From: Vaibhav Jain vaibhav@linux.ibm.com
[ Upstream commit 0e0946e22f3665d27325d389ff45ade6e93f3678 ]
Right now 'char *' elements allocated for individual 'stat_id' in 'papr_scm_priv.nvdimm_events_map[]' during papr_scm_pmu_check_events(), get leaked 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.
Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") Signed-off-by: Vaibhav Jain vaibhav@linux.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20220511082637.646714-1-vaibhav@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/platforms/pseries/papr_scm.c | 54 ++++++++++------------- 1 file changed, 24 insertions(+), 30 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c index 39962c905542..181b855b3050 100644 --- a/arch/powerpc/platforms/pseries/papr_scm.c +++ b/arch/powerpc/platforms/pseries/papr_scm.c @@ -125,8 +125,8 @@ struct papr_scm_priv { /* The bits which needs to be overridden */ u64 health_bitmap_inject_mask;
- /* array to have event_code and stat_id mappings */ - char **nvdimm_events_map; + /* array to have event_code and stat_id mappings */ + u8 *nvdimm_events_map; };
static int papr_scm_pmem_flush(struct nd_region *nd_region, @@ -370,7 +370,7 @@ static int papr_scm_pmu_get_value(struct perf_event *event, struct device *dev,
stat = &stats->scm_statistic[0]; memcpy(&stat->stat_id, - p->nvdimm_events_map[event->attr.config], + &p->nvdimm_events_map[event->attr.config * sizeof(stat->stat_id)], sizeof(stat->stat_id)); stat->stat_val = 0;
@@ -462,14 +462,13 @@ 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; u32 available_events; - - if (!p->stat_buffer_len) - return -ENOENT; + int index, rc = 0;
available_events = (p->stat_buffer_len - sizeof(struct papr_scm_perf_stats)) / sizeof(struct papr_scm_perf_stat); + if (available_events == 0) + return -EOPNOTSUPP;
/* Allocate the buffer for phyp where stats are written */ stats = kzalloc(p->stat_buffer_len, GFP_KERNEL); @@ -478,35 +477,30 @@ 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->stat_id), + 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 * sizeof(stat->stat_id)], + &stat->stat_id, sizeof(stat->stat_id)); + } +out: kfree(stats); return rc; }