1 /*
2  * Copyright (C) 2013 The Android Open Source Project
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  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 // This file perpetuates the mistakes of the past.
30 
31 #include <ctype.h>
32 #include <dirent.h>
33 #include <errno.h>
34 #include <inttypes.h>
35 #include <pthread.h>
36 #include <signal.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <sys/resource.h>
41 #include <sys/syscall.h>
42 #include <sys/time.h>
43 #include <sys/types.h>
44 #include <sys/wait.h>
45 #include <unistd.h>
46 #include <wchar.h>
47 
48 #include "private/bionic_macros.h"
49 #include "private/libc_logging.h"
50 
51 extern "C" {
52 
53 // LP64 doesn't need to support any legacy cruft.
54 #if !defined(__LP64__)
55 
56 // These were accidentally declared in <unistd.h> because we stupidly used to inline
57 // getpagesize() and __getpageshift(). Needed for backwards compatibility with old NDK apps.
58 unsigned int __page_size = PAGE_SIZE;
59 unsigned int __page_shift = 12;
60 
61 // TODO: remove this backward compatibility hack (for jb-mr1 strace binaries).
__wait4(pid_t pid,int * status,int options,struct rusage * rusage)62 pid_t __wait4(pid_t pid, int* status, int options, struct rusage* rusage) {
63   return wait4(pid, status, options, rusage);
64 }
65 
66 // TODO: does anything still need this?
__open()67 int __open() {
68   abort();
69 }
70 
71 // TODO: does anything still need this?
__get_tls()72 void** __get_tls() {
73 #include "private/__get_tls.h"
74   return __get_tls();
75 }
76 
77 // This non-standard function was in our <string.h> for some reason.
memswap(void * m1,void * m2,size_t n)78 void memswap(void* m1, void* m2, size_t n) {
79   char* p = reinterpret_cast<char*>(m1);
80   char* p_end = p + n;
81   char* q = reinterpret_cast<char*>(m2);
82   while (p < p_end) {
83     char tmp = *p;
84     *p = *q;
85     *q = tmp;
86     p++;
87     q++;
88   }
89 }
90 
pthread_attr_setstackaddr(pthread_attr_t *,void *)91 int pthread_attr_setstackaddr(pthread_attr_t*, void*) {
92   // This was removed from POSIX.1-2008, and is not implemented on bionic.
93   // Needed for ABI compatibility with the NDK.
94   return ENOSYS;
95 }
96 
pthread_attr_getstackaddr(const pthread_attr_t * attr,void ** stack_addr)97 int pthread_attr_getstackaddr(const pthread_attr_t* attr, void** stack_addr) {
98   // This was removed from POSIX.1-2008.
99   // Needed for ABI compatibility with the NDK.
100   *stack_addr = (char*)attr->stack_base + attr->stack_size;
101   return 0;
102 }
103 
104 // Non-standard cruft that should only ever have been in system/core/toolbox.
strtotimeval(const char * str,struct timeval * ts)105 char* strtotimeval(const char* str, struct timeval* ts) {
106   char* s;
107   ts->tv_sec = strtoumax(str, &s, 10);
108 
109   long fractional_seconds = 0;
110   if (*s == '.') {
111     s++;
112     int count = 0;
113 
114     // Read up to 6 digits (microseconds).
115     while (*s && isdigit(*s)) {
116       if (++count < 7) {
117         fractional_seconds = fractional_seconds*10 + (*s - '0');
118       }
119       s++;
120     }
121 
122     for (; count < 6; count++) {
123       fractional_seconds *= 10;
124     }
125   }
126 
127   ts->tv_usec = fractional_seconds;
128   return s;
129 }
130 
digitval(int ch)131 static inline int digitval(int ch) {
132   unsigned d;
133 
134   d = (unsigned)(ch - '0');
135   if (d < 10) return (int)d;
136 
137   d = (unsigned)(ch - 'a');
138   if (d < 6) return (int)(d+10);
139 
140   d = (unsigned)(ch - 'A');
141   if (d < 6) return (int)(d+10);
142 
143   return -1;
144 }
145 
146 // This non-standard function was in our <inttypes.h> for some reason.
strntoumax(const char * nptr,char ** endptr,int base,size_t n)147 uintmax_t strntoumax(const char *nptr, char **endptr, int base, size_t n) {
148   const unsigned char*  p   = (const unsigned char *)nptr;
149   const unsigned char*  end = p + n;
150   int                   minus = 0;
151   uintmax_t             v = 0;
152   int                   d;
153 
154   while (p < end && isspace(*p)) {
155     p++;
156   }
157 
158   if (p < end) {
159     char c = p[0];
160     if (c == '-' || c == '+') {
161       minus = (c == '-');
162       p++;
163     }
164   }
165 
166   if (base == 0) {
167     if (p+2 < end && p[0] == '0' && (p[1] == 'x' || p[1] == 'X')) {
168       p += 2;
169       base = 16;
170     } else if (p+1 < end && p[0] == '0') {
171       p   += 1;
172       base = 8;
173     } else {
174       base = 10;
175     }
176   } else if (base == 16) {
177     if (p+2 < end && p[0] == '0' && (p[1] == 'x' || p[1] == 'X')) {
178       p += 2;
179     }
180   }
181 
182   while (p < end && (d = digitval(*p)) >= 0 && d < base) {
183     v = v*base + d;
184     p += 1;
185   }
186 
187   if (endptr) {
188     *endptr = (char*) p;
189   }
190 
191   return minus ? -v : v;
192 }
193 
194 // This non-standard function was in our <inttypes.h> for some reason.
strntoimax(const char * nptr,char ** endptr,int base,size_t n)195 intmax_t strntoimax(const char* nptr, char** endptr, int base, size_t n) {
196   return (intmax_t) strntoumax(nptr, endptr, base, n);
197 }
198 
199 // POSIX calls this dprintf, but LP32 Android had fdprintf instead.
fdprintf(int fd,const char * fmt,...)200 int fdprintf(int fd, const char* fmt, ...) {
201   va_list ap;
202   va_start(ap, fmt);
203   int rc = vdprintf(fd, fmt, ap);
204   va_end(ap);
205   return rc;
206 }
207 
208 // POSIX calls this vdprintf, but LP32 Android had fdprintf instead.
vfdprintf(int fd,const char * fmt,va_list ap)209 int vfdprintf(int fd, const char* fmt, va_list ap) {
210   return vdprintf(fd, fmt, ap);
211 }
212 
213 #define __futex_wake __real_futex_wake
214 #define __futex_wait __real_futex_wait
215 #include "private/bionic_futex.h"
216 #undef __futex_wake
217 #undef __futex_wait
218 
219 // This used to be in <sys/atomics.h>.
__futex_wake(volatile void * ftx,int count)220 int __futex_wake(volatile void* ftx, int count) {
221   return __real_futex_wake(ftx, count);
222 }
223 
224 // This used to be in <sys/atomics.h>.
__futex_wait(volatile void * ftx,int value,const struct timespec * timeout)225 int __futex_wait(volatile void* ftx, int value, const struct timespec* timeout) {
226   return __real_futex_wait(ftx, value, timeout);
227 }
228 
229 // Unity's libmono uses this.
tkill(pid_t tid,int sig)230 int tkill(pid_t tid, int sig) {
231   return syscall(__NR_tkill, tid, sig);
232 }
233 
234 // This was removed from POSIX 2008.
wcswcs(wchar_t * haystack,wchar_t * needle)235 wchar_t* wcswcs(wchar_t* haystack, wchar_t* needle) {
236   return wcsstr(haystack, needle);
237 }
238 
239 // This was removed from POSIX 2008.
bsd_signal(int signum,sighandler_t handler)240 sighandler_t bsd_signal(int signum, sighandler_t handler) {
241   return signal(signum, handler);
242 }
243 
244 // This was removed from POSIX 2008.
245 #undef bcopy
bcopy(const void * src,void * dst,size_t n)246 void bcopy(const void* src, void* dst, size_t n) {
247   memmove(dst, src, n);
248 }
249 
250 // This was removed from POSIX 2008.
251 #undef bzero
bzero(void * dst,size_t n)252 void bzero(void* dst, size_t n) {
253   memset(dst, 0, n);
254 }
255 
256 // sysv_signal() was never in POSIX.
257 extern "C++" sighandler_t _signal(int signum, sighandler_t handler, int flags);
sysv_signal(int signum,sighandler_t handler)258 sighandler_t sysv_signal(int signum, sighandler_t handler) {
259   return _signal(signum, handler, SA_RESETHAND);
260 }
261 
262 // This is a system call that was never in POSIX. Use readdir(3) instead.
263 int __getdents64(unsigned int, dirent*, unsigned int);
getdents(unsigned int fd,dirent * dirp,unsigned int count)264 int getdents(unsigned int fd, dirent* dirp, unsigned int count) {
265   return __getdents64(fd, dirp, count);
266 }
267 
268 // This is a BSDism that we never implemented correctly. Used by Firefox.
issetugid()269 int issetugid() {
270   return 0;
271 }
272 
273 // This was removed from POSIX 2004.
wait3(int * status,int options,struct rusage * rusage)274 pid_t wait3(int* status, int options, struct rusage* rusage) {
275   return wait4(-1, status, options, rusage);
276 }
277 
278 // This was removed from POSIX 2004.
getdtablesize()279 int getdtablesize() {
280   struct rlimit r;
281 
282   if (getrlimit(RLIMIT_NOFILE, &r) < 0) {
283     return sysconf(_SC_OPEN_MAX);
284   }
285 
286   return r.rlim_cur;
287 }
288 
289 // A leaked BSD stdio implementation detail that's now a no-op.
__sinit()290 void __sinit() {}
291 int __sdidinit = 1;
292 
293 // Only used by ftime, which was removed from POSIX 2008.
294 struct timeb {
295   time_t          time;
296   unsigned short  millitm;
297   short           timezone;
298   short           dstflag;
299 };
300 
301 // This was removed from POSIX 2008.
ftime(struct timeb * tb)302 int ftime(struct timeb* tb) {
303   struct timeval  tv;
304   struct timezone tz;
305 
306   if (gettimeofday(&tv, &tz) < 0)
307     return -1;
308 
309   tb->time    = tv.tv_sec;
310   tb->millitm = (tv.tv_usec + 500) / 1000;
311 
312   if (tb->millitm == 1000) {
313     ++tb->time;
314     tb->millitm = 0;
315   }
316 
317   tb->timezone = tz.tz_minuteswest;
318   tb->dstflag  = tz.tz_dsttime;
319 
320   return 0;
321 }
322 
323 // This was removed from POSIX 2008.
index(const char * str,int ch)324 char* index(const char* str, int ch) {
325   return strchr(str, ch);
326 }
327 
328 // This was removed from BSD.
arc4random_stir(void)329 void arc4random_stir(void) {
330   // The current implementation stirs itself as needed.
331 }
332 
333 // This was removed from BSD.
arc4random_addrandom(unsigned char *,int)334 void arc4random_addrandom(unsigned char*, int) {
335   // The current implementation adds randomness as needed.
336 }
337 
338 // Old versions of the NDK did not export malloc_usable_size, but did
339 // export dlmalloc_usable_size. We are moving away from dlmalloc in L
340 // so make this call malloc_usable_size.
dlmalloc_usable_size(void * ptr)341 size_t dlmalloc_usable_size(void* ptr) {
342   return malloc_usable_size(ptr);
343 }
344 
345 // In L we added a public pthread_gettid_np, but some apps were using the private API.
__pthread_gettid(pthread_t t)346 pid_t __pthread_gettid(pthread_t t) {
347   return pthread_gettid_np(t);
348 }
349 
350 // Older versions of apportable used dlmalloc directly instead of malloc,
351 // so export this compatibility shim that simply calls malloc.
dlmalloc(size_t size)352 void* dlmalloc(size_t size) {
353   return malloc(size);
354 }
355 
356 #define __get_thread __real_get_thread
357 #include "pthread_internal.h"
358 #undef __get_thread
359 // Various third-party apps contain a backport of our pthread_rwlock implementation that uses this.
__get_thread()360 pthread_internal_t* __get_thread() {
361   return __real_get_thread();
362 }
363 
364 // This one exists only for the LP32 NDK and is not present anywhere else.
365 extern long __set_errno_internal(int);
__set_errno(int n)366 long __set_errno(int n) {
367   return __set_errno_internal(n);
368 }
369 
370 // Since dlmalloc_inspect_all and dlmalloc_trim are exported for systems
371 // that use dlmalloc, be consistent and export them everywhere.
dlmalloc_inspect_all(void (*)(void *,void *,size_t,void *),void *)372 void dlmalloc_inspect_all(void (*)(void*, void*, size_t, void*), void*) {
373 }
dlmalloc_trim(size_t)374 int dlmalloc_trim(size_t) {
375     return 0;
376 }
377 
378 // LP32's <stdio.h> had putw (but not getw).
putw(int value,FILE * fp)379 int putw(int value, FILE* fp) {
380     return fwrite(&value, sizeof(value), 1, fp) == 1 ? 0 : EOF;
381 }
382 
383 #endif // !defined (__LP64__)
384 
385 } // extern "C"
386