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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ide_platform.c
/*
* Platform IDE driver
*
* Copyright (C) 2007 MontaVista Software
*
* Maintainer: Kumar Gala <galak@kernel.crashing.org>
*
* 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.
*/
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/ide.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/ata_platform.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/io.h>
static void plat_ide_setup_ports(struct ide_hw *hw, void __iomem *base,
void __iomem *ctrl,
struct pata_platform_info *pdata, int irq)
{
unsigned long port = (unsigned long)base;
int i;
hw->io_ports.data_addr = port;
port += (1 << pdata->ioport_shift);
for (i = 1; i <= 7;
i++, port += (1 << pdata->ioport_shift))
hw->io_ports_array[i] = port;
hw->io_ports.ctl_addr = (unsigned long)ctrl;
hw->irq = irq;
}
static const struct ide_port_info platform_ide_port_info = {
.host_flags = IDE_HFLAG_NO_DMA,
.chipset = ide_generic,
};
static int plat_ide_probe(struct platform_device *pdev)
{
struct resource *res_base, *res_alt, *res_irq;
void __iomem *base, *alt_base;
struct pata_platform_info *pdata;
struct ide_host *host;
int ret = 0, mmio = 0;
struct ide_hw hw, *hws[] = { &hw };
struct ide_port_info d = platform_ide_port_info;
pdata = dev_get_platdata(&pdev->dev);
/* get a pointer to the register memory */
res_base = platform_get_resource(pdev, IORESOURCE_IO, 0);
res_alt = platform_get_resource(pdev, IORESOURCE_IO, 1);
if (!res_base || !res_alt) {
res_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
res_alt = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (!res_base || !res_alt) {
ret = -ENOMEM;
goto out;
}
mmio = 1;
}
res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res_irq) {
ret = -EINVAL;
goto out;
}
if (mmio) {
base = devm_ioremap(&pdev->dev,
res_base->start, resource_size(res_base));
alt_base = devm_ioremap(&pdev->dev,
res_alt->start, resource_size(res_alt));
} else {
base = devm_ioport_map(&pdev->dev,
res_base->start, resource_size(res_base));
alt_base = devm_ioport_map(&pdev->dev,
res_alt->start, resource_size(res_alt));
}
memset(&hw, 0, sizeof(hw));
plat_ide_setup_ports(&hw, base, alt_base, pdata, res_irq->start);
hw.dev = &pdev->dev;
d.irq_flags = res_irq->flags & IRQF_TRIGGER_MASK;
if (res_irq->flags & IORESOURCE_IRQ_SHAREABLE)
d.irq_flags |= IRQF_SHARED;
if (mmio)
d.host_flags |= IDE_HFLAG_MMIO;
ret = ide_host_add(&d, hws, 1, &host);
if (ret)
goto out;
platform_set_drvdata(pdev, host);
return 0;
out:
return ret;
}
static int plat_ide_remove(struct platform_device *pdev)
{
struct ide_host *host = dev_get_drvdata(&pdev->dev);
ide_host_remove(host);
return 0;
}
static struct platform_driver platform_ide_driver = {
.driver = {
.name = "pata_platform",
},
.probe = plat_ide_probe,
.remove = plat_ide_remove,
};
module_platform_driver(platform_ide_driver);
MODULE_DESCRIPTION("Platform IDE driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pata_platform");
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