The path length of 64 is way too low in some envirnoments, which leads to subtle failures due to truncation [1]. Replace BPFTOOL_PATH_MAX_LEN with PATH_MAX, and set BPFTOOL_FULL_CMD_MAX_LEN to double of PATH_MAX. [1] https://github.com/libbpf/libbpf/actions/runs/22980753016/job/66719800527 Signed-off-by: Ihor Solodrai --- tools/testing/selftests/bpf/bpftool_helpers.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/bpf/bpftool_helpers.c b/tools/testing/selftests/bpf/bpftool_helpers.c index 929fc257f431..0a2a4f0a2794 100644 --- a/tools/testing/selftests/bpf/bpftool_helpers.c +++ b/tools/testing/selftests/bpf/bpftool_helpers.c @@ -2,18 +2,18 @@ #include #include #include +#include #include "bpf_util.h" #include "bpftool_helpers.h" -#define BPFTOOL_PATH_MAX_LEN 64 -#define BPFTOOL_FULL_CMD_MAX_LEN 512 +#define BPFTOOL_FULL_CMD_MAX_LEN (PATH_MAX * 2) #define BPFTOOL_DEFAULT_PATH "tools/sbin/bpftool" static int detect_bpftool_path(char *buffer, size_t size) { - char tmp[BPFTOOL_PATH_MAX_LEN]; + char tmp[PATH_MAX]; const char *env_path; /* First, check if BPFTOOL environment variable is set */ @@ -29,7 +29,7 @@ static int detect_bpftool_path(char *buffer, size_t size) /* Check default bpftool location (will work if we are running the * default flavor of test_progs) */ - snprintf(tmp, BPFTOOL_PATH_MAX_LEN, "./%s", BPFTOOL_DEFAULT_PATH); + snprintf(tmp, sizeof(tmp), "./%s", BPFTOOL_DEFAULT_PATH); if (access(tmp, X_OK) == 0) { strscpy(buffer, tmp, size); return 0; @@ -38,7 +38,7 @@ static int detect_bpftool_path(char *buffer, size_t size) /* Check alternate bpftool location (will work if we are running a * specific flavor of test_progs, e.g. cpuv4 or no_alu32) */ - snprintf(tmp, BPFTOOL_PATH_MAX_LEN, "../%s", BPFTOOL_DEFAULT_PATH); + snprintf(tmp, sizeof(tmp), "../%s", BPFTOOL_DEFAULT_PATH); if (access(tmp, X_OK) == 0) { strscpy(buffer, tmp, size); return 0; @@ -50,7 +50,7 @@ static int detect_bpftool_path(char *buffer, size_t size) static int run_command(char *args, char *output_buf, size_t output_max_len) { - static char bpftool_path[BPFTOOL_PATH_MAX_LEN] = {0}; + static char bpftool_path[PATH_MAX] = {}; bool suppress_output = !(output_buf && output_max_len); char command[BPFTOOL_FULL_CMD_MAX_LEN]; FILE *f; @@ -60,7 +60,7 @@ static int run_command(char *args, char *output_buf, size_t output_max_len) 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", + ret = snprintf(command, sizeof(command), "%s %s%s", bpftool_path, args, suppress_output ? " > /dev/null 2>&1" : ""); @@ -84,4 +84,3 @@ int get_bpftool_command_output(char *args, char *output_buf, size_t output_max_l { return run_command(args, output_buf, output_max_len); } - -- 2.53.0