locking/pvqspinlock: Robustify init_qspinlock_stat()
Specifically around the debugfs file creation calls,
I have no idea if they could ever possibly fail, but
this is core code (debug aside) so lets at least
check the return value and inform anything fishy.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Waiman Long <Waiman.Long@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160420041725.GC3472@linux-uzut.site
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/locking/qspinlock_stat.h b/kernel/locking/qspinlock_stat.h
index 7272233..22e0253 100644
--- a/kernel/locking/qspinlock_stat.h
+++ b/kernel/locking/qspinlock_stat.h
@@ -212,10 +212,8 @@
struct dentry *d_qstat = debugfs_create_dir("qlockstat", NULL);
int i;
- if (!d_qstat) {
- pr_warn("Could not create 'qlockstat' debugfs directory\n");
- return 0;
- }
+ if (!d_qstat)
+ goto out;
/*
* Create the debugfs files
@@ -225,12 +223,20 @@
* performance.
*/
for (i = 0; i < qstat_num; i++)
- debugfs_create_file(qstat_names[i], 0400, d_qstat,
- (void *)(long)i, &fops_qstat);
+ if (!debugfs_create_file(qstat_names[i], 0400, d_qstat,
+ (void *)(long)i, &fops_qstat))
+ goto fail_undo;
- debugfs_create_file(qstat_names[qstat_reset_cnts], 0200, d_qstat,
- (void *)(long)qstat_reset_cnts, &fops_qstat);
+ if (!debugfs_create_file(qstat_names[qstat_reset_cnts], 0200, d_qstat,
+ (void *)(long)qstat_reset_cnts, &fops_qstat))
+ goto fail_undo;
+
return 0;
+fail_undo:
+ debugfs_remove_recursive(d_qstat);
+out:
+ pr_warn("Could not create 'qlockstat' debugfs entries\n");
+ return -ENOMEM;
}
fs_initcall(init_qspinlock_stat);
