Commit c73e8833 authored by Borislav Petkov's avatar Borislav Petkov
Browse files

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: default avatarYazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
parent 90e493d7

drivers/edac/edac_mc.c

+31 −18
Original line number Diff line number Diff line
@@ -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;

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