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-lib.c
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/ide.h>
#include <linux/bitops.h>
/**
* ide_toggle_bounce - handle bounce buffering
* @drive: drive to update
* @on: on/off boolean
*
* Enable or disable bounce buffering for the device. Drives move
* between PIO and DMA and that changes the rules we need.
*/
void ide_toggle_bounce(ide_drive_t *drive, int on)
{
u64 addr = BLK_BOUNCE_HIGH; /* dma64_addr_t */
if (!PCI_DMA_BUS_IS_PHYS) {
addr = BLK_BOUNCE_ANY;
} else if (on && drive->media == ide_disk) {
struct device *dev = drive->hwif->dev;
if (dev && dev->dma_mask)
addr = *dev->dma_mask;
}
if (drive->queue)
blk_queue_bounce_limit(drive->queue, addr);
}
u64 ide_get_lba_addr(struct ide_cmd *cmd, int lba48)
{
struct ide_taskfile *tf = &cmd->tf;
u32 high, low;
low = (tf->lbah << 16) | (tf->lbam << 8) | tf->lbal;
if (lba48) {
tf = &cmd->hob;
high = (tf->lbah << 16) | (tf->lbam << 8) | tf->lbal;
} else
high = tf->device & 0xf;
return ((u64)high << 24) | low;
}
EXPORT_SYMBOL_GPL(ide_get_lba_addr);
static void ide_dump_sector(ide_drive_t *drive)
{
struct ide_cmd cmd;
struct ide_taskfile *tf = &cmd.tf;
u8 lba48 = !!(drive->dev_flags & IDE_DFLAG_LBA48);
memset(&cmd, 0, sizeof(cmd));
if (lba48) {
cmd.valid.in.tf = IDE_VALID_LBA;
cmd.valid.in.hob = IDE_VALID_LBA;
cmd.tf_flags = IDE_TFLAG_LBA48;
} else
cmd.valid.in.tf = IDE_VALID_LBA | IDE_VALID_DEVICE;
ide_tf_readback(drive, &cmd);
if (lba48 || (tf->device & ATA_LBA))
printk(KERN_CONT ", LBAsect=%llu",
(unsigned long long)ide_get_lba_addr(&cmd, lba48));
else
printk(KERN_CONT ", CHS=%d/%d/%d", (tf->lbah << 8) + tf->lbam,
tf->device & 0xf, tf->lbal);
}
static void ide_dump_ata_error(ide_drive_t *drive, u8 err)
{
printk(KERN_CONT "{ ");
if (err & ATA_ABORTED)
printk(KERN_CONT "DriveStatusError ");
if (err & ATA_ICRC)
printk(KERN_CONT "%s",
(err & ATA_ABORTED) ? "BadCRC " : "BadSector ");
if (err & ATA_UNC)
printk(KERN_CONT "UncorrectableError ");
if (err & ATA_IDNF)
printk(KERN_CONT "SectorIdNotFound ");
if (err & ATA_TRK0NF)
printk(KERN_CONT "TrackZeroNotFound ");
if (err & ATA_AMNF)
printk(KERN_CONT "AddrMarkNotFound ");
printk(KERN_CONT "}");
if ((err & (ATA_BBK | ATA_ABORTED)) == ATA_BBK ||
(err & (ATA_UNC | ATA_IDNF | ATA_AMNF))) {
struct request *rq = drive->hwif->rq;
ide_dump_sector(drive);
if (rq)
printk(KERN_CONT ", sector=%llu",
(unsigned long long)blk_rq_pos(rq));
}
printk(KERN_CONT "\n");
}
static void ide_dump_atapi_error(ide_drive_t *drive, u8 err)
{
printk(KERN_CONT "{ ");
if (err & ATAPI_ILI)
printk(KERN_CONT "IllegalLengthIndication ");
if (err & ATAPI_EOM)
printk(KERN_CONT "EndOfMedia ");
if (err & ATA_ABORTED)
printk(KERN_CONT "AbortedCommand ");
if (err & ATA_MCR)
printk(KERN_CONT "MediaChangeRequested ");
if (err & ATAPI_LFS)
printk(KERN_CONT "LastFailedSense=0x%02x ",
(err & ATAPI_LFS) >> 4);
printk(KERN_CONT "}\n");
}
/**
* ide_dump_status - translate ATA/ATAPI error
* @drive: drive that status applies to
* @msg: text message to print
* @stat: status byte to decode
*
* Error reporting, in human readable form (luxurious, but a memory hog).
* Combines the drive name, message and status byte to provide a
* user understandable explanation of the device error.
*/
u8 ide_dump_status(ide_drive_t *drive, const char *msg, u8 stat)
{
u8 err = 0;
printk(KERN_ERR "%s: %s: status=0x%02x { ", drive->name, msg, stat);
if (stat & ATA_BUSY)
printk(KERN_CONT "Busy ");
else {
if (stat & ATA_DRDY)
printk(KERN_CONT "DriveReady ");
if (stat & ATA_DF)
printk(KERN_CONT "DeviceFault ");
if (stat & ATA_DSC)
printk(KERN_CONT "SeekComplete ");
if (stat & ATA_DRQ)
printk(KERN_CONT "DataRequest ");
if (stat & ATA_CORR)
printk(KERN_CONT "CorrectedError ");
if (stat & ATA_SENSE)
printk(KERN_CONT "Sense ");
if (stat & ATA_ERR)
printk(KERN_CONT "Error ");
}
printk(KERN_CONT "}\n");
if ((stat & (ATA_BUSY | ATA_ERR)) == ATA_ERR) {
err = ide_read_error(drive);
printk(KERN_ERR "%s: %s: error=0x%02x ", drive->name, msg, err);
if (drive->media == ide_disk)
ide_dump_ata_error(drive, err);
else
ide_dump_atapi_error(drive, err);
}
printk(KERN_ERR "%s: possibly failed opcode: 0x%02x\n",
drive->name, drive->hwif->cmd.tf.command);
return err;
}
EXPORT_SYMBOL(ide_dump_status);
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