Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.35 as permitted sender) client-ip=23.128.96.35;
From:   Lakshmi Yadlapati <lakshmiy@us.ibm.com>
To:     joel@jms.id.au, eajames@linux.ibm.com, ninad@linux.ibm.com,
        alistair@popple.id.au
Cc:     Lakshmi Yadlapati <lakshmiy@us.ibm.com>,
        linux-fsi@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH v1] fsi: Fix panic on scom file read
Date:   Wed, 13 Dec 2023 18:07:44 -0600
Message-Id: <20231214000744.1281464-1-lakshmiy@us.ibm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Reading the scom file without the custom open method (i2cr_scom_open)
causes a kernel panic. This change replaces simple_open with i2cr_scom_open
to properly initialize the private_data field in the file structure,
preventing the panic during scom file operations.

Signed-off-by: Lakshmi Yadlapati <lakshmiy@us.ibm.com>
---
 drivers/fsi/i2cr-scom.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/fsi/i2cr-scom.c b/drivers/fsi/i2cr-scom.c
index cb7e02213032..8d65c562b488 100644
--- a/drivers/fsi/i2cr-scom.c
+++ b/drivers/fsi/i2cr-scom.c
@@ -73,9 +73,18 @@ static ssize_t i2cr_scom_write(struct file *filep, const char __user *buf, size_
 	return len;
 }
 
+static int i2cr_scom_open(struct inode *inode, struct file *file)
+{
+	struct i2cr_scom *scom = container_of(inode->i_cdev, struct i2cr_scom, cdev);
+
+	file->private_data = scom;
+
+	return 0;
+}
+
 static const struct file_operations i2cr_scom_fops = {
 	.owner		= THIS_MODULE,
-	.open		= simple_open,
+	.open		= i2cr_scom_open,
 	.llseek		= i2cr_scom_llseek,
 	.read		= i2cr_scom_read,
 	.write		= i2cr_scom_write,
-- 
2.39.2