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From:   Christophe JAILLET <christophe.jaillet@wanadoo.fr>
To:     Nishanth Menon <nm@ti.com>, Tero Kristo <kristo@kernel.org>,
        Santosh Shilimkar <ssantosh@kernel.org>
Cc:     linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Tero Kristo <t-kristo@ti.com>,
        linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] firmware: ti_sci: Fix an off-by-one in ti_sci_debugfs_create()
Date:   Mon, 30 Oct 2023 11:12:26 +0100
Message-Id: <7158db0a4d7b19855ddd542ec61b666973aad8dc.1698660720.git.christophe.jaillet@wanadoo.fr>
MIME-Version: 1.0
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The ending NULL is not taken into account by strncat(), so switch to
snprintf() to correctly build 'debug_name'.

Using snprintf() also makes the code more readable.

Fixes: aa276781a64a ("firmware: Add basic support for TI System Control Interface (TI-SCI) protocol")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
v2:
   - use snprintf() to simplify code   [Dan Carpenter]

v1: https://lore.kernel.org/all/880aeea52f3bdde5e3e8843bbedb7fd068a58be2.1698565938.git.christophe.jaillet@wanadoo.fr/
---
 drivers/firmware/ti_sci.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index 7041befc756a..8b9a2556de16 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -164,7 +164,7 @@ static int ti_sci_debugfs_create(struct platform_device *pdev,
 {
 	struct device *dev = &pdev->dev;
 	struct resource *res;
-	char debug_name[50] = "ti_sci_debug@";
+	char debug_name[50];
 
 	/* Debug region is optional */
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
@@ -181,10 +181,10 @@ static int ti_sci_debugfs_create(struct platform_device *pdev,
 	/* Setup NULL termination */
 	info->debug_buffer[info->debug_region_size] = 0;
 
-	info->d = debugfs_create_file(strncat(debug_name, dev_name(dev),
-					      sizeof(debug_name) -
-					      sizeof("ti_sci_debug@")),
-				      0444, NULL, info, &ti_sci_debug_fops);
+	snprintf(debug_name, sizeof(debug_name), "ti_sci_debug@%s",
+		 dev_name(dev));
+	info->d = debugfs_create_file(debug_name, 0444, NULL, info,
+				      &ti_sci_debug_fops);
 	if (IS_ERR(info->d))
 		return PTR_ERR(info->d);
 
-- 
2.34.1