linux-kernel - [PATCH] fail_function: no need to check return value of debugfs

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Date:   Tue, 22 Jan 2019 16:21:44 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Kees Cook <keescook@...omium.org>, Josef Bacik <jbacik@...com>,
        Thomas Gleixner <tglx@...utronix.de>,
        "Naveen N. Rao" <naveen.n.rao@...ux.vnet.ibm.com>,
        zhong jiang <zhongjiang@...wei.com>
Subject: [PATCH] fail_function: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Masami Hiramatsu <mhiramat@...nel.org>
Cc: Kees Cook <keescook@...omium.org>
Cc: Josef Bacik <jbacik@...com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: "Naveen N. Rao" <naveen.n.rao@...ux.vnet.ibm.com>
Cc: zhong jiang <zhongjiang@...wei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 kernel/fail_function.c | 23 +++++------------------
 1 file changed, 5 insertions(+), 18 deletions(-)

diff --git a/kernel/fail_function.c b/kernel/fail_function.c
index 17f75b545f66..afc779be5ebb 100644
--- a/kernel/fail_function.c
+++ b/kernel/fail_function.c
@@ -152,20 +152,13 @@ static int fei_retval_get(void *data, u64 *val)
 DEFINE_DEBUGFS_ATTRIBUTE(fei_retval_ops, fei_retval_get, fei_retval_set,
 			 "%llx\n");
 
-static int fei_debugfs_add_attr(struct fei_attr *attr)
+static void fei_debugfs_add_attr(struct fei_attr *attr)
 {
 	struct dentry *dir;
 
 	dir = debugfs_create_dir(attr->kp.symbol_name, fei_debugfs_dir);
-	if (!dir)
-		return -ENOMEM;
-
-	if (!debugfs_create_file("retval", 0600, dir, attr, &fei_retval_ops)) {
-		debugfs_remove_recursive(dir);
-		return -ENOMEM;
-	}
 
-	return 0;
+	debugfs_create_file("retval", 0600, dir, attr, &fei_retval_ops);
 }
 
 static void fei_debugfs_remove_attr(struct fei_attr *attr)
@@ -306,7 +299,7 @@ static ssize_t fei_write(struct file *file, const char __user *buffer,
 
 	ret = register_kprobe(&attr->kp);
 	if (!ret)
-		ret = fei_debugfs_add_attr(attr);
+		fei_debugfs_add_attr(attr);
 	if (ret < 0)
 		fei_attr_remove(attr);
 	else {
@@ -337,19 +330,13 @@ static int __init fei_debugfs_init(void)
 		return PTR_ERR(dir);
 
 	/* injectable attribute is just a symlink of error_inject/list */
-	if (!debugfs_create_symlink("injectable", dir,
-				    "../error_injection/list"))
-		goto error;
+	debugfs_create_symlink("injectable", dir, "../error_injection/list");
 
-	if (!debugfs_create_file("inject", 0600, dir, NULL, &fei_ops))
-		goto error;
+	debugfs_create_file("inject", 0600, dir, NULL, &fei_ops);
 
 	fei_debugfs_dir = dir;
 
 	return 0;
-error:
-	debugfs_remove_recursive(dir);
-	return -ENOMEM;
 }
 
 late_initcall(fei_debugfs_init);
-- 
2.20.1