[PATCH 07/11] RAS/CEC: Sanity-check array on every insertion

Borislav Petkov
2019-05-09T18:09:53Z

Check the elements order in the array after every insertion.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
---
drivers/ras/cec.c | 37 +++++++++++++++++++++++++++++++------
1 file changed, 31 insertions(+), 6 deletions(-)

diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c
index 8a04b9864192..2c92a70fa2f0 100644
--- a/drivers/ras/cec.c
+++ b/drivers/ras/cec.c
@@ -276,11 +276,39 @@ static u64 __maybe_unused del_lru_elem(void)
return pfn;
}

+static bool sanity_check(struct ce_array *ca)
+{
+ bool ret = false;
+ u64 prev = 0;
+ int i;
+
+ for (i = 0; i < ca->n; i++) {
+ u64 this = PFN(ca->array[i]);
+
+ if (WARN(prev > this, "prev: 0x%016llx <-> this: 0x%016llx\n", prev, this))
+ ret = true;
+
+ prev = this;
+ }
+
+ if (!ret)
+ return ret;
+
+ pr_info("Sanity check dump:\n{ n: %d\n", ca->n);
+ for (i = 0; i < ca->n; i++) {
+ u64 this = PFN(ca->array[i]);
+
+ pr_info(" %03d: [%016llx|%03llx]\n", i, this, FULL_COUNT(ca->array[i]));
+ }
+ pr_info("}\n");
+
+ return ret;
+}

int cec_add_elem(u64 pfn)
{
struct ce_array *ca = &ce_arr;
- unsigned int to;
+ unsigned int to = 0;
int count, ret = 0;

/*
@@ -345,6 +373,8 @@ int cec_add_elem(u64 pfn)
if (ca->decay_count >= CLEAN_ELEMS)
do_spring_cleaning(ca);

+ WARN_ON_ONCE(sanity_check(ca));
+
unlock:
mutex_unlock(&ce_mutex);

@@ -402,7 +432,6 @@ DEFINE_DEBUGFS_ATTRIBUTE(count_threshold_ops, pfn_get, count_threshold_set, "%ll
static int array_dump(struct seq_file *m, void *v)
{
struct ce_array *ca = &ce_arr;
- u64 prev = 0;
int i;

mutex_lock(&ce_mutex);
@@ -412,10 +441,6 @@ static int array_dump(struct seq_file *m, void *v)
u64 this = PFN(ca->array[i]);

seq_printf(m, " %03d: [%016llx|%03llx]\n", i, this, FULL_COUNT(ca->array[i]));
-
- WARN_ON(prev > this);
-
- prev = this;
}

seq_printf(m, "}\n");
--
2.21.0