firmware: ti_sci: Fix an off-by-one in ti_sci_debugfs_create()

[ Upstream commit 964946b88887089f447a9b6a28c39ee97dc76360 ]

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>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/7158db0a4d7b19855ddd542ec61b666973aad8dc.1698660720.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index 66c3846..3b4c935 100644 (file)
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -161,7 +161,7 @@ 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,
@@ -178,10 +178,10 @@ 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);