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authorWen Congyang <wency@cn.fujitsu.com>2012-12-11 16:00:59 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-11 17:22:23 -0800
commit3ac19f8efe26451cacac31d0be34fa9c51114c2a (patch)
tree58613cb9ab1a9f3ab57849e7754332756e0c7a03 /mm/sparse.c
parent8c7b5b4ed948d1ddf9672ee932a16750b280822a (diff)
downloadlinux-3ac19f8efe26451cacac31d0be34fa9c51114c2a.tar.gz
memory-hotplug, mm/sparse.c: clear the memory to store struct page
If sparse memory vmemmap is enabled, we can't free the memory to store struct page when a memory device is hotremoved, because we may store struct page in the memory to manage the memory which doesn't belong to this memory device. When we hotadded this memory device again, we will reuse this memory to store struct page, and struct page may contain some obsolete information, and we will get bad-page state: init_memory_mapping: [mem 0x80000000-0x9fffffff] Built 2 zonelists in Node order, mobility grouping on. Total pages: 547617 Policy zone: Normal BUG: Bad page state in process bash pfn:9b6dc page:ffffea0002200020 count:0 mapcount:0 mapping: (null) index:0xfdfdfdfdfdfdfdfd page flags: 0x2fdfdfdfd5df9fd(locked|referenced|uptodate|dirty|lru|active|slab|owner_priv_1|private|private_2|writeback|head|tail|swapcache|reclaim|swapbacked|unevictable|uncached|compound_lock) Modules linked in: netconsole acpiphp pci_hotplug acpi_memhotplug loop kvm_amd kvm microcode tpm_tis tpm tpm_bios evdev psmouse serio_raw i2c_piix4 i2c_core parport_pc parport processor button thermal_sys ext3 jbd mbcache sg sr_mod cdrom ata_generic virtio_net ata_piix virtio_blk libata virtio_pci virtio_ring virtio scsi_mod Pid: 988, comm: bash Not tainted 3.6.0-rc7-guest #12 Call Trace: [<ffffffff810e9b30>] ? bad_page+0xb0/0x100 [<ffffffff810ea4c3>] ? free_pages_prepare+0xb3/0x100 [<ffffffff810ea668>] ? free_hot_cold_page+0x48/0x1a0 [<ffffffff8112cc08>] ? online_pages_range+0x68/0xa0 [<ffffffff8112cba0>] ? __online_page_increment_counters+0x10/0x10 [<ffffffff81045561>] ? walk_system_ram_range+0x101/0x110 [<ffffffff814c4f95>] ? online_pages+0x1a5/0x2b0 [<ffffffff8135663d>] ? __memory_block_change_state+0x20d/0x270 [<ffffffff81356756>] ? store_mem_state+0xb6/0xf0 [<ffffffff8119e482>] ? sysfs_write_file+0xd2/0x160 [<ffffffff8113769a>] ? vfs_write+0xaa/0x160 [<ffffffff81137977>] ? sys_write+0x47/0x90 [<ffffffff814e2f25>] ? async_page_fault+0x25/0x30 [<ffffffff814ea239>] ? system_call_fastpath+0x16/0x1b Disabling lock debugging due to kernel taint This patch clears the memory to store struct page to avoid unexpected error. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Minchan Kim <minchan.kim@gmail.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reported-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/sparse.c')
-rw-r--r--mm/sparse.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/sparse.c b/mm/sparse.c
index c7be0190699..6b5fb762e2c 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -638,7 +638,6 @@ static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
got_map_page:
ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
got_map_ptr:
- memset(ret, 0, memmap_size);
return ret;
}
@@ -758,6 +757,8 @@ int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
goto out;
}
+ memset(memmap, 0, sizeof(struct page) * nr_pages);
+
ms->section_mem_map |= SECTION_MARKED_PRESENT;
ret = sparse_init_one_section(ms, section_nr, memmap, usemap);