From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754036AbbCJRfL (ORCPT ); Tue, 10 Mar 2015 13:35:11 -0400 Received: from mail-qc0-f170.google.com ([209.85.216.170]:38428 "EHLO mail-qc0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753233AbbCJRfI (ORCPT ); Tue, 10 Mar 2015 13:35:08 -0400 Message-ID: <54FF2B45.8060407@hurleysoftware.com> Date: Tue, 10 Mar 2015 13:35:01 -0400 From: Peter Hurley User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Stas Sergeev , Andrew Morton CC: Linux kernel , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] n_tty: use kmalloc() instead of vmalloc() to avoid crash on armada-xp References: <54FF21BE.2040506@list.ru> In-Reply-To: <54FF21BE.2040506@list.ru> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/10/2015 12:54 PM, Stas Sergeev wrote: > Hello, the patch below is needed for a successful boot on armada-xp. > > > -=-=-=-=-=-=-=-=-=# Don't remove this line #=-=-=-=-=-=-=-=-=- > This fixes the following crash at boot: > > Unhandled fault: external abort on non-linefetch (0x808) at 0xf00ca018 > Internal error: : 808 [#1] SMP ARM > > CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.0.0-rc1 #3 > Hardware name: Marvell Armada 370/XP (Device Tree) > task: ed41e800 ti: ed43e000 task.ti: ed43e000 > PC is at _set_bit+0x28/0x50 > LR is at n_tty_set_termios+0x328/0x358 > pc : [] lr : [] psr: 40000113 > sp : ed43fd00 ip : 00000000 fp : 00000000 > r10: 00000002 r9 : 00000000 r8 : ec930200 > r7 : 00000000 r6 : f00ca018 r5 : f00ca000 r4 : ed69cc00 > r3 : 00002000 r2 : 00002000 r1 : f00ca018 r0 : 00000000 > Flags: nZcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel > Control: 10c5387d Table: 0000406a DAC: 00000015 > Process swapper/0 (pid: 1, stack limit = 0xed43e220) > > The offending instruction in _set_bit() is "strex r0, r2, [r1]" > For some reason the exclusive access instructions do not like the > vmalloc() space... While there may be another fix to make them > fine about vmalloc() space, it still looks like a good idea to > use kmalloc() for allocating a small (sub-page) struct. NAK. struct n_tty_data is order 2, not sub-page. The abort means something else is wrong; that's what needs tracking down and fixing. AFAIK this is not happening on any other ARM platform. Regards, Peter Hurley > Signed-off-by: Stas Sergeev > --- > drivers/tty/n_tty.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c > index cf6e0f2..e03622e 100644 > --- a/drivers/tty/n_tty.c > +++ b/drivers/tty/n_tty.c > @@ -50,7 +50,6 @@ > #include > #include > #include > -#include > > > /* number of characters left in xmit buffer before select has we have > room */ > @@ -1892,7 +1891,7 @@ static void n_tty_close(struct tty_struct *tty) > if (tty->link) > n_tty_packet_mode_flush(tty); > > - vfree(ldata); > + kfree(ldata); > tty->disc_data = NULL; > } > > @@ -1911,7 +1910,7 @@ static int n_tty_open(struct tty_struct *tty) > struct n_tty_data *ldata; > > /* Currently a malloc failure here can panic */ > - ldata = vmalloc(sizeof(*ldata)); > + ldata = kmalloc(sizeof(*ldata), GFP_KERNEL); > if (!ldata) > goto err; > >