: [<ffffffff8021b609>] do_page_fault+0x2ff/0x65a
Jan 7 14:35:43 twister kernel: [<ffffffff80344b8b>] tty_release+0xc/0x10
Jan 7 14:35:43 twister kernel: [<ffffffff80277013>] __fput+0xb1/0x16f
Jan 7 14:35:43 twister kernel: [<ffffffff80274961>] filp_close+0x5d/0x65
Jan 7 14:35:43 twister kernel: [<ffffffff80275ab3>] sys_close+0x73/0xa6
Jan 7 14:35:43 twister kernel: [<ffffffff8020b5fc>] tracesys+0xdc/0xe1
Jan 7 14:35:43 twister kernel:
Jan 7 14:35:43 twister kernel:
Jan 7 14:35:43 twister kernel: Code: ff 0f 79 05 e8 c9 00 00 00 58 5a 5b c3 41 54 48 8d 47 08 48
Jan 7 14:35:43 twister kernel: RIP [<ffffffff80473835>] mutex_lock+0x10/0x1d
Jan 7 14:35:43 twister kernel: RSP <ffff8100b5733d08>
Jan 7 14:35:43 twister kernel: CR2: 00000000000000b8
Jan 7 14:35:43 twister kernel: ---[ end trace 0e3a1176e9294792 ]---

Gabor

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MTA SZTAKI Computer and Automation Research Institute
Hungarian Academy of Sciences
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