EDAC: Balance workqueue setup and teardown

We use the ->edac_check function pointers to determine whether we need
to setup a polling workqueue. However, the destroy path is not balanced
and we might try to teardown an unitialized workqueue.

Balance init and destroy paths by looking at ->edac_check in both cases.
Set op_state to OP_OFFLINE *before* destroying anything.

Reported-by: Zhiqiang Hou <Zhiqiang.Hou@freescale.com>
Cc: Varun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: Borislav Petkov <bp@suse.de>

2 files changed, 10 insertions, 13 deletions

diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 8adfc167c2e3..50802c154915 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -583,8 +583,6 @@ static void edac_mc_workq_setup(struct mem_ctl_info *mci, unsigned msec)
  */
 static void edac_mc_workq_teardown(struct mem_ctl_info *mci)
 {
-        mci->op_state = OP_OFFLINE;
-
         edac_stop_work(&mci->work);
 }
 
@@ -772,7 +770,7 @@ int edac_mc_add_mc_with_groups(struct mem_ctl_info *mci,
         }
 
         /* If there IS a check routine, then we are running POLLED */
-        if (mci->edac_check != NULL) {
+        if (mci->edac_check) {
                 /* This instance is NOW RUNNING */
                 mci->op_state = OP_RUNNING_POLL;
 
@@ -823,15 +821,16 @@ struct mem_ctl_info *edac_mc_del_mc(struct device *dev)
                 return NULL;
         }
 
+        /* mark MCI offline: */
+        mci->op_state = OP_OFFLINE;
+
         if (!del_mc_from_global_list(mci))
                 edac_mc_owner = NULL;
-        mutex_unlock(&mem_ctls_mutex);
 
-        /* flush workq processes */
-        edac_mc_workq_teardown(mci);
+        mutex_unlock(&mem_ctls_mutex);
 
-        /* marking MCI offline */
-        mci->op_state = OP_OFFLINE;
+        if (mci->edac_check)
+                edac_mc_workq_teardown(mci);
 
         /* remove from sysfs */
         edac_remove_sysfs_mci_device(mci);
diff --git a/drivers/edac/edac_pci.c b/drivers/edac/edac_pci.c
index 99685388d3fb..f0e8c3d01ed5 100644
--- a/drivers/edac/edac_pci.c
+++ b/drivers/edac/edac_pci.c
@@ -241,8 +241,6 @@ static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
 {
         edac_dbg(0, "\n");
 
-        pci->op_state = OP_OFFLINE;
-
         edac_stop_work(&pci->work);
 }
 
@@ -289,7 +287,7 @@ int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
                 goto fail1;
         }
 
-        if (pci->edac_check != NULL) {
+        if (pci->edac_check) {
                 pci->op_state = OP_RUNNING_POLL;
 
                 edac_pci_workq_setup(pci, 1000);
@@ -350,8 +348,8 @@ struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
 
         mutex_unlock(&edac_pci_ctls_mutex);
 
-        /* stop the workq timer */
-        edac_pci_workq_teardown(pci);
+        if (pci->edac_check)
+                edac_pci_workq_teardown(pci);
 
         edac_printk(KERN_INFO, EDAC_PCI,
                 "Removed device %d for %s %s: DEV %s\n",