Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755389Ab0KMPZg (ORCPT ); Sat, 13 Nov 2010 10:25:36 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:40919 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754214Ab0KMPZe (ORCPT ); Sat, 13 Nov 2010 10:25:34 -0500 Date: Sat, 13 Nov 2010 16:25:14 +0100 From: Ingo Molnar To: Greg KH Cc: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, Alan Cox , Lawrence Rust Subject: Re: [boot crash] Re: [GIT PATCH] TTY/serial fixes for .37-rc1 Message-ID: <20101113152514.GA3069@elte.hu> References: <20101112213215.GB9294@kroah.com> <20101113151022.GA29085@elte.hu> <20101113152131.GA2606@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101113152131.GA2606@elte.hu> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5406 Lines: 126 * Ingo Molnar wrote: > * Ingo Molnar wrote: > > > It crashed almost immediately after i merged Linus's 9457b24a0955 into -tip, > > we were on yesterday's f6614b7bb405 before that - so i think the crash is > > both pretty generic. > > Yes, it crashes with an x86 defconfig too. Appears to be caused by: > > 47d3904fe40d: 8250: Fix tcsetattr to avoid ioctl(TIOCMIWAIT) hang > > It crashes any x86 serial console bootup. The revert below makes the system boot up fine. Thanks, Ingo ------------------------> >From a0758e8ea2a19de96d16db231be71f708980b86a Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sat, 13 Nov 2010 16:21:58 +0100 Subject: [PATCH] Revert "8250: Fix tcsetattr to avoid ioctl(TIOCMIWAIT) hang" This reverts commit 47d3904fe40d62deee8cd46e79ca784e7a548acd. Crashes any x86 serial console bootup: Console: colour VGA+ 80x25 BUG: unable to handle kernel NULL pointer dereference at 0000000000000158 IP: [] serial8250_do_set_termios+0x1d4/0x430 PGD 0 Oops: 0000 [#1] SMP last sysfs file: CPU 0 Modules linked in: Pid: 0, comm: swapper Not tainted 2.6.37-rc1-tip-02017-gba4813e-dirty #62970 / RIP: 0010:[] [] serial8250_do_set_termios+0x1d4/0x430 RSP: 0000:ffffffff8152fd88 EFLAGS: 00010082 RAX: 0000000000000000 RBX: ffffffff8207aa80 RCX: 0000000000002060 RDX: 0000000000000158 RSI: 0000000000000000 RDI: ffffffff8207aa80 RBP: ffffffff8152fdd8 R08: 000000000000000a R09: 000000000001c200 R10: 0000000000000025 R11: ffffffff81cec340 R12: 0000000000000013 R13: ffffffff8152fe08 R14: 0000000000000001 R15: 000000000001c200 FS: 0000000000000000(0000) GS:ffff88003e400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000158 CR3: 000000000153f000 CR4: 00000000000006b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process swapper (pid: 0, threadinfo ffffffff8152e000, task ffffffff81547020) Stack: ffffffff815567e0 ffffffff8207aa00 0000000000000286 00ffffff8207aa10 000000000000006e 000000000001c200 ffffffff8207aa80 ffffffff815762c0 000000000000006e 000000000000006e ffffffff8152fde8 ffffffff811ebf35 Call Trace: [] serial8250_set_termios+0x25/0x30 [] uart_set_options+0xf3/0x170 [] serial8250_console_setup+0xa8/0xaf [] register_console+0x22a/0x390 [] serial8250_console_init+0x28/0x2c [] console_init+0x19/0x2a [] start_kernel+0x27d/0x407 [] x86_64_start_reservations+0x132/0x136 [] x86_64_start_kernel+0x106/0x115 Code: 98 00 00 00 41 f6 45 00 04 0f 85 a8 01 00 00 41 f6 45 08 80 75 07 83 8b 98 00 00 00 01 48 8b 83 a0 00 00 00 48 8d 90 58 01 00 00 <48> 39 90 58 01 00 00 0f 84 17 02 00 00 0f b6 93 c1 01 00 00 89 RIP [] serial8250_do_set_termios+0x1d4/0x430 RSP CR2: 0000000000000158 ---[ end trace a7919e7f17c0a725 ]--- Kernel panic - not syncing: Fatal exception Pid: 0, comm: swapper Tainted: G D 2.6.37-rc1-tip-02017-gba4813e-dirty #62970 Call Trace: [] panic+0x8c/0x19c [] ? kmsg_dump+0x155/0x170 [] oops_end+0xd4/0xf0 [] no_context+0xf0/0x260 [] ? __kernel_text_address+0x40/0x70 [] __bad_area_nosemaphore+0x125/0x1e0 [] bad_area_nosemaphore+0xe/0x10 [] do_page_fault+0x3d1/0x4a0 [] ? save_stack_trace+0x2a/0x50 [] ? __lock_acquire.clone.20+0x6fd/0xab0 [] page_fault+0x25/0x30 [] ? serial8250_do_set_termios+0x1d4/0x430 [] ? serial8250_do_set_termios+0x14d/0x430 [] serial8250_set_termios+0x25/0x30 [] uart_set_options+0xf3/0x170 [] serial8250_console_setup+0xa8/0xaf [] register_console+0x22a/0x390 [] serial8250_console_init+0x28/0x2c [] console_init+0x19/0x2a [] start_kernel+0x27d/0x407 [] x86_64_start_reservations+0x132/0x136 [] x86_64_start_kernel+0x106/0x115 Signed-off-by: Ingo Molnar --- drivers/serial/8250.c | 5 +---- 1 files changed, 1 insertions(+), 4 deletions(-) diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index dd5e1ac..4d8e14b 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -2343,11 +2343,8 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, /* * CTS flow control flag and modem status interrupts - * Only disable MSI if no threads are waiting in - * serial_core::uart_wait_modem_status */ - if (!waitqueue_active(&up->port.state->port.delta_msr_wait)) - up->ier &= ~UART_IER_MSI; + up->ier &= ~UART_IER_MSI; if (!(up->bugs & UART_BUG_NOMSR) && UART_ENABLE_MS(&up->port, termios->c_cflag)) up->ier |= UART_IER_MSI; -- 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/