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      1 // Copyright 2013 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 // Platform-specific code for QNX goes here. For the POSIX-compatible
      6 // parts the implementation is in platform-posix.cc.
      7 
      8 #include <backtrace.h>
      9 #include <pthread.h>
     10 #include <semaphore.h>
     11 #include <signal.h>
     12 #include <stdlib.h>
     13 #include <sys/resource.h>
     14 #include <sys/time.h>
     15 #include <sys/types.h>
     16 #include <ucontext.h>
     17 
     18 // QNX requires memory pages to be marked as executable.
     19 // Otherwise, the OS raises an exception when executing code in that page.
     20 #include <errno.h>
     21 #include <fcntl.h>      // open
     22 #include <stdarg.h>
     23 #include <strings.h>    // index
     24 #include <sys/mman.h>   // mmap & munmap
     25 #include <sys/procfs.h>
     26 #include <sys/stat.h>   // open
     27 #include <unistd.h>     // sysconf
     28 
     29 #include <cmath>
     30 
     31 #undef MAP_TYPE
     32 
     33 #include "src/base/macros.h"
     34 #include "src/base/platform/platform.h"
     35 
     36 
     37 namespace v8 {
     38 namespace base {
     39 
     40 // 0 is never a valid thread id on Qnx since tids and pids share a
     41 // name space and pid 0 is reserved (see man 2 kill).
     42 static const pthread_t kNoThread = (pthread_t) 0;
     43 
     44 
     45 #ifdef __arm__
     46 
     47 bool OS::ArmUsingHardFloat() {
     48   // GCC versions 4.6 and above define __ARM_PCS or __ARM_PCS_VFP to specify
     49   // the Floating Point ABI used (PCS stands for Procedure Call Standard).
     50   // We use these as well as a couple of other defines to statically determine
     51   // what FP ABI used.
     52   // GCC versions 4.4 and below don't support hard-fp.
     53   // GCC versions 4.5 may support hard-fp without defining __ARM_PCS or
     54   // __ARM_PCS_VFP.
     55 
     56 #define GCC_VERSION (__GNUC__ * 10000                                          \
     57                      + __GNUC_MINOR__ * 100                                    \
     58                      + __GNUC_PATCHLEVEL__)
     59 #if GCC_VERSION >= 40600
     60 #if defined(__ARM_PCS_VFP)
     61   return true;
     62 #else
     63   return false;
     64 #endif
     65 
     66 #elif GCC_VERSION < 40500
     67   return false;
     68 
     69 #else
     70 #if defined(__ARM_PCS_VFP)
     71   return true;
     72 #elif defined(__ARM_PCS) || defined(__SOFTFP__) || defined(__SOFTFP) || \
     73       !defined(__VFP_FP__)
     74   return false;
     75 #else
     76 #error "Your version of GCC does not report the FP ABI compiled for."          \
     77        "Please report it on this issue"                                        \
     78        "http://code.google.com/p/v8/issues/detail?id=2140"
     79 
     80 #endif
     81 #endif
     82 #undef GCC_VERSION
     83 }
     84 
     85 #endif  // __arm__
     86 
     87 
     88 const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
     89   if (std::isnan(time)) return "";
     90   time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
     91   struct tm* t = localtime(&tv);  // NOLINT(runtime/threadsafe_fn)
     92   if (NULL == t) return "";
     93   return t->tm_zone;
     94 }
     95 
     96 
     97 double OS::LocalTimeOffset(TimezoneCache* cache) {
     98   time_t tv = time(NULL);
     99   struct tm* t = localtime(&tv);  // NOLINT(runtime/threadsafe_fn)
    100   // tm_gmtoff includes any daylight savings offset, so subtract it.
    101   return static_cast<double>(t->tm_gmtoff * msPerSecond -
    102                              (t->tm_isdst > 0 ? 3600 * msPerSecond : 0));
    103 }
    104 
    105 
    106 void* OS::Allocate(const size_t requested,
    107                    size_t* allocated,
    108                    bool is_executable) {
    109   const size_t msize = RoundUp(requested, AllocateAlignment());
    110   int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
    111   void* addr = OS::GetRandomMmapAddr();
    112   void* mbase = mmap(addr, msize, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    113   if (mbase == MAP_FAILED) return NULL;
    114   *allocated = msize;
    115   return mbase;
    116 }
    117 
    118 
    119 std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() {
    120   std::vector<SharedLibraryAddress> result;
    121   procfs_mapinfo *mapinfos = NULL, *mapinfo;
    122   int proc_fd, num, i;
    123 
    124   struct {
    125     procfs_debuginfo info;
    126     char buff[PATH_MAX];
    127   } map;
    128 
    129   char buf[PATH_MAX + 1];
    130   snprintf(buf, PATH_MAX + 1, "/proc/%d/as", getpid());
    131 
    132   if ((proc_fd = open(buf, O_RDONLY)) == -1) {
    133     close(proc_fd);
    134     return result;
    135   }
    136 
    137   /* Get the number of map entries.  */
    138   if (devctl(proc_fd, DCMD_PROC_MAPINFO, NULL, 0, &num) != EOK) {
    139     close(proc_fd);
    140     return result;
    141   }
    142 
    143   mapinfos = reinterpret_cast<procfs_mapinfo *>(
    144       malloc(num * sizeof(procfs_mapinfo)));
    145   if (mapinfos == NULL) {
    146     close(proc_fd);
    147     return result;
    148   }
    149 
    150   /* Fill the map entries.  */
    151   if (devctl(proc_fd, DCMD_PROC_PAGEDATA,
    152       mapinfos, num * sizeof(procfs_mapinfo), &num) != EOK) {
    153     free(mapinfos);
    154     close(proc_fd);
    155     return result;
    156   }
    157 
    158   for (i = 0; i < num; i++) {
    159     mapinfo = mapinfos + i;
    160     if (mapinfo->flags & MAP_ELF) {
    161       map.info.vaddr = mapinfo->vaddr;
    162       if (devctl(proc_fd, DCMD_PROC_MAPDEBUG, &map, sizeof(map), 0) != EOK) {
    163         continue;
    164       }
    165       result.push_back(SharedLibraryAddress(
    166           map.info.path, mapinfo->vaddr, mapinfo->vaddr + mapinfo->size));
    167     }
    168   }
    169   free(mapinfos);
    170   close(proc_fd);
    171   return result;
    172 }
    173 
    174 
    175 void OS::SignalCodeMovingGC() {
    176 }
    177 
    178 
    179 // Constants used for mmap.
    180 static const int kMmapFd = -1;
    181 static const int kMmapFdOffset = 0;
    182 
    183 
    184 VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { }
    185 
    186 
    187 VirtualMemory::VirtualMemory(size_t size)
    188     : address_(ReserveRegion(size)), size_(size) { }
    189 
    190 
    191 VirtualMemory::VirtualMemory(size_t size, size_t alignment)
    192     : address_(NULL), size_(0) {
    193   DCHECK((alignment % OS::AllocateAlignment()) == 0);
    194   size_t request_size = RoundUp(size + alignment,
    195                                 static_cast<intptr_t>(OS::AllocateAlignment()));
    196   void* reservation = mmap(OS::GetRandomMmapAddr(),
    197                            request_size,
    198                            PROT_NONE,
    199                            MAP_PRIVATE | MAP_ANONYMOUS | MAP_LAZY,
    200                            kMmapFd,
    201                            kMmapFdOffset);
    202   if (reservation == MAP_FAILED) return;
    203 
    204   uint8_t* base = static_cast<uint8_t*>(reservation);
    205   uint8_t* aligned_base = RoundUp(base, alignment);
    206   DCHECK_LE(base, aligned_base);
    207 
    208   // Unmap extra memory reserved before and after the desired block.
    209   if (aligned_base != base) {
    210     size_t prefix_size = static_cast<size_t>(aligned_base - base);
    211     OS::Free(base, prefix_size);
    212     request_size -= prefix_size;
    213   }
    214 
    215   size_t aligned_size = RoundUp(size, OS::AllocateAlignment());
    216   DCHECK_LE(aligned_size, request_size);
    217 
    218   if (aligned_size != request_size) {
    219     size_t suffix_size = request_size - aligned_size;
    220     OS::Free(aligned_base + aligned_size, suffix_size);
    221     request_size -= suffix_size;
    222   }
    223 
    224   DCHECK(aligned_size == request_size);
    225 
    226   address_ = static_cast<void*>(aligned_base);
    227   size_ = aligned_size;
    228 }
    229 
    230 
    231 VirtualMemory::~VirtualMemory() {
    232   if (IsReserved()) {
    233     bool result = ReleaseRegion(address(), size());
    234     DCHECK(result);
    235     USE(result);
    236   }
    237 }
    238 
    239 
    240 bool VirtualMemory::IsReserved() {
    241   return address_ != NULL;
    242 }
    243 
    244 
    245 void VirtualMemory::Reset() {
    246   address_ = NULL;
    247   size_ = 0;
    248 }
    249 
    250 
    251 bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) {
    252   return CommitRegion(address, size, is_executable);
    253 }
    254 
    255 
    256 bool VirtualMemory::Uncommit(void* address, size_t size) {
    257   return UncommitRegion(address, size);
    258 }
    259 
    260 
    261 bool VirtualMemory::Guard(void* address) {
    262   OS::Guard(address, OS::CommitPageSize());
    263   return true;
    264 }
    265 
    266 
    267 void* VirtualMemory::ReserveRegion(size_t size) {
    268   void* result = mmap(OS::GetRandomMmapAddr(),
    269                       size,
    270                       PROT_NONE,
    271                       MAP_PRIVATE | MAP_ANONYMOUS | MAP_LAZY,
    272                       kMmapFd,
    273                       kMmapFdOffset);
    274 
    275   if (result == MAP_FAILED) return NULL;
    276 
    277   return result;
    278 }
    279 
    280 
    281 bool VirtualMemory::CommitRegion(void* base, size_t size, bool is_executable) {
    282   int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
    283   if (MAP_FAILED == mmap(base,
    284                          size,
    285                          prot,
    286                          MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
    287                          kMmapFd,
    288                          kMmapFdOffset)) {
    289     return false;
    290   }
    291 
    292   return true;
    293 }
    294 
    295 
    296 bool VirtualMemory::UncommitRegion(void* base, size_t size) {
    297   return mmap(base,
    298               size,
    299               PROT_NONE,
    300               MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED | MAP_LAZY,
    301               kMmapFd,
    302               kMmapFdOffset) != MAP_FAILED;
    303 }
    304 
    305 
    306 bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
    307   return munmap(base, size) == 0;
    308 }
    309 
    310 
    311 bool VirtualMemory::HasLazyCommits() {
    312   return false;
    313 }
    314 
    315 }  // namespace base
    316 }  // namespace v8
    317