Commits
Chen Gong committed e35fca4791f
edac: avoid mce decoding crash after edac driver unloaded Some edac drivers register themselves as mce decoders via notifier_chain. But in current notifier_chain implementation logic, it doesn't accept same notifier registered twice. If so, it will be wrong when adding/removing the element from the list. For example, on one SandyBridge platform, remove module sb_edac and then trigger one error, it will hit oops because it has no mce decoder registered but related notifier_chain still points to an invalid callback function. Here is an example: Call Trace: [<ffffffff8150ef6a>] atomic_notifier_call_chain+0x1a/0x20 [<ffffffff8102b936>] mce_log+0x46/0x180 [<ffffffff8102eaea>] apei_mce_report_mem_error+0x4a/0x60 [<ffffffff812e19d2>] ghes_do_proc+0x192/0x210 [<ffffffff812e2066>] ghes_proc+0x46/0x70 [<ffffffff812e20d8>] ghes_notify_sci+0x48/0x80 [<ffffffff8150ef05>] notifier_call_chain+0x55/0x80 [<ffffffff81076f1a>] __blocking_notifier_call_chain+0x5a/0x80 [<ffffffff812aea11>] ? acpi_os_wait_events_complete+0x23/0x23 [<ffffffff81076f56>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff812ddc4d>] acpi_hed_notify+0x19/0x1b [<ffffffff812b16bd>] acpi_device_notify+0x19/0x1b [<ffffffff812beb38>] acpi_ev_notify_dispatch+0x67/0x7f [<ffffffff812aea3a>] acpi_os_execute_deferred+0x29/0x36 [<ffffffff81069dc2>] process_one_work+0x132/0x450 [<ffffffff8106bbcb>] worker_thread+0x17b/0x3c0 [<ffffffff8106ba50>] ? manage_workers+0x120/0x120 [<ffffffff81070aee>] kthread+0x9e/0xb0 [<ffffffff81514724>] kernel_thread_helper+0x4/0x10 [<ffffffff81070a50>] ? kthread_freezable_should_stop+0x70/0x70 [<ffffffff81514720>] ? gs_change+0x13/0x13 Code: f3 49 89 d4 45 85 ed 4d 89 c6 48 8b 0f 74 48 48 85 c9 75 17 eb 41 0f 1f 80 00 00 00 00 41 83 ed 01 4c 89 f9 74 22 4d 85 ff 74 1d <4c> 8b 79 08 4c 89 e2 48 89 de 48 89 cf ff 11 4d 85 f6 74 04 41 RIP [<ffffffff8150eef6>] notifier_call_chain+0x46/0x80 RSP <ffff88042868fb20> CR2: ffffffffa01af838 ---[ end trace 0100930068e73e6f ]--- BUG: unable to handle kernel paging request at fffffffffffffff8 IP: [<ffffffff810705b0>] kthread_data+0x10/0x20 PGD 1a0d067 PUD 1a0e067 PMD 0 Oops: 0000 [#2] SMP Only i7core_edac and sb_edac have such issues because they have more than one memory controller which means they have to register mce decoder many times. Cc: <stable@vger.kernel.org> # 3.2 and upper Signed-off-by: Chen Gong <gong.chen@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>