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-xfer-mode.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>
static const char *udma_str[] =
{ "UDMA/16", "UDMA/25", "UDMA/33", "UDMA/44",
"UDMA/66", "UDMA/100", "UDMA/133", "UDMA7" };
static const char *mwdma_str[] =
{ "MWDMA0", "MWDMA1", "MWDMA2", "MWDMA3", "MWDMA4" };
static const char *swdma_str[] =
{ "SWDMA0", "SWDMA1", "SWDMA2" };
static const char *pio_str[] =
{ "PIO0", "PIO1", "PIO2", "PIO3", "PIO4", "PIO5", "PIO6" };
/**
* ide_xfer_verbose - return IDE mode names
* @mode: transfer mode
*
* Returns a constant string giving the name of the mode
* requested.
*/
const char *ide_xfer_verbose(u8 mode)
{
const char *s;
u8 i = mode & 0xf;
if (mode >= XFER_UDMA_0 && mode <= XFER_UDMA_7)
s = udma_str[i];
else if (mode >= XFER_MW_DMA_0 && mode <= XFER_MW_DMA_4)
s = mwdma_str[i];
else if (mode >= XFER_SW_DMA_0 && mode <= XFER_SW_DMA_2)
s = swdma_str[i];
else if (mode >= XFER_PIO_0 && mode <= XFER_PIO_6)
s = pio_str[i & 0x7];
else if (mode == XFER_PIO_SLOW)
s = "PIO SLOW";
else
s = "XFER ERROR";
return s;
}
EXPORT_SYMBOL(ide_xfer_verbose);
/**
* ide_get_best_pio_mode - get PIO mode from drive
* @drive: drive to consider
* @mode_wanted: preferred mode
* @max_mode: highest allowed mode
*
* This routine returns the recommended PIO settings for a given drive,
* based on the drive->id information and the ide_pio_blacklist[].
*
* Drive PIO mode is auto-selected if 255 is passed as mode_wanted.
* This is used by most chipset support modules when "auto-tuning".
*/
static u8 ide_get_best_pio_mode(ide_drive_t *drive, u8 mode_wanted, u8 max_mode)
{
u16 *id = drive->id;
int pio_mode = -1, overridden = 0;
if (mode_wanted != 255)
return min_t(u8, mode_wanted, max_mode);
if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_BLACKLIST) == 0)
pio_mode = ide_scan_pio_blacklist((char *)&id[ATA_ID_PROD]);
if (pio_mode != -1) {
printk(KERN_INFO "%s: is on PIO blacklist\n", drive->name);
} else {
pio_mode = id[ATA_ID_OLD_PIO_MODES] >> 8;
if (pio_mode > 2) { /* 2 is maximum allowed tPIO value */
pio_mode = 2;
overridden = 1;
}
if (id[ATA_ID_FIELD_VALID] & 2) { /* ATA2? */
if (ata_id_is_cfa(id) && (id[ATA_ID_CFA_MODES] & 7))
pio_mode = 4 + min_t(int, 2,
id[ATA_ID_CFA_MODES] & 7);
else if (ata_id_has_iordy(id)) {
if (id[ATA_ID_PIO_MODES] & 7) {
overridden = 0;
if (id[ATA_ID_PIO_MODES] & 4)
pio_mode = 5;
else if (id[ATA_ID_PIO_MODES] & 2)
pio_mode = 4;
else
pio_mode = 3;
}
}
}
if (overridden)
printk(KERN_INFO "%s: tPIO > 2, assuming tPIO = 2\n",
drive->name);
}
if (pio_mode > max_mode)
pio_mode = max_mode;
return pio_mode;
}
int ide_pio_need_iordy(ide_drive_t *drive, const u8 pio)
{
/*
* IORDY may lead to controller lock up on certain controllers
* if the port is not occupied.
*/
if (pio == 0 && (drive->hwif->port_flags & IDE_PFLAG_PROBING))
return 0;
return ata_id_pio_need_iordy(drive->id, pio);
}
EXPORT_SYMBOL_GPL(ide_pio_need_iordy);
int ide_set_pio_mode(ide_drive_t *drive, const u8 mode)
{
ide_hwif_t *hwif = drive->hwif;
const struct ide_port_ops *port_ops = hwif->port_ops;
if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
return 0;
if (port_ops == NULL || port_ops->set_pio_mode == NULL)
return -1;
/*
* TODO: temporary hack for some legacy host drivers that didn't
* set transfer mode on the device in ->set_pio_mode method...
*/
if (port_ops->set_dma_mode == NULL) {
drive->pio_mode = mode;
port_ops->set_pio_mode(hwif, drive);
return 0;
}
if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
if (ide_config_drive_speed(drive, mode))
return -1;
drive->pio_mode = mode;
port_ops->set_pio_mode(hwif, drive);
return 0;
} else {
drive->pio_mode = mode;
port_ops->set_pio_mode(hwif, drive);
return ide_config_drive_speed(drive, mode);
}
}
int ide_set_dma_mode(ide_drive_t *drive, const u8 mode)
{
ide_hwif_t *hwif = drive->hwif;
const struct ide_port_ops *port_ops = hwif->port_ops;
if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
return 0;
if (port_ops == NULL || port_ops->set_dma_mode == NULL)
return -1;
if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
if (ide_config_drive_speed(drive, mode))
return -1;
drive->dma_mode = mode;
port_ops->set_dma_mode(hwif, drive);
return 0;
} else {
drive->dma_mode = mode;
port_ops->set_dma_mode(hwif, drive);
return ide_config_drive_speed(drive, mode);
}
}
EXPORT_SYMBOL_GPL(ide_set_dma_mode);
/* req_pio == "255" for auto-tune */
void ide_set_pio(ide_drive_t *drive, u8 req_pio)
{
ide_hwif_t *hwif = drive->hwif;
const struct ide_port_ops *port_ops = hwif->port_ops;
u8 host_pio, pio;
if (port_ops == NULL || port_ops->set_pio_mode == NULL ||
(hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
return;
BUG_ON(hwif->pio_mask == 0x00);
host_pio = fls(hwif->pio_mask) - 1;
pio = ide_get_best_pio_mode(drive, req_pio, host_pio);
/*
* TODO:
* - report device max PIO mode
* - check req_pio != 255 against device max PIO mode
*/
printk(KERN_DEBUG "%s: host max PIO%d wanted PIO%d%s selected PIO%d\n",
drive->name, host_pio, req_pio,
req_pio == 255 ? "(auto-tune)" : "", pio);
(void)ide_set_pio_mode(drive, XFER_PIO_0 + pio);
}
EXPORT_SYMBOL_GPL(ide_set_pio);
/**
* ide_rate_filter - filter transfer mode
* @drive: IDE device
* @speed: desired speed
*
* Given the available transfer modes this function returns
* the best available speed at or below the speed requested.
*
* TODO: check device PIO capabilities
*/
static u8 ide_rate_filter(ide_drive_t *drive, u8 speed)
{
ide_hwif_t *hwif = drive->hwif;
u8 mode = ide_find_dma_mode(drive, speed);
if (mode == 0) {
if (hwif->pio_mask)
mode = fls(hwif->pio_mask) - 1 + XFER_PIO_0;
else
mode = XFER_PIO_4;
}
/* printk("%s: mode 0x%02x, speed 0x%02x\n", __func__, mode, speed); */
return min(speed, mode);
}
/**
* ide_set_xfer_rate - set transfer rate
* @drive: drive to set
* @rate: speed to attempt to set
*
* General helper for setting the speed of an IDE device. This
* function knows about user enforced limits from the configuration
* which ->set_pio_mode/->set_dma_mode does not.
*/
int ide_set_xfer_rate(ide_drive_t *drive, u8 rate)
{
ide_hwif_t *hwif = drive->hwif;
const struct ide_port_ops *port_ops = hwif->port_ops;
if (port_ops == NULL || port_ops->set_dma_mode == NULL ||
(hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
return -1;
rate = ide_rate_filter(drive, rate);
BUG_ON(rate < XFER_PIO_0);
if (rate >= XFER_PIO_0 && rate <= XFER_PIO_6)
return ide_set_pio_mode(drive, rate);
return ide_set_dma_mode(drive, rate);
}
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