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 /*--------------------------------------------------------------------*/ 248
