1 2/*--------------------------------------------------------------------*/ 3/*--- Attaching a debugger. m_debugger.c ---*/ 4/*--------------------------------------------------------------------*/ 5 6/* 7 This file is part of Valgrind, a dynamic binary instrumentation 8 framework. 9 10 Copyright (C) 2000-2010 Julian Seward 11 jseward@acm.org 12 13 This program is free software; you can redistribute it and/or 14 modify it under the terms of the GNU General Public License as 15 published by the Free Software Foundation; either version 2 of the 16 License, or (at your option) any later version. 17 18 This program is distributed in the hope that it will be useful, but 19 WITHOUT ANY WARRANTY; without even the implied warranty of 20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 21 General Public License for more details. 22 23 You should have received a copy of the GNU General Public License 24 along with this program; if not, write to the Free Software 25 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 26 02111-1307, USA. 27 28 The GNU General Public License is contained in the file COPYING. 29*/ 30 31#include "pub_core_basics.h" 32#include "pub_core_vki.h" 33#include "pub_core_threadstate.h" 34#include "pub_core_xarray.h" 35#include "pub_core_clientstate.h" 36#include "pub_core_debugger.h" 37#include "pub_core_libcbase.h" 38#include "pub_core_libcprint.h" 39#include "pub_core_libcproc.h" 40#include "pub_core_libcsignal.h" 41#include "pub_core_libcassert.h" 42#include "pub_core_options.h" 43 44 45#define WIFSTOPPED(status) (((status) & 0xff) == 0x7f) 46#define WSTOPSIG(status) (((status) & 0xff00) >> 8) 47 48static Int ptrace_setregs(Int pid, VexGuestArchState* vex) 49{ 50#if defined(VGP_x86_linux) 51 struct vki_user_regs_struct regs; 52 VG_(memset)(®s, 0, sizeof(regs)); 53 regs.cs = vex->guest_CS; 54 regs.ss = vex->guest_SS; 55 regs.ds = vex->guest_DS; 56 regs.es = vex->guest_ES; 57 regs.fs = vex->guest_FS; 58 regs.gs = vex->guest_GS; 59 regs.eax = vex->guest_EAX; 60 regs.ebx = vex->guest_EBX; 61 regs.ecx = vex->guest_ECX; 62 regs.edx = vex->guest_EDX; 63 regs.esi = vex->guest_ESI; 64 regs.edi = vex->guest_EDI; 65 regs.ebp = vex->guest_EBP; 66 regs.esp = vex->guest_ESP; 67 regs.eflags = LibVEX_GuestX86_get_eflags(vex); 68 regs.eip = vex->guest_EIP; 69 return VG_(ptrace)(VKI_PTRACE_SETREGS, pid, NULL, ®s); 70 71#elif defined(VGP_amd64_linux) 72 struct vki_user_regs_struct regs; 73 VG_(memset)(®s, 0, sizeof(regs)); 74 regs.rax = vex->guest_RAX; 75 regs.rbx = vex->guest_RBX; 76 regs.rcx = vex->guest_RCX; 77 regs.rdx = vex->guest_RDX; 78 regs.rsi = vex->guest_RSI; 79 regs.rdi = vex->guest_RDI; 80 regs.rbp = vex->guest_RBP; 81 regs.rsp = vex->guest_RSP; 82 regs.r8 = vex->guest_R8; 83 regs.r9 = vex->guest_R9; 84 regs.r10 = vex->guest_R10; 85 regs.r11 = vex->guest_R11; 86 regs.r12 = vex->guest_R12; 87 regs.r13 = vex->guest_R13; 88 regs.r14 = vex->guest_R14; 89 regs.r15 = vex->guest_R15; 90 regs.eflags = LibVEX_GuestAMD64_get_rflags(vex); 91 regs.rip = vex->guest_RIP; 92 /* Set %{c,d,e,f,s,g}s and %{fs,gs}_base (whatever those are) to 93 values which don't fail the kernel's sanity checks. I have no 94 idea what these should really be set to. Anyway, mostly it 95 seems that zero is an allowable value, except for %cs and %ss 96 which have to have their lowest 2 bits be 11. See putreg() in 97 linux-2.6.23/arch/x86_64/kernel/ptrace.c for the apparently 98 relevant sanity checks. This fixes #145622. */ 99 regs.cs = 3; 100 regs.ds = 0; 101 regs.es = 0; 102 regs.fs = 0; 103 regs.ss = 3; 104 regs.gs = 0; 105 regs.fs_base = 0; 106 regs.gs_base = 0; 107 return VG_(ptrace)(VKI_PTRACE_SETREGS, pid, NULL, ®s); 108 109#elif defined(VGP_ppc32_linux) 110 Int rc = 0; 111 /* apparently the casting to void* is the Right Thing To Do */ 112 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R0 * 4), (void*)vex->guest_GPR0); 113 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R1 * 4), (void*)vex->guest_GPR1); 114 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R2 * 4), (void*)vex->guest_GPR2); 115 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R3 * 4), (void*)vex->guest_GPR3); 116 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R4 * 4), (void*)vex->guest_GPR4); 117 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R5 * 4), (void*)vex->guest_GPR5); 118 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R6 * 4), (void*)vex->guest_GPR6); 119 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R7 * 4), (void*)vex->guest_GPR7); 120 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R8 * 4), (void*)vex->guest_GPR8); 121 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R9 * 4), (void*)vex->guest_GPR9); 122 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R10 * 4), (void*)vex->guest_GPR10); 123 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R11 * 4), (void*)vex->guest_GPR11); 124 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R12 * 4), (void*)vex->guest_GPR12); 125 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R13 * 4), (void*)vex->guest_GPR13); 126 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R14 * 4), (void*)vex->guest_GPR14); 127 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R15 * 4), (void*)vex->guest_GPR15); 128 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R16 * 4), (void*)vex->guest_GPR16); 129 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R17 * 4), (void*)vex->guest_GPR17); 130 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R18 * 4), (void*)vex->guest_GPR18); 131 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R19 * 4), (void*)vex->guest_GPR19); 132 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R20 * 4), (void*)vex->guest_GPR20); 133 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R21 * 4), (void*)vex->guest_GPR21); 134 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R22 * 4), (void*)vex->guest_GPR22); 135 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R23 * 4), (void*)vex->guest_GPR23); 136 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R24 * 4), (void*)vex->guest_GPR24); 137 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R25 * 4), (void*)vex->guest_GPR25); 138 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R26 * 4), (void*)vex->guest_GPR26); 139 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R27 * 4), (void*)vex->guest_GPR27); 140 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R28 * 4), (void*)vex->guest_GPR28); 141 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R29 * 4), (void*)vex->guest_GPR29); 142 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R30 * 4), (void*)vex->guest_GPR30); 143 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R31 * 4), (void*)vex->guest_GPR31); 144 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_NIP * 4), (void*)vex->guest_CIA); 145 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_CCR * 4), 146 (void*)LibVEX_GuestPPC32_get_CR(vex)); 147 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_LNK * 4), (void*)vex->guest_LR); 148 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_CTR * 4), (void*)vex->guest_CTR); 149 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_XER * 4), 150 (void*)LibVEX_GuestPPC32_get_XER(vex)); 151 return rc; 152 153#elif defined(VGP_ppc64_linux) 154 Int rc = 0; 155 /* FRJ: copied nearly verbatim from the ppc32 case. I compared the 156 vki-ppc64-linux.h with its ppc32 counterpart and saw no 157 appreciable differences, other than the registers being 8 bytes 158 instead of 4. No idea why we don't set all of the entries 159 declared in vki_pt_regs, but ppc32 doesn't so there must be a 160 reason. 161 162 Finally, note that CR and XER are 32 bits even for ppc64 (see 163 libvex_guest_ppc64.h), but the vki_pt_regs struct still gives 164 them 64 bits. 165 */ 166 /* apparently the casting to void* is the Right Thing To Do */ 167 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R0 * 8), (void*)vex->guest_GPR0); 168 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R1 * 8), (void*)vex->guest_GPR1); 169 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R2 * 8), (void*)vex->guest_GPR2); 170 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R3 * 8), (void*)vex->guest_GPR3); 171 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R4 * 8), (void*)vex->guest_GPR4); 172 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R5 * 8), (void*)vex->guest_GPR5); 173 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R6 * 8), (void*)vex->guest_GPR6); 174 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R7 * 8), (void*)vex->guest_GPR7); 175 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R8 * 8), (void*)vex->guest_GPR8); 176 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R9 * 8), (void*)vex->guest_GPR9); 177 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R10 * 8), (void*)vex->guest_GPR10); 178 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R11 * 8), (void*)vex->guest_GPR11); 179 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R12 * 8), (void*)vex->guest_GPR12); 180 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R13 * 8), (void*)vex->guest_GPR13); 181 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R14 * 8), (void*)vex->guest_GPR14); 182 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R15 * 8), (void*)vex->guest_GPR15); 183 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R16 * 8), (void*)vex->guest_GPR16); 184 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R17 * 8), (void*)vex->guest_GPR17); 185 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R18 * 8), (void*)vex->guest_GPR18); 186 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R19 * 8), (void*)vex->guest_GPR19); 187 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R20 * 8), (void*)vex->guest_GPR20); 188 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R21 * 8), (void*)vex->guest_GPR21); 189 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R22 * 8), (void*)vex->guest_GPR22); 190 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R23 * 8), (void*)vex->guest_GPR23); 191 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R24 * 8), (void*)vex->guest_GPR24); 192 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R25 * 8), (void*)vex->guest_GPR25); 193 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R26 * 8), (void*)vex->guest_GPR26); 194 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R27 * 8), (void*)vex->guest_GPR27); 195 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R28 * 8), (void*)vex->guest_GPR28); 196 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R29 * 8), (void*)vex->guest_GPR29); 197 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R30 * 8), (void*)vex->guest_GPR30); 198 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_R31 * 8), (void*)vex->guest_GPR31); 199 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_NIP * 8), (void*)vex->guest_CIA); 200 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_CCR * 8), 201 (void*)(long)LibVEX_GuestPPC64_get_CR(vex)); 202 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_LNK * 8), (void*)vex->guest_LR); 203 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_CTR * 8), (void*)vex->guest_CTR); 204 rc |= VG_(ptrace)(VKI_PTRACE_POKEUSR, pid, (void*)(VKI_PT_XER * 8), 205 (void*)(long)LibVEX_GuestPPC64_get_XER(vex)); 206 return rc; 207 208#elif defined(VGP_arm_linux) 209 struct vki_user_regs_struct uregs; 210 VG_(memset)(&uregs, 0, sizeof(uregs)); 211 uregs.ARM_r0 = vex->guest_R0; 212 uregs.ARM_r1 = vex->guest_R1; 213 uregs.ARM_r2 = vex->guest_R2; 214 uregs.ARM_r3 = vex->guest_R3; 215 uregs.ARM_r4 = vex->guest_R4; 216 uregs.ARM_r5 = vex->guest_R5; 217 uregs.ARM_r6 = vex->guest_R6; 218 uregs.ARM_r7 = vex->guest_R7; 219 uregs.ARM_r8 = vex->guest_R8; 220 uregs.ARM_r9 = vex->guest_R9; 221 uregs.ARM_r10 = vex->guest_R10; 222 uregs.ARM_fp = vex->guest_R11; 223 uregs.ARM_ip = vex->guest_R12; 224 uregs.ARM_sp = vex->guest_R13; 225 uregs.ARM_lr = vex->guest_R14; 226 // Remove the T bit from the bottom of R15T. It will get shipped 227 // over in CPSR.T instead, since LibVEX_GuestARM_get_cpsr copies 228 // it from R15T[0]. 229 uregs.ARM_pc = vex->guest_R15T & 0xFFFFFFFE; 230 uregs.ARM_cpsr = LibVEX_GuestARM_get_cpsr(vex); 231 return VG_(ptrace)(VKI_PTRACE_SETREGS, pid, NULL, &uregs); 232 233#elif defined(VGP_ppc32_aix5) 234 I_die_here; 235 236#elif defined(VGP_ppc64_aix5) 237 I_die_here; 238 239#elif defined(VGP_x86_darwin) 240 I_die_here; 241 242#elif defined(VGP_amd64_darwin) 243 I_die_here; 244 245#else 246# error Unknown arch 247#endif 248} 249 250/* Start debugger and get it to attach to this process. Called if the 251 user requests this service after an error has been shown, so she can 252 poke around and look at parameters, memory, etc. You can't 253 meaningfully get the debugger to continue the program, though; to 254 continue, quit the debugger. */ 255void VG_(start_debugger) ( ThreadId tid ) 256{ 257# define N_BUF 4096 258 Int pid, rc; 259 260 pid = VG_(fork)(); 261 262 if (pid == 0) { 263 /* child */ 264 rc = VG_(ptrace)(VKI_PTRACE_TRACEME, 0, NULL, NULL); 265 vg_assert(rc == 0); 266 rc = VG_(kill)(VG_(getpid)(), VKI_SIGSTOP); 267 vg_assert(rc == 0); 268 269 } else if (pid > 0) { 270 /* parent */ 271 Int status; 272 Int res; 273 274 if ((res = VG_(waitpid)(pid, &status, 0)) == pid && 275 WIFSTOPPED(status) && WSTOPSIG(status) == VKI_SIGSTOP && 276 ptrace_setregs(pid, &(VG_(threads)[tid].arch.vex)) == 0 && 277 VG_(kill)(pid, VKI_SIGSTOP) == 0 && 278 VG_(ptrace)(VKI_PTRACE_DETACH, pid, NULL, 0) == 0) 279 { 280 Char pidbuf[15]; 281 Char file[50]; 282 Char buf[N_BUF]; 283 Char *bufptr; 284 Char *cmdptr; 285 286 VG_(sprintf)(pidbuf, "%d", pid); 287 VG_(sprintf)(file, "/proc/%d/fd/%d", pid, VG_(cl_exec_fd)); 288 289 bufptr = buf; 290 cmdptr = VG_(clo_db_command); 291 292 while (*cmdptr) { 293 /* each iteration can advance bufptr by at most the length 294 of file[], so the following assertion is generously 295 over-paranoid. */ 296 vg_assert(bufptr - buf < N_BUF-15-50-10/*paranoia*/); 297 switch (*cmdptr) { 298 case '%': 299 switch (*++cmdptr) { 300 case 'f': 301 VG_(memcpy)(bufptr, file, VG_(strlen)(file)); 302 bufptr += VG_(strlen)(file); 303 cmdptr++; 304 break; 305 case 'p': 306 VG_(memcpy)(bufptr, pidbuf, VG_(strlen)(pidbuf)); 307 bufptr += VG_(strlen)(pidbuf); 308 cmdptr++; 309 break; 310 default: 311 *bufptr++ = *cmdptr++; 312 break; 313 } 314 break; 315 default: 316 *bufptr++ = *cmdptr++; 317 break; 318 } 319 vg_assert(bufptr - buf < N_BUF-15-50-10/*paranoia*/); 320 } 321 322 *bufptr++ = '\0'; 323 324 VG_(message)(Vg_UserMsg, "starting debugger with cmd: %s\n", buf); 325 res = VG_(system)(buf); 326 if (res == 0) { 327 VG_(message)(Vg_UserMsg, "\n"); 328 VG_(message)(Vg_UserMsg, 329 "Debugger has detached. Valgrind regains control." 330 " We continue.\n"); 331 } else { 332 VG_(message)(Vg_UserMsg, 333 "Warning: Debugger attach failed! (sys_system)\n"); 334 VG_(message)(Vg_UserMsg, "\n"); 335 } 336 } else { 337 VG_(message)(Vg_UserMsg, 338 "Warning: Debugger attach failed! (ptrace problem?)\n"); 339 VG_(message)(Vg_UserMsg, "\n"); 340 } 341 342 VG_(kill)(pid, VKI_SIGKILL); 343 VG_(waitpid)(pid, &status, 0); 344 } 345# undef N_BUF 346} 347 348 349 350/*--------------------------------------------------------------------*/ 351/*--- end ---*/ 352/*--------------------------------------------------------------------*/ 353