coregrind/pub_core_gdbserver.h

   1
   2 /*--------------------------------------------------------------------*/
   3 /*--- Handle remote gdb protocol.             pub_core_gdbserver.h ---*/
   4 /*--------------------------------------------------------------------*/
   5
   6 /*
   7    This file is part of Valgrind, a dynamic binary instrumentation
   8    framework.
   9
  10    Copyright (C) 2011-2017 Philippe Waroquiers
  11
  12    This program is free software; you can redistribute it and/or
  13    modify it under the terms of the GNU General Public License as
  14    published by the Free Software Foundation; either version 2 of the
  15    License, or (at your option) any later version.
  16
  17    This program is distributed in the hope that it will be useful, but
  18    WITHOUT ANY WARRANTY; without even the implied warranty of
  19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20    General Public License for more details.
  21
  22    You should have received a copy of the GNU General Public License
  23    along with this program; if not, write to the Free Software
  24    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  25    02111-1307, USA.
  26
  27    The GNU General Public License is contained in the file COPYING.
  28 */
  29
  30 #ifndef __PUB_CORE_GDBSERVER_H
  31 #define __PUB_CORE_GDBSERVER_H
  32
  33 #include "pub_tool_gdbserver.h"
  34 #include "pub_core_options.h"
  35 #include "pub_core_threadstate.h"   // VgSchedReturnCode
  36
  37 /* Return the default path prefix for the named pipes (FIFOs) used by vgdb/gdb
  38    to communicate with valgrind */
  39 HChar* VG_(vgdb_prefix_default)(void);
  40
  41 // After a fork or after an exec, call the below to (possibly) terminate
  42 // the previous gdbserver and then activate a new gdbserver
  43 // before any guest code execution, to e.g. allow the user to set
  44 // breakpoints before execution.
  45 // If VG_(clo_vgdb) == No, the below has no effect.
  46 void VG_(gdbserver_prerun_action) (ThreadId tid);
  47
  48 // True if the initialisation of gdbserver was done,
  49 // i.e. VG_(gdbserver_prerun_action) was called.
  50 Bool VG_(gdbserver_init_done) (void);
  51
  52 // True if gdbserver should stop execution for the specified stop at reason
  53 Bool VG_(gdbserver_stop_at) (VgdbStopAt stopat);
  54
  55 // True if there is some activity from vgdb
  56 // If it returns True, then extern void VG_(gdbserver) can be called
  57 // to handle this incoming vgdb request.
  58 extern Bool VG_(gdbserver_activity) (ThreadId tid);
  59
  60 // If connected to GDB, VG_(gdbserver_exit) reports to GDB that the process
  61 // is about to exit.
  62 // gdbserver is then stopped (using VG_(gdbserver) (0))
  63 void VG_(gdbserver_exit) (ThreadId tid, VgSchedReturnCode tids_schedretcode);
  64
  65 /* On systems that defines PR_SET_PTRACER, verify if ptrace_scope is
  66    is permissive enough for vgdb.
  67    Otherwise, call set_ptracer.
  68    This is especially aimed at Ubuntu >= 10.10 which has added
  69    the ptrace_scope context. */
  70 void VG_(set_ptracer)(void);
  71
  72 /* Called by low level to insert or remove a break or watch point.
  73    Break or watch point implementation is done using help from the tool.
  74    break point support implies some (small) specific instrumentation
  75    taken in charge for all tools by m_translate.c.
  76
  77    Write/read/access watchpoint can only be provided by tools which are
  78    tracking addressability and/or accessibility of memory
  79    (so typically memcheck can provide it). Note that memcheck addressability
  80    bits do not differentiate between read and write accessibility.
  81    However, when accessing unaddressable byte, memcheck can differentiate
  82    reads from write, thereby providing read/write or access watchpoints.
  83
  84    Note that gdbserver assumes that software breakpoint is supported
  85    (as this will be done by re-instrumenting the code).
  86    Note that len is ignored for software breakpoints. hardware_breakpoint
  87    are not supported.
  88
  89    Returns True if the point has properly been inserted or removed
  90    Returns False otherwise. */
  91 Bool VG_(gdbserver_point) (PointKind kind, Bool insert,
  92                            Addr addr, int len);
  93
  94 /* True if there is a breakpoint at addr. */
  95 Bool VG_(has_gdbserver_breakpoint) (Addr addr);
  96
  97 /* Entry point invoked by vgdb when it uses ptrace to cause a gdbserver
  98    invocation. A magic value is passed by vgdb in check as a verification
  99    that the call has been properly pushed by vgdb. */
 100 extern void VG_(invoke_gdbserver) ( int check );
 101
 102 // To be called by core (m_signals.c) before delivering a signal.
 103 // Returns False if gdb user asks to not pass the signal to the client.
 104 // Returns True if signal must be passed to the client, either because
 105 // no gdb is connected, or gdb instructs to pass the signal.
 106 // Note that if the below returns True, the signal might
 107 // still be ignored if this is the action desired by the
 108 // guest program. Using GDB, the user can also modify the signal to be
 109 // reported (e.g. changing the signo to pass to the guest).
 110 // If this function returns True, m_signals.c should deliver the signal
 111 // info as modified by VG_(gdbserver_report_signal).
 112 // If this function returns False, no signal should be reported.
 113 extern Bool VG_(gdbserver_report_signal) (vki_siginfo_t *info, ThreadId tid);
 114
 115 // If no gdb is connected yet, wait for a gdb to connect and report
 116 // this (supposedly) fatal signal.
 117 // If a gdb is already connected, this does nothing (as normally
 118 // the signal was already reported to the already connected gdb).
 119 extern void VG_(gdbserver_report_fatal_signal) (const vki_siginfo_t *info,
 120                                                 ThreadId tid);
 121
 122 // To be called by core before and after a client syscall.
 123 // If GDB has asked to observe the syscall, control will be given to GDB.
 124 // When Before is True, it is a report before the syscall,
 125 // False means a report after the syscall.
 126 extern void VG_(gdbserver_report_syscall) (Bool before, UWord sysno,
 127                                            ThreadId tid);
 128
 129 /* Entry point invoked by scheduler.c to execute the request
 130    VALGRIND_CLIENT_MONITOR_COMMAND.
 131    Returns True if command was not recognised. */
 132 extern Bool VG_(client_monitor_command) (HChar* cmd);
 133
 134 /* software_breakpoint, single step and jump support ------------------------*/
 135 /* VG_(instrument_for_gdbserver_if_needed) allows to do "standard and easy"
 136    instrumentation for gdbserver.
 137    VG_(instrument_for_gdbserver_if_needed) does the following:
 138       * checks if gdbserver instrumentation is needed for vge.
 139       * if no gdbserver instrumentation needed,
 140            returns sb_in
 141       * otherwise
 142         It will instrument sb_in to allow gdbserver to properly
 143         handle breakpoints and single_stepping in sb_in.
 144         All the target jumps of sb_in will also be invalidated
 145         if these are not yet instrumented for gdbserver.
 146         This allows to have single_step working, using a lazily
 147         translation of the blocks which are being single stepped
 148         in.
 149
 150    The typical usage of this function is to call it on the block
 151    instrumented by the tool instrument function i.e. :
 152      return VG_(instrument_for_gdbserver_if_needed) (sb_out,
 153                                                      layout,
 154                                                      vge,
 155                                                      gWordTy,
 156                                                      hWordTy);
 157    where sb_out is the block instrumented by the tool.
 158
 159    If the block contains a call to a dirty helper that indirectly
 160    calls gdbserver, then this dirty helper can (indirectly) change
 161    the IP. This implies to jump to this IP after the call to
 162    gdbserver. */
 163 extern IRSB* VG_(instrument_for_gdbserver_if_needed)
 164      (IRSB* sb_in,                   /* block to be instrumented */
 165       const VexGuestLayout* layout,
 166       const VexGuestExtents* vge,
 167       IRType gWordTy, IRType hWordTy);
 168
 169 /* reason for which gdbserver connection must be finished */
 170 typedef
 171    enum {
 172       orderly_finish,
 173       reset_after_error,
 174       reset_after_fork} FinishReason;
 175
 176 /* output various gdbserver statistics and status. */
 177 extern void VG_(gdbserver_status_output)(void);
 178
 179 /* Shared structure between vgdb and the process running
 180    under valgrind.
 181    We define two variants: a 32 bit and a 64 bit.
 182    The valgrind process will use the appropriate size,
 183    according to the architecture.
 184    vgdb will use what the valgrind process is using. */
 185 /* The below takes care that sizes will be 32 or 64 bits,
 186    whatever the architecture. A.o., vgdb.c cannot use directly
 187    the types from pub_core_threadstate.h as we want vgdb.c to
 188    be independent of the arch it is debugging in case of bi-arch
 189    Valgrind (e.g. x86 and amd64). So, the valgrind process must
 190    give all the needed info/offset to vgdb in the below structure. */
 191
 192 typedef
 193    struct {
 194       // nr of bytes vgdb has written to valgrind
 195       volatile int written_by_vgdb;
 196       // nr of bytes seen by valgrind
 197       volatile int seen_by_valgrind;
 198
 199       // address at which gdbserver can be invoked
 200       Addr32 invoke_gdbserver;
 201
 202       // address of VG_(threads) and various sizes
 203       // and offset needed by vgdb.
 204       Addr32 threads;
 205       int vg_n_threads;
 206       int sizeof_ThreadState;
 207       int offset_status;
 208       int offset_lwpid;
 209
 210       // PID of the vgdb that last connected to the Valgrind gdbserver.
 211       // It will be set by vgdb after connecting.
 212       int vgdb_pid;
 213    } VgdbShared32;
 214
 215 /* Same as VgdbShared32 but for 64 bits arch. */
 216 typedef
 217    struct {
 218       volatile int written_by_vgdb;
 219       volatile int seen_by_valgrind;
 220
 221       Addr64 invoke_gdbserver;
 222
 223       Addr64 threads;
 224       int vg_n_threads;
 225       int sizeof_ThreadState;
 226       int offset_status;
 227       int offset_lwpid;
 228
 229       int vgdb_pid;
 230    } VgdbShared64;
 231
 232 // The below typedef makes the life of valgrind easier.
 233 // vgdb must however work explicitly with the specific 32 or 64 bits version.
 234
 235 #if VEX_HOST_WORDSIZE == 8
 236 typedef VgdbShared64 VgdbShared;
 237 #elif VEX_HOST_WORDSIZE == 4
 238 typedef VgdbShared32 VgdbShared;
 239 #else
 240 # error "unexpected wordsize"
 241 #endif
 242
 243
 244 #endif   // __PUB_CORE_GDBSERVER_H
 245 /*--------------------------------------------------------------------*/
 246 /*--- end                                                          ---*/
 247 /*--------------------------------------------------------------------*/