linux-kernel - [PATCH 02/12] cgroup: rstat: Make cgroup_rstat_cpu

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: <20220208194324.85333-3-namhyung@kernel.org>
Date:   Tue,  8 Feb 2022 11:43:14 -0800
From:   Namhyung Kim <namhyung@...nel.org>
To:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...nel.org>, Will Deacon <will@...nel.org>,
        Waiman Long <longman@...hat.com>,
        Boqun Feng <boqun.feng@...il.com>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Steven Rostedt <rostedt@...dmis.org>,
        Byungchul Park <byungchul.park@....com>,
        "Paul E. McKenney" <paulmck@...nel.org>,
        Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
        Radoslaw Burny <rburny@...gle.com>,
        Zefan Li <lizefan.x@...edance.com>,
        Johannes Weiner <hannes@...xchg.org>, cgroups@...r.kernel.org,
        Tejun Heo <tj@...nel.org>
Subject: [PATCH 02/12] cgroup: rstat: Make cgroup_rstat_cpu_lock name readable

The raw_spin_lock_init() uses the argument to name its lockdep map.
But passing per_cpu_ptr() macro directly makes it a very very long
name as it expanded like below:

  ({ do { const void *__vpp_verify = (typeof((&cgroup_rstat_cpu_lock) ...

Let's fix it by passing a local variable instead.  With this change,
the name now looks like:

  cgrp_rstat_cpu_lock

Cc: Zefan Li <lizefan.x@...edance.com>
Cc: Johannes Weiner <hannes@...xchg.org>
Cc: cgroups@...r.kernel.org
Acked-by: Tejun Heo <tj@...nel.org>
Signed-off-by: Namhyung Kim <namhyung@...nel.org>
---
 kernel/cgroup/rstat.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c
index 9d331ba44870..371f54a59c38 100644
--- a/kernel/cgroup/rstat.c
+++ b/kernel/cgroup/rstat.c
@@ -286,9 +286,17 @@ void cgroup_rstat_exit(struct cgroup *cgrp)
 void __init cgroup_rstat_boot(void)
 {
 	int cpu;
+	raw_spinlock_t *cgrp_rstat_cpu_lock;
 
-	for_each_possible_cpu(cpu)
-		raw_spin_lock_init(per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu));
+	for_each_possible_cpu(cpu) {
+		/*
+		 * raw_spin_lock_init() uses the argument to name the lock in
+		 * lockdep results.  Passing per_cpu_ptr() directly created a
+		 * cryptic name as the macro was expanded before stringified.
+		 */
+		cgrp_rstat_cpu_lock = per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu);
+		raw_spin_lock_init(cgrp_rstat_cpu_lock);
+	}
 }
 
 /*
-- 
2.35.0.263.gb82422642f-goog