Revision 85bd839983778fcd0c1c043327b14a046e979b39 authored by Gu Zheng on 10 June 2015, 18:14:43 UTC, committed by Linus Torvalds on 10 June 2015, 23:43:43 UTC
Izumi found the following oops when hot re-adding a node:

    BUG: unable to handle kernel paging request at ffffc90008963690
    IP: __wake_up_bit+0x20/0x70
    Oops: 0000 [#1] SMP
    CPU: 68 PID: 1237 Comm: rs:main Q:Reg Not tainted 4.1.0-rc5 #80
    Hardware name: FUJITSU PRIMEQUEST2800E/SB, BIOS PRIMEQUEST 2000 Series BIOS Version 1.87 04/28/2015
    task: ffff880838df8000 ti: ffff880017b94000 task.ti: ffff880017b94000
    RIP: 0010:[<ffffffff810dff80>]  [<ffffffff810dff80>] __wake_up_bit+0x20/0x70
    RSP: 0018:ffff880017b97be8  EFLAGS: 00010246
    RAX: ffffc90008963690 RBX: 00000000003c0000 RCX: 000000000000a4c9
    RDX: 0000000000000000 RSI: ffffea101bffd500 RDI: ffffc90008963648
    RBP: ffff880017b97c08 R08: 0000000002000020 R09: 0000000000000000
    R10: 0000000000000000 R11: 0000000000000000 R12: ffff8a0797c73800
    R13: ffffea101bffd500 R14: 0000000000000001 R15: 00000000003c0000
    FS:  00007fcc7ffff700(0000) GS:ffff880874800000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: ffffc90008963690 CR3: 0000000836761000 CR4: 00000000001407e0
    Call Trace:
      unlock_page+0x6d/0x70
      generic_write_end+0x53/0xb0
      xfs_vm_write_end+0x29/0x80 [xfs]
      generic_perform_write+0x10a/0x1e0
      xfs_file_buffered_aio_write+0x14d/0x3e0 [xfs]
      xfs_file_write_iter+0x79/0x120 [xfs]
      __vfs_write+0xd4/0x110
      vfs_write+0xac/0x1c0
      SyS_write+0x58/0xd0
      system_call_fastpath+0x12/0x76
    Code: 5d c3 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 48 83 ec 20 65 48 8b 04 25 28 00 00 00 48 89 45 f8 31 c0 48 8d 47 48 <48> 39 47 48 48 c7 45 e8 00 00 00 00 48 c7 45 f0 00 00 00 00 48
    RIP  [<ffffffff810dff80>] __wake_up_bit+0x20/0x70
     RSP <ffff880017b97be8>
    CR2: ffffc90008963690

Reproduce method (re-add a node)::
  Hot-add nodeA --> remove nodeA --> hot-add nodeA (panic)

This seems an use-after-free problem, and the root cause is
zone->wait_table was not set to *NULL* after free it in
try_offline_node.

When hot re-add a node, we will reuse the pgdat of it, so does the zone
struct, and when add pages to the target zone, it will init the zone
first (including the wait_table) if the zone is not initialized.  The
judgement of zone initialized is based on zone->wait_table:

	static inline bool zone_is_initialized(struct zone *zone)
	{
		return !!zone->wait_table;
	}

so if we do not set the zone->wait_table to *NULL* after free it, the
memory hotplug routine will skip the init of new zone when hot re-add
the node, and the wait_table still points to the freed memory, then we
will access the invalid address when trying to wake up the waiting
people after the i/o operation with the page is done, such as mentioned
above.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Reported-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Reviewed by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 5879ae5
Raw File
ntb_regs.h
/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 *   redistributing this file, you may do so under either license.
 *
 *   GPL LICENSE SUMMARY
 *
 *   Copyright(c) 2012 Intel Corporation. All rights reserved.
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of version 2 of the GNU General Public License as
 *   published by the Free Software Foundation.
 *
 *   BSD LICENSE
 *
 *   Copyright(c) 2012 Intel Corporation. All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copy
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Intel PCIe NTB Linux driver
 *
 * Contact Information:
 * Jon Mason <jon.mason@intel.com>
 */

#define NTB_LINK_STATUS_ACTIVE	0x2000
#define NTB_LINK_SPEED_MASK	0x000f
#define NTB_LINK_WIDTH_MASK	0x03f0

#define SNB_MSIX_CNT		4
#define SNB_MAX_B2B_SPADS	16
#define SNB_MAX_COMPAT_SPADS	16
/* Reserve the uppermost bit for link interrupt */
#define SNB_MAX_DB_BITS		15
#define SNB_LINK_DB		15
#define SNB_DB_BITS_PER_VEC	5
#define HSX_SPLITBAR_MAX_MW	3
#define SNB_MAX_MW		2
#define SNB_ERRATA_MAX_MW	1

#define SNB_DB_HW_LINK		0x8000

#define SNB_UNCERRSTS_OFFSET	0x014C
#define SNB_CORERRSTS_OFFSET	0x0158
#define SNB_LINK_STATUS_OFFSET	0x01A2
#define SNB_PCICMD_OFFSET	0x0504
#define SNB_DEVCTRL_OFFSET	0x0598
#define SNB_DEVSTS_OFFSET	0x059A
#define SNB_SLINK_STATUS_OFFSET	0x05A2

#define SNB_PBAR2LMT_OFFSET	0x0000
#define SNB_PBAR4LMT_OFFSET	0x0008
#define SNB_PBAR5LMT_OFFSET	0x000C
#define SNB_PBAR2XLAT_OFFSET	0x0010
#define SNB_PBAR4XLAT_OFFSET	0x0018
#define SNB_PBAR5XLAT_OFFSET	0x001C
#define SNB_SBAR2LMT_OFFSET	0x0020
#define SNB_SBAR4LMT_OFFSET	0x0028
#define SNB_SBAR5LMT_OFFSET	0x002C
#define SNB_SBAR2XLAT_OFFSET	0x0030
#define SNB_SBAR4XLAT_OFFSET	0x0038
#define SNB_SBAR5XLAT_OFFSET	0x003C
#define SNB_SBAR0BASE_OFFSET	0x0040
#define SNB_SBAR2BASE_OFFSET	0x0048
#define SNB_SBAR4BASE_OFFSET	0x0050
#define SNB_SBAR5BASE_OFFSET	0x0054
#define SNB_NTBCNTL_OFFSET	0x0058
#define SNB_SBDF_OFFSET		0x005C
#define SNB_PDOORBELL_OFFSET	0x0060
#define SNB_PDBMSK_OFFSET	0x0062
#define SNB_SDOORBELL_OFFSET	0x0064
#define SNB_SDBMSK_OFFSET	0x0066
#define SNB_USMEMMISS_OFFSET	0x0070
#define SNB_SPAD_OFFSET		0x0080
#define SNB_SPADSEMA4_OFFSET	0x00c0
#define SNB_WCCNTRL_OFFSET	0x00e0
#define SNB_B2B_SPAD_OFFSET	0x0100
#define SNB_B2B_DOORBELL_OFFSET	0x0140
#define SNB_B2B_XLAT_OFFSETL	0x0144
#define SNB_B2B_XLAT_OFFSETU	0x0148

/*
 * The addresses are setup so the 32bit BARs can function. Thus
 * the addresses are all in 32bit space
 */
#define SNB_MBAR01_USD_ADDR	0x000000002100000CULL
#define SNB_MBAR23_USD_ADDR	0x000000004100000CULL
#define SNB_MBAR4_USD_ADDR	0x000000008100000CULL
#define SNB_MBAR5_USD_ADDR	0x00000000A100000CULL
#define SNB_MBAR01_DSD_ADDR	0x000000002000000CULL
#define SNB_MBAR23_DSD_ADDR	0x000000004000000CULL
#define SNB_MBAR4_DSD_ADDR	0x000000008000000CULL
#define SNB_MBAR5_DSD_ADDR	0x00000000A000000CULL

#define BWD_MSIX_CNT		34
#define BWD_MAX_SPADS		16
#define BWD_MAX_DB_BITS		34
#define BWD_DB_BITS_PER_VEC	1
#define BWD_MAX_MW		2

#define BWD_PCICMD_OFFSET	0xb004
#define BWD_MBAR23_OFFSET	0xb018
#define BWD_MBAR45_OFFSET	0xb020
#define BWD_DEVCTRL_OFFSET	0xb048
#define BWD_LINK_STATUS_OFFSET	0xb052
#define BWD_ERRCORSTS_OFFSET	0xb110

#define BWD_SBAR2XLAT_OFFSET	0x0008
#define BWD_SBAR4XLAT_OFFSET	0x0010
#define BWD_PDOORBELL_OFFSET	0x0020
#define BWD_PDBMSK_OFFSET	0x0028
#define BWD_NTBCNTL_OFFSET	0x0060
#define BWD_EBDF_OFFSET		0x0064
#define BWD_SPAD_OFFSET		0x0080
#define BWD_SPADSEMA_OFFSET	0x00c0
#define BWD_STKYSPAD_OFFSET	0x00c4
#define BWD_PBAR2XLAT_OFFSET	0x8008
#define BWD_PBAR4XLAT_OFFSET	0x8010
#define BWD_B2B_DOORBELL_OFFSET	0x8020
#define BWD_B2B_SPAD_OFFSET	0x8080
#define BWD_B2B_SPADSEMA_OFFSET	0x80c0
#define BWD_B2B_STKYSPAD_OFFSET	0x80c4

#define BWD_MODPHY_PCSREG4	0x1c004
#define BWD_MODPHY_PCSREG6	0x1c006

#define BWD_IP_BASE		0xC000
#define BWD_DESKEWSTS_OFFSET	(BWD_IP_BASE + 0x3024)
#define BWD_LTSSMERRSTS0_OFFSET (BWD_IP_BASE + 0x3180)
#define BWD_LTSSMSTATEJMP_OFFSET	(BWD_IP_BASE + 0x3040)
#define BWD_IBSTERRRCRVSTS0_OFFSET	(BWD_IP_BASE + 0x3324)

#define BWD_DESKEWSTS_DBERR	(1 << 15)
#define BWD_LTSSMERRSTS0_UNEXPECTEDEI	(1 << 20)
#define BWD_LTSSMSTATEJMP_FORCEDETECT	(1 << 2)
#define BWD_IBIST_ERR_OFLOW	0x7FFF7FFF

#define NTB_CNTL_CFG_LOCK		(1 << 0)
#define NTB_CNTL_LINK_DISABLE		(1 << 1)
#define NTB_CNTL_S2P_BAR23_SNOOP	(1 << 2)
#define NTB_CNTL_P2S_BAR23_SNOOP	(1 << 4)
#define NTB_CNTL_S2P_BAR4_SNOOP	(1 << 6)
#define NTB_CNTL_P2S_BAR4_SNOOP	(1 << 8)
#define NTB_CNTL_S2P_BAR5_SNOOP	(1 << 12)
#define NTB_CNTL_P2S_BAR5_SNOOP	(1 << 14)
#define BWD_CNTL_LINK_DOWN		(1 << 16)

#define NTB_PPD_OFFSET		0x00D4
#define SNB_PPD_CONN_TYPE	0x0003
#define SNB_PPD_DEV_TYPE	0x0010
#define SNB_PPD_SPLIT_BAR	(1 << 6)
#define BWD_PPD_INIT_LINK	0x0008
#define BWD_PPD_CONN_TYPE	0x0300
#define BWD_PPD_DEV_TYPE	0x1000
back to top