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
common.c
/*
* Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*/
#include <linux/export.h>
#include <linux/regmap.h>
#include <linux/platform_device.h>
#include <linux/clk-provider.h>
#include <linux/reset-controller.h>
#include "common.h"
#include "clk-rcg.h"
#include "clk-regmap.h"
#include "reset.h"
struct qcom_cc {
struct qcom_reset_controller reset;
struct clk_onecell_data data;
struct clk *clks[];
};
const
struct freq_tbl *qcom_find_freq(const struct freq_tbl *f, unsigned long rate)
{
if (!f)
return NULL;
for (; f->freq; f++)
if (rate <= f->freq)
return f;
/* Default to our fastest rate */
return f - 1;
}
EXPORT_SYMBOL_GPL(qcom_find_freq);
int qcom_find_src_index(struct clk_hw *hw, const struct parent_map *map, u8 src)
{
int i, num_parents = __clk_get_num_parents(hw->clk);
for (i = 0; i < num_parents; i++)
if (src == map[i].src)
return i;
return -ENOENT;
}
EXPORT_SYMBOL_GPL(qcom_find_src_index);
struct regmap *
qcom_cc_map(struct platform_device *pdev, const struct qcom_cc_desc *desc)
{
void __iomem *base;
struct resource *res;
struct device *dev = &pdev->dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(dev, res);
if (IS_ERR(base))
return ERR_CAST(base);
return devm_regmap_init_mmio(dev, base, desc->config);
}
EXPORT_SYMBOL_GPL(qcom_cc_map);
int qcom_cc_really_probe(struct platform_device *pdev,
const struct qcom_cc_desc *desc, struct regmap *regmap)
{
int i, ret;
struct device *dev = &pdev->dev;
struct clk *clk;
struct clk_onecell_data *data;
struct clk **clks;
struct qcom_reset_controller *reset;
struct qcom_cc *cc;
size_t num_clks = desc->num_clks;
struct clk_regmap **rclks = desc->clks;
cc = devm_kzalloc(dev, sizeof(*cc) + sizeof(*clks) * num_clks,
GFP_KERNEL);
if (!cc)
return -ENOMEM;
clks = cc->clks;
data = &cc->data;
data->clks = clks;
data->clk_num = num_clks;
for (i = 0; i < num_clks; i++) {
if (!rclks[i]) {
clks[i] = ERR_PTR(-ENOENT);
continue;
}
clk = devm_clk_register_regmap(dev, rclks[i]);
if (IS_ERR(clk))
return PTR_ERR(clk);
clks[i] = clk;
}
ret = of_clk_add_provider(dev->of_node, of_clk_src_onecell_get, data);
if (ret)
return ret;
reset = &cc->reset;
reset->rcdev.of_node = dev->of_node;
reset->rcdev.ops = &qcom_reset_ops;
reset->rcdev.owner = dev->driver->owner;
reset->rcdev.nr_resets = desc->num_resets;
reset->regmap = regmap;
reset->reset_map = desc->resets;
platform_set_drvdata(pdev, &reset->rcdev);
ret = reset_controller_register(&reset->rcdev);
if (ret)
of_clk_del_provider(dev->of_node);
return ret;
}
EXPORT_SYMBOL_GPL(qcom_cc_really_probe);
int qcom_cc_probe(struct platform_device *pdev, const struct qcom_cc_desc *desc)
{
struct regmap *regmap;
regmap = qcom_cc_map(pdev, desc);
if (IS_ERR(regmap))
return PTR_ERR(regmap);
return qcom_cc_really_probe(pdev, desc, regmap);
}
EXPORT_SYMBOL_GPL(qcom_cc_probe);
void qcom_cc_remove(struct platform_device *pdev)
{
of_clk_del_provider(pdev->dev.of_node);
reset_controller_unregister(platform_get_drvdata(pdev));
}
EXPORT_SYMBOL_GPL(qcom_cc_remove);
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