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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/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).
     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?
     67 int __open() {
     68   abort();
     69 }
     70 
     71 // TODO: does anything still need this?
     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.
     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 
     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 
     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.
    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 
    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.
    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.
    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.
    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.
    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>.
    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>.
    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.
    230 int tkill(pid_t tid, int sig) {
    231   return syscall(__NR_tkill, tid, sig);
    232 }
    233 
    234 // This was removed from POSIX 2008.
    235 wchar_t* wcswcs(wchar_t* haystack, wchar_t* needle) {
    236   return wcsstr(haystack, needle);
    237 }
    238 
    239 // This was removed from POSIX 2008.
    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
    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
    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);
    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);
    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.
    269 int issetugid() {
    270   return 0;
    271 }
    272 
    273 // This was removed from POSIX 2004.
    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.
    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.
    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.
    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.
    324 char* index(const char* str, int ch) {
    325   return strchr(str, ch);
    326 }
    327 
    328 // This was removed from BSD.
    329 void arc4random_stir(void) {
    330   // The current implementation stirs itself as needed.
    331 }
    332 
    333 // This was removed from BSD.
    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.
    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.
    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.
    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.
    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);
    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.
    372 void dlmalloc_inspect_all(void (*)(void*, void*, size_t, void*), void*) {
    373 }
    374 int dlmalloc_trim(size_t) {
    375     return 0;
    376 }
    377 
    378 // LP32's <stdio.h> had putw (but not getw).
    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