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[avr-libc-commit] [2131] bug #27235, malloc: Several things go wrong
|
From: |
Joerg Wunsch |
|
Subject: |
[avr-libc-commit] [2131] bug #27235, malloc: Several things go wrong |
|
Date: |
Mon, 07 Jun 2010 18:09:17 +0000 |
Revision: 2131
http://svn.sv.gnu.org/viewvc/?view=rev&root=avr-libc&revision=2131
Author: joerg_wunsch
Date: 2010-06-07 18:09:17 +0000 (Mon, 07 Jun 2010)
Log Message:
-----------
bug #27235, malloc: Several things go wrong
* libc/stdlib/malloc.c (malloc): Revert the patch
from r2123, as it is no longer needed.
* libc/stdlib/malloc.c (free): When freeing the
topmost chunk of the heap, reduce __brkval again,
returning the area from the heap entirely.
* doc/api/malloc.dox: Mention that the heap is now
reduced if possible.
* tests/simulate/regression/bug-27242.c: Adapt testscript
to match the new behaviour.
* tests/simulate/stdlib/malloc-1.c: (Ditto.)
* tests/simulate/stdlib/malloc-6.c: (Ditto.)
* tests/simulate/stdlib/malloc-7.c: (Ditto.)
* tests/simulate/stdlib/realloc-2.c: New file (test whether
subsequent allocation does not extend the heap).
* tests/simulate/regression/bug-28135.c: New file, another
regression test (actual bugfix from bug #28135 is no longer
needed)
Ticket Links:
:-----------
http://savannah.gnu.org/bugs/?27235
http://savannah.gnu.org/bugs/?28135
Modified Paths:
--------------
trunk/avr-libc/ChangeLog
trunk/avr-libc/NEWS
trunk/avr-libc/doc/api/malloc.dox
trunk/avr-libc/libc/stdlib/malloc.c
trunk/avr-libc/tests/simulate/regression/bug-27242.c
trunk/avr-libc/tests/simulate/stdlib/malloc-1.c
trunk/avr-libc/tests/simulate/stdlib/malloc-6.c
trunk/avr-libc/tests/simulate/stdlib/malloc-7.c
Added Paths:
-----------
trunk/avr-libc/tests/simulate/regression/bug-28135.c
trunk/avr-libc/tests/simulate/stdlib/realloc-2.c
Modified: trunk/avr-libc/ChangeLog
===================================================================
--- trunk/avr-libc/ChangeLog 2010-06-07 16:27:16 UTC (rev 2130)
+++ trunk/avr-libc/ChangeLog 2010-06-07 18:09:17 UTC (rev 2131)
@@ -1,5 +1,26 @@
2010-06-07 Joerg Wunsch <address@hidden>
+ bug #27235, malloc: Several things go wrong
+ * libc/stdlib/malloc.c (malloc): Revert the patch
+ from r2123, as it is no longer needed.
+ * libc/stdlib/malloc.c (free): When freeing the
+ topmost chunk of the heap, reduce __brkval again,
+ returning the area from the heap entirely.
+ * doc/api/malloc.dox: Mention that the heap is now
+ reduced if possible.
+ * tests/simulate/regression/bug-27242.c: Adapt testscript
+ to match the new behaviour.
+ * tests/simulate/stdlib/malloc-1.c: (Ditto.)
+ * tests/simulate/stdlib/malloc-6.c: (Ditto.)
+ * tests/simulate/stdlib/malloc-7.c: (Ditto.)
+ * tests/simulate/stdlib/realloc-2.c: New file (test whether
+ subsequent allocation does not extend the heap).
+ * tests/simulate/regression/bug-28135.c: New file, another
+ regression test (actual bugfix from bug #28135 is no longer
+ needed)
+
+2010-06-07 Joerg Wunsch <address@hidden>
+
More testscripts: test free() works as expected.
* tests/simulate/stdlib/malloc-5.c: New file.
* tests/simulate/stdlib/malloc-6.c: (Ditto.)
Modified: trunk/avr-libc/NEWS
===================================================================
--- trunk/avr-libc/NEWS 2010-06-07 16:27:16 UTC (rev 2130)
+++ trunk/avr-libc/NEWS 2010-06-07 18:09:17 UTC (rev 2131)
@@ -103,7 +103,7 @@
[#26840] Missing #define in iom32m1.h
[#26876] include io.h into fuse.h
[#27201] _WORDREGISTER in xmega headers does not work in C99 mode
- [#27235] malloc: Several things go wrong (part 1)
+ [#27235] malloc: Several things go wrong
[#27242] realloc: serious error when size shrinks
[#27243] malloc: small error in comment
[#27367] RAMSTART missing in elder device header files
Modified: trunk/avr-libc/doc/api/malloc.dox
===================================================================
--- trunk/avr-libc/doc/api/malloc.dox 2010-06-07 16:27:16 UTC (rev 2130)
+++ trunk/avr-libc/doc/api/malloc.dox 2010-06-07 18:09:17 UTC (rev 2131)
@@ -214,7 +214,8 @@
attempt is then made to aggregate the new entry with possible adjacent
entries, yielding a single larger entry available for further
allocations. That way, the potential for heap fragmentation is hopefully
-reduced.
+reduced. When deallocating the topmost chunk of memory, the size of the
+heap is reduced.
A call to realloc() first determines whether the operation is about to
grow or shrink the current allocation. When shrinking, the case is
Modified: trunk/avr-libc/libc/stdlib/malloc.c
===================================================================
--- trunk/avr-libc/libc/stdlib/malloc.c 2010-06-07 16:27:16 UTC (rev 2130)
+++ trunk/avr-libc/libc/stdlib/malloc.c 2010-06-07 18:09:17 UTC (rev 2131)
@@ -164,22 +164,7 @@
* segment as dynamically requested from the operating system.
* Since we don't have an operating system, just make sure
* that we don't collide with the stack.
- * But first we check if there is a free chunk at the end of
- * the allocation area. Brkval is corrected downwards then,
- * so the free chunk gets added to the new chunk.
- * (fp2 still points to the last list entry from step 1)
*/
- if (fp2 && (char*)fp2 + fp2->sz + sizeof(size_t) == __brkval) {
- __brkval = (char*)fp2;
- for (fp1 = __flp, fp2 = 0;
- fp1->nx;
- fp2 = fp1, fp1 = fp1->nx)
- {}
- if (fp2)
- fp2->nx = 0;
- else
- __flp = 0;
- }
if (__brkval == 0)
__brkval = __malloc_heap_start;
cp = __malloc_heap_end;
@@ -225,10 +210,14 @@
/*
* Trivial case first: if there's no freelist yet, our entry
- * will be the only one on it.
+ * will be the only one on it. If this is the last entry, we
+ * can reduce __brkval instead.
*/
if (__flp == 0) {
- __flp = fpnew;
+ if ((char *)p + fpnew->sz == __brkval)
+ __brkval = cpnew;
+ else
+ __flp = fpnew;
return;
}
@@ -269,6 +258,22 @@
fp2->sz += fpnew->sz + sizeof(size_t);
fp2->nx = fpnew->nx;
}
+ /*
+ * If there's a new topmost chunk, lower __brkval instead.
+ */
+ while (fp2->nx != NULL) {
+ fp1 = fp2;
+ fp2 = fp2->nx;
+ }
+ cp2 = (char *)&(fp2->nx);
+ if (cp2 + fp2->sz == __brkval) {
+ if (fp1 == NULL)
+ /* Freelist is empty now. */
+ __flp = NULL;
+ else
+ fp1->nx = NULL;
+ __brkval = cp2 - sizeof(size_t);
+ }
}
#ifdef MALLOC_TEST
Modified: trunk/avr-libc/tests/simulate/regression/bug-27242.c
===================================================================
--- trunk/avr-libc/tests/simulate/regression/bug-27242.c 2010-06-07
16:27:16 UTC (rev 2130)
+++ trunk/avr-libc/tests/simulate/regression/bug-27242.c 2010-06-07
18:09:17 UTC (rev 2131)
@@ -53,11 +53,11 @@
/*
* The patch for bug #25723 introduces a regression to realloc()
* when called to shrink a memory chunk. We simply verify if
- * the new free chunk starts immediately after the last allocated
+ * the new __brkval starts immediately after the last allocated
* chunk.
*/
p = p1 + 10;
- if ((char*)__flp != p)
+ if (__brkval != p)
return 3;
/* use the last free chunk */
@@ -73,13 +73,14 @@
if (!p)
return 6;
- /* force creation of a new minimal free chunk (sz = 3) */
+ /* force creation of a new minimal free chunk (sz = 3), which
+ will be returned from heap then */
p1 = realloc(p, 5);
if (p != p1)
return 7;
p = p1 + 5;
- if ((char*)__flp != p)
+ if (__brkval != p)
return 8;
/* merge with the free chunk (incr = 4 > sz = 3) */
@@ -87,9 +88,9 @@
if (p != p1)
return 9;
- /* chunk size should be 10 */
+ /* chunk size should be 9 */
p -= sizeof(size_t);
- if (*(size_t *)p != 10)
+ if (*(size_t *)p != 9)
return 10;
/* should be empty */
Added: trunk/avr-libc/tests/simulate/regression/bug-28135.c
===================================================================
--- trunk/avr-libc/tests/simulate/regression/bug-28135.c
(rev 0)
+++ trunk/avr-libc/tests/simulate/regression/bug-28135.c 2010-06-07
18:09:17 UTC (rev 2131)
@@ -0,0 +1,126 @@
+/* Copyright (c) 2009 Aleksandar Kanchev
+ 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.
+
+ * Neither the name of the copyright holders nor the names of
+ contributors may be used to endorse or promote products derived
+ from this software without specific prior written permission.
+
+ 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 OWNER 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.
+*/
+
+/* $Id$ */
+
+#include <stdlib.h>
+
+#include "../../libc/stdlib/stdlib_private.h"
+
+
+/* Test code from bug # */
+int main(void)
+{
+ char *p, *p1;
+
+ /* Step 1: test with just one free chunk */
+
+ p = malloc(20);
+ if (!p)
+ return 1;
+
+ /* releasing 10 bytes returns them from the heap */
+ p1 = realloc(p, 10);
+ if (p != p1)
+ return 2;
+
+ if (__flp)
+ return 3;
+
+ /* should extend the free chunk */
+ p = malloc(15);
+ if (!p)
+ return 4;
+
+ /* should be empty */
+ if (__flp)
+ return 5;
+
+ /* should be the following chunk */
+ p1 += 10 + sizeof(size_t);
+ if (p != p1)
+ return 6;
+
+ /* should point right after the last chunk */
+ p += 15;
+ if (p != __brkval)
+ return 7;
+
+ /* Step 2: Test with 2 free chunks. */
+
+ p = malloc(8);
+ if (!p)
+ return 8;
+
+ p1 = malloc(9);
+ if (!p1)
+ return 9;
+
+ free(p);
+
+ p = malloc(20);
+ if (!p)
+ return 10;
+
+ if (!__flp)
+ return 11;
+
+ p1 = realloc(p, 10);
+ if (p1 != p)
+ return 12;
+
+ if (!__flp)
+ return 13;
+
+ if (__flp->nx)
+ return 14;
+
+ p = malloc(15);
+ if (!p)
+ return 15;
+
+ if (!__flp)
+ return 16;
+
+ if (__flp->nx)
+ return 17;
+
+ p1 += 10 + sizeof(size_t);
+ if (p != p1)
+ return 18;
+
+ p += 15;
+ if (p != __brkval)
+ return 19;
+
+ return 0;
+}
+
Property changes on: trunk/avr-libc/tests/simulate/regression/bug-28135.c
___________________________________________________________________
Added: svn:mime-type
+ text/plain
Added: svn:keywords
+ Author Id Date
Added: svn:eol-style
+ native
Modified: trunk/avr-libc/tests/simulate/stdlib/malloc-1.c
===================================================================
--- trunk/avr-libc/tests/simulate/stdlib/malloc-1.c 2010-06-07 16:27:16 UTC
(rev 2130)
+++ trunk/avr-libc/tests/simulate/stdlib/malloc-1.c 2010-06-07 18:09:17 UTC
(rev 2131)
@@ -93,11 +93,8 @@
free(ptrs[i]);
}
- /* after freeing everything, the freelist must contain one
- chunk of the full TARGETVAL size (minus the size for one
- pointer), and the "nx" pointer must be NULL */
- if (__flp->nx != NULL) return __LINE__;
- if (__flp->sz != TARGETVAL - 2) return __LINE__;
+ /* after freeing everything, the freelist must be empty */
+ if (__flp != NULL) return __LINE__;
return 0;
}
Modified: trunk/avr-libc/tests/simulate/stdlib/malloc-6.c
===================================================================
--- trunk/avr-libc/tests/simulate/stdlib/malloc-6.c 2010-06-07 16:27:16 UTC
(rev 2130)
+++ trunk/avr-libc/tests/simulate/stdlib/malloc-6.c 2010-06-07 18:09:17 UTC
(rev 2131)
@@ -67,11 +67,9 @@
}
free(ptrs[5]);
- /* There must be exactly one entry in freelist. */
- if ((char *)(ptrs[5]) - 2 != (void *)__flp) return __LINE__;
- if (__flp->sz != 10) return __LINE__;
- if (__flp->nx != NULL) return __LINE__;
- if ((char *)(ptrs[5]) + 10 != (void *)__brkval) return __LINE__;
+ /* Freelist must be still empty, and __brkval reduced. */
+ if (__flp != NULL) return __LINE__;
+ if ((char *)(ptrs[5]) - 2 != __brkval) return __LINE__;
return 0;
}
Modified: trunk/avr-libc/tests/simulate/stdlib/malloc-7.c
===================================================================
--- trunk/avr-libc/tests/simulate/stdlib/malloc-7.c 2010-06-07 16:27:16 UTC
(rev 2130)
+++ trunk/avr-libc/tests/simulate/stdlib/malloc-7.c 2010-06-07 18:09:17 UTC
(rev 2131)
@@ -67,39 +67,32 @@
}
free(ptrs[5]);
- /* There must be exactly one entry in freelist. */
- if ((char *)(ptrs[5]) - 2 != (void *)__flp) return __LINE__;
- if (__flp->sz != 10) return __LINE__;
- if (__flp->nx != NULL) return __LINE__;
- if ((char *)(ptrs[5]) + 10 != (void *)__brkval) return __LINE__;
+ /* Freelist must be still empty, and __brkval reduced. */
+ if (__flp != NULL) return __LINE__;
+ if ((char *)(ptrs[5]) - 2 != __brkval) return __LINE__;
free(ptrs[4]);
- /* Still one entry expected. */
- if ((char *)(ptrs[4]) - 2 != (void *)__flp) return __LINE__;
- if (__flp->sz != 22) return __LINE__;
- if (__flp->nx != NULL) return __LINE__;
- if ((char *)(ptrs[4]) + 22 != (void *)__brkval) return __LINE__;
+ /* Still no entry, and __brkval further down. */
+ if (__flp != NULL) return __LINE__;
+ if ((char *)(ptrs[4]) - 2 != __brkval) return __LINE__;
struct __freelist *ofp = __flp;
free(ptrs[1]);
- /* Another entry added. */
+ /* One entry added. */
if ((char *)(ptrs[1]) - 2 != (void *)__flp) return __LINE__;
if (__flp->sz != 10) return __LINE__;
if (__flp->nx != (void *)ofp) return __LINE__;
free(ptrs[3]);
- /* Second entry must have been extended. */
- if ((char *)(ptrs[3]) - 2 != (void *)__flp->nx) return __LINE__;
- if (__flp->nx->sz != 34) return __LINE__;
- if (__flp->nx->nx != NULL) return __LINE__;
- if ((char *)(ptrs[3]) + 34 != (void *)__brkval) return __LINE__;
+ /* __brkval lowered again. */
+ if (__flp->nx != NULL) return __LINE__;
+ if ((char *)(ptrs[3]) - 2 != __brkval) return __LINE__;
free(ptrs[2]);
- /* Both chunks must have been combined. */
- if (__flp->sz != 58) return __LINE__;
+ /* ...and again. */
if (__flp->nx != NULL) return __LINE__;
- if ((char *)(ptrs[1]) + 58 != (void *)__brkval) return __LINE__;
+ if ((char *)(ptrs[1]) - 2 != __brkval) return __LINE__;
return 0;
}
Added: trunk/avr-libc/tests/simulate/stdlib/realloc-2.c
===================================================================
--- trunk/avr-libc/tests/simulate/stdlib/realloc-2.c
(rev 0)
+++ trunk/avr-libc/tests/simulate/stdlib/realloc-2.c 2010-06-07 18:09:17 UTC
(rev 2131)
@@ -0,0 +1,119 @@
+/* Copyright (c) 2010 Joerg Wunsch
+ 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.
+ * Neither the name of the copyright holders nor the names of
+ contributors may be used to endorse or promote products derived
+ from this software without specific prior written permission.
+
+ 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 OWNER 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.
+ */
+
+/* $Id$ */
+
+/* Like malloc-1.c, but after freeing everything, try to subsequently
+ allocate everything through a single pointer, and realloc(). */
+
+#ifndef __AVR__
+
+/* There is no sense to check on host computer. */
+int main ()
+{
+ return 0;
+}
+
+#else
+
+#include <stdint.h>
+#include <stdlib.h>
+
+struct __freelist {
+ size_t sz;
+ struct __freelist *nx;
+};
+
+extern char *__brkval; /* first location not yet allocated */
+extern struct __freelist *__flp; /* freelist pointer (head of freelist) */
+extern char *__malloc_heap_start;
+extern char *__malloc_heap_end;
+
+#if defined(__AVR_ATmega128__)
+static const int sizes[8] =
+{
+ 5, 8, 2, 122, 256, 1, 32, 25 /* 451 + 1 [padding] + 2 * 8 [ptrs] = 468 */
+};
+#define TARGETVAL 468
+#elif defined(__AVR_AT90S8515__)
+static const int sizes[8] =
+{
+ 5, 8, 2, 22, 256, 1, 12, 25 /* 331 + 1 [padding] + 2 * 8 [ptrs] = 348 */
+};
+#define TARGETVAL 348
+#else
+# error "Unknown MCU type"
+#endif
+
+
+int main(void)
+{
+ void *ptrs[8];
+ uint8_t i;
+
+ for (i = 0; i < 8; i++)
+ {
+ void *p = malloc(sizes[i]);
+ /* first test: all allocations are supposed to fit */
+ if (p == NULL) return __LINE__;
+ ptrs[i] = p;
+ }
+ /* second test: the amount of memory allocated to the heap must
+ match the expected TARGETVAL */
+ if (__brkval - __malloc_heap_start != TARGETVAL) return __LINE__;
+
+ char *obrk = __brkval;
+
+ for (i = 0; i < 8; i++)
+ {
+ free(ptrs[i]);
+ }
+
+ /* after freeing everything, the freelist must be empty */
+ if (__flp != NULL) return __LINE__;
+ if (__brkval != __malloc_heap_start) return __LINE__;
+
+ size_t s = sizes[0];
+ void *p = malloc(s);
+ if (p == NULL) return __LINE__;
+ for (i = 1; i < 8; i++)
+ {
+ s += sizes[i];
+ void *q = realloc(p, s);
+ if (q == NULL) return __LINE__;
+ if (q != p) return __LINE__;
+ }
+
+ /* Verify the allocation length did not increase. */
+ if (__brkval > obrk) return __LINE__;
+
+ return 0;
+}
+
+#endif /* !AVR */
Property changes on: trunk/avr-libc/tests/simulate/stdlib/realloc-2.c
___________________________________________________________________
Added: svn:mime-type
+ text/plain
Added: svn:keywords
+ Author Id Date
Added: svn:eol-style
+ native
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- [avr-libc-commit] [2131] bug #27235, malloc: Several things go wrong,
Joerg Wunsch <=