Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757895Ab2EEBTW (ORCPT ); Fri, 4 May 2012 21:19:22 -0400 Received: from mga09.intel.com ([134.134.136.24]:63745 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752322Ab2EEBTT (ORCPT ); Fri, 4 May 2012 21:19:19 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,351,1309762800"; d="scan'208";a="140317344" From: Chen Gong To: mchehab@redhat.com Cc: linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Chen Gong Subject: [PATCH] edac: avoid mce decoding crash after edac driver unloaded Date: Sat, 5 May 2012 09:20:36 +0800 Message-Id: <1336180836-9108-1-git-send-email-gong.chen@linux.intel.com> X-Mailer: git-send-email 1.7.10 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5502 Lines: 149 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 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: [] atomic_notifier_call_chain+0x1a/0x20 [] mce_log+0x46/0x180 [] apei_mce_report_mem_error+0x4a/0x60 [] ghes_do_proc+0x192/0x210 [] ghes_proc+0x46/0x70 [] ghes_notify_sci+0x48/0x80 [] notifier_call_chain+0x55/0x80 [] __blocking_notifier_call_chain+0x5a/0x80 [] ? acpi_os_wait_events_complete+0x23/0x23 [] blocking_notifier_call_chain+0x16/0x20 [] acpi_hed_notify+0x19/0x1b [] acpi_device_notify+0x19/0x1b [] acpi_ev_notify_dispatch+0x67/0x7f [] acpi_os_execute_deferred+0x29/0x36 [] process_one_work+0x132/0x450 [] worker_thread+0x17b/0x3c0 [] ? manage_workers+0x120/0x120 [] kthread+0x9e/0xb0 [] kernel_thread_helper+0x4/0x10 [] ? kthread_freezable_should_stop+0x70/0x70 [] ? 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 [] notifier_call_chain+0x46/0x80 RSP CR2: ffffffffa01af838 ---[ end trace 0100930068e73e6f ]--- BUG: unable to handle kernel paging request at fffffffffffffff8 IP: [] 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. Signed-off-by: Chen Gong --- drivers/edac/i7core_edac.c | 12 ++++++++++-- drivers/edac/sb_edac.c | 12 ++++++++++-- 2 files changed, 20 insertions(+), 4 deletions(-) diff --git a/drivers/edac/i7core_edac.c b/drivers/edac/i7core_edac.c index 85226cc..1852a52 100644 --- a/drivers/edac/i7core_edac.c +++ b/drivers/edac/i7core_edac.c @@ -2216,6 +2216,7 @@ static void i7core_unregister_mci(struct i7core_dev *i7core_dev) { struct mem_ctl_info *mci = i7core_dev->mci; struct i7core_pvt *pvt; + static int once; if (unlikely(!mci || !mci->pvt_info)) { debugf0("MC: " __FILE__ ": %s(): dev = %p\n", @@ -2234,7 +2235,10 @@ static void i7core_unregister_mci(struct i7core_dev *i7core_dev) if (pvt->enable_scrub) disable_sdram_scrub_setting(mci); - mce_unregister_decode_chain(&i7_mce_dec); + if (!once) { + mce_unregister_decode_chain(&i7_mce_dec); + once = 1; + } /* Disable EDAC polling */ i7core_pci_ctl_release(pvt); @@ -2253,6 +2257,7 @@ static int i7core_register_mci(struct i7core_dev *i7core_dev) struct mem_ctl_info *mci; struct i7core_pvt *pvt; int rc, channels, csrows; + static int once; /* Check the number of active and not disabled channels */ rc = i7core_get_active_channels(i7core_dev->socket, &channels, &csrows); @@ -2336,7 +2341,10 @@ static int i7core_register_mci(struct i7core_dev *i7core_dev) /* DCLK for scrub rate setting */ pvt->dclk_freq = get_dclk_freq(); - mce_register_decode_chain(&i7_mce_dec); + if (!once) { + mce_register_decode_chain(&i7_mce_dec); + once = 1; + } return 0; diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c index a203536..20fabc8 100644 --- a/drivers/edac/sb_edac.c +++ b/drivers/edac/sb_edac.c @@ -1655,6 +1655,7 @@ static void sbridge_unregister_mci(struct sbridge_dev *sbridge_dev) { struct mem_ctl_info *mci = sbridge_dev->mci; struct sbridge_pvt *pvt; + static int once; if (unlikely(!mci || !mci->pvt_info)) { debugf0("MC: " __FILE__ ": %s(): dev = %p\n", @@ -1669,7 +1670,10 @@ static void sbridge_unregister_mci(struct sbridge_dev *sbridge_dev) debugf0("MC: " __FILE__ ": %s(): mci = %p, dev = %p\n", __func__, mci, &sbridge_dev->pdev[0]->dev); - mce_unregister_decode_chain(&sbridge_mce_dec); + if (!once) { + mce_unregister_decode_chain(&sbridge_mce_dec); + once = 1; + } /* Remove MC sysfs nodes */ edac_mc_del_mc(mci->dev); @@ -1685,6 +1689,7 @@ static int sbridge_register_mci(struct sbridge_dev *sbridge_dev) struct mem_ctl_info *mci; struct sbridge_pvt *pvt; int rc, channels, csrows; + static int once; /* Check the number of active and not disabled channels */ rc = sbridge_get_active_channels(sbridge_dev->bus, &channels, &csrows); @@ -1738,7 +1743,10 @@ static int sbridge_register_mci(struct sbridge_dev *sbridge_dev) goto fail0; } - mce_register_decode_chain(&sbridge_mce_dec); + if (!once) { + mce_register_decode_chain(&sbridge_mce_dec); + once = 1; + } return 0; fail0: -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/