Right now 'char *' elements allocated individual 'stat_id' in
'papr_scm_priv.nvdimm_events_map' during papr_scm_pmu_check_events() leak in
papr_scm_remove() and papr_scm_pmu_register(), papr_scm_pmu_check_events() error
paths.
Also individual 'stat_id' arent NULL terminated 'char *' instead they are fixed
8-byte sized identifiers. However papr_scm_pmu_register() assumes it to be a
NULL terminated 'char *' and at other places it assumes it to be a
'papr_scm_perf_stat.stat_id' sized string which is 8-byes in size.
Fix this by allocating the memory for papr_scm_priv.nvdimm_events_map to also
include space for 'stat_id' entries. This is possible since number of available
events/stat_ids are known upfront. This saves some memory and one extra level of
indirection from 'nvdimm_events_map' to 'stat_id'. Also rest of the code
can continue to call 'kfree(papr_scm_priv.nvdimm_events_map)' without needing to
iterate over the array and free up individual elements.
Also introduce a new typedef called 'state_id_t' thats a 'u8[8]' and can be used
across papr_scm to deal with stat_ids.
Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support")
Signed-off-by: Vaibhav Jain <vaib...@linux.ibm.com>
---
arch/powerpc/platforms/pseries/papr_scm.c | 48 +++++++++++------------
1 file changed, 22 insertions(+), 26 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c
b/arch/powerpc/platforms/pseries/papr_scm.c
index 39962c905542..f33a865ad5fb 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -70,8 +70,10 @@
#define PAPR_SCM_PERF_STATS_VERSION 0x1
/* Struct holding a single performance metric */
+typedef u8 stat_id_t[8];
+
struct papr_scm_perf_stat {
- u8 stat_id[8];
+ stat_id_t stat_id;
__be64 stat_val;
} __packed;
@@ -126,7 +128,7 @@ struct papr_scm_priv {
u64 health_bitmap_inject_mask;
/* array to have event_code and stat_id mappings */
- char **nvdimm_events_map;
+ stat_id_t *nvdimm_events_map;
};
static int papr_scm_pmem_flush(struct nd_region *nd_region,
@@ -462,7 +464,7 @@ static int papr_scm_pmu_check_events(struct papr_scm_priv
*p, struct nvdimm_pmu
{
struct papr_scm_perf_stat *stat;
struct papr_scm_perf_stats *stats;
- int index, rc, count;
+ int index, rc = 0;
u32 available_events;
if (!p->stat_buffer_len)
@@ -478,35 +480,29 @@ static int papr_scm_pmu_check_events(struct papr_scm_priv
*p, struct nvdimm_pmu
return rc;
}
- /* Allocate memory to nvdimm_event_map */
- p->nvdimm_events_map = kcalloc(available_events, sizeof(char *),
GFP_KERNEL);
- if (!p->nvdimm_events_map) {
- rc = -ENOMEM;
- goto out_stats;
- }
-
/* Called to get list of events supported */
rc = drc_pmem_query_stats(p, stats, 0);
if (rc)
- goto out_nvdimm_events_map;
-
- for (index = 0, stat = stats->scm_statistic, count = 0;
- index < available_events; index++, ++stat) {
- p->nvdimm_events_map[count] = kmemdup_nul(stat->stat_id, 8,
GFP_KERNEL);
- if (!p->nvdimm_events_map[count]) {
- rc = -ENOMEM;
- goto out_nvdimm_events_map;
- }
+ goto out;
- count++;
+ /*
+ * Allocate memory and populate nvdimm_event_map.
+ * Allocate an extra element for NULL entry
+ */
+ p->nvdimm_events_map = kcalloc(available_events + 1,
+ sizeof(stat_id_t), GFP_KERNEL);
+ if (!p->nvdimm_events_map) {
+ rc = -ENOMEM;
+ goto out;
}
- p->nvdimm_events_map[count] = NULL;
- kfree(stats);
- return 0;
-out_nvdimm_events_map:
- kfree(p->nvdimm_events_map);
-out_stats:
+ /* Copy all stat_ids to event map */
+ for (index = 0, stat = stats->scm_statistic;
+ index < available_events; index++, ++stat) {
+ memcpy(&p->nvdimm_events_map[index], &stat->stat_id,
+ sizeof(stat_id_t));
+ }
+out:
kfree(stats);
return rc;
}
base-commit: 348c71344111d7a48892e3e52264ff11956fc196
--
2.35.1
