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Message-Id: <1455602265-16490-6-git-send-email-boqun.feng@gmail.com>
Date: Tue, 16 Feb 2016 13:57:44 +0800
From: Boqun Feng <boqun.feng@...il.com>
To: linux-kernel@...r.kernel.org
Cc: Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...nel.org>,
"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
Josh Triplett <josh@...htriplett.org>,
Steven Rostedt <rostedt@...dmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
Lai Jiangshan <jiangshanlai@...il.com>, sasha.levin@...cle.com,
Boqun Feng <boqun.feng@...il.com>
Subject: [RFC v2 5/6] lockdep: LOCKED_ACCESS: Add proc interface for locked access class
Provide the proc filesystem interface for LOCKED_ACCESS, for a locked
access class whose name is <name>, there will be a file at
/proc/locked_access/<name> containing all the information the
LOCKED_ACCESS has collected so far.
Also add a macro to define a locked access class.
Signed-off-by: Boqun Feng <boqun.feng@...il.com>
---
kernel/locking/lockdep_internals.h | 17 +++++
kernel/locking/lockdep_proc.c | 127 +++++++++++++++++++++++++++++++++++++
2 files changed, 144 insertions(+)
diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h
index 5e2e133..cacf869 100644
--- a/kernel/locking/lockdep_internals.h
+++ b/kernel/locking/lockdep_internals.h
@@ -241,4 +241,21 @@ struct locked_access_class {
.nr_acqchain_hlocks = 0,\
.nr_access_structs = 0, \
}
+
+extern int create_laclass_proc(const char *name,
+ struct locked_access_class *laclass);
+
+#define DEFINE_CREATE_LACLASS_PROC(name) \
+static int __init ___create_##name##_laclass_proc(void) \
+{ \
+ return create_laclass_proc(#name, &name##_laclass); \
+} \
+late_initcall(___create_##name##_laclass_proc)
+
+/* Define a Locked Access Class and create its proc file */
+#define DEFINE_LACLASS(name) \
+ struct locked_access_class name##_laclass = \
+ INIT_LOCKED_ACCESS_DATA(name); \
+ EXPORT_SYMBOL(name##_laclass); \
+ DEFINE_CREATE_LACLASS_PROC(name)
#endif /* CONFIG_LOCKED_ACCESS */
diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index dbb61a3..a278d1b 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -673,6 +673,130 @@ static const struct file_operations proc_lock_stat_operations = {
};
#endif /* CONFIG_LOCK_STAT */
+#ifdef CONFIG_LOCKED_ACCESS
+#include <linux/slab.h>
+static struct proc_dir_entry *locked_access_dir;
+static int seq_laclass_show(struct seq_file *m, void *v)
+{
+ struct locked_access_class *laclass;
+ loff_t *pos = v;
+ struct acqchain *acqchain;
+ struct locked_access_struct *s;
+ struct locked_access_location *loc;
+ unsigned long acq_ip;
+ int i;
+
+ laclass = (struct locked_access_class *)m->private;
+
+ /* Pair with the smp_store_release() in add_acqchain() */
+ if (*pos >= smp_load_acquire(&laclass->nr_acqchains) || *pos < 0)
+ return SEQ_SKIP;
+
+ acqchain = laclass->acqchains + *pos;
+
+ seq_printf(m, "ACQCHAIN 0x%llx, %d locks, irq_context %x:\n",
+ acqchain->chain_key, acqchain->depth,
+ acqchain->irq_context);
+ for (i = 0; i < acqchain->depth; i++) {
+ acq_ip = laclass->acqchain_hlocks[acqchain->base + i];
+ seq_printf(m, "%*sLOCK at [<%p>] %pSR\n",
+ (i+1) * 2, "", (void *) acq_ip,
+ (void *) acq_ip);
+ }
+
+ /* Pair with the list_add_tail_rcu() in add_locked_access() */
+ list_for_each_entry_lockless(s, &acqchain->accesses, list) {
+ loc = s->loc;
+ seq_printf(m, "%*sACCESS TYPE %x at %s:%ld\n",
+ (i+1) * 2, "", s->type, loc->filename,
+ loc->lineno);
+
+ }
+ return 0;
+}
+
+static void *seq_laclass_start(struct seq_file *m, loff_t *pos)
+{
+ struct locked_access_class *laclass;
+ loff_t *rpos;
+
+ laclass = (struct locked_access_class *)m->private;
+
+ /* Pair with the smp_store_release() in add_acqchain() */
+ if (*pos >= smp_load_acquire(&laclass->nr_acqchains) || *pos < 0)
+ return NULL;
+
+ rpos = kzalloc(sizeof(loff_t), GFP_KERNEL);
+
+ if (!rpos)
+ return NULL;
+
+ *rpos = *pos;
+
+ return rpos;
+}
+
+static void *seq_laclass_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct locked_access_class *laclass;
+ loff_t *rpos = v;
+
+ laclass = (struct locked_access_class *)m->private;
+
+ /* Pair with the smp_store_release() in add_acqchain() */
+ if (*pos + 1 < smp_load_acquire(&laclass->nr_acqchains) && *pos >= 0) {
+ *pos = ++*rpos;
+ return rpos;
+ }
+
+ return NULL;
+}
+
+static void seq_laclass_stop(struct seq_file *m, void *v)
+{
+ kfree(v);
+}
+
+static const struct seq_operations seq_laclass_ops = {
+ .start = seq_laclass_start,
+ .next = seq_laclass_next,
+ .stop = seq_laclass_stop,
+ .show = seq_laclass_show
+};
+
+static int proc_laclass_open(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq;
+ int rc;
+
+ rc = seq_open(file, &seq_laclass_ops);
+
+ if (rc != 0)
+ return rc;
+
+ if (!PDE_DATA(inode))
+ return -ENOENT;
+
+ seq = file->private_data;
+ seq->private = PDE_DATA(inode);
+
+ return 0;
+}
+
+static const struct file_operations proc_laclass_operations = {
+ .open = proc_laclass_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release
+};
+
+int create_laclass_proc(const char *name, struct locked_access_class *laclass)
+{
+ return !proc_create_data(name, S_IRUSR, locked_access_dir,
+ &proc_laclass_operations, laclass);
+}
+#endif /* CONFIG_LOCKED_ACCESS */
+
static int __init lockdep_proc_init(void)
{
proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
@@ -688,6 +812,9 @@ static int __init lockdep_proc_init(void)
&proc_lock_stat_operations);
#endif
+#ifdef CONFIG_LOCKED_ACCESS
+ locked_access_dir = proc_mkdir("locked_access", NULL);
+#endif /* CONFIG_LOCKED_ACCESS */
return 0;
}
--
2.7.1
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