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>
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hid-lg3ff.c
/*
* Force feedback support for Logitech Flight System G940
*
* Copyright (c) 2009 Gary Stein <LordCnidarian@gmail.com>
*/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/input.h>
#include <linux/hid.h>
#include "hid-lg.h"
/*
* G940 Theory of Operation (from experimentation)
*
* There are 63 fields (only 3 of them currently used)
* 0 - seems to be command field
* 1 - 30 deal with the x axis
* 31 -60 deal with the y axis
*
* Field 1 is x axis constant force
* Field 31 is y axis constant force
*
* other interesting fields 1,2,3,4 on x axis
* (same for 31,32,33,34 on y axis)
*
* 0 0 127 127 makes the joystick autocenter hard
*
* 127 0 127 127 makes the joystick loose on the right,
* but stops all movemnt left
*
* -127 0 -127 -127 makes the joystick loose on the left,
* but stops all movement right
*
* 0 0 -127 -127 makes the joystick rattle very hard
*
* I'm sure these are effects that I don't know enough about them
*/
struct lg3ff_device {
struct hid_report *report;
};
static int hid_lg3ff_play(struct input_dev *dev, void *data,
struct ff_effect *effect)
{
struct hid_device *hid = input_get_drvdata(dev);
struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
int x, y;
/*
* Available values in the field should always be 63, but we only use up to
* 35. Instead, clear the entire area, however big it is.
*/
memset(report->field[0]->value, 0,
sizeof(__s32) * report->field[0]->report_count);
switch (effect->type) {
case FF_CONSTANT:
/*
* Already clamped in ff_memless
* 0 is center (different then other logitech)
*/
x = effect->u.ramp.start_level;
y = effect->u.ramp.end_level;
/* send command byte */
report->field[0]->value[0] = 0x51;
/*
* Sign backwards from other Force3d pro
* which get recast here in two's complement 8 bits
*/
report->field[0]->value[1] = (unsigned char)(-x);
report->field[0]->value[31] = (unsigned char)(-y);
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
break;
}
return 0;
}
static void hid_lg3ff_set_autocenter(struct input_dev *dev, u16 magnitude)
{
struct hid_device *hid = input_get_drvdata(dev);
struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
/*
* Auto Centering probed from device
* NOTE: deadman's switch on G940 must be covered
* for effects to work
*/
report->field[0]->value[0] = 0x51;
report->field[0]->value[1] = 0x00;
report->field[0]->value[2] = 0x00;
report->field[0]->value[3] = 0x7F;
report->field[0]->value[4] = 0x7F;
report->field[0]->value[31] = 0x00;
report->field[0]->value[32] = 0x00;
report->field[0]->value[33] = 0x7F;
report->field[0]->value[34] = 0x7F;
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
}
static const signed short ff3_joystick_ac[] = {
FF_CONSTANT,
FF_AUTOCENTER,
-1
};
int lg3ff_init(struct hid_device *hid)
{
struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
struct input_dev *dev = hidinput->input;
const signed short *ff_bits = ff3_joystick_ac;
int error;
int i;
/* Check that the report looks ok */
if (!hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 35))
return -ENODEV;
/* Assume single fixed device G940 */
for (i = 0; ff_bits[i] >= 0; i++)
set_bit(ff_bits[i], dev->ffbit);
error = input_ff_create_memless(dev, NULL, hid_lg3ff_play);
if (error)
return error;
if (test_bit(FF_AUTOCENTER, dev->ffbit))
dev->ff->set_autocenter = hid_lg3ff_set_autocenter;
hid_info(hid, "Force feedback for Logitech Flight System G940 by Gary Stein <LordCnidarian@gmail.com>\n");
return 0;
}
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