[PATCH v3] ras: cec: Fix debugfs error checking

[Haotian Zhang <vulab@iscas.ac.cn>]

The debugfs_create_dir() and debugfs_create_file() functions return
ERR_PTR() on error, not NULL. The current null-checks fail to detect
errors because ERR_PTR() encodes error codes as non-null pointer values.

Remove all null-checks for all debugfs_create_dir() and
debugfs_create_file() since they are unnecessary.

Fixes: 011d82611172 ("RAS: Add a Corrected Errors Collector")
Suggested-by: Zhuo, Qiuxu <qiuxu.zhuo@intel.com>
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
---
Changes in v3:
  -Remove all error handling as suggested by Borislav Petkov.
---
Changes in v2:
  -Also add fixes in create_debugfs_nodes() and ras_add_daemon_trace()
   as suggested by Zhuo, Qiuxu.
---
 drivers/ras/cec.c     | 42 +++++-------------------------------------
 drivers/ras/debugfs.c | 11 +----------
 2 files changed, 6 insertions(+), 47 deletions(-)

diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c
index e440b15fbabc..5891f30641b7 100644
--- a/drivers/ras/cec.c
+++ b/drivers/ras/cec.c
@@ -480,55 +480,23 @@ DEFINE_SHOW_ATTRIBUTE(array);
 
 static int __init create_debugfs_nodes(void)
 {
-	struct dentry *d, *pfn, *decay, *count, *array, *dfs;
+	struct dentry *d, *dfs;
 
 	dfs = ras_get_debugfs_root();
-	if (!dfs) {
-		pr_warn("Error getting RAS debugfs root!\n");
-		return -1;
-	}
-
 	d = debugfs_create_dir("cec", dfs);
-	if (!d) {
-		pr_warn("Error creating cec debugfs node!\n");
-		return -1;
-	}
 
-	decay = debugfs_create_file("decay_interval", S_IRUSR | S_IWUSR, d,
+	debugfs_create_file("decay_interval", S_IRUSR | S_IWUSR, d,
 				    &decay_interval, &decay_interval_ops);
-	if (!decay) {
-		pr_warn("Error creating decay_interval debugfs node!\n");
-		goto err;
-	}
-
-	count = debugfs_create_file("action_threshold", S_IRUSR | S_IWUSR, d,
+	debugfs_create_file("action_threshold", S_IRUSR | S_IWUSR, d,
 				    &action_threshold, &action_threshold_ops);
-	if (!count) {
-		pr_warn("Error creating action_threshold debugfs node!\n");
-		goto err;
-	}
 
 	if (!IS_ENABLED(CONFIG_RAS_CEC_DEBUG))
 		return 0;
 
-	pfn = debugfs_create_file("pfn", S_IRUSR | S_IWUSR, d, &dfs_pfn, &pfn_ops);
-	if (!pfn) {
-		pr_warn("Error creating pfn debugfs node!\n");
-		goto err;
-	}
-
-	array = debugfs_create_file("array", S_IRUSR, d, NULL, &array_fops);
-	if (!array) {
-		pr_warn("Error creating array debugfs node!\n");
-		goto err;
-	}
+	debugfs_create_file("pfn", S_IRUSR | S_IWUSR, d, &dfs_pfn, &pfn_ops);
+	debugfs_create_file("array", S_IRUSR, d, NULL, &array_fops);
 
 	return 0;
-
-err:
-	debugfs_remove_recursive(d);
-
-	return 1;
 }
 
 static int cec_notifier(struct notifier_block *nb, unsigned long val,
diff --git a/drivers/ras/debugfs.c b/drivers/ras/debugfs.c
index 42afd3de68b2..a1149e48b34a 100644
--- a/drivers/ras/debugfs.c
+++ b/drivers/ras/debugfs.c
@@ -45,18 +45,9 @@ static const struct file_operations trace_fops = {
 
 int __init ras_add_daemon_trace(void)
 {
-	struct dentry *fentry;
-
-	if (!ras_debugfs_dir)
-		return -ENOENT;
-
-	fentry = debugfs_create_file("daemon_active", S_IRUSR, ras_debugfs_dir,
+	debugfs_create_file("daemon_active", S_IRUSR, ras_debugfs_dir,
 				     NULL, &trace_fops);
-	if (IS_ERR(fentry))
-		return -ENODEV;
-
 	return 0;
-
 }
 
 void __init ras_debugfs_init(void)
-- 
2.50.1.windows.1