linux-toradex.git/mm/memory_hotplug.c, branch v3.10.89

mm/memory_hotplug.c: set zone->wait_table to null after freeing it

2015-06-22T23:55:54+00:00

commit 85bd839983778fcd0c1c043327b14a046e979b39 upstream.

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:[]  [] __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  [] __wake_up_bit+0x20/0x70
     RSP 
    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 
Reported-by: Taku Izumi 
Reviewed by: Yasuaki Ishimatsu 
Cc: KAMEZAWA Hiroyuki 
Cc: Tang Chen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm/memory hotplug: postpone the reset of obsolete pgdat

2015-04-19T08:10:47+00:00

commit b0dc3a342af36f95a68fe229b8f0f73552c5ca08 upstream.

Qiu Xishi reported the following BUG when testing hot-add/hot-remove node under
stress condition:

  BUG: unable to handle kernel paging request at 0000000000025f60
  IP: next_online_pgdat+0x1/0x50
  PGD 0
  Oops: 0000 [#1] SMP
  ACPI: Device does not support D3cold
  Modules linked in: fuse nls_iso8859_1 nls_cp437 vfat fat loop dm_mod coretemp mperf crc32c_intel ghash_clmulni_intel aesni_intel ablk_helper cryptd lrw gf128mul glue_helper aes_x86_64 pcspkr microcode igb dca i2c_algo_bit ipv6 megaraid_sas iTCO_wdt i2c_i801 i2c_core iTCO_vendor_support tg3 sg hwmon ptp lpc_ich pps_core mfd_core acpi_pad rtc_cmos button ext3 jbd mbcache sd_mod crc_t10dif scsi_dh_alua scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc scsi_dh ahci libahci libata scsi_mod [last unloaded: rasf]
  CPU: 23 PID: 238 Comm: kworker/23:1 Tainted: G           O 3.10.15-5885-euler0302 #1
  Hardware name: HUAWEI TECHNOLOGIES CO.,LTD. Huawei N1/Huawei N1, BIOS V100R001 03/02/2015
  Workqueue: events vmstat_update
  task: ffffa800d32c0000 ti: ffffa800d32ae000 task.ti: ffffa800d32ae000
  RIP: 0010: next_online_pgdat+0x1/0x50
  RSP: 0018:ffffa800d32afce8  EFLAGS: 00010286
  RAX: 0000000000001440 RBX: ffffffff81da53b8 RCX: 0000000000000082
  RDX: 0000000000000000 RSI: 0000000000000082 RDI: 0000000000000000
  RBP: ffffa800d32afd28 R08: ffffffff81c93bfc R09: ffffffff81cbdc96
  R10: 00000000000040ec R11: 00000000000000a0 R12: ffffa800fffb3440
  R13: ffffa800d32afd38 R14: 0000000000000017 R15: ffffa800e6616800
  FS:  0000000000000000(0000) GS:ffffa800e6600000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000025f60 CR3: 0000000001a0b000 CR4: 00000000001407e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
    refresh_cpu_vm_stats+0xd0/0x140
    vmstat_update+0x11/0x50
    process_one_work+0x194/0x3d0
    worker_thread+0x12b/0x410
    kthread+0xc6/0xd0
    ret_from_fork+0x7c/0xb0

The cause is the "memset(pgdat, 0, sizeof(*pgdat))" at the end of
try_offline_node, which will reset all the content of pgdat to 0, as the
pgdat is accessed lock-free, so that the users still using the pgdat
will panic, such as the vmstat_update routine.

process A:				offline node XX:

vmstat_updat()
   refresh_cpu_vm_stats()
     for_each_populated_zone()
       find online node XX
     cond_resched()
					offline cpu and memory, then try_offline_node()
					node_set_offline(nid), and memset(pgdat, 0, sizeof(*pgdat))
       zone = next_zone(zone)
         pg_data_t *pgdat = zone->zone_pgdat;  // here pgdat is NULL now
           next_online_pgdat(pgdat)
             next_online_node(pgdat->node_id);  // NULL pointer access

So the solution here is postponing the reset of obsolete pgdat from
try_offline_node() to hotadd_new_pgdat(), and just resetting
pgdat->nr_zones and pgdat->classzone_idx to be 0 rather than the memset
0 to avoid breaking pointer information in pgdat.

Signed-off-by: Gu Zheng 
Reported-by: Xishi Qiu 
Suggested-by: KAMEZAWA Hiroyuki 
Cc: David Rientjes 
Cc: Yasuaki Ishimatsu 
Cc: Taku Izumi 
Cc: Tang Chen 
Cc: Xie XiuQi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm/memory_hotplug.c: fix printk format warnings

2013-05-24T23:22:52+00:00

Fix printk format warnings in mm/memory_hotplug.c by using "%pa":

  mm/memory_hotplug.c: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 2 has type 'resource_size_t' [-Wformat]
  mm/memory_hotplug.c: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'resource_size_t' [-Wformat]

Signed-off-by: Randy Dunlap 
Reported-by: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: fix memory_hotplug.c printk format warning

2013-04-29T22:54:39+00:00

PFN_PHYS() is a phys_addr_t, which can be u32 or u64.
Fix the build warning when phys_addr_t is u32.

  mm/memory_hotplug.c: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 2 has type 'unsigned int' [-Wformat]:  => 1685:3
  mm/memory_hotplug.c: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'unsigned int' [-Wformat]:  => 1685:3

Signed-off-by: Randy Dunlap 
Reported-by: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, hotplug: avoid compiling memory hotremove functions when disabled

2013-04-29T22:54:37+00:00

__remove_pages() is only necessary for CONFIG_MEMORY_HOTREMOVE.  PowerPC
pseries will return -EOPNOTSUPP if unsupported.

Adding an #ifdef causes several other functions it depends on to also
become unnecessary, which saves in .text when disabled (it's disabled in
most defconfigs besides powerpc, including x86).  remove_memory_block()
becomes static since it is not referenced outside of
drivers/base/memory.c.

Build tested on x86 and powerpc with CONFIG_MEMORY_HOTREMOVE both enabled
and disabled.

Signed-off-by: David Rientjes 
Acked-by: Toshi Kani 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Greg Kroah-Hartman 
Cc: Wen Congyang 
Cc: Tang Chen 
Cc: Yasuaki Ishimatsu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: change __remove_pages() to call release_mem_region_adjustable()

2013-04-29T22:54:37+00:00

Change __remove_pages() to call release_mem_region_adjustable().  This
allows a requested memory range to be released from the iomem_resource
table even if it does not match exactly to an resource entry but still
fits into.  The resource entries initialized at bootup usually cover the
whole contiguous memory ranges and may not necessarily match with the
size of memory hot-delete requests.

If release_mem_region_adjustable() failed, __remove_pages() emits a
warning message and continues to proceed as it was the case with
release_mem_region().  release_mem_region(), which is defined to
__release_region(), emits a warning message and returns no error since a
void function.

Signed-off-by: Toshi Kani 
Reviewed-by : Yasuaki Ishimatsu 
Acked-by: David Rientjes 
Cc: Ram Pai 
Cc: T Makphaibulchoke 
Cc: Wen Congyang 
Cc: Tang Chen 
Cc: Jiang Liu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: walk_memory_range(): fix typo in comment

2013-04-29T22:54:28+00:00

Fix a typo "end_pft" in the comment of walk_memory_range().

Signed-off-by: Toshi Kani 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/hotplug: only free wait_table if it's allocated by vmalloc

2013-03-22T23:41:20+00:00

zone->wait_table may be allocated from bootmem, it can not be freed.

Signed-off-by: Jianguo Wu 
Reviewed-by: Tang Chen 
Cc: Tang Chen 
Cc: Jiang Liu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove_memory(): fix end_pfn setting

2013-03-13T22:21:44+00:00

remove_memory() calls walk_memory_range() with [start_pfn, end_pfn), where
end_pfn is exclusive in this range.  Therefore, end_pfn needs to be set to
the next page of the end address.

Signed-off-by: Toshi Kani 
Cc: Wen Congyang 
Cc: Tang Chen 
Cc: Kamezawa Hiroyuki 
Cc: KOSAKI Motohiro 
Cc: Jiang Liu 
Cc: Jianguo Wu 
Cc: Lai Jiangshan 
Cc: Wu Jianguo 
Cc: Yasuaki Ishimatsu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug: use pgdat_end_pfn() instead of open coding the same.

2013-02-24T01:50:21+00:00

Replace open coded pgdat_end_pfn() with helper function.

Signed-off-by: Cody P Schafer 
Cc: David Hansen 
Cc: Catalin Marinas 
Cc: Johannes Weiner 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds