7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #pragma weak _sbrk = sbrk
30 #pragma weak _brk = brk
31
32 #include "lint.h"
33 #include <synch.h>
34 #include <errno.h>
35 #include <sys/isa_defs.h>
36 #include <sys/types.h>
37 #include <sys/sysmacros.h>
38 #include <inttypes.h>
39 #include <unistd.h>
40 #include "mtlib.h"
41 #include "libc.h"
42
43 extern int _end;
44 void *_nd = &_end;
45 mutex_t __sbrk_lock = DEFAULTMUTEX;
46
47 extern int _brk_unlocked(void *);
48 extern void *_sbrk_unlocked(intptr_t);
49
50 /*
51 * The break must always be at least 8-byte aligned
52 */
53 #if (_MAX_ALIGNMENT < 8)
54 #define ALIGNSZ 8
55 #else
56 #define ALIGNSZ _MAX_ALIGNMENT
57 #endif
58
59 #define BRKALIGN(x) (caddr_t)P2ROUNDUP((uintptr_t)(x), ALIGNSZ)
60
61 void *
62 sbrk(intptr_t addend)
63 {
64 void *result;
65
66 if (!primary_link_map) {
67 errno = ENOTSUP;
68 return ((void *)-1);
70 lmutex_lock(&__sbrk_lock);
71 result = _sbrk_unlocked(addend);
72 lmutex_unlock(&__sbrk_lock);
73
74 return (result);
75 }
76
77 /*
78 * _sbrk_unlocked() aligns the old break, adds the addend, aligns
79 * the new break, and calls _brk_unlocked() to set the new break.
80 * We must align the old break because _nd may begin life misaligned.
81 * The addend can be either positive or negative, so there are two
82 * overflow/underflow edge conditions to reject:
83 *
84 * - the addend is negative and brk + addend < 0.
85 * - the addend is positive and brk + addend > ULONG_MAX
86 */
87 void *
88 _sbrk_unlocked(intptr_t addend)
89 {
90 char *old_brk = BRKALIGN(_nd);
91 char *new_brk = BRKALIGN(old_brk + addend);
92
93 if ((addend > 0 && new_brk < old_brk) ||
94 (addend < 0 && new_brk > old_brk)) {
95 errno = ENOMEM;
96 return ((void *)-1);
97 }
98 if (_brk_unlocked(new_brk) != 0)
99 return ((void *)-1);
100 _nd = new_brk;
101 return (old_brk);
102 }
103
104 /*
105 * _sbrk_grow_aligned() aligns the old break to a low_align boundry,
106 * adds min_size, aligns to a high_align boundry, and calls _brk_unlocked()
107 * to set the new break. The low_aligned-aligned value is returned, and
108 * the actual space allocated is returned through actual_size.
109 *
110 * Unlike sbrk(2), _sbrk_grow_aligned takes an unsigned size, and does
111 * not allow shrinking the heap.
117 uintptr_t old_brk;
118 uintptr_t ret_brk;
119 uintptr_t high_brk;
120 uintptr_t new_brk;
121 int brk_result;
122
123 if (!primary_link_map) {
124 errno = ENOTSUP;
125 return ((void *)-1);
126 }
127 if ((low_align & (low_align - 1)) != 0 ||
128 (high_align & (high_align - 1)) != 0) {
129 errno = EINVAL;
130 return ((void *)-1);
131 }
132 low_align = MAX(low_align, ALIGNSZ);
133 high_align = MAX(high_align, ALIGNSZ);
134
135 lmutex_lock(&__sbrk_lock);
136
137 old_brk = (uintptr_t)BRKALIGN(_nd);
138 ret_brk = P2ROUNDUP(old_brk, low_align);
139 high_brk = ret_brk + min_size;
140 new_brk = P2ROUNDUP(high_brk, high_align);
141
142 /*
143 * Check for overflow
144 */
145 if (ret_brk < old_brk || high_brk < ret_brk || new_brk < high_brk) {
146 lmutex_unlock(&__sbrk_lock);
147 errno = ENOMEM;
148 return ((void *)-1);
149 }
150
151 if ((brk_result = _brk_unlocked((void *)new_brk)) == 0)
152 _nd = (void *)new_brk;
153 lmutex_unlock(&__sbrk_lock);
154
155 if (brk_result != 0)
156 return ((void *)-1);
157
158 if (actual_size != NULL)
159 *actual_size = (new_brk - ret_brk);
160 return ((void *)ret_brk);
161 }
162
163 int
164 brk(void *new_brk)
165 {
166 int result;
167
168 if (!primary_link_map) {
169 errno = ENOTSUP;
170 return (-1);
171 }
172 /*
173 * Need to align this here; _brk_unlocked won't do it for us.
174 */
175 new_brk = BRKALIGN(new_brk);
176
177 lmutex_lock(&__sbrk_lock);
178 if ((result = _brk_unlocked(new_brk)) == 0)
179 _nd = new_brk;
180 lmutex_unlock(&__sbrk_lock);
181
182 return (result);
183 }
|
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma weak _sbrk = sbrk
28 #pragma weak _brk = brk
29
30 #include "lint.h"
31 #include <synch.h>
32 #include <errno.h>
33 #include <sys/isa_defs.h>
34 #include <sys/types.h>
35 #include <sys/sysmacros.h>
36 #include <inttypes.h>
37 #include <unistd.h>
38 #include "mtlib.h"
39 #include "libc.h"
40
41 void *_nd = NULL;
42 mutex_t __sbrk_lock = DEFAULTMUTEX;
43
44 extern intptr_t _brk_unlocked(void *);
45 void *_sbrk_unlocked(intptr_t);
46
47 /*
48 * The break must always be at least 8-byte aligned
49 */
50 #if (_MAX_ALIGNMENT < 8)
51 #define ALIGNSZ 8
52 #else
53 #define ALIGNSZ _MAX_ALIGNMENT
54 #endif
55
56 #define BRKALIGN(x) (caddr_t)P2ROUNDUP((uintptr_t)(x), ALIGNSZ)
57
58 void *
59 sbrk(intptr_t addend)
60 {
61 void *result;
62
63 if (!primary_link_map) {
64 errno = ENOTSUP;
65 return ((void *)-1);
67 lmutex_lock(&__sbrk_lock);
68 result = _sbrk_unlocked(addend);
69 lmutex_unlock(&__sbrk_lock);
70
71 return (result);
72 }
73
74 /*
75 * _sbrk_unlocked() aligns the old break, adds the addend, aligns
76 * the new break, and calls _brk_unlocked() to set the new break.
77 * We must align the old break because _nd may begin life misaligned.
78 * The addend can be either positive or negative, so there are two
79 * overflow/underflow edge conditions to reject:
80 *
81 * - the addend is negative and brk + addend < 0.
82 * - the addend is positive and brk + addend > ULONG_MAX
83 */
84 void *
85 _sbrk_unlocked(intptr_t addend)
86 {
87 char *old_brk;
88 char *new_brk;
89
90 if (_nd == NULL) {
91 _nd = (void *)_brk_unlocked(0);
92 }
93
94 old_brk = BRKALIGN(_nd);
95 new_brk = BRKALIGN(old_brk + addend);
96
97 if ((addend > 0 && new_brk < old_brk) ||
98 (addend < 0 && new_brk > old_brk)) {
99 errno = ENOMEM;
100 return ((void *)-1);
101 }
102 if (_brk_unlocked(new_brk) != 0)
103 return ((void *)-1);
104 _nd = new_brk;
105 return (old_brk);
106 }
107
108 /*
109 * _sbrk_grow_aligned() aligns the old break to a low_align boundry,
110 * adds min_size, aligns to a high_align boundry, and calls _brk_unlocked()
111 * to set the new break. The low_aligned-aligned value is returned, and
112 * the actual space allocated is returned through actual_size.
113 *
114 * Unlike sbrk(2), _sbrk_grow_aligned takes an unsigned size, and does
115 * not allow shrinking the heap.
121 uintptr_t old_brk;
122 uintptr_t ret_brk;
123 uintptr_t high_brk;
124 uintptr_t new_brk;
125 int brk_result;
126
127 if (!primary_link_map) {
128 errno = ENOTSUP;
129 return ((void *)-1);
130 }
131 if ((low_align & (low_align - 1)) != 0 ||
132 (high_align & (high_align - 1)) != 0) {
133 errno = EINVAL;
134 return ((void *)-1);
135 }
136 low_align = MAX(low_align, ALIGNSZ);
137 high_align = MAX(high_align, ALIGNSZ);
138
139 lmutex_lock(&__sbrk_lock);
140
141 if (_nd == NULL) {
142 _nd = (void *)_brk_unlocked(0);
143 }
144
145 old_brk = (uintptr_t)BRKALIGN(_nd);
146 ret_brk = P2ROUNDUP(old_brk, low_align);
147 high_brk = ret_brk + min_size;
148 new_brk = P2ROUNDUP(high_brk, high_align);
149
150 /*
151 * Check for overflow
152 */
153 if (ret_brk < old_brk || high_brk < ret_brk || new_brk < high_brk) {
154 lmutex_unlock(&__sbrk_lock);
155 errno = ENOMEM;
156 return ((void *)-1);
157 }
158
159 if ((brk_result = (int)_brk_unlocked((void *)new_brk)) == 0)
160 _nd = (void *)new_brk;
161 lmutex_unlock(&__sbrk_lock);
162
163 if (brk_result != 0)
164 return ((void *)-1);
165
166 if (actual_size != NULL)
167 *actual_size = (new_brk - ret_brk);
168 return ((void *)ret_brk);
169 }
170
171 int
172 brk(void *new_brk)
173 {
174 int result;
175
176 /*
177 * brk(2) will return the current brk if given an argument of 0, so we
178 * need to fail it here
179 */
180 if (new_brk == 0) {
181 errno = ENOMEM;
182 return (-1);
183 }
184
185 if (!primary_link_map) {
186 errno = ENOTSUP;
187 return (-1);
188 }
189 /*
190 * Need to align this here; _brk_unlocked won't do it for us.
191 */
192 new_brk = BRKALIGN(new_brk);
193
194 lmutex_lock(&__sbrk_lock);
195 if ((result = (int)_brk_unlocked(new_brk)) == 0)
196 _nd = new_brk;
197 lmutex_unlock(&__sbrk_lock);
198
199 return (result);
200 }
|