[PATCH v6 02/24] x86/resctrl: kfree() rmid_ptrs from rdtgroup_exit()

James Morse
2023-09-14T17:22:07Z

rmid_ptrs[] is allocated from dom_data_init() but never free()d.

While the exit text ends up in the linker script's DISCARD section,
the direction of travel is for resctrl to be/have loadable modules.

Add resctrl_exit_mon_l3_config() to cleanup any memory allocated
by rdt_get_mon_l3_config().

There is no reason to backport this to a stable kernel.

Signed-off-by: James Morse <james.morse@arm.com>
---
Changes since v5:
* This patch is new
---
arch/x86/kernel/cpu/resctrl/internal.h | 1 +
arch/x86/kernel/cpu/resctrl/monitor.c | 10 ++++++++++
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 5 +++++
3 files changed, 16 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 85ceaf9a31ac..57cf1e6a57bd 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -537,6 +537,7 @@ void closid_free(int closid);
int alloc_rmid(void);
void free_rmid(u32 rmid);
int rdt_get_mon_l3_config(struct rdt_resource *r);
+void resctrl_exit_mon_l3_config(struct rdt_resource *r);
bool __init rdt_cpu_has(int flag);
void mon_event_count(void *info);
int rdtgroup_mondata_show(struct seq_file *m, void *arg);
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index ded1fc7cb7cb..cfb3f632a4b2 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -741,6 +741,16 @@ static int dom_data_init(struct rdt_resource *r)
return 0;
}

+void resctrl_exit_mon_l3_config(struct rdt_resource *r)
+{
+ mutex_lock(&rdtgroup_mutex);
+
+ kfree(rmid_ptrs);
+ rmid_ptrs = NULL;
+
+ mutex_unlock(&rdtgroup_mutex);
+}
+
static struct mon_evt llc_occupancy_event = {
.name = "llc_occupancy",
.evtid = QOS_L3_OCCUP_EVENT_ID,
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 725344048f85..a2158c266e41 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -3867,6 +3867,11 @@ int __init rdtgroup_init(void)

void __exit rdtgroup_exit(void)
{
+ struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
+
+ if (r->mon_capable)
+ resctrl_exit_mon_l3_config(r);
+
debugfs_remove_recursive(debugfs_resctrl);
unregister_filesystem(&rdt_fs_type);
sysfs_remove_mount_point(fs_kobj, "resctrl");
--
2.39.2