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, GByteArray *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                 return gdb_get_regl(mem_buf, 0);
 102             }
 103         } else {
 104             return gdb_get_reg32(mem_buf, env->regs[gpr_map32[n]]);
 105         }
 106     } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) {
 107         floatx80 *fp = (floatx80 *) &env->fpregs[n - IDX_FP_REGS];
 108         int len = gdb_get_reg64(mem_buf, cpu_to_le64(fp->low));
 109         len += gdb_get_reg16(mem_buf, cpu_to_le16(fp->high));
 110         return len;
 111     } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) {
 112         n -= IDX_XMM_REGS;
 113         if (n < CPU_NB_REGS32 || TARGET_LONG_BITS == 64) {
 114             return gdb_get_reg128(mem_buf,
 115                                   env->xmm_regs[n].ZMM_Q(0),
 116                                   env->xmm_regs[n].ZMM_Q(1));
 117         }
 118     } else {
 119         switch (n) {
 120         case IDX_IP_REG:
 121             if (TARGET_LONG_BITS == 64) {
 122                 if (env->hflags & HF_CS64_MASK) {
 123                     return gdb_get_reg64(mem_buf, env->eip);
 124                 } else {
 125                     return gdb_get_reg64(mem_buf, env->eip & 0xffffffffUL);
 126                 }
 127             } else {
 128                 return gdb_get_reg32(mem_buf, env->eip);
 129             }
 130         case IDX_FLAGS_REG:
 131             return gdb_get_reg32(mem_buf, env->eflags);
 132
 133         case IDX_SEG_REGS:
 134             return gdb_get_reg32(mem_buf, env->segs[R_CS].selector);
 135         case IDX_SEG_REGS + 1:
 136             return gdb_get_reg32(mem_buf, env->segs[R_SS].selector);
 137         case IDX_SEG_REGS + 2:
 138             return gdb_get_reg32(mem_buf, env->segs[R_DS].selector);
 139         case IDX_SEG_REGS + 3:
 140             return gdb_get_reg32(mem_buf, env->segs[R_ES].selector);
 141         case IDX_SEG_REGS + 4:
 142             return gdb_get_reg32(mem_buf, env->segs[R_FS].selector);
 143         case IDX_SEG_REGS + 5:
 144             return gdb_get_reg32(mem_buf, env->segs[R_GS].selector);
 145
 146         case IDX_SEG_REGS + 6:
 147             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 148                 return gdb_get_reg64(mem_buf, env->segs[R_FS].base);
 149             }
 150             return gdb_get_reg32(mem_buf, env->segs[R_FS].base);
 151
 152         case IDX_SEG_REGS + 7:
 153             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 154                 return gdb_get_reg64(mem_buf, env->segs[R_GS].base);
 155             }
 156             return gdb_get_reg32(mem_buf, env->segs[R_GS].base);
 157
 158         case IDX_SEG_REGS + 8:
 159 #ifdef TARGET_X86_64
 160             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 161                 return gdb_get_reg64(mem_buf, env->kernelgsbase);
 162             }
 163             return gdb_get_reg32(mem_buf, env->kernelgsbase);
 164 #else
 165             return gdb_get_reg32(mem_buf, 0);
 166 #endif
 167
 168         case IDX_FP_REGS + 8:
 169             return gdb_get_reg32(mem_buf, env->fpuc);
 170         case IDX_FP_REGS + 9:
 171             return gdb_get_reg32(mem_buf, (env->fpus & ~0x3800) |
 172                                           (env->fpstt & 0x7) << 11);
 173         case IDX_FP_REGS + 10:
 174             return gdb_get_reg32(mem_buf, 0); /* ftag */
 175         case IDX_FP_REGS + 11:
 176             return gdb_get_reg32(mem_buf, 0); /* fiseg */
 177         case IDX_FP_REGS + 12:
 178             return gdb_get_reg32(mem_buf, 0); /* fioff */
 179         case IDX_FP_REGS + 13:
 180             return gdb_get_reg32(mem_buf, 0); /* foseg */
 181         case IDX_FP_REGS + 14:
 182             return gdb_get_reg32(mem_buf, 0); /* fooff */
 183         case IDX_FP_REGS + 15:
 184             return gdb_get_reg32(mem_buf, 0); /* fop */
 185
 186         case IDX_MXCSR_REG:
 187             update_mxcsr_from_sse_status(env);
 188             return gdb_get_reg32(mem_buf, env->mxcsr);
 189
 190         case IDX_CTL_CR0_REG:
 191             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 192                 return gdb_get_reg64(mem_buf, env->cr[0]);
 193             }
 194             return gdb_get_reg32(mem_buf, env->cr[0]);
 195
 196         case IDX_CTL_CR2_REG:
 197             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 198                 return gdb_get_reg64(mem_buf, env->cr[2]);
 199             }
 200             return gdb_get_reg32(mem_buf, env->cr[2]);
 201
 202         case IDX_CTL_CR3_REG:
 203             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 204                 return gdb_get_reg64(mem_buf, env->cr[3]);
 205             }
 206             return gdb_get_reg32(mem_buf, env->cr[3]);
 207
 208         case IDX_CTL_CR4_REG:
 209             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 210                 return gdb_get_reg64(mem_buf, env->cr[4]);
 211             }
 212             return gdb_get_reg32(mem_buf, env->cr[4]);
 213
 214         case IDX_CTL_CR8_REG:
 215 #ifdef CONFIG_SOFTMMU
 216             tpr = cpu_get_apic_tpr(cpu->apic_state);
 217 #else
 218             tpr = 0;
 219 #endif
 220             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 221                 return gdb_get_reg64(mem_buf, tpr);
 222             }
 223             return gdb_get_reg32(mem_buf, tpr);
 224
 225         case IDX_CTL_EFER_REG:
 226             if ((env->hflags & HF_CS64_MASK) || GDB_FORCE_64) {
 227                 return gdb_get_reg64(mem_buf, env->efer);
 228             }
 229             return gdb_get_reg32(mem_buf, env->efer);
 230         }
 231     }
 232     return 0;
 233 }
 234
 235 static int x86_cpu_gdb_load_seg(X86CPU *cpu, int sreg, uint8_t *mem_buf)
 236 {
 237     CPUX86State *env = &cpu->env;
 238     uint16_t selector = ldl_p(mem_buf);
 239
 240     if (selector != env->segs[sreg].selector) {
 241 #if defined(CONFIG_USER_ONLY)
 242         cpu_x86_load_seg(env, sreg, selector);
 243 #else
 244         unsigned int limit, flags;
 245         target_ulong base;
 246
 247         if (!(env->cr[0] & CR0_PE_MASK) || (env->eflags & VM_MASK)) {
 248             int dpl = (env->eflags & VM_MASK) ? 3 : 0;
 249             base = selector << 4;
 250             limit = 0xffff;
 251             flags = DESC_P_MASK | DESC_S_MASK | DESC_W_MASK |
 252                     DESC_A_MASK | (dpl << DESC_DPL_SHIFT);
 253         } else {
 254             if (!cpu_x86_get_descr_debug(env, selector, &base, &limit,
 255                                          &flags)) {
 256                 return 4;
 257             }
 258         }
 259         cpu_x86_load_seg_cache(env, sreg, selector, base, limit, flags);
 260 #endif
 261     }
 262     return 4;
 263 }
 264
 265 int x86_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
 266 {
 267     X86CPU *cpu = X86_CPU(cs);
 268     CPUX86State *env = &cpu->env;
 269     uint32_t tmp;
 270
 271     /* N.B. GDB can't deal with changes in registers or sizes in the middle
 272        of a session. So if we're in 32-bit mode on a 64-bit cpu, still act
 273        as if we're on a 64-bit cpu. */
 274
 275     if (n < CPU_NB_REGS) {
 276         if (TARGET_LONG_BITS == 64) {
 277             if (env->hflags & HF_CS64_MASK) {
 278                 env->regs[gpr_map[n]] = ldtul_p(mem_buf);
 279             } else if (n < CPU_NB_REGS32) {
 280                 env->regs[gpr_map[n]] = ldtul_p(mem_buf) & 0xffffffffUL;
 281             }
 282             return sizeof(target_ulong);
 283         } else if (n < CPU_NB_REGS32) {
 284             n = gpr_map32[n];
 285             env->regs[n] &= ~0xffffffffUL;
 286             env->regs[n] |= (uint32_t)ldl_p(mem_buf);
 287             return 4;
 288         }
 289     } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) {
 290         floatx80 *fp = (floatx80 *) &env->fpregs[n - IDX_FP_REGS];
 291         fp->low = le64_to_cpu(* (uint64_t *) mem_buf);
 292         fp->high = le16_to_cpu(* (uint16_t *) (mem_buf + 8));
 293         return 10;
 294     } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) {
 295         n -= IDX_XMM_REGS;
 296         if (n < CPU_NB_REGS32 || TARGET_LONG_BITS == 64) {
 297             env->xmm_regs[n].ZMM_Q(0) = ldq_p(mem_buf);
 298             env->xmm_regs[n].ZMM_Q(1) = ldq_p(mem_buf + 8);
 299             return 16;
 300         }
 301     } else {
 302         switch (n) {
 303         case IDX_IP_REG:
 304             if (TARGET_LONG_BITS == 64) {
 305                 if (env->hflags & HF_CS64_MASK) {
 306                     env->eip = ldq_p(mem_buf);
 307                 } else {
 308                     env->eip = ldq_p(mem_buf) & 0xffffffffUL;
 309                 }
 310                 return 8;
 311             } else {
 312                 env->eip &= ~0xffffffffUL;
 313                 env->eip |= (uint32_t)ldl_p(mem_buf);
 314                 return 4;
 315             }
 316         case IDX_FLAGS_REG:
 317             env->eflags = ldl_p(mem_buf);
 318             return 4;
 319
 320         case IDX_SEG_REGS:
 321             return x86_cpu_gdb_load_seg(cpu, R_CS, mem_buf);
 322         case IDX_SEG_REGS + 1:
 323             return x86_cpu_gdb_load_seg(cpu, R_SS, mem_buf);
 324         case IDX_SEG_REGS + 2:
 325             return x86_cpu_gdb_load_seg(cpu, R_DS, mem_buf);
 326         case IDX_SEG_REGS + 3:
 327             return x86_cpu_gdb_load_seg(cpu, R_ES, mem_buf);
 328         case IDX_SEG_REGS + 4:
 329             return x86_cpu_gdb_load_seg(cpu, R_FS, mem_buf);
 330         case IDX_SEG_REGS + 5:
 331             return x86_cpu_gdb_load_seg(cpu, R_GS, mem_buf);
 332
 333         case IDX_SEG_REGS + 6:
 334             if (env->hflags & HF_CS64_MASK) {
 335                 env->segs[R_FS].base = ldq_p(mem_buf);
 336                 return 8;
 337             }
 338             env->segs[R_FS].base = ldl_p(mem_buf);
 339             return 4;
 340
 341         case IDX_SEG_REGS + 7:
 342             if (env->hflags & HF_CS64_MASK) {
 343                 env->segs[R_GS].base = ldq_p(mem_buf);
 344                 return 8;
 345             }
 346             env->segs[R_GS].base = ldl_p(mem_buf);
 347             return 4;
 348
 349         case IDX_SEG_REGS + 8:
 350 #ifdef TARGET_X86_64
 351             if (env->hflags & HF_CS64_MASK) {
 352                 env->kernelgsbase = ldq_p(mem_buf);
 353                 return 8;
 354             }
 355             env->kernelgsbase = ldl_p(mem_buf);
 356 #endif
 357             return 4;
 358
 359         case IDX_FP_REGS + 8:
 360             cpu_set_fpuc(env, ldl_p(mem_buf));
 361             return 4;
 362         case IDX_FP_REGS + 9:
 363             tmp = ldl_p(mem_buf);
 364             env->fpstt = (tmp >> 11) & 7;
 365             env->fpus = tmp & ~0x3800;
 366             return 4;
 367         case IDX_FP_REGS + 10: /* ftag */
 368             return 4;
 369         case IDX_FP_REGS + 11: /* fiseg */
 370             return 4;
 371         case IDX_FP_REGS + 12: /* fioff */
 372             return 4;
 373         case IDX_FP_REGS + 13: /* foseg */
 374             return 4;
 375         case IDX_FP_REGS + 14: /* fooff */
 376             return 4;
 377         case IDX_FP_REGS + 15: /* fop */
 378             return 4;
 379
 380         case IDX_MXCSR_REG:
 381             cpu_set_mxcsr(env, ldl_p(mem_buf));
 382             return 4;
 383
 384         case IDX_CTL_CR0_REG:
 385             if (env->hflags & HF_CS64_MASK) {
 386                 cpu_x86_update_cr0(env, ldq_p(mem_buf));
 387                 return 8;
 388             }
 389             cpu_x86_update_cr0(env, ldl_p(mem_buf));
 390             return 4;
 391
 392         case IDX_CTL_CR2_REG:
 393             if (env->hflags & HF_CS64_MASK) {
 394                 env->cr[2] = ldq_p(mem_buf);
 395                 return 8;
 396             }
 397             env->cr[2] = ldl_p(mem_buf);
 398             return 4;
 399
 400         case IDX_CTL_CR3_REG:
 401             if (env->hflags & HF_CS64_MASK) {
 402                 cpu_x86_update_cr3(env, ldq_p(mem_buf));
 403                 return 8;
 404             }
 405             cpu_x86_update_cr3(env, ldl_p(mem_buf));
 406             return 4;
 407
 408         case IDX_CTL_CR4_REG:
 409             if (env->hflags & HF_CS64_MASK) {
 410                 cpu_x86_update_cr4(env, ldq_p(mem_buf));
 411                 return 8;
 412             }
 413             cpu_x86_update_cr4(env, ldl_p(mem_buf));
 414             return 4;
 415
 416         case IDX_CTL_CR8_REG:
 417             if (env->hflags & HF_CS64_MASK) {
 418 #ifdef CONFIG_SOFTMMU
 419                 cpu_set_apic_tpr(cpu->apic_state, ldq_p(mem_buf));
 420 #endif
 421                 return 8;
 422             }
 423 #ifdef CONFIG_SOFTMMU
 424             cpu_set_apic_tpr(cpu->apic_state, ldl_p(mem_buf));
 425 #endif
 426             return 4;
 427
 428         case IDX_CTL_EFER_REG:
 429             if (env->hflags & HF_CS64_MASK) {
 430                 cpu_load_efer(env, ldq_p(mem_buf));
 431                 return 8;
 432             }
 433             cpu_load_efer(env, ldl_p(mem_buf));
 434             return 4;
 435
 436         }
 437     }
 438     /* Unrecognised register.  */
 439     return 0;
 440 }