[tip: x86/urgent] RAS/CEC: Correct ce_add_elem()'s returned values

tip-bot2 for William Roche
2021-04-07T09:57:35Z

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID: 3a62583c2853b0ab37a57dde79decea210b5fb89
Gitweb: https://git.kernel.org/tip/3a62583c2853b0ab37a57dde79decea210b5fb89
Author: William Roche <william.roche@oracle.com>
AuthorDate: Tue, 06 Apr 2021 11:28:59 -04:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 07 Apr 2021 11:52:26 +02:00

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
---
drivers/ras/cec.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c
index ddecf25..d7894f1 100644
--- 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.
*/