hv_fcopy_uio_daemon.c:436:53: warning: '%s' directive output may be truncated
writing up to 14 bytes into a region of size 10 [-Wformat-truncation=]
  436 |  snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name);

Also added 'static' for the array 'desc[]'.

Fixes: 82b0945ce2c2 ("tools: hv: Add new fcopy application based on uio driver")
Cc: stable@vger.kernel.org # 6.10+
Signed-off-by: Dexuan Cui <decui@microsoft.com>
---
 tools/hv/hv_fcopy_uio_daemon.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/tools/hv/hv_fcopy_uio_daemon.c b/tools/hv/hv_fcopy_uio_daemon.c
index 3ce316cc9f97..f7741af08a79 100644
--- a/tools/hv/hv_fcopy_uio_daemon.c
+++ b/tools/hv/hv_fcopy_uio_daemon.c
@@ -35,8 +35,6 @@
 #define WIN8_SRV_MINOR		1
 #define WIN8_SRV_VERSION	(WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
 
-#define MAX_FOLDER_NAME		15
-#define MAX_PATH_LEN		15
 #define FCOPY_UIO		"/sys/bus/vmbus/devices/eb765408-105f-49b6-b4aa-c123b64d17d4/uio"
 
 #define FCOPY_VER_COUNT		1
@@ -51,7 +49,7 @@ static const int fw_versions[] = {
 
 #define HV_RING_SIZE		0x4000 /* 16KB ring buffer size */
 
-unsigned char desc[HV_RING_SIZE];
+static unsigned char desc[HV_RING_SIZE];
 
 static int target_fd;
 static char target_fname[PATH_MAX];
@@ -402,8 +400,8 @@ int main(int argc, char *argv[])
 	struct vmbus_br txbr, rxbr;
 	void *ring;
 	uint32_t len = HV_RING_SIZE;
-	char uio_name[MAX_FOLDER_NAME] = {0};
-	char uio_dev_path[MAX_PATH_LEN] = {0};
+	char uio_name[NAME_MAX] = {0};
+	char uio_dev_path[PATH_MAX] = {0};
 
 	static struct option long_options[] = {
 		{"help",	no_argument,	   0,  'h' },
-- 
2.25.1

On Tue, Sep 10, 2024 at 12:44:32AM +0000, Dexuan Cui wrote:
> hv_fcopy_uio_daemon.c:436:53: warning: '%s' directive output may be truncated
> writing up to 14 bytes into a region of size 10 [-Wformat-truncation=]
>   436 |  snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name);

Makefile today doesn't have -Wformat-truncation flag enabled, I tried to add
-Wformat-truncation=2 but I don't see any error in this file.

Do you mind sharing more details how you get this error ?

- Saurabh