tree-diff: catch integer overflow in combine_diff_path allocation
[git/git.git] / wrapper.c
CommitLineData
112db553
LT
1/*
2 * Various trivial helper wrappers around standard functions
3 */
4#include "cache.h"
5
e0500293 6static void do_nothing(size_t size)
a9a74636 7{
a9a74636
NP
8}
9
e0500293 10static void (*try_to_free_routine)(size_t size) = do_nothing;
a9a74636 11
f8bb1d94 12static int memory_limit_check(size_t size, int gentle)
d41489a6 13{
9927d962
SP
14 static size_t limit = 0;
15 if (!limit) {
16 limit = git_env_ulong("GIT_ALLOC_LIMIT", 0);
17 if (!limit)
18 limit = SIZE_MAX;
d41489a6 19 }
f0d89001 20 if (size > limit) {
f8bb1d94 21 if (gentle) {
f0d89001
JH
22 error("attempting to allocate %"PRIuMAX" over limit %"PRIuMAX,
23 (uintmax_t)size, (uintmax_t)limit);
f8bb1d94
NTND
24 return -1;
25 } else
f0d89001
JH
26 die("attempting to allocate %"PRIuMAX" over limit %"PRIuMAX,
27 (uintmax_t)size, (uintmax_t)limit);
f8bb1d94
NTND
28 }
29 return 0;
d41489a6
NTND
30}
31
851c34b0 32try_to_free_t set_try_to_free_routine(try_to_free_t routine)
a9a74636 33{
851c34b0 34 try_to_free_t old = try_to_free_routine;
00b0d7f7
JH
35 if (!routine)
36 routine = do_nothing;
851c34b0
JS
37 try_to_free_routine = routine;
38 return old;
a9a74636
NP
39}
40
112db553
LT
41char *xstrdup(const char *str)
42{
43 char *ret = strdup(str);
44 if (!ret) {
a9a74636 45 try_to_free_routine(strlen(str) + 1);
112db553
LT
46 ret = strdup(str);
47 if (!ret)
48 die("Out of memory, strdup failed");
49 }
50 return ret;
51}
52
f8bb1d94 53static void *do_xmalloc(size_t size, int gentle)
112db553 54{
d41489a6
NTND
55 void *ret;
56
f8bb1d94
NTND
57 if (memory_limit_check(size, gentle))
58 return NULL;
d41489a6 59 ret = malloc(size);
112db553
LT
60 if (!ret && !size)
61 ret = malloc(1);
62 if (!ret) {
a9a74636 63 try_to_free_routine(size);
112db553
LT
64 ret = malloc(size);
65 if (!ret && !size)
66 ret = malloc(1);
f8bb1d94
NTND
67 if (!ret) {
68 if (!gentle)
69 die("Out of memory, malloc failed (tried to allocate %lu bytes)",
70 (unsigned long)size);
71 else {
72 error("Out of memory, malloc failed (tried to allocate %lu bytes)",
73 (unsigned long)size);
74 return NULL;
75 }
76 }
112db553
LT
77 }
78#ifdef XMALLOC_POISON
79 memset(ret, 0xA5, size);
80#endif
81 return ret;
82}
83
f8bb1d94
NTND
84void *xmalloc(size_t size)
85{
86 return do_xmalloc(size, 0);
87}
88
89static void *do_xmallocz(size_t size, int gentle)
5bf9219d
IL
90{
91 void *ret;
f8bb1d94
NTND
92 if (unsigned_add_overflows(size, 1)) {
93 if (gentle) {
94 error("Data too large to fit into virtual memory space.");
95 return NULL;
96 } else
97 die("Data too large to fit into virtual memory space.");
98 }
99 ret = do_xmalloc(size + 1, gentle);
100 if (ret)
101 ((char*)ret)[size] = 0;
5bf9219d
IL
102 return ret;
103}
104
f8bb1d94
NTND
105void *xmallocz(size_t size)
106{
107 return do_xmallocz(size, 0);
108}
109
110void *xmallocz_gently(size_t size)
111{
112 return do_xmallocz(size, 1);
113}
114
112db553
LT
115/*
116 * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
117 * "data" to the allocated memory, zero terminates the allocated memory,
118 * and returns a pointer to the allocated memory. If the allocation fails,
119 * the program dies.
120 */
121void *xmemdupz(const void *data, size_t len)
122{
5bf9219d 123 return memcpy(xmallocz(len), data, len);
112db553
LT
124}
125
126char *xstrndup(const char *str, size_t len)
127{
128 char *p = memchr(str, '\0', len);
129 return xmemdupz(str, p ? p - str : len);
130}
131
132void *xrealloc(void *ptr, size_t size)
133{
d41489a6
NTND
134 void *ret;
135
f8bb1d94 136 memory_limit_check(size, 0);
d41489a6 137 ret = realloc(ptr, size);
112db553
LT
138 if (!ret && !size)
139 ret = realloc(ptr, 1);
140 if (!ret) {
a9a74636 141 try_to_free_routine(size);
112db553
LT
142 ret = realloc(ptr, size);
143 if (!ret && !size)
144 ret = realloc(ptr, 1);
145 if (!ret)
146 die("Out of memory, realloc failed");
147 }
148 return ret;
149}
150
151void *xcalloc(size_t nmemb, size_t size)
152{
d41489a6
NTND
153 void *ret;
154
f8bb1d94 155 memory_limit_check(size * nmemb, 0);
d41489a6 156 ret = calloc(nmemb, size);
112db553
LT
157 if (!ret && (!nmemb || !size))
158 ret = calloc(1, 1);
159 if (!ret) {
a9a74636 160 try_to_free_routine(nmemb * size);
112db553
LT
161 ret = calloc(nmemb, size);
162 if (!ret && (!nmemb || !size))
163 ret = calloc(1, 1);
164 if (!ret)
165 die("Out of memory, calloc failed");
166 }
167 return ret;
168}
169
0b6806b9
SP
170/*
171 * Limit size of IO chunks, because huge chunks only cause pain. OS X
172 * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
382d20e3 173 * the absence of bugs, large chunks can result in bad latencies when
0b6806b9 174 * you decide to kill the process.
a983e6ac
JH
175 *
176 * We pick 8 MiB as our default, but if the platform defines SSIZE_MAX
177 * that is smaller than that, clip it to SSIZE_MAX, as a call to
178 * read(2) or write(2) larger than that is allowed to fail. As the last
179 * resort, we allow a port to pass via CFLAGS e.g. "-DMAX_IO_SIZE=value"
180 * to override this, if the definition of SSIZE_MAX given by the platform
181 * is broken.
0b6806b9 182 */
a983e6ac
JH
183#ifndef MAX_IO_SIZE
184# define MAX_IO_SIZE_DEFAULT (8*1024*1024)
185# if defined(SSIZE_MAX) && (SSIZE_MAX < MAX_IO_SIZE_DEFAULT)
186# define MAX_IO_SIZE SSIZE_MAX
187# else
188# define MAX_IO_SIZE MAX_IO_SIZE_DEFAULT
189# endif
190#endif
0b6806b9 191
3ff53df7
PT
192/**
193 * xopen() is the same as open(), but it die()s if the open() fails.
194 */
195int xopen(const char *path, int oflag, ...)
196{
197 mode_t mode = 0;
198 va_list ap;
199
200 /*
201 * va_arg() will have undefined behavior if the specified type is not
202 * compatible with the argument type. Since integers are promoted to
203 * ints, we fetch the next argument as an int, and then cast it to a
204 * mode_t to avoid undefined behavior.
205 */
206 va_start(ap, oflag);
207 if (oflag & O_CREAT)
208 mode = va_arg(ap, int);
209 va_end(ap);
210
211 for (;;) {
212 int fd = open(path, oflag, mode);
213 if (fd >= 0)
214 return fd;
215 if (errno == EINTR)
216 continue;
217
218 if ((oflag & O_RDWR) == O_RDWR)
219 die_errno(_("could not open '%s' for reading and writing"), path);
220 else if ((oflag & O_WRONLY) == O_WRONLY)
221 die_errno(_("could not open '%s' for writing"), path);
222 else
223 die_errno(_("could not open '%s' for reading"), path);
224 }
225}
226
112db553
LT
227/*
228 * xread() is the same a read(), but it automatically restarts read()
229 * operations with a recoverable error (EAGAIN and EINTR). xread()
230 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
231 */
232ssize_t xread(int fd, void *buf, size_t len)
233{
234 ssize_t nr;
0b6806b9
SP
235 if (len > MAX_IO_SIZE)
236 len = MAX_IO_SIZE;
112db553
LT
237 while (1) {
238 nr = read(fd, buf, len);
239 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
240 continue;
241 return nr;
242 }
243}
244
245/*
246 * xwrite() is the same a write(), but it automatically restarts write()
247 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
248 * GUARANTEE that "len" bytes is written even if the operation is successful.
249 */
250ssize_t xwrite(int fd, const void *buf, size_t len)
251{
252 ssize_t nr;
0b6806b9
SP
253 if (len > MAX_IO_SIZE)
254 len = MAX_IO_SIZE;
112db553
LT
255 while (1) {
256 nr = write(fd, buf, len);
257 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
9aa91af0
YM
258 continue;
259 return nr;
260 }
261}
262
263/*
264 * xpread() is the same as pread(), but it automatically restarts pread()
265 * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
266 * NOT GUARANTEE that "len" bytes is read even if the data is available.
267 */
268ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
269{
270 ssize_t nr;
271 if (len > MAX_IO_SIZE)
272 len = MAX_IO_SIZE;
273 while (1) {
274 nr = pread(fd, buf, len, offset);
275 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
112db553
LT
276 continue;
277 return nr;
278 }
279}
280
559e840b
JH
281ssize_t read_in_full(int fd, void *buf, size_t count)
282{
283 char *p = buf;
284 ssize_t total = 0;
285
286 while (count > 0) {
287 ssize_t loaded = xread(fd, p, count);
56d7c27a
JK
288 if (loaded < 0)
289 return -1;
290 if (loaded == 0)
291 return total;
559e840b
JH
292 count -= loaded;
293 p += loaded;
294 total += loaded;
295 }
296
297 return total;
298}
299
300ssize_t write_in_full(int fd, const void *buf, size_t count)
301{
302 const char *p = buf;
303 ssize_t total = 0;
304
305 while (count > 0) {
306 ssize_t written = xwrite(fd, p, count);
307 if (written < 0)
308 return -1;
309 if (!written) {
310 errno = ENOSPC;
311 return -1;
312 }
313 count -= written;
314 p += written;
315 total += written;
316 }
317
318 return total;
319}
320
426ddeea
YM
321ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
322{
323 char *p = buf;
324 ssize_t total = 0;
325
326 while (count > 0) {
327 ssize_t loaded = xpread(fd, p, count, offset);
328 if (loaded < 0)
329 return -1;
330 if (loaded == 0)
331 return total;
332 count -= loaded;
333 p += loaded;
334 total += loaded;
335 offset += loaded;
336 }
337
338 return total;
339}
340
112db553
LT
341int xdup(int fd)
342{
343 int ret = dup(fd);
344 if (ret < 0)
d824cbba 345 die_errno("dup failed");
112db553
LT
346 return ret;
347}
348
260eec29
PT
349/**
350 * xfopen() is the same as fopen(), but it die()s if the fopen() fails.
351 */
352FILE *xfopen(const char *path, const char *mode)
353{
354 for (;;) {
355 FILE *fp = fopen(path, mode);
356 if (fp)
357 return fp;
358 if (errno == EINTR)
359 continue;
360
361 if (*mode && mode[1] == '+')
362 die_errno(_("could not open '%s' for reading and writing"), path);
363 else if (*mode == 'w' || *mode == 'a')
364 die_errno(_("could not open '%s' for writing"), path);
365 else
366 die_errno(_("could not open '%s' for reading"), path);
367 }
368}
369
112db553
LT
370FILE *xfdopen(int fd, const char *mode)
371{
372 FILE *stream = fdopen(fd, mode);
373 if (stream == NULL)
d824cbba 374 die_errno("Out of memory? fdopen failed");
112db553
LT
375 return stream;
376}
377
79d7582e
JS
378FILE *fopen_for_writing(const char *path)
379{
380 FILE *ret = fopen(path, "w");
381
382 if (!ret && errno == EPERM) {
383 if (!unlink(path))
384 ret = fopen(path, "w");
385 else
386 errno = EPERM;
387 }
388 return ret;
389}
390
112db553
LT
391int xmkstemp(char *template)
392{
393 int fd;
6cf6bb3e
AE
394 char origtemplate[PATH_MAX];
395 strlcpy(origtemplate, template, sizeof(origtemplate));
112db553
LT
396
397 fd = mkstemp(template);
6cf6bb3e
AE
398 if (fd < 0) {
399 int saved_errno = errno;
400 const char *nonrelative_template;
401
f7be59b4 402 if (strlen(template) != strlen(origtemplate))
6cf6bb3e
AE
403 template = origtemplate;
404
e2a57aac 405 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
406 errno = saved_errno;
407 die_errno("Unable to create temporary file '%s'",
408 nonrelative_template);
409 }
112db553
LT
410 return fd;
411}
39c68542 412
33f23936
JN
413/* git_mkstemp() - create tmp file honoring TMPDIR variable */
414int git_mkstemp(char *path, size_t len, const char *template)
415{
416 const char *tmp;
417 size_t n;
418
419 tmp = getenv("TMPDIR");
420 if (!tmp)
421 tmp = "/tmp";
422 n = snprintf(path, len, "%s/%s", tmp, template);
423 if (len <= n) {
424 errno = ENAMETOOLONG;
425 return -1;
426 }
427 return mkstemp(path);
428}
429
430/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
431int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
432{
433 const char *tmp;
434 size_t n;
435
436 tmp = getenv("TMPDIR");
437 if (!tmp)
438 tmp = "/tmp";
439 n = snprintf(path, len, "%s/%s", tmp, template);
440 if (len <= n) {
441 errno = ENAMETOOLONG;
442 return -1;
443 }
444 return mkstemps(path, suffix_len);
445}
446
447/* Adapted from libiberty's mkstemp.c. */
448
449#undef TMP_MAX
450#define TMP_MAX 16384
451
452int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
453{
454 static const char letters[] =
455 "abcdefghijklmnopqrstuvwxyz"
456 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
457 "0123456789";
458 static const int num_letters = 62;
459 uint64_t value;
460 struct timeval tv;
461 char *template;
462 size_t len;
463 int fd, count;
464
465 len = strlen(pattern);
466
467 if (len < 6 + suffix_len) {
468 errno = EINVAL;
469 return -1;
470 }
471
472 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
473 errno = EINVAL;
474 return -1;
475 }
476
477 /*
478 * Replace pattern's XXXXXX characters with randomness.
479 * Try TMP_MAX different filenames.
480 */
481 gettimeofday(&tv, NULL);
482 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
483 template = &pattern[len - 6 - suffix_len];
484 for (count = 0; count < TMP_MAX; ++count) {
485 uint64_t v = value;
486 /* Fill in the random bits. */
487 template[0] = letters[v % num_letters]; v /= num_letters;
488 template[1] = letters[v % num_letters]; v /= num_letters;
489 template[2] = letters[v % num_letters]; v /= num_letters;
490 template[3] = letters[v % num_letters]; v /= num_letters;
491 template[4] = letters[v % num_letters]; v /= num_letters;
492 template[5] = letters[v % num_letters]; v /= num_letters;
493
494 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
a2cb86c1 495 if (fd >= 0)
33f23936
JN
496 return fd;
497 /*
498 * Fatal error (EPERM, ENOSPC etc).
499 * It doesn't make sense to loop.
500 */
501 if (errno != EEXIST)
502 break;
503 /*
504 * This is a random value. It is only necessary that
505 * the next TMP_MAX values generated by adding 7777 to
506 * VALUE are different with (module 2^32).
507 */
508 value += 7777;
509 }
510 /* We return the null string if we can't find a unique file name. */
511 pattern[0] = '\0';
512 return -1;
513}
514
515int git_mkstemp_mode(char *pattern, int mode)
516{
517 /* mkstemp is just mkstemps with no suffix */
518 return git_mkstemps_mode(pattern, 0, mode);
519}
520
ec145c9c 521#ifdef NO_MKSTEMPS
33f23936
JN
522int gitmkstemps(char *pattern, int suffix_len)
523{
524 return git_mkstemps_mode(pattern, suffix_len, 0600);
525}
ec145c9c 526#endif
33f23936 527
b862b61c
MM
528int xmkstemp_mode(char *template, int mode)
529{
530 int fd;
6cf6bb3e
AE
531 char origtemplate[PATH_MAX];
532 strlcpy(origtemplate, template, sizeof(origtemplate));
b862b61c
MM
533
534 fd = git_mkstemp_mode(template, mode);
6cf6bb3e
AE
535 if (fd < 0) {
536 int saved_errno = errno;
537 const char *nonrelative_template;
538
539 if (!template[0])
540 template = origtemplate;
541
e2a57aac 542 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
543 errno = saved_errno;
544 die_errno("Unable to create temporary file '%s'",
545 nonrelative_template);
546 }
b862b61c
MM
547 return fd;
548}
549
10e13ec8 550static int warn_if_unremovable(const char *op, const char *file, int rc)
fc71db39 551{
1054af7d
RS
552 int err;
553 if (!rc || errno == ENOENT)
554 return 0;
555 err = errno;
556 warning("unable to %s %s: %s", op, file, strerror(errno));
557 errno = err;
fc71db39
AR
558 return rc;
559}
560
9ccc0c08
RS
561int unlink_or_msg(const char *file, struct strbuf *err)
562{
563 int rc = unlink(file);
564
565 assert(err);
566
567 if (!rc || errno == ENOENT)
568 return 0;
569
570 strbuf_addf(err, "unable to unlink %s: %s",
571 file, strerror(errno));
572 return -1;
573}
574
10e13ec8
PC
575int unlink_or_warn(const char *file)
576{
577 return warn_if_unremovable("unlink", file, unlink(file));
578}
d1723296
PC
579
580int rmdir_or_warn(const char *file)
581{
582 return warn_if_unremovable("rmdir", file, rmdir(file));
583}
80d706af
PC
584
585int remove_or_warn(unsigned int mode, const char *file)
586{
587 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
588}
2f705875 589
55b38a48
JH
590void warn_on_inaccessible(const char *path)
591{
592 warning(_("unable to access '%s': %s"), path, strerror(errno));
593}
594
4698c8fe
JN
595static int access_error_is_ok(int err, unsigned flag)
596{
597 return err == ENOENT || err == ENOTDIR ||
598 ((flag & ACCESS_EACCES_OK) && err == EACCES);
599}
600
601int access_or_warn(const char *path, int mode, unsigned flag)
ba8bd830
JK
602{
603 int ret = access(path, mode);
4698c8fe 604 if (ret && !access_error_is_ok(errno, flag))
55b38a48 605 warn_on_inaccessible(path);
ba8bd830
JK
606 return ret;
607}
608
4698c8fe 609int access_or_die(const char *path, int mode, unsigned flag)
96b9e0e3
JN
610{
611 int ret = access(path, mode);
4698c8fe 612 if (ret && !access_error_is_ok(errno, flag))
96b9e0e3
JN
613 die_errno(_("unable to access '%s'"), path);
614 return ret;
615}
616
aa14e980
RS
617char *xgetcwd(void)
618{
619 struct strbuf sb = STRBUF_INIT;
620 if (strbuf_getcwd(&sb))
621 die_errno(_("unable to get current working directory"));
622 return strbuf_detach(&sb, NULL);
623}
316e53e6 624
7b03c89e
JK
625int xsnprintf(char *dst, size_t max, const char *fmt, ...)
626{
627 va_list ap;
628 int len;
629
630 va_start(ap, fmt);
631 len = vsnprintf(dst, max, fmt, ap);
632 va_end(ap);
633
634 if (len < 0)
635 die("BUG: your snprintf is broken");
636 if (len >= max)
637 die("BUG: attempt to snprintf into too-small buffer");
638 return len;
639}
640
12d6ce1d
JH
641static int write_file_v(const char *path, int fatal,
642 const char *fmt, va_list params)
316e53e6
NTND
643{
644 struct strbuf sb = STRBUF_INIT;
316e53e6
NTND
645 int fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 0666);
646 if (fd < 0) {
647 if (fatal)
648 die_errno(_("could not open %s for writing"), path);
649 return -1;
650 }
316e53e6 651 strbuf_vaddf(&sb, fmt, params);
e7ffa38c 652 strbuf_complete_line(&sb);
316e53e6
NTND
653 if (write_in_full(fd, sb.buf, sb.len) != sb.len) {
654 int err = errno;
655 close(fd);
656 strbuf_release(&sb);
657 errno = err;
658 if (fatal)
659 die_errno(_("could not write to %s"), path);
660 return -1;
661 }
662 strbuf_release(&sb);
663 if (close(fd)) {
664 if (fatal)
665 die_errno(_("could not close %s"), path);
666 return -1;
667 }
668 return 0;
669}
2024d317 670
12d6ce1d
JH
671int write_file(const char *path, const char *fmt, ...)
672{
673 int status;
674 va_list params;
675
676 va_start(params, fmt);
677 status = write_file_v(path, 1, fmt, params);
678 va_end(params);
679 return status;
680}
681
682int write_file_gently(const char *path, const char *fmt, ...)
683{
684 int status;
685 va_list params;
686
687 va_start(params, fmt);
688 status = write_file_v(path, 0, fmt, params);
689 va_end(params);
690 return status;
691}
692
2024d317
JS
693void sleep_millisec(int millisec)
694{
695 poll(NULL, 0, millisec);
696}