x86/resctrl: Free rmid_ptrs from resctrl_exit()

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_put_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>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-3-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>

1 files changed, 15 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 3a6c069614eb..3a73db0579d8 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -719,6 +719,16 @@ static int dom_data_init(struct rdt_resource *r)
 	return 0;
 }
 
+static void __exit dom_data_exit(void)
+{
+	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,
@@ -814,6 +824,11 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
 	return 0;
 }
 
+void __exit rdt_put_mon_l3_config(void)
+{
+	dom_data_exit();
+}
+
 void __init intel_rdt_mbm_apply_quirk(void)
 {
 	int cf_index;