[PATCH bpf v4 04/20] selftests/bpf: Use strscpy in bpftool_helpers.c

From: Ihor Solodrai

Date: Mon Feb 23 2026 - 14:10:26 EST


Replace strncpy() calls in bpftool_helpers.c with strscpy().

Pass the destination buffer size to detect_bpftool_path() instead of
hardcoding BPFTOOL_PATH_MAX_LEN.

Signed-off-by: Ihor Solodrai <ihor.solodrai@xxxxxxxxx>
---
tools/testing/selftests/bpf/bpftool_helpers.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/bpf/bpftool_helpers.c b/tools/testing/selftests/bpf/bpftool_helpers.c
index a5824945a4a5..595a636fa13b 100644
--- a/tools/testing/selftests/bpf/bpftool_helpers.c
+++ b/tools/testing/selftests/bpf/bpftool_helpers.c
@@ -1,15 +1,17 @@
// SPDX-License-Identifier: GPL-2.0-only
-#include "bpftool_helpers.h"
#include <unistd.h>
#include <string.h>
#include <stdbool.h>

+#include "bpf_util.h"
+#include "bpftool_helpers.h"
+
#define BPFTOOL_PATH_MAX_LEN 64
#define BPFTOOL_FULL_CMD_MAX_LEN 512

#define BPFTOOL_DEFAULT_PATH "tools/sbin/bpftool"

-static int detect_bpftool_path(char *buffer)
+static int detect_bpftool_path(char *buffer, size_t size)
{
char tmp[BPFTOOL_PATH_MAX_LEN];

@@ -18,7 +20,7 @@ static int detect_bpftool_path(char *buffer)
*/
snprintf(tmp, BPFTOOL_PATH_MAX_LEN, "./%s", BPFTOOL_DEFAULT_PATH);
if (access(tmp, X_OK) == 0) {
- strncpy(buffer, tmp, BPFTOOL_PATH_MAX_LEN);
+ strscpy(buffer, tmp, size);
return 0;
}

@@ -27,7 +29,7 @@ static int detect_bpftool_path(char *buffer)
*/
snprintf(tmp, BPFTOOL_PATH_MAX_LEN, "../%s", BPFTOOL_DEFAULT_PATH);
if (access(tmp, X_OK) == 0) {
- strncpy(buffer, tmp, BPFTOOL_PATH_MAX_LEN);
+ strscpy(buffer, tmp, size);
return 0;
}

@@ -44,7 +46,7 @@ static int run_command(char *args, char *output_buf, size_t output_max_len)
int ret;

/* Detect and cache bpftool binary location */
- if (bpftool_path[0] == 0 && detect_bpftool_path(bpftool_path))
+ if (bpftool_path[0] == 0 && detect_bpftool_path(bpftool_path, sizeof(bpftool_path)))
return 1;

ret = snprintf(command, BPFTOOL_FULL_CMD_MAX_LEN, "%s %s%s",
--
2.53.0