hphp/runtime/vm/debug/gdb-jit.cpp

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present 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 #include "hphp/runtime/vm/debug/gdb-jit.h"
  17 #include "hphp/util/lock.h"
  18 #include "hphp/runtime/base/execution-context.h"
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22
  23 #include <folly/portability/SysMman.h>
  24
  25 using namespace HPHP;
  26
  27 struct jit_descriptor __jit_debug_descriptor = { 1, 0, 0, 0 };
  28
  29 void unregister_gdb_hook(struct jit_code_entry *e) {
  30   __jit_debug_descriptor.action_flag = JIT_UNREGISTER_FN;
  31   __jit_debug_descriptor.relevant_entry = e;
  32   __jit_debug_register_code();
  33 }
  34
  35 void delete_symfile(const char *old) {
  36   struct jit_code_entry *e, *prev;
  37
  38   e = __jit_debug_descriptor.first_entry;
  39   prev = nullptr;
  40   while (e != nullptr) {
  41     if (e->symfile_addr == old) {
  42       if (prev !=  nullptr) {
  43         prev->next_entry = e->next_entry;
  44       } else {
  45         __jit_debug_descriptor.first_entry = e->next_entry;
  46       }
  47       if (e->next_entry != nullptr) {
  48         e->next_entry->prev_entry = prev;
  49       }
  50       unregister_gdb_hook(e);
  51       free((void *)e->symfile_addr);
  52       free(e);
  53       return;
  54     }
  55     prev = e;
  56     e = e->next_entry;
  57   }
  58 }
  59
  60 Mutex gdbLock;
  61
  62 void unregister_gdb_chunk(DwarfChunk* d) {
  63   Lock lock(gdbLock);
  64
  65   if (d->m_symfile != nullptr) {
  66     delete_symfile(d->m_symfile);
  67     d->m_symfile = nullptr;
  68   }
  69 }
  70
  71 int register_gdb_hook(char *symfile_addr, uint64_t symfile_size,
  72   DwarfChunk* d) {
  73   struct jit_code_entry *entry;
  74   Lock lock(gdbLock);
  75
  76   if ((entry =
  77       (struct jit_code_entry *)malloc(sizeof (struct jit_code_entry))) == nullptr)
  78     return -1;
  79
  80   entry->symfile_addr = symfile_addr;
  81   entry->symfile_size = symfile_size;
  82
  83   if (d->m_symfile != nullptr) {
  84     delete_symfile(d->m_symfile);
  85   }
  86   d->m_symfile = symfile_addr;
  87
  88   entry->prev_entry = nullptr;
  89   entry->next_entry = __jit_debug_descriptor.first_entry;
  90   if (__jit_debug_descriptor.first_entry) {
  91     __jit_debug_descriptor.first_entry->prev_entry = entry;
  92   }
  93   __jit_debug_descriptor.first_entry = entry;
  94   __jit_debug_descriptor.relevant_entry = entry;
  95
  96   __jit_debug_descriptor.action_flag = JIT_REGISTER_FN;
  97   __jit_debug_register_code();
  98   return 0;
  99 }