static int create_tmp_vdso_image()

in helpers/trace_helpers.c [529:593]

• 58 lines of code
• 13 McCabe index (conditional complexity)

static int create_tmp_vdso_image(struct dso *dso)
{
	uint64_t start_addr, end_addr;
	long pid = getpid();
	char buf[PATH_MAX];
	void *image = NULL;
	char tmpfile[128];
	int ret, fd = -1;
	uint64_t sz;
	char *name;
	FILE *f;

	snprintf(tmpfile, sizeof(tmpfile), "/proc/%ld/maps", pid);
	f = fopen(tmpfile, "r");
	if (!f)
		return -1;

	while (true) {
		ret = fscanf(f, "%lx-%lx %*s %*x %*x:%*x %*u%[^\n]",
			     &start_addr, &end_addr, buf);
		if (ret == EOF && feof(f))
			break;
		if (ret != 3)
			goto err_out;

		name = buf;
		while (isspace(*name))
			name++;
		if (!is_file_backed(name))
			continue;
		if (is_vdso(name))
			break;
	}

	sz = end_addr - start_addr;
	image = malloc(sz);
	if (!image)
		goto err_out;
	memcpy(image, (void *)start_addr, sz);

	snprintf(tmpfile, sizeof(tmpfile),
		 "/tmp/libbpf_%ld_vdso_image_XXXXXX", pid);
	fd = mkostemp(tmpfile, O_CLOEXEC);
	if (fd < 0) {
		fprintf(stderr, "failed to create temp file: %s\n",
			strerror(errno));
		goto err_out;
	}
	/* Unlink the file to avoid leaking */
	if (unlink(tmpfile) == -1)
		fprintf(stderr, "failed to unlink %s: %s\n", tmpfile,
			strerror(errno));
	if (write(fd, image, sz) == -1) {
		fprintf(stderr, "failed to write to vDSO image: %s\n",
			strerror(errno));
		close(fd);
		fd = -1;
		goto err_out;
	}

err_out:
	fclose(f);
	free(image);
	return fd;
}