Messages in this thread Patch in this message | | | Date | Thu, 2 Dec 2010 18:06:10 +0100 | From | Borislav Petkov <> | Subject | Re: edac_core: crashes on shutdown |
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On Thu, Dec 02, 2010 at 11:21:12AM -0500, Tobias Karnat wrote: > Am Donnerstag, den 02.12.2010, 16:21 +0100 schrieb Borislav Petkov: > > Well, thanks for the photos. I don't have an idea what might cause this > > workqueue corruption I'm seeing, all reg/unreg paths look ok. The only > > change that came in between .35 and .36.1 I can think of being relevant > > is 00740c58541b6087d78418cebca1fcb86dc6077d. You could try backing that > > one out to see whether it fixes the issue. > > Yes, reverting this fixed the issue! > > But why?
Dang, I know why. This whole ->op_state fumbling is pretty fragile and needs de-fragilizing :o).
Please try out the one below after re-reverting 00740c58541b6087d78418cebca1fcb86dc6077d (i.e., ontop of .36.1).
Thanks.
-- From: Borislav Petkov <borislav.petkov@amd.com> Date: Thu, 2 Dec 2010 17:48:35 +0100 Subject: [PATCH] EDAC: Fix workqueue-related crashes
00740c58541b6087d78418cebca1fcb86dc6077d changed edac_core to un-/register a workqueue item only if a lowlevel driver supplies a polling routine. Normally, when we remove a polling low-level driver, we go and teardown the workqueue and cancel all the queued work. However, the workqueue unreg happens based on the ->op_state setting, and edac_mc_del_mc() sets this to OP_OFFLINE _before_ we cancel the work item, leading to NULL ptr oops on the workqueue list.
Fix it by putting the unreg stuff in proper order.
Cc: <stable@kernel.org> #36.x Reported-by: Tobias Karnat <tobias.karnat@googlemail.com> LKML-Reference: <1291201307.3029.21.camel@Tobias-Karnat> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> --- drivers/edac/edac_mc.c | 10 ++++++---- 1 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c index 6b21e25..6d2e34d 100644 --- a/drivers/edac/edac_mc.c +++ b/drivers/edac/edac_mc.c @@ -578,14 +578,16 @@ struct mem_ctl_info *edac_mc_del_mc(struct device *dev) return NULL; } - /* marking MCI offline */ - mci->op_state = OP_OFFLINE; - del_mc_from_global_list(mci); mutex_unlock(&mem_ctls_mutex); - /* flush workq processes and remove sysfs */ + /* flush workq processes */ edac_mc_workq_teardown(mci); + + /* marking MCI offline */ + mci->op_state = OP_OFFLINE; + + /* remove from sysfs */ edac_remove_sysfs_mci_device(mci); edac_printk(KERN_INFO, EDAC_MC, -- 1.7.3.1.50.g1e633
-- Regards/Gruss, Boris.
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