RAS/CEC: Correct ce_add_elem()'s returned values

ce_add_elem() uses different return values to signal a result from
adding an element to the collector. Commit in Fixes: broke the case
where the element being added is not found in the array. Correct that.

 [ bp: Rewrite commit message, add kernel-doc comments. ]

Fixes: de0e0624d86f ("RAS/CEC: Check count_threshold unconditionally")
Signed-off-by: William Roche <william.roche@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/1617722939-29670-1-git-send-email-william.roche@oracle.com

diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c
index ddecf25b5dd40766a75f74c39890dc52c4ece944..d7894f178bd4fa91264020b62acfa65fc271f4f8 100644 (file)
--- a/drivers/ras/cec.c
+++ b/drivers/ras/cec.c
@@ -309,11 +309,20 @@ static bool sanity_check(struct ce_array *ca)
        return ret;
 }
 
+/**
+ * cec_add_elem - Add an element to the CEC array.
+ * @pfn:       page frame number to insert
+ *
+ * Return values:
+ * - <0:       on error
+ * -  0:       on success
+ * - >0:       when the inserted pfn was offlined
+ */
 static int cec_add_elem(u64 pfn)
 {
        struct ce_array *ca = &ce_arr;
+       int count, err, ret = 0;
        unsigned int to = 0;
-       int count, ret = 0;
 
        /*
         * We can be called very early on the identify_cpu() path where we are
@@ -330,8 +339,8 @@ static int cec_add_elem(u64 pfn)
        if (ca->n == MAX_ELEMS)
                WARN_ON(!del_lru_elem_unlocked(ca));
 
-       ret = find_elem(ca, pfn, &to);
-       if (ret < 0) {
+       err = find_elem(ca, pfn, &to);
+       if (err < 0) {
                /*
                 * Shift range [to-end] to make room for one more element.
                 */