Index: uspace/lib/c/test/main.c
===================================================================
--- uspace/lib/c/test/main.c	(revision c8dc9ac9566c253fb921beb73223f3afeacf3272)
+++ uspace/lib/c/test/main.c	(revision 525c5ac5b9fa9910f16d49c50efb5ca3369bc0e6)
@@ -33,4 +33,5 @@
 
 PCUT_IMPORT(odict);
+PCUT_IMPORT(qsort);
 PCUT_IMPORT(sprintf);
 PCUT_IMPORT(str);
Index: uspace/lib/c/test/qsort.c
===================================================================
--- uspace/lib/c/test/qsort.c	(revision 525c5ac5b9fa9910f16d49c50efb5ca3369bc0e6)
+++ uspace/lib/c/test/qsort.c	(revision 525c5ac5b9fa9910f16d49c50efb5ca3369bc0e6)
@@ -0,0 +1,174 @@
+/*
+ * Copyright (c) 2017 Jiri Svoboda
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <pcut/pcut.h>
+#include <qsort.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+enum {
+	/** Length of test number sequences */
+	test_seq_len = 5
+};
+
+/** Test compare function.
+ *
+ * @param a First key
+ * @param b Second key
+ * @return <0, 0, >0 if @a a is less than, equal or greater than @a b
+ */
+static int test_cmp(const void *a, const void *b)
+{
+	int *ia = (int *)a;
+	int *ib = (int *)b;
+
+	return *ia - *ib;
+}
+
+static void bubble_sort(int *seq, size_t nmemb)
+{
+	size_t i;
+	size_t j;
+	int t;
+
+	for (i = 0; i < nmemb - 1; i++)
+		for (j = 0; j < nmemb - 1; j++) {
+			if (seq[j] > seq[j + 1]) {
+				t = seq[j];
+				seq[j] = seq[j + 1];
+				seq[j + 1] = t;
+			}
+		}
+}
+
+PCUT_INIT
+
+PCUT_TEST_SUITE(qsort);
+
+/** Test sorting already sorted increasing sequence */
+PCUT_TEST(incr_seq)
+{
+	int *seq;
+	int i;
+
+	seq = calloc(test_seq_len, sizeof(int));
+	PCUT_ASSERT_NOT_NULL(seq);
+
+	for (i = 0; i < test_seq_len; i++)
+		seq[i] = i;
+
+	qsort(seq, test_seq_len, sizeof(int), test_cmp);
+
+	for (i = 0; i < test_seq_len; i++) {
+		PCUT_ASSERT_INT_EQUALS(i, seq[i]);
+	}
+
+	free(seq);
+}
+
+/** Test sorting reverse-sorted decreasing sequence. */
+PCUT_TEST(decr_seq)
+{
+	int *seq;
+	int i;
+
+	seq = calloc(test_seq_len, sizeof(int));
+	PCUT_ASSERT_NOT_NULL(seq);
+
+	for (i = 0; i < test_seq_len; i++)
+		seq[i] = test_seq_len - 1 - i;
+
+	qsort(seq, test_seq_len, sizeof(int), test_cmp);
+
+	for (i = 0; i < test_seq_len; i++) {
+		PCUT_ASSERT_INT_EQUALS(i, seq[i]);
+	}
+
+	free(seq);
+}
+
+/** Test sorting reverse-sorted decreasing sequence where each member repeats twice. */
+PCUT_TEST(decr2_seq)
+{
+	int *seq;
+	int i;
+
+	seq = calloc(test_seq_len, sizeof(int));
+	PCUT_ASSERT_NOT_NULL(seq);
+
+	for (i = 0; i < test_seq_len; i++) {
+		seq[i] = (test_seq_len - 1 - i) / 2;
+	}
+
+	qsort(seq, test_seq_len, sizeof(int), test_cmp);
+
+	for (i = 0; i < test_seq_len; i++) {
+		PCUT_ASSERT_INT_EQUALS(i / 2, seq[i]);
+	}
+
+	free(seq);
+}
+
+/** Generate pseudorandom sequence. */
+static int seq_next(int cur)
+{
+	return (cur * 1951) % 1000000;
+}
+
+/** Test sorting pseudorandom sequence. */
+PCUT_TEST(pseudorandom_seq)
+{
+	int *seq, *seq2;
+	int i;
+	int v;
+
+	seq = calloc(test_seq_len, sizeof(int));
+	PCUT_ASSERT_NOT_NULL(seq);
+
+	seq2 = calloc(test_seq_len, sizeof(int));
+	PCUT_ASSERT_NOT_NULL(seq);
+
+	v = 1;
+	for (i = 0; i < test_seq_len; i++) {
+		seq[i] = v;
+		seq2[i] = v;
+		v = seq_next(v);
+	}
+
+	qsort(seq, test_seq_len, sizeof(int), test_cmp);
+	bubble_sort(seq2, test_seq_len);
+
+	for (i = 0; i < test_seq_len; i++) {
+		PCUT_ASSERT_INT_EQUALS(seq2[i], seq[i]);
+	}
+
+	free(seq);
+	free(seq2);
+}
+
+PCUT_EXPORT(qsort);