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      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).
     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?
     66 int __open() {
     67   abort();
     68 }
     69 
     70 // TODO: does anything still need this?
     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.
     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 
     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 
     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.
    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 
    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.
    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.
    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.
    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.
    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>.
    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>.
    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.
    229 int tkill(pid_t tid, int sig) {
    230   return syscall(__NR_tkill, tid, sig);
    231 }
    232 
    233 // This was removed from POSIX 2008.
    234 wchar_t* wcswcs(wchar_t* haystack, wchar_t* needle) {
    235   return wcsstr(haystack, needle);
    236 }
    237 
    238 // This was removed from POSIX 2008.
    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
    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);
    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);
    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.
    266 int issetugid() {
    267   return 0;
    268 }
    269 
    270 // This was removed from POSIX 2004.
    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.
    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.
    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.
    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.
    321 char* index(const char* str, int ch) {
    322   return strchr(str, ch);
    323 }
    324 
    325 // This was removed from BSD.
    326 void arc4random_stir(void) {
    327   // The current implementation stirs itself as needed.
    328 }
    329 
    330 // This was removed from BSD.
    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.
    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.
    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.
    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.
    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);
    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!
    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.
    373 void dlmalloc_inspect_all(void (*)(void*, void*, size_t, void*), void*) {
    374 }
    375 int dlmalloc_trim(size_t) {
    376     return 0;
    377 }
    378 
    379 #endif // !defined(__BRILLO__) && !defined (__LP64__)
    380 
    381 } // extern "C"
    382