Add a regress test to test various malloc API and heap mismanagement

errors which should cause abort. A few are not enabled yet, they
will be once the corresponding diffs in malloc are committed.

regress/lib/libc/malloc/malloc_errs/Makefile

@@ -0,0 +1,5 @@
+#	$OpenBSD: Makefile,v 1.1 2023/05/08 11:12:44 otto Exp $
+
+PROG=	malloc_errs
+
+.include <bsd.regress.mk>

regress/lib/libc/malloc/malloc_errs/malloc_errs.c

@@ -0,0 +1,286 @@
+/*	$OpenBSD: malloc_errs.c,v 1.1 2023/05/08 11:12:44 otto Exp $	*/
+/*
+ * Copyright (c) 2023 Otto Moerbeek <otto@drijf.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/resource.h>
+#include <sys/wait.h>
+#include <err.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <signal.h>
+#include <unistd.h>
+
+/* Test erroneous use of API and heap that malloc should catch */
+
+void
+clearq(void *p)
+{
+	int i;
+	void *q;
+
+	/* Clear delayed free queue */
+	for (i = 0; i < 400; i++) {
+		q = malloc(100);
+		free(q);
+		if (p == q) {
+			fprintf(stderr, "Re-use\n");
+			abort();
+		}
+	}
+}
+
+/* test the test setup */
+void
+t0(void)
+{
+	abort();
+}
+
+/* double free >= page size */
+void
+t1(void)
+{
+	void *p = malloc(10000);
+	free(p);
+	free(p);
+}
+
+/* double free chunks are different, have a delayed free list */
+void
+t2(void)
+{
+	void *p, *q;
+	int i;
+
+	p = malloc(100);
+	free(p);
+	clearq(p);
+	free(p);
+}
+
+/* double free without clearing delayed free list, needs F */
+void
+t3(void)
+{
+	void *p = malloc(100);
+	free(p);
+	free(p);
+}
+
+/* free without prior allocation */
+void
+t4(void)
+{
+	free((void*)1);
+}
+
+/* realloc of bogus pointer */
+void
+t5(void)
+{
+	realloc((void*)1, 10);
+}
+
+/* write after free for chunk */
+void
+t6(void)
+{
+	char *p = malloc(32);
+	free(p);
+	p[0] = ~p[0];
+	clearq(NULL);
+}
+
+/* write after free large alloction */
+void
+t7(void)
+{
+	char *p, *q;
+	int i;
+
+	p = malloc(10000);
+	free(p);
+	p[0] = ~p[0];
+	/* force re-use from the cache */
+	for (i = 0; i < 100; i++) {
+		q = malloc(10000);
+		free(q);
+	}
+}
+
+/* write after free for chunk, no clearing of delayed free queue */
+void
+t8(void)
+{
+	char *p, *q;
+
+	p = malloc(32);
+	q = malloc(32);
+	free(p);
+	p[0] = ~p[0];
+	free(q);
+}
+
+/* canary check */
+void
+t9(void)
+{
+	char *p;
+
+	p = malloc(100);
+	p[100] = 0;
+	free(p);
+}
+
+/* t10 is the same as t9 with different flags */
+
+/* modified chunk pointer */
+void
+t11(void)
+{
+	char *p = malloc(100);
+	free(p + 1);
+}
+
+/* free chunk pointer */
+void
+t12(void)
+{
+	char *p = malloc(16);
+	free(p + 16);
+}
+
+/* freezero with wrong size */
+void
+t13(void)
+{
+	char *p = malloc(16);
+	freezero(p, 17);
+}
+
+/* freezero with wrong size 2 */
+void
+t14(void)
+{
+	char *p = malloc(15);
+	freezero(p, 16);
+}
+
+/* freezero with wrong size, pages */
+void
+t15(void)
+{
+	char *p = malloc(getpagesize());
+	freezero(p, getpagesize() + 1);
+}
+
+/* recallocarray with wrong size */
+void
+t16(void)
+{
+	abort(); /* not yet */
+	char *p = recallocarray(NULL, 0, 16, 1);
+	char *q = recallocarray(p, 2, 3, 16);
+}
+
+/* recallocarray with wrong size 2 */
+void
+t17(void)
+{
+	char *p = recallocarray(NULL, 0, 15, 1);
+	char *q = recallocarray(p, 2, 3, 15);
+}
+
+/* recallocarray with wrong size, pages */
+void
+t18(void)
+{
+	abort(); /* not yet */
+	char *p = recallocarray(NULL, 0, 1, getpagesize());
+	char *q = recallocarray(p, 2, 3, getpagesize());
+}
+
+struct test {
+	void (*test)(void);
+	const char *flags;
+};
+
+struct test tests[] = {
+	{ t0, "" },
+	{ t1, "" },
+	{ t2, "" },
+	{ t3, "F" },
+	{ t4, "" },
+	{ t5, "" },
+	{ t6, "J" },
+	{ t7, "JJ" },
+	{ t8, "FJ" },
+	{ t9, "C" },
+	{ t9, "JC" }, /* t10 re-uses code from t9 */
+	{ t11, "" },
+	{ t12, "" },
+	{ t13, "" },
+	{ t14, "C" },
+	{ t15, "" },
+	{ t16, "" },
+	{ t17, "C" },
+	{ t18, "" },
+};
+
+int main(int argc, char *argv[])
+{
+
+	const struct rlimit lim = {0, 0};
+	int i, status;
+	pid_t pid;
+	char num[10];
+	char options[10];
+	extern char* malloc_options;
+
+	if (argc == 3) {
+		malloc_options = argv[2];
+		/* prevent coredumps */
+		setrlimit(RLIMIT_CORE, &lim);
+		i = atoi(argv[1]);
+		fprintf(stderr, "Test %d\n", i);
+		(*tests[i].test)();
+		return 0;
+	}
+
+	for (i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
+		pid = fork();
+		switch (pid) {
+		case 0:
+			snprintf(options, sizeof(options), "cfjgu%s", tests[i].flags);
+			snprintf(num, sizeof(num), "%d", i);
+			execl(argv[0], argv[0], num, options, NULL);
+			err(1, "exec");
+		break;
+		case -1:
+			err(1, "fork");
+		break;
+		default: 
+			if (waitpid(pid, &status, 0) == -1)
+				err(1, "wait");
+			if (!WIFSIGNALED(status) || 
+			    WTERMSIG(status) != SIGABRT)
+			errx(1, "Test %d did not abort", i);
+		break;
+		}
+	}
+	return 0;
+}
+