hphp/runtime/vm/jit/relocation.cpp

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-2016 Facebook, Inc. (http://www.facebook.com)     |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16
  17 #include "hphp/runtime/vm/jit/relocation.h"
  18 #include "hphp/runtime/vm/jit/relocation-arm.h"
  19 #include "hphp/runtime/vm/jit/relocation-ppc64.h"
  20 #include "hphp/runtime/vm/jit/relocation-x64.h"
  21
  22 #include "hphp/util/arch.h"
  23
  24 namespace HPHP { namespace jit {
  25
  26 void RelocationInfo::recordRange(TCA start, TCA end,
  27                                  TCA destStart, TCA destEnd) {
  28   m_srcRanges.emplace_back(start, end);
  29   m_dstRanges.emplace_back(destStart, destEnd);
  30   m_adjustedAddresses[start].second = destStart;
  31   m_adjustedAddresses[end].first = destEnd;
  32 }
  33
  34 void RelocationInfo::recordAddress(TCA src, TCA dest, int range) {
  35   m_adjustedAddresses.emplace(src, std::make_pair(dest, dest + range));
  36 }
  37
  38 TCA RelocationInfo::adjustedAddressAfter(TCA addr) const {
  39   auto it = m_adjustedAddresses.find(addr);
  40   if (it == m_adjustedAddresses.end()) return nullptr;
  41
  42   return it->second.second;
  43 }
  44
  45 TCA RelocationInfo::adjustedAddressBefore(TCA addr) const {
  46   auto it = m_adjustedAddresses.find(addr);
  47   if (it == m_adjustedAddresses.end()) return nullptr;
  48
  49   return it->second.first;
  50 }
  51
  52 void RelocationInfo::rewind(TCA start, TCA end) {
  53   if (m_srcRanges.size() && m_srcRanges.back().first == start) {
  54     assertx(m_dstRanges.size() == m_srcRanges.size());
  55     assertx(m_srcRanges.back().second == end);
  56     m_srcRanges.pop_back();
  57     m_dstRanges.pop_back();
  58   }
  59   auto it = m_adjustedAddresses.lower_bound(start);
  60   if (it == m_adjustedAddresses.end()) return;
  61
  62   // convenience function for erasing a m_smashableRelocations entry
  63   auto eraseSmashableRelocation = [this](TCA addr) {
  64     auto it = m_smashableRelocations.find(addr);
  65     if (it != m_smashableRelocations.end()) m_smashableRelocations.erase(it);
  66   };
  67
  68   if (it->first == start) {
  69     // if it->second.first is set, start is also the end
  70     // of an existing region. Don't erase it in that case
  71     if (it->second.first) {
  72       eraseSmashableRelocation(it->second.second);
  73       it++->second.second = 0;
  74     } else {
  75       m_adjustedAddresses.erase(it++);
  76     }
  77   }
  78   while (it != m_adjustedAddresses.end() && it->first < end) {
  79     eraseSmashableRelocation(it->second.second);
  80     m_adjustedAddresses.erase(it++);
  81   }
  82   if (it == m_adjustedAddresses.end()) return;
  83   if (it->first == end) {
  84     // Similar to start above, end could be the start of an
  85     // existing region.
  86     if (it->second.second) {
  87       eraseSmashableRelocation(it->second.second);
  88       it++->second.first = 0;
  89     } else {
  90       m_adjustedAddresses.erase(it++);
  91     }
  92   }
  93 }
  94
  95 //////////////////////////////////////////////////////////////////////
  96
  97 /*
  98  * Wrappers.
  99  */
 100
 101 void adjustForRelocation(RelocationInfo& rel) {
 102   return ARCH_SWITCH_CALL(adjustForRelocation, rel);
 103 }
 104 void adjustForRelocation(RelocationInfo& rel, TCA srcStart, TCA srcEnd) {
 105   return ARCH_SWITCH_CALL(adjustForRelocation, rel, srcStart, srcEnd);
 106 }
 107 void adjustCodeForRelocation(RelocationInfo& rel, CGMeta& fixups) {
 108   return ARCH_SWITCH_CALL(adjustCodeForRelocation, rel, fixups);
 109 }
 110 void adjustMetaDataForRelocation(RelocationInfo& rel,
 111                                  AsmInfo* asmInfo,
 112                                  CGMeta& fixups) {
 113   return ARCH_SWITCH_CALL(adjustMetaDataForRelocation, rel, asmInfo, fixups);
 114 }
 115 void findFixups(TCA start, TCA end, CGMeta& fixups) {
 116   return ARCH_SWITCH_CALL(findFixups, start, end, fixups);
 117 }
 118 size_t relocate(RelocationInfo& rel,
 119                 CodeBlock& destBlock,
 120                 TCA start, TCA end,
 121                 CodeBlock& srcBlock,
 122                 CGMeta& fixups,
 123                 TCA* exitAddr) {
 124   return ARCH_SWITCH_CALL(relocate, rel, destBlock, start, end, srcBlock,
 125                           fixups, exitAddr);
 126 }
 127
 128 //////////////////////////////////////////////////////////////////////
 129
 130 }}