• Qian Cai's avatar
    mm/memory_hotplug.c: fix notification in offline error path · c4efe484
    Qian Cai authored
    When start_isolate_page_range() returned -EBUSY in __offline_pages(), it
    calls memory_notify(MEM_CANCEL_OFFLINE, &arg) with an uninitialized
    "arg".  As the result, it triggers warnings below.  Also, it is only
    necessary to notify MEM_CANCEL_OFFLINE after MEM_GOING_OFFLINE.
    
      page:ffffea0001200000 count:1 mapcount:0 mapping:0000000000000000
      index:0x0
      flags: 0x3fffe000001000(reserved)
      raw: 003fffe000001000 ffffea0001200008 ffffea0001200008 0000000000000000
      raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
      page dumped because: unmovable page
      WARNING: CPU: 25 PID: 1665 at mm/kasan/common.c:665
      kasan_mem_notifier+0x34/0x23b
      CPU: 25 PID: 1665 Comm: bash Tainted: G        W         5.0.0+ #94
      Hardware name: HP ProLiant DL180 Gen9/ProLiant DL180 Gen9, BIOS U20
      10/25/2017
      RIP: 0010:kasan_mem_notifier+0x34/0x23b
      RSP: 0018:ffff8883ec737890 EFLAGS: 00010206
      RAX: 0000000000000246 RBX: ff10f0f4435f1000 RCX: f887a7a21af88000
      RDX: dffffc0000000000 RSI: 0000000000000020 RDI: ffff8881f221af88
      RBP: ffff8883ec737898 R08: ffff888000000000 R09: ffffffffb0bddcd0
      R10: ffffed103e857088 R11: ffff8881f42b8443 R12: dffffc0000000000
      R13: 00000000fffffff9 R14: dffffc0000000000 R15: 0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 0000560fbd31d730 CR3: 00000004049c6003 CR4: 00000000001606a0
      Call Trace:
       notifier_call_chain+0xbf/0x130
       __blocking_notifier_call_chain+0x76/0xc0
       blocking_notifier_call_chain+0x16/0x20
       memory_notify+0x1b/0x20
       __offline_pages+0x3e2/0x1210
       offline_pages+0x11/0x20
       memory_block_action+0x144/0x300
       memory_subsys_offline+0xe5/0x170
       device_offline+0x13f/0x1e0
       state_store+0xeb/0x110
       dev_attr_store+0x3f/0x70
       sysfs_kf_write+0x104/0x150
       kernfs_fop_write+0x25c/0x410
       __vfs_write+0x66/0x120
       vfs_write+0x15a/0x4f0
       ksys_write+0xd2/0x1b0
       __x64_sys_write+0x73/0xb0
       do_syscall_64+0xeb/0xb78
       entry_SYSCALL_64_after_hwframe+0x44/0xa9
      RIP: 0033:0x7f14f75cc3b8
      RSP: 002b:00007ffe84d01d68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
      RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f14f75cc3b8
      RDX: 0000000000000008 RSI: 0000563f8e433d70 RDI: 0000000000000001
      RBP: 0000563f8e433d70 R08: 000000000000000a R09: 00007ffe84d018f0
      R10: 000000000000000a R11: 0000000000000246 R12: 00007f14f789e780
      R13: 0000000000000008 R14: 00007f14f7899740 R15: 0000000000000008
    
    Link: http://lkml.kernel.org/r/20190320204255.53571-1-cai@lca.pw
    Fixes: 79605093 ("mm, memory_hotplug: print reason for the offlining failure")
    Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
    Acked-by: default avatarMichal Hocko <mhocko@suse.com>
    Signed-off-by: default avatarQian Cai <cai@lca.pw>
    Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Cc: <stable@vger.kernel.org>	[5.0.x]
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    c4efe484
memory_hotplug.c 48.7 KB