target/i386/gdbstub.c

   1 /*
   2  * x86 gdb server stub
   3  *
   4  * Copyright (c) 2003-2005 Fabrice Bellard
   5  * Copyright (c) 2013 SUSE LINUX Products GmbH
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20 #include "qemu/osdep.h"
  21 #include "cpu.h"
  22 #include "exec/gdbstub.h"
  23
  24 #ifdef TARGET_X86_64
  25 static const int gpr_map[16] = {
  26     R_EAX, R_EBX, R_ECX, R_EDX, R_ESI, R_EDI, R_EBP, R_ESP,
  27     8, 9, 10, 11, 12, 13, 14, 15
  28 };
  29 #else
  30 #define gpr_map gpr_map32
  31 #endif
  32 static const int gpr_map32[8] = { 0, 1, 2, 3, 4, 5, 6, 7 };
  33
  34 /*
  35  * Keep these in sync with assignment to
  36  * gdb_num_core_regs in target/i386/cpu.c
  37  * and with the machine description
  38  */
  39
  40 /*
  41  * SEG: 6 segments, plus fs_base, gs_base, kernel_gs_base
  42  */
  43
  44 /*
  45  * general regs ----->  8 or 16
  46  */
  47 #define IDX_NB_IP       1
  48 #define IDX_NB_FLAGS    1
  49 #define IDX_NB_SEG      (6 + 3)
  50 #define IDX_NB_CTL      6
  51 #define IDX_NB_FP       16
  52 /*
  53  * fpu regs ----------> 8 or 16
  54  */
  55 #define IDX_NB_MXCSR    1
  56 /*
  57  *          total ----> 8+1+1+9+6+16+8+1=50 or 16+1+1+9+6+16+16+1=66
  58  */
  59
  60 #define IDX_IP_REG      CPU_NB_REGS
  61 #define IDX_FLAGS_REG   (IDX_IP_REG + IDX_NB_IP)
  62 #define IDX_SEG_REGS    (IDX_FLAGS_REG + IDX_NB_FLAGS)
  63 #define IDX_CTL_REGS    (IDX_SEG_REGS + IDX_NB_SEG)
  64 #define IDX_FP_REGS     (IDX_CTL_REGS + IDX_NB_CTL)
  65 #define IDX_XMM_REGS    (IDX_FP_REGS + IDX_NB_FP)
  66 #define IDX_MXCSR_REG   (IDX_XMM_REGS + CPU_NB_REGS)
  67
  68 #define IDX_CTL_CR0_REG     (IDX_CTL_REGS + 0)
  69 #define IDX_CTL_CR2_REG     (IDX_CTL_REGS + 1)
  70 #define IDX_CTL_CR3_REG     (IDX_CTL_REGS + 2)
  71 #define IDX_CTL_CR4_REG     (IDX_CTL_REGS + 3)
  72 #define IDX_CTL_CR8_REG     (IDX_CTL_REGS + 4)
  73 #define IDX_CTL_EFER_REG    (IDX_CTL_REGS + 5)
  74
  75 #ifdef TARGET_X86_64
  76 #define GDB_FORCE_64 1
  77 #else
  78 #define GDB_FORCE_64 0
  79 #endif
  80
  81
  82 int x86_cpu_gdb_read_register(CPUState *cs, uint8_t *mem_buf, int n)
  83 {
  84     X86CPU *cpu = X86_CPU(cs);
  85     CPUX86State *env = &cpu->env;
  86
  87     uint64_t tpr;
  88
  89     /* N.B. GDB can't deal with changes in registers or sizes in the middle
  90        of a session. So if we're in 32-bit mode on a 64-bit cpu, still act
  91        as if we're on a 64-bit cpu. */
  92
  93     if (n < CPU_NB_REGS) {
  94         if (TARGET_LONG_BITS == 64) {
  95             if (env->hflags & HF_CS64_MASK) {
  96                 return gdb_get_reg64(mem_buf, env->regs[gpr_map[n]]);
  97             } else if (n < CPU_NB_REGS32) {
  98                 return gdb_get_reg64(mem_buf,
  99                                      env->regs[gpr_map[n]] & 0xffffffffUL);
 100             } else {
 101                 memset(mem_buf, 0, sizeof(target_ulong));
 102                 return sizeof(target_ulong);
 103             }
 104         } else {
 105             return gdb_get_reg32(mem_buf, env->regs[gpr_map32[n]]);
 106         }
 107     } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) {
 108 #ifdef USE_X86LDOUBLE
 109         /* FIXME: byteswap float values - after fixing fpregs layout. */
 110         memcpy(mem_buf, &env->fpregs[n - IDX_FP_REGS], 10);
 111 #else
 112         memset(mem_buf, 0, 10);
 113 #endif
 114         return 10;
 115     } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) {
 116         n -= IDX_XMM_REGS;
 117         if (n < CPU_NB_REGS32 || TARGET_LONG_BITS == 64) {
 118             stq_p(mem_buf, env->xmm_regs[n].ZMM_Q(0));
 119             stq_p(mem_buf + 8, env->xmm_regs[n].ZMM_Q(1));
 120             return 16;
 121         }
 122     } else {
 123         switch (n) {
 124         case IDX_IP_REG:
 125             if (TARGET_LONG_BITS == 64) {
 126                 if (env->hflags & HF_CS64_MASK) {
 127                     return gdb_get_reg64(mem_buf, env->eip);
 128                 } else {
 129                     return gdb_get_reg64(mem_buf, env->eip & 0xffffffffUL);
 130                 }
 131             } else {
 132                 return gdb_get_reg32(mem_buf, env->eip);
 133             }
 134         case IDX_FLAGS_REG:
 135             return gdb_get_reg32(mem_buf, env->eflags);
 136
 137         case IDX_SEG_REGS:
 138             return gdb_get_reg32(mem_buf, env->segs[R_CS].selector);
 139         case IDX_SEG_REGS + 1:
 140             return gdb_get_reg32(mem_buf, env->segs[R_SS].selector);
 141         case IDX_SEG_REGS + 2:
 142             return gdb_get_reg32(mem_buf, env->segs[R_DS].selector);
 143         case IDX_SEG_REGS + 3:
 144             return gdb_get_reg32(mem_buf, env->segs[R_ES].selector);
 145         case IDX_SEG_REGS + 4:
 146             return gdb_get_reg32(mem_buf, env->segs[R_FS].selector);
 147         case IDX_SEG_REGS + 5:
 148             return gdb_get_reg32(mem_buf, env->segs[R_GS].selector);
 149
 150         case IDX_SEG_REGS + 6:
 151             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 152                 return gdb_get_reg64(mem_buf, env->segs[R_FS].base);
 153             }
 154             return gdb_get_reg32(mem_buf, env->segs[R_FS].base);
 155
 156         case IDX_SEG_REGS + 7:
 157             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 158                 return gdb_get_reg64(mem_buf, env->segs[R_GS].base);
 159             }
 160             return gdb_get_reg32(mem_buf, env->segs[R_GS].base);
 161
 162         case IDX_SEG_REGS + 8:
 163 #ifdef TARGET_X86_64
 164             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 165                 return gdb_get_reg64(mem_buf, env->kernelgsbase);
 166             }
 167             return gdb_get_reg32(mem_buf, env->kernelgsbase);
 168 #else
 169             return gdb_get_reg32(mem_buf, 0);
 170 #endif
 171
 172         case IDX_FP_REGS + 8:
 173             return gdb_get_reg32(mem_buf, env->fpuc);
 174         case IDX_FP_REGS + 9:
 175             return gdb_get_reg32(mem_buf, (env->fpus & ~0x3800) |
 176                                           (env->fpstt & 0x7) << 11);
 177         case IDX_FP_REGS + 10:
 178             return gdb_get_reg32(mem_buf, 0); /* ftag */
 179         case IDX_FP_REGS + 11:
 180             return gdb_get_reg32(mem_buf, 0); /* fiseg */
 181         case IDX_FP_REGS + 12:
 182             return gdb_get_reg32(mem_buf, 0); /* fioff */
 183         case IDX_FP_REGS + 13:
 184             return gdb_get_reg32(mem_buf, 0); /* foseg */
 185         case IDX_FP_REGS + 14:
 186             return gdb_get_reg32(mem_buf, 0); /* fooff */
 187         case IDX_FP_REGS + 15:
 188             return gdb_get_reg32(mem_buf, 0); /* fop */
 189
 190         case IDX_MXCSR_REG:
 191             return gdb_get_reg32(mem_buf, env->mxcsr);
 192
 193         case IDX_CTL_CR0_REG:
 194             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 195                 return gdb_get_reg64(mem_buf, env->cr[0]);
 196             }
 197             return gdb_get_reg32(mem_buf, env->cr[0]);
 198
 199         case IDX_CTL_CR2_REG:
 200             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 201                 return gdb_get_reg64(mem_buf, env->cr[2]);
 202             }
 203             return gdb_get_reg32(mem_buf, env->cr[2]);
 204
 205         case IDX_CTL_CR3_REG:
 206             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 207                 return gdb_get_reg64(mem_buf, env->cr[3]);
 208             }
 209             return gdb_get_reg32(mem_buf, env->cr[3]);
 210
 211         case IDX_CTL_CR4_REG:
 212             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 213                 return gdb_get_reg64(mem_buf, env->cr[4]);
 214             }
 215             return gdb_get_reg32(mem_buf, env->cr[4]);
 216
 217         case IDX_CTL_CR8_REG:
 218 #ifdef CONFIG_SOFTMMU
 219             tpr = cpu_get_apic_tpr(cpu->apic_state);
 220 #else
 221             tpr = 0;
 222 #endif
 223             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 224                 return gdb_get_reg64(mem_buf, tpr);
 225             }
 226             return gdb_get_reg32(mem_buf, tpr);
 227
 228         case IDX_CTL_EFER_REG:
 229             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 230                 return gdb_get_reg64(mem_buf, env->efer);
 231             }
 232             return gdb_get_reg32(mem_buf, env->efer);
 233         }
 234     }
 235     return 0;
 236 }
 237
 238 static int x86_cpu_gdb_load_seg(X86CPU *cpu, int sreg, uint8_t *mem_buf)
 239 {
 240     CPUX86State *env = &cpu->env;
 241     uint16_t selector = ldl_p(mem_buf);
 242
 243     if (selector != env->segs[sreg].selector) {
 244 #if defined(CONFIG_USER_ONLY)
 245         cpu_x86_load_seg(env, sreg, selector);
 246 #else
 247         unsigned int limit, flags;
 248         target_ulong base;
 249
 250         if (!(env->cr[0] & CR0_PE_MASK) || (env->eflags & VM_MASK)) {
 251             int dpl = (env->eflags & VM_MASK) ? 3 : 0;
 252             base = selector << 4;
 253             limit = 0xffff;
 254             flags = DESC_P_MASK | DESC_S_MASK | DESC_W_MASK |
 255                     DESC_A_MASK | (dpl << DESC_DPL_SHIFT);
 256         } else {
 257             if (!cpu_x86_get_descr_debug(env, selector, &base, &limit,
 258                                          &flags)) {
 259                 return 4;
 260             }
 261         }
 262         cpu_x86_load_seg_cache(env, sreg, selector, base, limit, flags);
 263 #endif
 264     }
 265     return 4;
 266 }
 267
 268 int x86_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
 269 {
 270     X86CPU *cpu = X86_CPU(cs);
 271     CPUX86State *env = &cpu->env;
 272     uint32_t tmp;
 273
 274     /* N.B. GDB can't deal with changes in registers or sizes in the middle
 275        of a session. So if we're in 32-bit mode on a 64-bit cpu, still act
 276        as if we're on a 64-bit cpu. */
 277
 278     if (n < CPU_NB_REGS) {
 279         if (TARGET_LONG_BITS == 64) {
 280             if (env->hflags & HF_CS64_MASK) {
 281                 env->regs[gpr_map[n]] = ldtul_p(mem_buf);
 282             } else if (n < CPU_NB_REGS32) {
 283                 env->regs[gpr_map[n]] = ldtul_p(mem_buf) & 0xffffffffUL;
 284             }
 285             return sizeof(target_ulong);
 286         } else if (n < CPU_NB_REGS32) {
 287             n = gpr_map32[n];
 288             env->regs[n] &= ~0xffffffffUL;
 289             env->regs[n] |= (uint32_t)ldl_p(mem_buf);
 290             return 4;
 291         }
 292     } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) {
 293 #ifdef USE_X86LDOUBLE
 294         /* FIXME: byteswap float values - after fixing fpregs layout. */
 295         memcpy(&env->fpregs[n - IDX_FP_REGS], mem_buf, 10);
 296 #endif
 297         return 10;
 298     } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) {
 299         n -= IDX_XMM_REGS;
 300         if (n < CPU_NB_REGS32 || TARGET_LONG_BITS == 64) {
 301             env->xmm_regs[n].ZMM_Q(0) = ldq_p(mem_buf);
 302             env->xmm_regs[n].ZMM_Q(1) = ldq_p(mem_buf + 8);
 303             return 16;
 304         }
 305     } else {
 306         switch (n) {
 307         case IDX_IP_REG:
 308             if (TARGET_LONG_BITS == 64) {
 309                 if (env->hflags & HF_CS64_MASK) {
 310                     env->eip = ldq_p(mem_buf);
 311                 } else {
 312                     env->eip = ldq_p(mem_buf) & 0xffffffffUL;
 313                 }
 314                 return 8;
 315             } else {
 316                 env->eip &= ~0xffffffffUL;
 317                 env->eip |= (uint32_t)ldl_p(mem_buf);
 318                 return 4;
 319             }
 320         case IDX_FLAGS_REG:
 321             env->eflags = ldl_p(mem_buf);
 322             return 4;
 323
 324         case IDX_SEG_REGS:
 325             return x86_cpu_gdb_load_seg(cpu, R_CS, mem_buf);
 326         case IDX_SEG_REGS + 1:
 327             return x86_cpu_gdb_load_seg(cpu, R_SS, mem_buf);
 328         case IDX_SEG_REGS + 2:
 329             return x86_cpu_gdb_load_seg(cpu, R_DS, mem_buf);
 330         case IDX_SEG_REGS + 3:
 331             return x86_cpu_gdb_load_seg(cpu, R_ES, mem_buf);
 332         case IDX_SEG_REGS + 4:
 333             return x86_cpu_gdb_load_seg(cpu, R_FS, mem_buf);
 334         case IDX_SEG_REGS + 5:
 335             return x86_cpu_gdb_load_seg(cpu, R_GS, mem_buf);
 336
 337         case IDX_SEG_REGS + 6:
 338             if (env->hflags & HF_CS64_MASK) {
 339                 env->segs[R_FS].base = ldq_p(mem_buf);
 340                 return 8;
 341             }
 342             env->segs[R_FS].base = ldl_p(mem_buf);
 343             return 4;
 344
 345         case IDX_SEG_REGS + 7:
 346             if (env->hflags & HF_CS64_MASK) {
 347                 env->segs[R_GS].base = ldq_p(mem_buf);
 348                 return 8;
 349             }
 350             env->segs[R_GS].base = ldl_p(mem_buf);
 351             return 4;
 352
 353         case IDX_SEG_REGS + 8:
 354 #ifdef TARGET_X86_64
 355             if (env->hflags & HF_CS64_MASK) {
 356                 env->kernelgsbase = ldq_p(mem_buf);
 357                 return 8;
 358             }
 359             env->kernelgsbase = ldl_p(mem_buf);
 360 #endif
 361             return 4;
 362
 363         case IDX_FP_REGS + 8:
 364             cpu_set_fpuc(env, ldl_p(mem_buf));
 365             return 4;
 366         case IDX_FP_REGS + 9:
 367             tmp = ldl_p(mem_buf);
 368             env->fpstt = (tmp >> 11) & 7;
 369             env->fpus = tmp & ~0x3800;
 370             return 4;
 371         case IDX_FP_REGS + 10: /* ftag */
 372             return 4;
 373         case IDX_FP_REGS + 11: /* fiseg */
 374             return 4;
 375         case IDX_FP_REGS + 12: /* fioff */
 376             return 4;
 377         case IDX_FP_REGS + 13: /* foseg */
 378             return 4;
 379         case IDX_FP_REGS + 14: /* fooff */
 380             return 4;
 381         case IDX_FP_REGS + 15: /* fop */
 382             return 4;
 383
 384         case IDX_MXCSR_REG:
 385             cpu_set_mxcsr(env, ldl_p(mem_buf));
 386             return 4;
 387
 388         case IDX_CTL_CR0_REG:
 389             if (env->hflags & HF_CS64_MASK) {
 390                 cpu_x86_update_cr0(env, ldq_p(mem_buf));
 391                 return 8;
 392             }
 393             cpu_x86_update_cr0(env, ldl_p(mem_buf));
 394             return 4;
 395
 396         case IDX_CTL_CR2_REG:
 397             if (env->hflags & HF_CS64_MASK) {
 398                 env->cr[2] = ldq_p(mem_buf);
 399                 return 8;
 400             }
 401             env->cr[2] = ldl_p(mem_buf);
 402             return 4;
 403
 404         case IDX_CTL_CR3_REG:
 405             if (env->hflags & HF_CS64_MASK) {
 406                 cpu_x86_update_cr3(env, ldq_p(mem_buf));
 407                 return 8;
 408             }
 409             cpu_x86_update_cr3(env, ldl_p(mem_buf));
 410             return 4;
 411
 412         case IDX_CTL_CR4_REG:
 413             if (env->hflags & HF_CS64_MASK) {
 414                 cpu_x86_update_cr4(env, ldq_p(mem_buf));
 415                 return 8;
 416             }
 417             cpu_x86_update_cr4(env, ldl_p(mem_buf));
 418             return 4;
 419
 420         case IDX_CTL_CR8_REG:
 421             if (env->hflags & HF_CS64_MASK) {
 422 #ifdef CONFIG_SOFTMMU
 423                 cpu_set_apic_tpr(cpu->apic_state, ldq_p(mem_buf));
 424 #endif
 425                 return 8;
 426             }
 427 #ifdef CONFIG_SOFTMMU
 428             cpu_set_apic_tpr(cpu->apic_state, ldl_p(mem_buf));
 429 #endif
 430             return 4;
 431
 432         case IDX_CTL_EFER_REG:
 433             if (env->hflags & HF_CS64_MASK) {
 434                 cpu_load_efer(env, ldq_p(mem_buf));
 435                 return 8;
 436             }
 437             cpu_load_efer(env, ldl_p(mem_buf));
 438             return 4;
 439
 440         }
 441     }
 442     /* Unrecognised register.  */
 443     return 0;
 444 }