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 2.1 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 "gdbstub/helpers.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 static int gdb_read_reg_cs64(uint32_t hflags, GByteArray *buf, target_ulong val) 82 { 83 if ((hflags & HF_CS64_MASK) || GDB_FORCE_64) { 84 return gdb_get_reg64(buf, val); 85 } 86 return gdb_get_reg32(buf, val); 87 } 88 89 static int gdb_write_reg_cs64(uint32_t hflags, uint8_t *buf, target_ulong *val) 90 { 91 if (hflags & HF_CS64_MASK) { 92 *val = ldq_p(buf); 93 return 8; 94 } 95 *val = ldl_p(buf); 96 return 4; 97 } 98 99 int x86_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n) 100 { 101 X86CPU *cpu = X86_CPU(cs); 102 CPUX86State *env = &cpu->env; 103 104 uint64_t tpr; 105 106 /* N.B. GDB can't deal with changes in registers or sizes in the middle 107 of a session. So if we're in 32-bit mode on a 64-bit cpu, still act 108 as if we're on a 64-bit cpu. */ 109 110 if (n < CPU_NB_REGS) { 111 if (TARGET_LONG_BITS == 64) { 112 if (env->hflags & HF_CS64_MASK) { 113 return gdb_get_reg64(mem_buf, env->regs[gpr_map[n]]); 114 } else if (n < CPU_NB_REGS32) { 115 return gdb_get_reg64(mem_buf, 116 env->regs[gpr_map[n]] & 0xffffffffUL); 117 } else { 118 return gdb_get_regl(mem_buf, 0); 119 } 120 } else { 121 return gdb_get_reg32(mem_buf, env->regs[gpr_map32[n]]); 122 } 123 } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) { 124 int st_index = n - IDX_FP_REGS; 125 int r_index = (st_index + env->fpstt) % 8; 126 floatx80 *fp = &env->fpregs[r_index].d; 127 int len = gdb_get_reg64(mem_buf, cpu_to_le64(fp->low)); 128 len += gdb_get_reg16(mem_buf, cpu_to_le16(fp->high)); 129 return len; 130 } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) { 131 n -= IDX_XMM_REGS; 132 if (n < CPU_NB_REGS32 || TARGET_LONG_BITS == 64) { 133 return gdb_get_reg128(mem_buf, 134 env->xmm_regs[n].ZMM_Q(1), 135 env->xmm_regs[n].ZMM_Q(0)); 136 } 137 } else { 138 switch (n) { 139 case IDX_IP_REG: 140 if (TARGET_LONG_BITS == 64) { 141 if (env->hflags & HF_CS64_MASK) { 142 return gdb_get_reg64(mem_buf, env->eip); 143 } else { 144 return gdb_get_reg64(mem_buf, env->eip & 0xffffffffUL); 145 } 146 } else { 147 return gdb_get_reg32(mem_buf, env->eip); 148 } 149 case IDX_FLAGS_REG: 150 return gdb_get_reg32(mem_buf, env->eflags); 151 152 case IDX_SEG_REGS: 153 return gdb_get_reg32(mem_buf, env->segs[R_CS].selector); 154 case IDX_SEG_REGS + 1: 155 return gdb_get_reg32(mem_buf, env->segs[R_SS].selector); 156 case IDX_SEG_REGS + 2: 157 return gdb_get_reg32(mem_buf, env->segs[R_DS].selector); 158 case IDX_SEG_REGS + 3: 159 return gdb_get_reg32(mem_buf, env->segs[R_ES].selector); 160 case IDX_SEG_REGS + 4: 161 return gdb_get_reg32(mem_buf, env->segs[R_FS].selector); 162 case IDX_SEG_REGS + 5: 163 return gdb_get_reg32(mem_buf, env->segs[R_GS].selector); 164 case IDX_SEG_REGS + 6: 165 return gdb_read_reg_cs64(env->hflags, mem_buf, env->segs[R_FS].base); 166 case IDX_SEG_REGS + 7: 167 return gdb_read_reg_cs64(env->hflags, mem_buf, env->segs[R_GS].base); 168 169 case IDX_SEG_REGS + 8: 170 #ifdef TARGET_X86_64 171 return gdb_read_reg_cs64(env->hflags, mem_buf, env->kernelgsbase); 172 #else 173 return gdb_get_reg32(mem_buf, 0); 174 #endif 175 176 case IDX_FP_REGS + 8: 177 return gdb_get_reg32(mem_buf, env->fpuc); 178 case IDX_FP_REGS + 9: 179 return gdb_get_reg32(mem_buf, (env->fpus & ~0x3800) | 180 (env->fpstt & 0x7) << 11); 181 case IDX_FP_REGS + 10: 182 return gdb_get_reg32(mem_buf, 0); /* ftag */ 183 case IDX_FP_REGS + 11: 184 return gdb_get_reg32(mem_buf, 0); /* fiseg */ 185 case IDX_FP_REGS + 12: 186 return gdb_get_reg32(mem_buf, 0); /* fioff */ 187 case IDX_FP_REGS + 13: 188 return gdb_get_reg32(mem_buf, 0); /* foseg */ 189 case IDX_FP_REGS + 14: 190 return gdb_get_reg32(mem_buf, 0); /* fooff */ 191 case IDX_FP_REGS + 15: 192 return gdb_get_reg32(mem_buf, 0); /* fop */ 193 194 case IDX_MXCSR_REG: 195 update_mxcsr_from_sse_status(env); 196 return gdb_get_reg32(mem_buf, env->mxcsr); 197 198 case IDX_CTL_CR0_REG: 199 return gdb_read_reg_cs64(env->hflags, mem_buf, env->cr[0]); 200 case IDX_CTL_CR2_REG: 201 return gdb_read_reg_cs64(env->hflags, mem_buf, env->cr[2]); 202 case IDX_CTL_CR3_REG: 203 return gdb_read_reg_cs64(env->hflags, mem_buf, env->cr[3]); 204 case IDX_CTL_CR4_REG: 205 return gdb_read_reg_cs64(env->hflags, mem_buf, env->cr[4]); 206 case IDX_CTL_CR8_REG: 207 #ifndef CONFIG_USER_ONLY 208 tpr = cpu_get_apic_tpr(cpu->apic_state); 209 #else 210 tpr = 0; 211 #endif 212 return gdb_read_reg_cs64(env->hflags, mem_buf, tpr); 213 214 case IDX_CTL_EFER_REG: 215 return gdb_read_reg_cs64(env->hflags, mem_buf, env->efer); 216 } 217 } 218 return 0; 219 } 220 221 static int x86_cpu_gdb_load_seg(X86CPU *cpu, X86Seg sreg, uint8_t *mem_buf) 222 { 223 CPUX86State *env = &cpu->env; 224 uint16_t selector = ldl_p(mem_buf); 225 226 if (selector != env->segs[sreg].selector) { 227 #if defined(CONFIG_USER_ONLY) 228 cpu_x86_load_seg(env, sreg, selector); 229 #else 230 unsigned int limit, flags; 231 target_ulong base; 232 233 if (!(env->cr[0] & CR0_PE_MASK) || (env->eflags & VM_MASK)) { 234 int dpl = (env->eflags & VM_MASK) ? 3 : 0; 235 base = selector << 4; 236 limit = 0xffff; 237 flags = DESC_P_MASK | DESC_S_MASK | DESC_W_MASK | 238 DESC_A_MASK | (dpl << DESC_DPL_SHIFT); 239 } else { 240 if (!cpu_x86_get_descr_debug(env, selector, &base, &limit, 241 &flags)) { 242 return 4; 243 } 244 } 245 cpu_x86_load_seg_cache(env, sreg, selector, base, limit, flags); 246 #endif 247 } 248 return 4; 249 } 250 251 int x86_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n) 252 { 253 X86CPU *cpu = X86_CPU(cs); 254 CPUX86State *env = &cpu->env; 255 target_ulong tmp; 256 int len; 257 258 /* N.B. GDB can't deal with changes in registers or sizes in the middle 259 of a session. So if we're in 32-bit mode on a 64-bit cpu, still act 260 as if we're on a 64-bit cpu. */ 261 262 if (n < CPU_NB_REGS) { 263 if (TARGET_LONG_BITS == 64) { 264 if (env->hflags & HF_CS64_MASK) { 265 env->regs[gpr_map[n]] = ldtul_p(mem_buf); 266 } else if (n < CPU_NB_REGS32) { 267 env->regs[gpr_map[n]] = ldtul_p(mem_buf) & 0xffffffffUL; 268 } 269 return sizeof(target_ulong); 270 } else if (n < CPU_NB_REGS32) { 271 n = gpr_map32[n]; 272 env->regs[n] &= ~0xffffffffUL; 273 env->regs[n] |= (uint32_t)ldl_p(mem_buf); 274 return 4; 275 } 276 } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) { 277 floatx80 *fp = (floatx80 *) &env->fpregs[n - IDX_FP_REGS]; 278 fp->low = le64_to_cpu(* (uint64_t *) mem_buf); 279 fp->high = le16_to_cpu(* (uint16_t *) (mem_buf + 8)); 280 return 10; 281 } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) { 282 n -= IDX_XMM_REGS; 283 if (n < CPU_NB_REGS32 || TARGET_LONG_BITS == 64) { 284 env->xmm_regs[n].ZMM_Q(0) = ldq_p(mem_buf); 285 env->xmm_regs[n].ZMM_Q(1) = ldq_p(mem_buf + 8); 286 return 16; 287 } 288 } else { 289 switch (n) { 290 case IDX_IP_REG: 291 if (TARGET_LONG_BITS == 64) { 292 if (env->hflags & HF_CS64_MASK) { 293 env->eip = ldq_p(mem_buf); 294 } else { 295 env->eip = ldq_p(mem_buf) & 0xffffffffUL; 296 } 297 return 8; 298 } else { 299 env->eip &= ~0xffffffffUL; 300 env->eip |= (uint32_t)ldl_p(mem_buf); 301 return 4; 302 } 303 case IDX_FLAGS_REG: 304 env->eflags = ldl_p(mem_buf); 305 return 4; 306 307 case IDX_SEG_REGS: 308 return x86_cpu_gdb_load_seg(cpu, R_CS, mem_buf); 309 case IDX_SEG_REGS + 1: 310 return x86_cpu_gdb_load_seg(cpu, R_SS, mem_buf); 311 case IDX_SEG_REGS + 2: 312 return x86_cpu_gdb_load_seg(cpu, R_DS, mem_buf); 313 case IDX_SEG_REGS + 3: 314 return x86_cpu_gdb_load_seg(cpu, R_ES, mem_buf); 315 case IDX_SEG_REGS + 4: 316 return x86_cpu_gdb_load_seg(cpu, R_FS, mem_buf); 317 case IDX_SEG_REGS + 5: 318 return x86_cpu_gdb_load_seg(cpu, R_GS, mem_buf); 319 case IDX_SEG_REGS + 6: 320 return gdb_write_reg_cs64(env->hflags, mem_buf, &env->segs[R_FS].base); 321 case IDX_SEG_REGS + 7: 322 return gdb_write_reg_cs64(env->hflags, mem_buf, &env->segs[R_GS].base); 323 case IDX_SEG_REGS + 8: 324 #ifdef TARGET_X86_64 325 return gdb_write_reg_cs64(env->hflags, mem_buf, &env->kernelgsbase); 326 #endif 327 return 4; 328 329 case IDX_FP_REGS + 8: 330 cpu_set_fpuc(env, ldl_p(mem_buf)); 331 return 4; 332 case IDX_FP_REGS + 9: 333 tmp = ldl_p(mem_buf); 334 env->fpstt = (tmp >> 11) & 7; 335 env->fpus = tmp & ~0x3800; 336 return 4; 337 case IDX_FP_REGS + 10: /* ftag */ 338 return 4; 339 case IDX_FP_REGS + 11: /* fiseg */ 340 return 4; 341 case IDX_FP_REGS + 12: /* fioff */ 342 return 4; 343 case IDX_FP_REGS + 13: /* foseg */ 344 return 4; 345 case IDX_FP_REGS + 14: /* fooff */ 346 return 4; 347 case IDX_FP_REGS + 15: /* fop */ 348 return 4; 349 350 case IDX_MXCSR_REG: 351 cpu_set_mxcsr(env, ldl_p(mem_buf)); 352 return 4; 353 354 case IDX_CTL_CR0_REG: 355 len = gdb_write_reg_cs64(env->hflags, mem_buf, &tmp); 356 #ifndef CONFIG_USER_ONLY 357 cpu_x86_update_cr0(env, tmp); 358 #endif 359 return len; 360 361 case IDX_CTL_CR2_REG: 362 len = gdb_write_reg_cs64(env->hflags, mem_buf, &tmp); 363 #ifndef CONFIG_USER_ONLY 364 env->cr[2] = tmp; 365 #endif 366 return len; 367 368 case IDX_CTL_CR3_REG: 369 len = gdb_write_reg_cs64(env->hflags, mem_buf, &tmp); 370 #ifndef CONFIG_USER_ONLY 371 cpu_x86_update_cr3(env, tmp); 372 #endif 373 return len; 374 375 case IDX_CTL_CR4_REG: 376 len = gdb_write_reg_cs64(env->hflags, mem_buf, &tmp); 377 #ifndef CONFIG_USER_ONLY 378 cpu_x86_update_cr4(env, tmp); 379 #endif 380 return len; 381 382 case IDX_CTL_CR8_REG: 383 len = gdb_write_reg_cs64(env->hflags, mem_buf, &tmp); 384 #ifndef CONFIG_USER_ONLY 385 cpu_set_apic_tpr(cpu->apic_state, tmp); 386 #endif 387 return len; 388 389 case IDX_CTL_EFER_REG: 390 len = gdb_write_reg_cs64(env->hflags, mem_buf, &tmp); 391 #ifndef CONFIG_USER_ONLY 392 cpu_load_efer(env, tmp); 393 #endif 394 return len; 395 } 396 } 397 /* Unrecognised register. */ 398 return 0; 399 } 400