linux-kernel - [PATCH v3 15/38] x86/resctrl: Move monitor exit work to a restrl exit call

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20240614150033.10454-16-james.morse@arm.com>
Date: Fri, 14 Jun 2024 15:00:10 +0000
From: James Morse <james.morse@....com>
To: x86@...nel.org,
	linux-kernel@...r.kernel.org
Cc: Fenghua Yu <fenghua.yu@...el.com>,
	Reinette Chatre <reinette.chatre@...el.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	H Peter Anvin <hpa@...or.com>,
	Babu Moger <Babu.Moger@....com>,
	James Morse <james.morse@....com>,
	shameerali.kolothum.thodi@...wei.com,
	D Scott Phillips OS <scott@...amperecomputing.com>,
	carl@...amperecomputing.com,
	lcherian@...vell.com,
	bobo.shaobowang@...wei.com,
	tan.shaopeng@...itsu.com,
	baolin.wang@...ux.alibaba.com,
	Jamie Iles <quic_jiles@...cinc.com>,
	Xin Hao <xhao@...ux.alibaba.com>,
	peternewman@...gle.com,
	dfustini@...libre.com,
	amitsinght@...vell.com,
	David Hildenbrand <david@...hat.com>,
	Rex Nie <rex.nie@...uarmicro.com>,
	Dave Martin <dave.martin@....com>,
	Shaopeng Tan <tan.shaopeng@...fujitsu.com>
Subject: [PATCH v3 15/38] x86/resctrl: Move monitor exit work to a restrl exit call

rdt_put_mon_l3_config() is called via the architecture's
resctrl_arch_exit() call, and appears to free the rmid_ptrs[]
and closid_num_dirty_rmid[] arrays. In reality this code is marked
__exit, and is removed by the linker as resctl can't be built
as a module.

To separate the filesystem and architecture parts of resctrl,
this free()ing work needs to be triggered by the filesystem,
as these structures belong to the filesystem code.

Rename rdt_put_mon_l3_config() resctrl_mon_resource_exit()
and call it from resctrl_exit(). The kfree() is currently
dependent on r->mon_capable. resctrl_mon_resource_init()
takes no arguments, so resctrl_mon_resource_exit() shouldn't
take any either. Add the check to dom_data_exit(), making it
take the resource as an argument. This makes it more symmetrical
with dom_data_init().

Signed-off-by: James Morse <james.morse@....com>
Tested-by: Peter Newman <peternewman@...gle.com>
Tested-by: Shaopeng Tan <tan.shaopeng@...fujitsu.com>
---
Changes since v2:
 * Dropped __exit as needed in the next patch.

Change since v1:
 * [Commit message only] Typo fixes:
   s/restrl/resctrl/g
   s/resctl/resctrl/g

 * [Commit message only] Reword second paragraph to remove reference to
   the MPAM error interrupt, which provides background rationale for a
   later patch rather than for this patch, and so it is not really
   relevant here.
---
 arch/x86/kernel/cpu/resctrl/core.c     |  5 -----
 arch/x86/kernel/cpu/resctrl/internal.h |  2 +-
 arch/x86/kernel/cpu/resctrl/monitor.c  | 12 ++++++++----
 arch/x86/kernel/cpu/resctrl/rdtgroup.c |  2 ++
 4 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 9ad660b2b097..2540a7cb11b0 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -950,14 +950,9 @@ late_initcall(resctrl_arch_late_init);
 
 static void __exit resctrl_arch_exit(void)
 {
-	struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
-
 	cpuhp_remove_state(rdt_online);
 
 	resctrl_exit();
-
-	if (r->mon_capable)
-		rdt_put_mon_l3_config();
 }
 
 __exitcall(resctrl_arch_exit);
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 7ede340b1301..9aa7f587484c 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -535,7 +535,7 @@ void closid_free(int closid);
 int alloc_rmid(u32 closid);
 void free_rmid(u32 closid, u32 rmid);
 int rdt_get_mon_l3_config(struct rdt_resource *r);
-void __exit rdt_put_mon_l3_config(void);
+void resctrl_mon_resource_exit(void);
 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 3e5375c365e6..7d6aebce75c1 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -965,10 +965,12 @@ static int dom_data_init(struct rdt_resource *r)
 	return err;
 }
 
-static void __exit dom_data_exit(void)
+static void dom_data_exit(struct rdt_resource *r)
 {
-	mutex_lock(&rdtgroup_mutex);
+	if (!r->mon_capable)
+		return;
 
+	mutex_lock(&rdtgroup_mutex);
 	if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
 		kfree(closid_num_dirty_rmid);
 		closid_num_dirty_rmid = NULL;
@@ -1075,9 +1077,11 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
 	return 0;
 }
 
-void __exit rdt_put_mon_l3_config(void)
+void resctrl_mon_resource_exit(void)
 {
-	dom_data_exit();
+	struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+
+	dom_data_exit(r);
 }
 
 void __init intel_rdt_mbm_apply_quirk(void)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 82d64885c6c0..8c380f389b93 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -4212,4 +4212,6 @@ void __exit resctrl_exit(void)
 	debugfs_remove_recursive(debugfs_resctrl);
 	unregister_filesystem(&rdt_fs_type);
 	sysfs_remove_mount_point(fs_kobj, "resctrl");
+
+	resctrl_mon_resource_exit();
 }
-- 
2.39.2