From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964889AbWFHSPK (ORCPT ); Thu, 8 Jun 2006 14:15:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964891AbWFHSPK (ORCPT ); Thu, 8 Jun 2006 14:15:10 -0400 Received: from liaag1ab.mx.compuserve.com ([149.174.40.28]:24752 "EHLO liaag1ab.mx.compuserve.com") by vger.kernel.org with ESMTP id S964889AbWFHSPI (ORCPT ); Thu, 8 Jun 2006 14:15:08 -0400 Date: Thu, 8 Jun 2006 14:09:10 -0400 From: Chuck Ebbert <76306.1226@compuserve.com> Subject: 2.6.16.18 kernel freezes while pppd is exiting To: linux-kernel Cc: Alan Cox Message-ID: <200606081412_MC3-1-C1EF-69A3@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Very infrequently I get kernel freezes while pppd is exiting. Today I finally got traces from the serial console. [1410445.728958] Pid: 887, comm: sendmail [1410445.743307] EIP: 0060:[] CPU: 1 [1410445.755837] EIP is at lock_kernel+0x18/0x30 [1410445.768882] EFLAGS: 00000286 Not tainted (2.6.16.18-d4 #6) [1410445.787126] EAX: d791fa70 EBX: d78dbf2c ECX: 00000000 EDX: d78da000 [1410445.806408] ESI: fffffffe EDI: 00000000 EBP: c139bf14 DS: 007b ES: 007b [1410445.826787] CR0: 8005003b CR2: 0064ef90 CR3: 174e5000 CR4: 000002d0 [1410445.846068] [] proc_lookup+0x1b/0xd0 [1410445.860260] [] proc_root_lookup+0x2b/0x70 [1410445.875748] [] real_lookup+0xc5/0xf0 [1410445.889939] [] do_lookup+0x9d/0xb0 [1410445.903607] [] __link_path_walk+0x6bc/0xc80 [1410445.919619] [] link_path_walk+0x49/0xd0 [1410445.934588] [] schedule+0x38d/0x760 [1410445.948518] [] do_path_lookup+0x138/0x2b0 [1410445.964007] [] get_empty_filp+0x6a/0xf0 [1410445.978978] [] __path_lookup_intent_open+0x4a/0x90 [1410445.996805] [] path_lookup_open+0x35/0x40 [1410446.012297] [] open_namei+0x87/0x680 [1410446.026486] [] do_filp_open+0x40/0x60 [1410446.040937] [] do_sys_open+0x51/0x90 [1410446.055125] [] sys_open+0x27/0x30 [1410446.068536] [] syscall_call+0x7/0xb [1410462.415500] Pid: 22020, comm: pppd [1410462.430365] EIP: 0060:[] CPU: 0 [1410462.442913] EIP is at kfree+0x4e/0x70 [1410462.454413] EFLAGS: 00000286 Not tainted (2.6.16.18-d4 #6) [1410462.472652] EAX: 0000001d EBX: c137a160 ECX: 00000000 EDX: c137f600 [1410462.491936] ESI: c4823800 EDI: 00000286 EBP: 00000001 DS: 007b ES: 007b [1410462.512314] CR0: 8005003b CR2: 0069f6a0 CR3: 032c5000 CR4: 000002d0 [1410462.531597] [] tty_buffer_free_all+0x60/0x80 [1410462.547890] [] release_mem+0x18d/0x1a0 [1410462.562598] [] n_tty_close+0x0/0x40 [1410462.576529] [] release_dev+0x601/0x760 [1410462.591238] [] enqueue_hrtimer+0x75/0xc0 [1410462.606469] [] lock_hrtimer_base+0x2b/0x60 [1410462.622218] [] hrtimer_try_to_cancel+0x42/0x70 [1410462.639009] [] hrtimer_cancel+0x18/0x20 [1410462.653976] [] schedule_hrtimer+0x4a/0xa0 [1410462.669467] [] hrtimer_nanosleep+0x6f/0x130 [1410462.685477] [] copy_to_user+0x42/0x60 [1410462.699926] [] do_ioctl+0x77/0xa0 [1410462.713337] [] tty_release+0x14/0x20 [1410462.727525] [] __fput+0xbd/0xd0 [1410462.740417] [] filp_close+0x4d/0x80 [1410462.754349] [] sys_close+0x6d/0x90 [1410462.768018] [] syscall_call+0x7/0xb pppd seems to be looping here while holding the BKL: static void tty_buffer_free_all(struct tty_struct *tty) { struct tty_buffer *thead; while((thead = tty->buf.head) != NULL) { tty->buf.head = thead->next; kfree(thead); } while((thead = tty->buf.free) != NULL) { tty->buf.free = thead->next; ====> kfree(thead); } tty->buf.tail = NULL; } I did alt-sysrq-p over and over and all I got was basically these two traces -- CPU 1 in lock_kernel() and CPU 0 in kfree(). -- Chuck