1 files changed, 133 insertions, 0 deletions
diff --git a/src/lib/libc/stdlib/atexit.c b/src/lib/libc/stdlib/atexit.c
new file mode 100644
index 0000000000..4fd2c57318
--- /dev/null
+++ b/src/lib/libc/stdlib/atexit.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2002 Daniel Hartmeier
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "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
+ * COPYRIGHT HOLDERS OR CONTRIBUTORS 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.
+ *
+ */
+#if defined(LIBC_SCCS) && !defined(lint)
+static char *rcsid = "$OpenBSD: atexit.c,v 1.8 2005/03/30 18:51:49 pat Exp $";
+#endif /* LIBC_SCCS and not lint */
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "atexit.h"
+int __atexit_invalid = 1;
+struct atexit *__atexit;
+/*
+ * Function pointers are stored in a linked list of pages. The list
+ * is initially empty, and pages are allocated on demand. The first
+ * function pointer in the first allocated page (the last one in
+ * the linked list) is reserved for the cleanup function.
+ *
+ * Outside the following two functions, all pages are mprotect()'ed
+ * to prevent unintentional/malicious corruption.
+ *
+ * The free(malloc(1)) is a workaround causing malloc_init() to
+ * ensure that malloc.c gets the first mmap() call for its sbrk()
+ * games.
+ */
+/*
+ * Register a function to be performed at exit.
+ */
+int
+atexit(void (*fn)(void))
+{
+        struct atexit *p = __atexit;
+        int pgsize = getpagesize();
+        if (pgsize < sizeof(*p))
+                return (-1);
+        if (p != NULL) {
+                if (p->ind + 1 >= p->max)
+                        p = NULL;
+                else if (mprotect(p, pgsize, PROT_READ | PROT_WRITE))
+                        return (-1);
+        }
+        if (p == NULL) {
+                if (__atexit_invalid) {
+                        free(malloc(1));
+                        __atexit_invalid = 0;
+                }
+                p = mmap(NULL, pgsize, PROT_READ | PROT_WRITE,
+                    MAP_ANON | MAP_PRIVATE, -1, 0);
+                if (p == MAP_FAILED)
+                        return (-1);
+                if (__atexit == NULL) {
+                        p->fns[0] = NULL;
+                        p->ind = 1;
+                } else
+                        p->ind = 0;
+                p->max = (pgsize - ((char *)&p->fns[0] - (char *)p)) /
+                    sizeof(p->fns[0]);
+                p->next = __atexit;
+                __atexit = p;
+        }
+        p->fns[p->ind++] = fn;
+        if (mprotect(p, pgsize, PROT_READ))
+                return (-1);
+        return (0);
+}
+/*
+ * Register the cleanup function
+ */
+void
+__atexit_register_cleanup(void (*fn)(void))
+{
+        struct atexit *p = __atexit;
+        int pgsize = getpagesize();
+        if (pgsize < sizeof(*p))
+                return;
+        while (p != NULL && p->next != NULL)
+                p = p->next;
+        if (p == NULL) {
+                if (__atexit_invalid) {
+                        free(malloc(1));
+                        __atexit_invalid = 0;
+                }
+                p = mmap(NULL, pgsize, PROT_READ | PROT_WRITE,
+                    MAP_ANON | MAP_PRIVATE, -1, 0);
+                if (p == MAP_FAILED)
+                        return;
+                p->ind = 1;
+                p->max = (pgsize - ((char *)&p->fns[0] - (char *)p)) /
+                    sizeof(p->fns[0]);
+                p->next = NULL;
+                __atexit = p;
+        } else {
+                if (mprotect(p, pgsize, PROT_READ | PROT_WRITE))
+                    return;
+        }
+        p->fns[0] = fn;
+        mprotect(p, pgsize, PROT_READ);
+}

diff --git a/src/lib/libc/stdlib/atexit.c b/src/lib/libc/stdlib/atexit.c new file mode 100644 index 0000000000..4fd2c57318 --- /dev/null +++ b/src/lib/libc/stdlib/atexit.c
@@ -0,0 +1,133 @@
	1	/*
	2	* Copyright (c) 2002 Daniel Hartmeier
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	*
	9	* - Redistributions of source code must retain the above copyright
	10	* notice, this list of conditions and the following disclaimer.
	11	* - Redistributions in binary form must reproduce the above
	12	* copyright notice, this list of conditions and the following
	13	* disclaimer in the documentation and/or other materials provided
	14	* with the distribution.
	15	*
	16	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	17	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	18	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	19	* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
	20	* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
	22	* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	23	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	24	* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	25	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
	26	* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	27	* POSSIBILITY OF SUCH DAMAGE.
	28	*
	29	*/
	30
	31	#if defined(LIBC_SCCS) && !defined(lint)
	32	static char *rcsid = "$OpenBSD: atexit.c,v 1.8 2005/03/30 18:51:49 pat Exp $";
	33	#endif /* LIBC_SCCS and not lint */
	34
	35	#include <sys/types.h>
	36	#include <sys/mman.h>
	37	#include <stdlib.h>
	38	#include <unistd.h>
	39	#include "atexit.h"
	40
	41	int __atexit_invalid = 1;
	42	struct atexit *__atexit;
	43
	44	/*
	45	* Function pointers are stored in a linked list of pages. The list
	46	* is initially empty, and pages are allocated on demand. The first
	47	* function pointer in the first allocated page (the last one in
	48	* the linked list) is reserved for the cleanup function.
	49	*
	50	* Outside the following two functions, all pages are mprotect()'ed
	51	* to prevent unintentional/malicious corruption.
	52	*
	53	* The free(malloc(1)) is a workaround causing malloc_init() to
	54	* ensure that malloc.c gets the first mmap() call for its sbrk()
	55	* games.
	56	*/
	57
	58	/*
	59	* Register a function to be performed at exit.
	60	*/
	61	int
	62	atexit(void (*fn)(void))
	63	{
	64	struct atexit *p = __atexit;
	65	int pgsize = getpagesize();
	66
	67	if (pgsize < sizeof(*p))
	68	return (-1);
	69	if (p != NULL) {
	70	if (p->ind + 1 >= p->max)
	71	p = NULL;
	72	else if (mprotect(p, pgsize, PROT_READ \| PROT_WRITE))
	73	return (-1);
	74	}
	75	if (p == NULL) {
	76	if (__atexit_invalid) {
	77	free(malloc(1));
	78	__atexit_invalid = 0;
	79	}
	80	p = mmap(NULL, pgsize, PROT_READ \| PROT_WRITE,
	81	MAP_ANON \| MAP_PRIVATE, -1, 0);
	82	if (p == MAP_FAILED)
	83	return (-1);
	84	if (__atexit == NULL) {
	85	p->fns[0] = NULL;
	86	p->ind = 1;
	87	} else
	88	p->ind = 0;
	89	p->max = (pgsize - ((char )&p->fns[0] - (char )p)) /
	90	sizeof(p->fns[0]);
	91	p->next = __atexit;
	92	__atexit = p;
	93	}
	94	p->fns[p->ind++] = fn;
	95	if (mprotect(p, pgsize, PROT_READ))
	96	return (-1);
	97	return (0);
	98	}
	99
	100	/*
	101	* Register the cleanup function
	102	*/
	103	void
	104	__atexit_register_cleanup(void (*fn)(void))
	105	{
	106	struct atexit *p = __atexit;
	107	int pgsize = getpagesize();
	108
	109	if (pgsize < sizeof(*p))
	110	return;
	111	while (p != NULL && p->next != NULL)
	112	p = p->next;
	113	if (p == NULL) {
	114	if (__atexit_invalid) {
	115	free(malloc(1));
	116	__atexit_invalid = 0;
	117	}
	118	p = mmap(NULL, pgsize, PROT_READ \| PROT_WRITE,
	119	MAP_ANON \| MAP_PRIVATE, -1, 0);
	120	if (p == MAP_FAILED)
	121	return;
	122	p->ind = 1;
	123	p->max = (pgsize - ((char )&p->fns[0] - (char )p)) /
	124	sizeof(p->fns[0]);
	125	p->next = NULL;
	126	__atexit = p;
	127	} else {
	128	if (mprotect(p, pgsize, PROT_READ \| PROT_WRITE))
	129	return;
	130	}
	131	p->fns[0] = fn;
	132	mprotect(p, pgsize, PROT_READ);
	133	}