Bug Summary

File:build-scan/../src/libsystemd/sd-id128/sd-id128.c
Warning:line 163, column 9
Use of zero-allocated memory

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-unknown-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name sd-id128.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -menable-no-infs -menable-no-nans -menable-unsafe-fp-math -fno-signed-zeros -mreassociate -freciprocal-math -fdenormal-fp-math=preserve-sign,preserve-sign -ffp-contract=fast -fno-rounding-math -ffast-math -ffinite-math-only -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -fno-split-dwarf-inlining -debugger-tuning=gdb -resource-dir /usr/lib64/clang/12.0.0 -include config.h -I src/libsystemd/libsystemd_static.a.p -I src/libsystemd -I ../src/libsystemd -I src/basic -I ../src/basic -I src/shared -I ../src/shared -I src/systemd -I ../src/systemd -I src/journal -I ../src/journal -I src/journal-remote -I ../src/journal-remote -I src/nspawn -I ../src/nspawn -I src/resolve -I ../src/resolve -I src/timesync -I ../src/timesync -I ../src/time-wait-sync -I src/login -I ../src/login -I src/udev -I ../src/udev -I src/libudev -I ../src/libudev -I src/core -I ../src/core -I ../src/libsystemd/sd-bus -I ../src/libsystemd/sd-device -I ../src/libsystemd/sd-hwdb -I ../src/libsystemd/sd-id128 -I ../src/libsystemd/sd-netlink -I ../src/libsystemd/sd-network -I src/libsystemd-network -I ../src/libsystemd-network -I . -I .. -D _FILE_OFFSET_BITS=64 -internal-isystem /usr/local/include -internal-isystem /usr/lib64/clang/12.0.0/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -Wwrite-strings -Wno-unused-parameter -Wno-missing-field-initializers -Wno-unused-result -Wno-format-signedness -Wno-error=nonnull -std=gnu99 -fconst-strings -fdebug-compilation-dir /home/mrc0mmand/repos/@redhat-plumbers/systemd-rhel8/build-scan -ferror-limit 19 -fvisibility default -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -analyzer-output=html -faddrsig -o /tmp/scan-build-2021-07-16-221226-1465241-1 -x c ../src/libsystemd/sd-id128/sd-id128.c

../src/libsystemd/sd-id128/sd-id128.c

→
1/* SPDX-License-Identifier: LGPL-2.1+ */
2/***
3***/
4
5#include <errno(*__errno_location ()).h>
6#include <fcntl.h>
7#include <unistd.h>
8
9#include "sd-id128.h"
10
11#include "alloc-util.h"
12#include "fd-util.h"
13#include "hexdecoct.h"
14#include "id128-util.h"
15#include "io-util.h"
16#include "khash.h"
17#include "macro.h"
18#include "missing.h"
19#include "random-util.h"
20#include "user-util.h"
21#include "util.h"
22
23_public___attribute__ ((visibility("default"))) char *sd_id128_to_string(sd_id128_t id, char s[SD_ID128_STRING_MAX33]) {
24 unsigned n;
25
26 assert_return(s, NULL)do { if (!(((__builtin_expect(!!(s),1))) ? (1) : (log_assert_failed_return_realm
(LOG_REALM_SYSTEMD, ("s"), "../src/libsystemd/sd-id128/sd-id128.c"
, 26, __PRETTY_FUNCTION__), 0))) return (((void*)0)); } while
(0);
27
28 for (n = 0; n < 16; n++) {
29 s[n*2] = hexchar(id.bytes[n] >> 4);
30 s[n*2+1] = hexchar(id.bytes[n] & 0xF);
31 }
32
33 s[32] = 0;
34
35 return s;
36}
37
38_public___attribute__ ((visibility("default"))) int sd_id128_from_string(const char s[], sd_id128_t *ret) {
39 unsigned n, i;
40 sd_id128_t t;
41 bool_Bool is_guid = false0;
42
43 assert_return(s, -EINVAL)do { if (!(((__builtin_expect(!!(s),1))) ? (1) : (log_assert_failed_return_realm
(LOG_REALM_SYSTEMD, ("s"), "../src/libsystemd/sd-id128/sd-id128.c"
, 43, __PRETTY_FUNCTION__), 0))) return (-22); } while (0);
44
45 for (n = 0, i = 0; n < 16;) {
46 int a, b;
47
48 if (s[i] == '-') {
49 /* Is this a GUID? Then be nice, and skip over
50 * the dashes */
51
52 if (i == 8)
53 is_guid = true1;
54 else if (IN_SET(i, 13, 18, 23)({ _Bool _found = 0; static __attribute__ ((unused)) char _static_assert__macros_need_to_be_extended
[20 - sizeof((int[]){13, 18, 23})/sizeof(int)]; switch(i) { case
13: case 18: case 23: _found = 1; break; default: break; } _found
; })) {
55 if (!is_guid)
56 return -EINVAL22;
57 } else
58 return -EINVAL22;
59
60 i++;
61 continue;
62 }
63
64 a = unhexchar(s[i++]);
65 if (a < 0)
66 return -EINVAL22;
67
68 b = unhexchar(s[i++]);
69 if (b < 0)
70 return -EINVAL22;
71
72 t.bytes[n++] = (a << 4) | b;
73 }
74
75 if (i != (is_guid ? 36 : 32))
76 return -EINVAL22;
77
78 if (s[i] != 0)
79 return -EINVAL22;
80
81 if (ret)
82 *ret = t;
83 return 0;
84}
85
86_public___attribute__ ((visibility("default"))) int sd_id128_get_machine(sd_id128_t *ret) {
87 static thread_local__thread sd_id128_t saved_machine_id = {};
88 int r;
89
90 assert_return(ret, -EINVAL)do { if (!(((__builtin_expect(!!(ret),1))) ? (1) : (log_assert_failed_return_realm
(LOG_REALM_SYSTEMD, ("ret"), "../src/libsystemd/sd-id128/sd-id128.c"
, 90, __PRETTY_FUNCTION__), 0))) return (-22); } while (0);
91
92 if (sd_id128_is_null(saved_machine_id)) {
93 r = id128_read("/etc/machine-id", ID128_PLAIN, &saved_machine_id);
94 if (r < 0)
95 return r;
96
97 if (sd_id128_is_null(saved_machine_id))
98 return -ENOMEDIUM123;
99 }
100
101 *ret = saved_machine_id;
102 return 0;
103}
104
105_public___attribute__ ((visibility("default"))) int sd_id128_get_boot(sd_id128_t *ret) {
106 static thread_local__thread sd_id128_t saved_boot_id = {};
107 int r;
108
109 assert_return(ret, -EINVAL)do { if (!(((__builtin_expect(!!(ret),1))) ? (1) : (log_assert_failed_return_realm
(LOG_REALM_SYSTEMD, ("ret"), "../src/libsystemd/sd-id128/sd-id128.c"
, 109, __PRETTY_FUNCTION__), 0))) return (-22); } while (0);
110
111 if (sd_id128_is_null(saved_boot_id)) {
112 r = id128_read("/proc/sys/kernel/random/boot_id", ID128_UUID, &saved_boot_id);
113 if (r < 0)
114 return r;
115 }
116
117 *ret = saved_boot_id;
118 return 0;
119}
120
121static int get_invocation_from_keyring(sd_id128_t *ret) {
122
123 _cleanup_free___attribute__((cleanup(freep))) char *description = NULL((void*)0);
124 char *d, *p, *g, *u, *e;
125 unsigned long perms;
126 key_serial_t key;
127 size_t sz = 256;
128 uid_t uid;
129 gid_t gid;
130 int r, c;
131
132#define MAX_PERMS((unsigned long) (0x01000000|0x02000000|0x08000000| 0x00010000
|0x00020000|0x00080000)) ((unsigned long) (KEY_POS_VIEW0x01000000|KEY_POS_READ0x02000000|KEY_POS_SEARCH0x08000000| \
133 KEY_USR_VIEW0x00010000|KEY_USR_READ0x00020000|KEY_USR_SEARCH0x00080000))
134
135 assert(ret)do { if ((__builtin_expect(!!(!(ret)),0))) log_assert_failed_realm
(LOG_REALM_SYSTEMD, ("ret"), "../src/libsystemd/sd-id128/sd-id128.c"
, 135, __PRETTY_FUNCTION__); } while (0);
1
Assuming 'ret' is non-null
→
2
←
Taking false branch
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3
←
Loop condition is false. Exiting loop
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136
137 key = request_keymissing_request_key("user", "invocation_id", NULL((void*)0), 0);
138 if (key == -1) {
4
←
Assuming the condition is false
→
5
←
Taking false branch
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139 /* Keyring support not available? No invocation key stored? */
140 if (IN_SET(errno, ENOSYS, ENOKEY)({ _Bool _found = 0; static __attribute__ ((unused)) char _static_assert__macros_need_to_be_extended
[20 - sizeof((int[]){38, 126})/sizeof(int)]; switch((*__errno_location
())) { case 38: case 126: _found = 1; break; default: break;
} _found; }))
141 return 0;
142
143 return -errno(*__errno_location ());
144 }
145
146 for (;;) {
6
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Loop condition is true. Entering loop body
→
13
←
Loop condition is true. Entering loop body
→
20
←
Loop condition is true. Entering loop body
→
147 description = new(char, sz)((char*) malloc_multiply(sizeof(char), (sz)));
21
←
Calling 'malloc_multiply'
→
24
←
Returned allocated memory
→
148 if (!description)
7
←
Assuming 'description' is non-null
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8
←
Taking false branch
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14
←
Assuming 'description' is non-null
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15
←
Taking false branch
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25
←
Assuming 'description' is non-null
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26
←
Taking false branch
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149 return -ENOMEM12;
150
151 c = keyctlmissing_keyctl(KEYCTL_DESCRIBE6, key, (unsigned long) description, sz, 0);
152 if (c < 0)
9
←
Assuming 'c' is >= 0
→
10
←
Taking false branch
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16
←
Assuming 'c' is >= 0
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17
←
Taking false branch
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27
←
Assuming 'c' is >= 0
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28
←
Taking false branch
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153 return -errno(*__errno_location ());
154
155 if ((size_t) c <= sz)
11
←
Assuming 'c' is > 'sz'
→
12
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Taking false branch
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18
←
Assuming 'c' is > 'sz'
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19
←
Taking false branch
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29
←
Assuming 'c' is <= 'sz'
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30
←
Taking true branch
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156 break;
31
←
 Execution continues on line 163
→
157
158 sz = c;
159 free(description);
160 }
161
162 /* The kernel returns a final NUL in the string, verify that. */
163 assert(description[c-1] == 0)do { if ((__builtin_expect(!!(!(description[c-1] == 0)),0))) log_assert_failed_realm
(LOG_REALM_SYSTEMD, ("description[c-1] == 0"), "../src/libsystemd/sd-id128/sd-id128.c"
, 163, __PRETTY_FUNCTION__); } while (0);
32
←
Use of zero-allocated memory
164
165 /* Chop off the final description string */
166 d = strrchr(description, ';');
167 if (!d)
168 return -EIO5;
169 *d = 0;
170
171 /* Look for the permissions */
172 p = strrchr(description, ';');
173 if (!p)
174 return -EIO5;
175
176 errno(*__errno_location ()) = 0;
177 perms = strtoul(p + 1, &e, 16);
178 if (errno(*__errno_location ()) > 0)
179 return -errno(*__errno_location ());
180 if (e == p + 1) /* Read at least one character */
181 return -EIO5;
182 if (e != d) /* Must reached the end */
183 return -EIO5;
184
185 if ((perms & ~MAX_PERMS((unsigned long) (0x01000000|0x02000000|0x08000000| 0x00010000
|0x00020000|0x00080000))) != 0)
186 return -EPERM1;
187
188 *p = 0;
189
190 /* Look for the group ID */
191 g = strrchr(description, ';');
192 if (!g)
193 return -EIO5;
194 r = parse_gid(g + 1, &gid);
195 if (r < 0)
196 return r;
197 if (gid != 0)
198 return -EPERM1;
199 *g = 0;
200
201 /* Look for the user ID */
202 u = strrchr(description, ';');
203 if (!u)
204 return -EIO5;
205 r = parse_uid(u + 1, &uid);
206 if (r < 0)
207 return r;
208 if (uid != 0)
209 return -EPERM1;
210
211 c = keyctlmissing_keyctl(KEYCTL_READ11, key, (unsigned long) ret, sizeof(sd_id128_t), 0);
212 if (c < 0)
213 return -errno(*__errno_location ());
214 if (c != sizeof(sd_id128_t))
215 return -EIO5;
216
217 return 1;
218}
219
220_public___attribute__ ((visibility("default"))) int sd_id128_get_invocation(sd_id128_t *ret) {
221 static thread_local__thread sd_id128_t saved_invocation_id = {};
222 int r;
223
224 assert_return(ret, -EINVAL)do { if (!(((__builtin_expect(!!(ret),1))) ? (1) : (log_assert_failed_return_realm
(LOG_REALM_SYSTEMD, ("ret"), "../src/libsystemd/sd-id128/sd-id128.c"
, 224, __PRETTY_FUNCTION__), 0))) return (-22); } while (0);
225
226 if (sd_id128_is_null(saved_invocation_id)) {
227
228 /* We first try to read the invocation ID from the kernel keyring. This has the benefit that it is not
229 * fakeable by unprivileged code. If the information is not available in the keyring, we use
230 * $INVOCATION_ID but ignore the data if our process was called by less privileged code
231 * (i.e. secure_getenv() instead of getenv()).
232 *
233 * The kernel keyring is only relevant for system services (as for user services we don't store the
234 * invocation ID in the keyring, as there'd be no trust benefit in that). The environment variable is
235 * primarily relevant for user services, and sufficiently safe as no privilege boundary is involved. */
236
237 r = get_invocation_from_keyring(&saved_invocation_id);
238 if (r < 0)
239 return r;
240
241 if (r == 0) {
242 const char *e;
243
244 e = secure_getenv("INVOCATION_ID");
245 if (!e)
246 return -ENXIO6;
247
248 r = sd_id128_from_string(e, &saved_invocation_id);
249 if (r < 0)
250 return r;
251 }
252 }
253
254 *ret = saved_invocation_id;
255 return 0;
256}
257
258static sd_id128_t make_v4_uuid(sd_id128_t id) {
259 /* Stolen from generate_random_uuid() of drivers/char/random.c
260 * in the kernel sources */
261
262 /* Set UUID version to 4 --- truly random generation */
263 id.bytes[6] = (id.bytes[6] & 0x0F) | 0x40;
264
265 /* Set the UUID variant to DCE */
266 id.bytes[8] = (id.bytes[8] & 0x3F) | 0x80;
267
268 return id;
269}
270
271_public___attribute__ ((visibility("default"))) int sd_id128_randomize(sd_id128_t *ret) {
272 sd_id128_t t;
273 int r;
274
275 assert_return(ret, -EINVAL)do { if (!(((__builtin_expect(!!(ret),1))) ? (1) : (log_assert_failed_return_realm
(LOG_REALM_SYSTEMD, ("ret"), "../src/libsystemd/sd-id128/sd-id128.c"
, 275, __PRETTY_FUNCTION__), 0))) return (-22); } while (0);
276
277 r = acquire_random_bytes(&t, sizeof t, true1);
278 if (r < 0)
279 return r;
280
281 /* Turn this into a valid v4 UUID, to be nice. Note that we
282 * only guarantee this for newly generated UUIDs, not for
283 * pre-existing ones. */
284
285 *ret = make_v4_uuid(t);
286 return 0;
287}
288
289_public___attribute__ ((visibility("default"))) int sd_id128_get_machine_app_specific(sd_id128_t app_id, sd_id128_t *ret) {
290 _cleanup_(khash_unrefp)__attribute__((cleanup(khash_unrefp))) khash *h = NULL((void*)0);
291 sd_id128_t m, result;
292 const void *p;
293 int r;
294
295 assert_return(ret, -EINVAL)do { if (!(((__builtin_expect(!!(ret),1))) ? (1) : (log_assert_failed_return_realm
(LOG_REALM_SYSTEMD, ("ret"), "../src/libsystemd/sd-id128/sd-id128.c"
, 295, __PRETTY_FUNCTION__), 0))) return (-22); } while (0);
296
297 r = sd_id128_get_machine(&m);
298 if (r < 0)
299 return r;
300
301 r = khash_new_with_key(&h, "hmac(sha256)", &m, sizeof(m));
302 if (r < 0)
303 return r;
304
305 r = khash_put(h, &app_id, sizeof(app_id));
306 if (r < 0)
307 return r;
308
309 r = khash_digest_data(h, &p);
310 if (r < 0)
311 return r;
312
313 /* We chop off the trailing 16 bytes */
314 memcpy(&result, p, MIN(khash_get_size(h), sizeof(result))__extension__ ({ const typeof((khash_get_size(h))) __unique_prefix_A6
= ((khash_get_size(h))); const typeof((sizeof(result))) __unique_prefix_B7
= ((sizeof(result))); __unique_prefix_A6 < __unique_prefix_B7
? __unique_prefix_A6 : __unique_prefix_B7; }));
315
316 *ret = make_v4_uuid(result);
317 return 0;
318}
←

../src/basic/alloc-util.h

1/* SPDX-License-Identifier: LGPL-2.1+ */
2#pragma once
3
4#include <alloca.h>
5#include <stddef.h>
6#include <stdlib.h>
7#include <string.h>
8
9#include "macro.h"
10
11#define new(t, n)((t*) malloc_multiply(sizeof(t), (n))) ((t*) malloc_multiply(sizeof(t), (n)))
12
13#define new0(t, n)((t*) calloc((n), sizeof(t))) ((t*) calloc((n), sizeof(t)))
14
15#define newa(t, n)({ do { if ((__builtin_expect(!!(!(!size_multiply_overflow(sizeof
(t), n))),0))) log_assert_failed_realm(LOG_REALM_SYSTEMD, ("!size_multiply_overflow(sizeof(t), n)"
), "../src/basic/alloc-util.h", 15, __PRETTY_FUNCTION__); } while
(0); (t*) __builtin_alloca (sizeof(t)*(n)); }) \
16 ({ \
17 assert(!size_multiply_overflow(sizeof(t), n))do { if ((__builtin_expect(!!(!(!size_multiply_overflow(sizeof
(t), n))),0))) log_assert_failed_realm(LOG_REALM_SYSTEMD, ("!size_multiply_overflow(sizeof(t), n)"
), "../src/basic/alloc-util.h", 17, __PRETTY_FUNCTION__); } while
(0); \
18 (t*) alloca(sizeof(t)*(n))__builtin_alloca (sizeof(t)*(n)); \
19 })
20
21#define newa0(t, n)({ do { if ((__builtin_expect(!!(!(!size_multiply_overflow(sizeof
(t), n))),0))) log_assert_failed_realm(LOG_REALM_SYSTEMD, ("!size_multiply_overflow(sizeof(t), n)"
), "../src/basic/alloc-util.h", 21, __PRETTY_FUNCTION__); } while
(0); (t*) ({ char *_new_; size_t _len_ = sizeof(t)*(n); _new_
= __builtin_alloca (_len_); (void *) memset(_new_, 0, _len_)
; }); }) \
22 ({ \
23 assert(!size_multiply_overflow(sizeof(t), n))do { if ((__builtin_expect(!!(!(!size_multiply_overflow(sizeof
(t), n))),0))) log_assert_failed_realm(LOG_REALM_SYSTEMD, ("!size_multiply_overflow(sizeof(t), n)"
), "../src/basic/alloc-util.h", 23, __PRETTY_FUNCTION__); } while
(0); \
24 (t*) alloca0(sizeof(t)*(n))({ char *_new_; size_t _len_ = sizeof(t)*(n); _new_ = __builtin_alloca
(_len_); (void *) memset(_new_, 0, _len_); }); \
25 })
26
27#define newdup(t, p, n)((t*) memdup_multiply(p, sizeof(t), (n))) ((t*) memdup_multiply(p, sizeof(t), (n)))
28
29#define newdup_suffix0(t, p, n)((t*) memdup_suffix0_multiply(p, sizeof(t), (n))) ((t*) memdup_suffix0_multiply(p, sizeof(t), (n)))
30
31#define malloc0(n)(calloc(1, (n))) (calloc(1, (n)))
32
33static inline void *mfree(void *memory) {
34 free(memory);
35 return NULL((void*)0);
36}
37
38#define free_and_replace(a, b)({ free(a); (a) = (b); (b) = ((void*)0); 0; }) \
39 ({ \
40 free(a); \
41 (a) = (b); \
42 (b) = NULL((void*)0); \
43 0; \
44 })
45
46void* memdup(const void *p, size_t l) _alloc_(2);
47void* memdup_suffix0(const void *p, size_t l) _alloc_(2);
48
49static inline void freep(void *p) {
50 free(*(void**) p);
51}
52
53#define _cleanup_free___attribute__((cleanup(freep))) _cleanup_(freep)__attribute__((cleanup(freep)))
54
55static inline bool_Bool size_multiply_overflow(size_t size, size_t need) {
56 return _unlikely_(need != 0 && size > (SIZE_MAX / need))(__builtin_expect(!!(need != 0 && size > ((18446744073709551615UL
) / need)),0));
57}
58
59_malloc___attribute__ ((malloc)) _alloc_(1, 2) static inline void *malloc_multiply(size_t size, size_t need) {
60 if (size_multiply_overflow(size, need))
22
←
Taking false branch
→
61 return NULL((void*)0);
62
63 return malloc(size * need);
23
←
Memory is allocated
→
64}
65
66#if !HAVE_REALLOCARRAY1
67_alloc_(2, 3) static inline void *reallocarray(void *p, size_t need, size_t size) {
68 if (size_multiply_overflow(size, need))
69 return NULL((void*)0);
70
71 return realloc(p, size * need);
72}
73#endif
74
75_alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t size, size_t need) {
76 if (size_multiply_overflow(size, need))
77 return NULL((void*)0);
78
79 return memdup(p, size * need);
80}
81
82_alloc_(2, 3) static inline void *memdup_suffix0_multiply(const void *p, size_t size, size_t need) {
83 if (size_multiply_overflow(size, need))
84 return NULL((void*)0);
85
86 return memdup_suffix0(p, size * need);
87}
88
89void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size);
90void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
91
92#define GREEDY_REALLOC(array, allocated, need)greedy_realloc((void**) &(array), &(allocated), (need
), sizeof((array)[0])) \
93 greedy_realloc((void**) &(array), &(allocated), (need), sizeof((array)[0]))
94
95#define GREEDY_REALLOC0(array, allocated, need)greedy_realloc0((void**) &(array), &(allocated), (need
), sizeof((array)[0])) \
96 greedy_realloc0((void**) &(array), &(allocated), (need), sizeof((array)[0]))
97
98#define alloca0(n)({ char *_new_; size_t _len_ = n; _new_ = __builtin_alloca (_len_
); (void *) memset(_new_, 0, _len_); }) \
99 ({ \
100 char *_new_; \
101 size_t _len_ = n; \
102 _new_ = alloca(_len_)__builtin_alloca (_len_); \
103 (void *) memset(_new_, 0, _len_); \
104 })
105
106/* It's not clear what alignment glibc/gcc alloca() guarantee, hence provide a guaranteed safe version */
107#define alloca_align(size, align)({ void *_ptr_; size_t _mask_ = (align) - 1; _ptr_ = __builtin_alloca
((size) + _mask_); (void*)(((uintptr_t)_ptr_ + _mask_) &
~_mask_); }) \
108 ({ \
109 void *_ptr_; \
110 size_t _mask_ = (align) - 1; \
111 _ptr_ = alloca((size) + _mask_)__builtin_alloca ((size) + _mask_); \
112 (void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_); \
113 })
114
115#define alloca0_align(size, align)({ void *_new_; size_t _size_ = (size); _new_ = ({ void *_ptr_
; size_t _mask_ = ((align)) - 1; _ptr_ = __builtin_alloca ((_size_
) + _mask_); (void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_
); }); (void*)memset(_new_, 0, _size_); }) \
116 ({ \
117 void *_new_; \
118 size_t _size_ = (size); \
119 _new_ = alloca_align(_size_, (align))({ void *_ptr_; size_t _mask_ = ((align)) - 1; _ptr_ = __builtin_alloca
((_size_) + _mask_); (void*)(((uintptr_t)_ptr_ + _mask_) &
~_mask_); }); \
120 (void*)memset(_new_, 0, _size_); \
121 })
122
123/* Takes inspiration from Rusts's Option::take() method: reads and returns a pointer, but at the same time resets it to
124 * NULL. See: https://doc.rust-lang.org/std/option/enum.Option.html#method.take */
125#define TAKE_PTR(ptr)({ typeof(ptr) _ptr_ = (ptr); (ptr) = ((void*)0); _ptr_; }) \
126 ({ \
127 typeof(ptr) _ptr_ = (ptr); \
128 (ptr) = NULL((void*)0); \
129 _ptr_; \
130 })