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/libc_logging.h"
49 
50 extern "C" {
51 
52 // Brillo and LP64 don't need to support any legacy cruft.
53 #if !defined(__BRILLO__) && !defined(__LP64__)
54 
55 // These were accidentally declared in <unistd.h> because we stupidly used to inline
56 // getpagesize() and __getpageshift(). Needed for backwards compatibility with old NDK apps.
57 unsigned int __page_size = PAGE_SIZE;
58 unsigned int __page_shift = 12;
59 
60 // TODO: remove this backward compatibility hack (for jb-mr1 strace binaries).
__wait4(pid_t pid,int * status,int options,struct rusage * rusage)61 pid_t __wait4(pid_t pid, int* status, int options, struct rusage* rusage) {
62   return wait4(pid, status, options, rusage);
63 }
64 
65 // TODO: does anything still need this?
__open()66 int __open() {
67   abort();
68 }
69 
70 // TODO: does anything still need this?
__get_tls()71 void** __get_tls() {
72 #include "private/__get_tls.h"
73   return __get_tls();
74 }
75 
76 // This non-standard function was in our <string.h> for some reason.
memswap(void * m1,void * m2,size_t n)77 void memswap(void* m1, void* m2, size_t n) {
78   char* p = reinterpret_cast<char*>(m1);
79   char* p_end = p + n;
80   char* q = reinterpret_cast<char*>(m2);
81   while (p < p_end) {
82     char tmp = *p;
83     *p = *q;
84     *q = tmp;
85     p++;
86     q++;
87   }
88 }
89 
pthread_attr_setstackaddr(pthread_attr_t *,void *)90 int pthread_attr_setstackaddr(pthread_attr_t*, void*) {
91   // This was removed from POSIX.1-2008, and is not implemented on bionic.
92   // Needed for ABI compatibility with the NDK.
93   return ENOSYS;
94 }
95 
pthread_attr_getstackaddr(const pthread_attr_t * attr,void ** stack_addr)96 int pthread_attr_getstackaddr(const pthread_attr_t* attr, void** stack_addr) {
97   // This was removed from POSIX.1-2008.
98   // Needed for ABI compatibility with the NDK.
99   *stack_addr = (char*)attr->stack_base + attr->stack_size;
100   return 0;
101 }
102 
103 // Non-standard cruft that should only ever have been in system/core/toolbox.
strtotimeval(const char * str,struct timeval * ts)104 char* strtotimeval(const char* str, struct timeval* ts) {
105   char* s;
106   ts->tv_sec = strtoumax(str, &s, 10);
107 
108   long fractional_seconds = 0;
109   if (*s == '.') {
110     s++;
111     int count = 0;
112 
113     // Read up to 6 digits (microseconds).
114     while (*s && isdigit(*s)) {
115       if (++count < 7) {
116         fractional_seconds = fractional_seconds*10 + (*s - '0');
117       }
118       s++;
119     }
120 
121     for (; count < 6; count++) {
122       fractional_seconds *= 10;
123     }
124   }
125 
126   ts->tv_usec = fractional_seconds;
127   return s;
128 }
129 
digitval(int ch)130 static inline int digitval(int ch) {
131   unsigned d;
132 
133   d = (unsigned)(ch - '0');
134   if (d < 10) return (int)d;
135 
136   d = (unsigned)(ch - 'a');
137   if (d < 6) return (int)(d+10);
138 
139   d = (unsigned)(ch - 'A');
140   if (d < 6) return (int)(d+10);
141 
142   return -1;
143 }
144 
145 // This non-standard function was in our <inttypes.h> for some reason.
strntoumax(const char * nptr,char ** endptr,int base,size_t n)146 uintmax_t strntoumax(const char *nptr, char **endptr, int base, size_t n) {
147   const unsigned char*  p   = (const unsigned char *)nptr;
148   const unsigned char*  end = p + n;
149   int                   minus = 0;
150   uintmax_t             v = 0;
151   int                   d;
152 
153   while (p < end && isspace(*p)) {
154     p++;
155   }
156 
157   if (p < end) {
158     char c = p[0];
159     if (c == '-' || c == '+') {
160       minus = (c == '-');
161       p++;
162     }
163   }
164 
165   if (base == 0) {
166     if (p+2 < end && p[0] == '0' && (p[1] == 'x' || p[1] == 'X')) {
167       p += 2;
168       base = 16;
169     } else if (p+1 < end && p[0] == '0') {
170       p   += 1;
171       base = 8;
172     } else {
173       base = 10;
174     }
175   } else if (base == 16) {
176     if (p+2 < end && p[0] == '0' && (p[1] == 'x' || p[1] == 'X')) {
177       p += 2;
178     }
179   }
180 
181   while (p < end && (d = digitval(*p)) >= 0 && d < base) {
182     v = v*base + d;
183     p += 1;
184   }
185 
186   if (endptr) {
187     *endptr = (char*) p;
188   }
189 
190   return minus ? -v : v;
191 }
192 
193 // This non-standard function was in our <inttypes.h> for some reason.
strntoimax(const char * nptr,char ** endptr,int base,size_t n)194 intmax_t strntoimax(const char* nptr, char** endptr, int base, size_t n) {
195   return (intmax_t) strntoumax(nptr, endptr, base, n);
196 }
197 
198 // POSIX calls this dprintf, but LP32 Android had fdprintf instead.
fdprintf(int fd,const char * fmt,...)199 int fdprintf(int fd, const char* fmt, ...) {
200   va_list ap;
201   va_start(ap, fmt);
202   int rc = vdprintf(fd, fmt, ap);
203   va_end(ap);
204   return rc;
205 }
206 
207 // POSIX calls this vdprintf, but LP32 Android had fdprintf instead.
vfdprintf(int fd,const char * fmt,va_list ap)208 int vfdprintf(int fd, const char* fmt, va_list ap) {
209   return vdprintf(fd, fmt, ap);
210 }
211 
212 #define __futex_wake __real_futex_wake
213 #define __futex_wait __real_futex_wait
214 #include "private/bionic_futex.h"
215 #undef __futex_wake
216 #undef __futex_wait
217 
218 // This used to be in <sys/atomics.h>.
__futex_wake(volatile void * ftx,int count)219 int __futex_wake(volatile void* ftx, int count) {
220   return __real_futex_wake(ftx, count);
221 }
222 
223 // This used to be in <sys/atomics.h>.
__futex_wait(volatile void * ftx,int value,const struct timespec * timeout)224 int __futex_wait(volatile void* ftx, int value, const struct timespec* timeout) {
225   return __real_futex_wait(ftx, value, timeout);
226 }
227 
228 // Unity's libmono uses this.
tkill(pid_t tid,int sig)229 int tkill(pid_t tid, int sig) {
230   return syscall(__NR_tkill, tid, sig);
231 }
232 
233 // This was removed from POSIX 2008.
wcswcs(wchar_t * haystack,wchar_t * needle)234 wchar_t* wcswcs(wchar_t* haystack, wchar_t* needle) {
235   return wcsstr(haystack, needle);
236 }
237 
238 // This was removed from POSIX 2008.
bsd_signal(int signum,sighandler_t handler)239 sighandler_t bsd_signal(int signum, sighandler_t handler) {
240   return signal(signum, handler);
241 }
242 
243 #if !defined(__i386__)
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 #else
250 // x86 has an assembler implementation.
251 #endif
252 
253 // sysv_signal() was never in POSIX.
254 extern "C++" sighandler_t _signal(int signum, sighandler_t handler, int flags);
sysv_signal(int signum,sighandler_t handler)255 sighandler_t sysv_signal(int signum, sighandler_t handler) {
256   return _signal(signum, handler, SA_RESETHAND);
257 }
258 
259 // This is a system call that was never in POSIX. Use readdir(3) instead.
260 int __getdents64(unsigned int, dirent*, unsigned int);
getdents(unsigned int fd,dirent * dirp,unsigned int count)261 int getdents(unsigned int fd, dirent* dirp, unsigned int count) {
262   return __getdents64(fd, dirp, count);
263 }
264 
265 // This is a BSDism that we never implemented correctly. Used by Firefox.
issetugid()266 int issetugid() {
267   return 0;
268 }
269 
270 // This was removed from POSIX 2004.
wait3(int * status,int options,struct rusage * rusage)271 pid_t wait3(int* status, int options, struct rusage* rusage) {
272   return wait4(-1, status, options, rusage);
273 }
274 
275 // This was removed from POSIX 2004.
getdtablesize()276 int getdtablesize() {
277   struct rlimit r;
278 
279   if (getrlimit(RLIMIT_NOFILE, &r) < 0) {
280     return sysconf(_SC_OPEN_MAX);
281   }
282 
283   return r.rlim_cur;
284 }
285 
286 // A leaked BSD stdio implementation detail that's now a no-op.
__sinit()287 void __sinit() {}
288 int __sdidinit = 1;
289 
290 // Only used by ftime, which was removed from POSIX 2008.
291 struct timeb {
292   time_t          time;
293   unsigned short  millitm;
294   short           timezone;
295   short           dstflag;
296 };
297 
298 // This was removed from POSIX 2008.
ftime(struct timeb * tb)299 int ftime(struct timeb* tb) {
300   struct timeval  tv;
301   struct timezone tz;
302 
303   if (gettimeofday(&tv, &tz) < 0)
304     return -1;
305 
306   tb->time    = tv.tv_sec;
307   tb->millitm = (tv.tv_usec + 500) / 1000;
308 
309   if (tb->millitm == 1000) {
310     ++tb->time;
311     tb->millitm = 0;
312   }
313 
314   tb->timezone = tz.tz_minuteswest;
315   tb->dstflag  = tz.tz_dsttime;
316 
317   return 0;
318 }
319 
320 // This was removed from POSIX 2008.
index(const char * str,int ch)321 char* index(const char* str, int ch) {
322   return strchr(str, ch);
323 }
324 
325 // This was removed from BSD.
arc4random_stir(void)326 void arc4random_stir(void) {
327   // The current implementation stirs itself as needed.
328 }
329 
330 // This was removed from BSD.
arc4random_addrandom(unsigned char *,int)331 void arc4random_addrandom(unsigned char*, int) {
332   // The current implementation adds randomness as needed.
333 }
334 
335 // Old versions of the NDK did not export malloc_usable_size, but did
336 // export dlmalloc_usable_size. We are moving away from dlmalloc in L
337 // so make this call malloc_usable_size.
dlmalloc_usable_size(void * ptr)338 size_t dlmalloc_usable_size(void* ptr) {
339   return malloc_usable_size(ptr);
340 }
341 
342 // In L we added a public pthread_gettid_np, but some apps were using the private API.
__pthread_gettid(pthread_t t)343 pid_t __pthread_gettid(pthread_t t) {
344   return pthread_gettid_np(t);
345 }
346 
347 // Older versions of apportable used dlmalloc directly instead of malloc,
348 // so export this compatibility shim that simply calls malloc.
dlmalloc(size_t size)349 void* dlmalloc(size_t size) {
350   return malloc(size);
351 }
352 
353 #define __get_thread __real_get_thread
354 #include "pthread_internal.h"
355 #undef __get_thread
356 // Various third-party apps contain a backport of our pthread_rwlock implementation that uses this.
__get_thread()357 pthread_internal_t* __get_thread() {
358   return __real_get_thread();
359 }
360 
361 // This one exists only for the LP32 NDK and is not present anywhere else.
362 extern long __set_errno_internal(int);
__set_errno(int n)363 long __set_errno(int n) {
364   return __set_errno_internal(n);
365 }
366 
367 // This was never implemented in bionic, only needed for ABI compatibility with the NDK.
368 // In the M time frame, over 1000 apps have a reference to this!
endpwent()369 void endpwent() { }
370 
371 // Since dlmalloc_inspect_all and dlmalloc_trim are exported for systems
372 // that use dlmalloc, be consistent and export them everywhere.
dlmalloc_inspect_all(void (*)(void *,void *,size_t,void *),void *)373 void dlmalloc_inspect_all(void (*)(void*, void*, size_t, void*), void*) {
374 }
dlmalloc_trim(size_t)375 int dlmalloc_trim(size_t) {
376     return 0;
377 }
378 
379 #endif // !defined(__BRILLO__) && !defined (__LP64__)
380 
381 } // extern "C"
382