Function get_ps_strings

freebsd/kern/kern_proc.c:1987–2033

#define GET_PS_STRINGS_CHUNK_SZ	256	/* Chunk size (bytes) for ps_strings operations. */

static int
get_ps_strings(struct thread *td, struct proc *p, struct sbuf *sb,
    enum proc_vector_type type)
{
	size_t done, len, nchr, vsize;
	int error, i;
	char **proc_vector, *sptr;
	char pss_string[GET_PS_STRINGS_CHUNK_SZ];

	PROC_ASSERT_HELD(p);

	/*
	 * We are not going to read more than 2 * (PATH_MAX + ARG_MAX) bytes.
	 */
	nchr = 2 * (PATH_MAX + ARG_MAX);

	error = get_proc_vector(td, p, &proc_vector, &vsize, type);
	if (error != 0)
		return (error);
	for (done = 0, i = 0; i < (int)vsize && done < nchr; i++) {
		/*
		 * The program may have scribbled into its argv array, e.g. to
		 * remove some arguments.  If that has happened, break out
		 * before trying to read from NULL.
		 */
		if (proc_vector[i] == NULL)
			break;
		for (sptr = proc_vector[i]; ; sptr += GET_PS_STRINGS_CHUNK_SZ) {
			error = proc_read_string(td, p, sptr, pss_string,
			    sizeof(pss_string));
			if (error != 0)
				goto done;
			len = strnlen(pss_string, GET_PS_STRINGS_CHUNK_SZ);
			if (done + len >= nchr)
				len = nchr - done - 1;
			sbuf_bcat(sb, pss_string, len);
			if (len != GET_PS_STRINGS_CHUNK_SZ)
				break;
			done += GET_PS_STRINGS_CHUNK_SZ;
		}
		sbuf_bcat(sb, "", 1);
		done += len + 1;
	}
done:
	free(proc_vector, M_TEMP);
	return (error);
}

int
proc_getargv(struct thread *td, struct proc *p, struct sbuf *sb)