Commit de0e0624 authored by Borislav Petkov's avatar Borislav Petkov
Browse files

RAS/CEC: Check count_threshold unconditionally 



The count_threshold should be checked unconditionally, after insertion
too, so that a count_threshold value of 1 can cause an immediate
offlining. I.e., offline the page on the *first* error encountered.

Add comments to make it clear what cec_add_elem() does, while at it.

Reported-by: default avatarWANG Chao <chao.wang@ucloud.cn>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac@vger.kernel.org
Link: https://lkml.kernel.org/r/20190418034115.75954-3-chao.wang@ucloud.cn
parent 6d8e294b

drivers/ras/cec.c

+10 −17
Original line number Diff line number Diff line
@@ -294,6 +294,7 @@ int cec_add_elem(u64 pfn) 


	ca->ces_entered++;



	/* Array full, free the LRU slot. */

	if (ca->n == MAX_ELEMS)

		WARN_ON(!del_lru_elem_unlocked(ca));
@@ -306,24 +307,17 @@ int cec_add_elem(u64 pfn) 
			(void *)&ca->array[to],

			(ca->n - to) * sizeof(u64));



		ca->array[to] = (pfn << PAGE_SHIFT) |

				(DECAY_MASK << COUNT_BITS) | 1;



		ca->array[to] = pfn << PAGE_SHIFT;

		ca->n++;



		ret = 0;



		goto decay;

	}



	count = COUNT(ca->array[to]);



	if (count < count_threshold) {

		ca->array[to] |= (DECAY_MASK << COUNT_BITS);

	/* Add/refresh element generation and increment count */

	ca->array[to] |= DECAY_MASK << COUNT_BITS;

	ca->array[to]++;



		ret = 0;

	} else {

	/* Check action threshold and soft-offline, if reached. */

	count = COUNT(ca->array[to]);

	if (count >= count_threshold) {

		u64 pfn = ca->array[to] >> PAGE_SHIFT;



		if (!pfn_valid(pfn)) {
@@ -338,15 +332,14 @@ int cec_add_elem(u64 pfn) 
		del_elem(ca, to);



		/*

		 * Return a >0 value to denote that we've reached the offlining

		 * threshold.

		 * Return a >0 value to callers, to denote that we've reached

		 * the offlining threshold.

		 */

		ret = 1;



		goto unlock;

	}



decay:

	ca->decay_count++;



	if (ca->decay_count >= CLEAN_ELEMS)

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