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authorBorislav Petkov <bp@suse.de>2016-11-14 13:26:11 +0100
committerBorislav Petkov <bp@suse.de>2016-11-14 13:26:11 +0100
commitc73e8833bec5a8ed4f55db0ca964cc1e998656df (patch)
treeb69476c5ed7827c7e545c75bc189a296eabb60f9 /drivers/edac
parent90e493d7d51c791a2adc2de962cbd5000f1b7460 (diff)
EDAC, mc: Fix locking around mc_devices list
When accessing the mc_devices list of memory controller descriptors, we need to hold mem_ctls_mutex. This was not always the case, fix that. Make all external callers call a version which grabs the mutex since the last is local to edac_mc.c. Reported-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'drivers/edac')
-rw-r--r--drivers/edac/edac_mc.c49
1 files changed, 31 insertions, 18 deletions
diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index c3ee3ad98a63..d2ea9c4f1824 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -482,15 +482,8 @@ void edac_mc_free(struct mem_ctl_info *mci)
}
EXPORT_SYMBOL_GPL(edac_mc_free);
-
-/**
- * find_mci_by_dev
- *
- * scan list of controllers looking for the one that manages
- * the 'dev' device
- * @dev: pointer to a struct device related with the MCI
- */
-struct mem_ctl_info *find_mci_by_dev(struct device *dev)
+/* Caller must hold mem_ctls_mutex */
+static struct mem_ctl_info *__find_mci_by_dev(struct device *dev)
{
struct mem_ctl_info *mci;
struct list_head *item;
@@ -506,6 +499,24 @@ struct mem_ctl_info *find_mci_by_dev(struct device *dev)
return NULL;
}
+
+/**
+ * find_mci_by_dev
+ *
+ * scan list of controllers looking for the one that manages
+ * the 'dev' device
+ * @dev: pointer to a struct device related with the MCI
+ */
+struct mem_ctl_info *find_mci_by_dev(struct device *dev)
+{
+ struct mem_ctl_info *ret;
+
+ mutex_lock(&mem_ctls_mutex);
+ ret = __find_mci_by_dev(dev);
+ mutex_unlock(&mem_ctls_mutex);
+
+ return ret;
+}
EXPORT_SYMBOL_GPL(find_mci_by_dev);
/*
@@ -588,7 +599,7 @@ static int add_mc_to_global_list(struct mem_ctl_info *mci)
insert_before = &mc_devices;
- p = find_mci_by_dev(mci->pdev);
+ p = __find_mci_by_dev(mci->pdev);
if (unlikely(p != NULL))
goto fail0;
@@ -640,26 +651,28 @@ static int del_mc_from_global_list(struct mem_ctl_info *mci)
*
* If found, return a pointer to the structure.
* Else return NULL.
- *
- * Caller must hold mem_ctls_mutex.
*/
struct mem_ctl_info *edac_mc_find(int idx)
{
+ struct mem_ctl_info *mci = NULL;
struct list_head *item;
- struct mem_ctl_info *mci;
+
+ mutex_lock(&mem_ctls_mutex);
list_for_each(item, &mc_devices) {
mci = list_entry(item, struct mem_ctl_info, link);
if (mci->mc_idx >= idx) {
- if (mci->mc_idx == idx)
- return mci;
-
+ if (mci->mc_idx == idx) {
+ goto unlock;
+ }
break;
}
}
- return NULL;
+unlock:
+ mutex_unlock(&mem_ctls_mutex);
+ return mci;
}
EXPORT_SYMBOL(edac_mc_find);
@@ -779,7 +792,7 @@ struct mem_ctl_info *edac_mc_del_mc(struct device *dev)
mutex_lock(&mem_ctls_mutex);
/* find the requested mci struct in the global list */
- mci = find_mci_by_dev(dev);
+ mci = __find_mci_by_dev(dev);
if (mci == NULL) {
mutex_unlock(&mem_ctls_mutex);
return NULL;