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 "config.h"
  21 #include "qemu-common.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 #define IDX_IP_REG      CPU_NB_REGS
  35 #define IDX_FLAGS_REG   (IDX_IP_REG + 1)
  36 #define IDX_SEG_REGS    (IDX_FLAGS_REG + 1)
  37 #define IDX_FP_REGS     (IDX_SEG_REGS + 6)
  38 #define IDX_XMM_REGS    (IDX_FP_REGS + 16)
  39 #define IDX_MXCSR_REG   (IDX_XMM_REGS + CPU_NB_REGS)
  40
  41 int x86_cpu_gdb_read_register(CPUState *cs, uint8_t *mem_buf, int n)
  42 {
  43     X86CPU *cpu = X86_CPU(cs);
  44     CPUX86State *env = &cpu->env;
  45
  46     if (n < CPU_NB_REGS) {
  47         if (TARGET_LONG_BITS == 64 && env->hflags & HF_CS64_MASK) {
  48             return gdb_get_reg64(mem_buf, env->regs[gpr_map[n]]);
  49         } else if (n < CPU_NB_REGS32) {
  50             return gdb_get_reg32(mem_buf, env->regs[gpr_map32[n]]);
  51         }
  52     } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) {
  53 #ifdef USE_X86LDOUBLE
  54         /* FIXME: byteswap float values - after fixing fpregs layout. */
  55         memcpy(mem_buf, &env->fpregs[n - IDX_FP_REGS], 10);
  56 #else
  57         memset(mem_buf, 0, 10);
  58 #endif
  59         return 10;
  60     } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) {
  61         n -= IDX_XMM_REGS;
  62         if (n < CPU_NB_REGS32 ||
  63             (TARGET_LONG_BITS == 64 && env->hflags & HF_CS64_MASK)) {
  64             stq_p(mem_buf, env->xmm_regs[n].XMM_Q(0));
  65             stq_p(mem_buf + 8, env->xmm_regs[n].XMM_Q(1));
  66             return 16;
  67         }
  68     } else {
  69         switch (n) {
  70         case IDX_IP_REG:
  71             if (TARGET_LONG_BITS == 64 && env->hflags & HF_CS64_MASK) {
  72                 return gdb_get_reg64(mem_buf, env->eip);
  73             } else {
  74                 return gdb_get_reg32(mem_buf, env->eip);
  75             }
  76         case IDX_FLAGS_REG:
  77             return gdb_get_reg32(mem_buf, env->eflags);
  78
  79         case IDX_SEG_REGS:
  80             return gdb_get_reg32(mem_buf, env->segs[R_CS].selector);
  81         case IDX_SEG_REGS + 1:
  82             return gdb_get_reg32(mem_buf, env->segs[R_SS].selector);
  83         case IDX_SEG_REGS + 2:
  84             return gdb_get_reg32(mem_buf, env->segs[R_DS].selector);
  85         case IDX_SEG_REGS + 3:
  86             return gdb_get_reg32(mem_buf, env->segs[R_ES].selector);
  87         case IDX_SEG_REGS + 4:
  88             return gdb_get_reg32(mem_buf, env->segs[R_FS].selector);
  89         case IDX_SEG_REGS + 5:
  90             return gdb_get_reg32(mem_buf, env->segs[R_GS].selector);
  91
  92         case IDX_FP_REGS + 8:
  93             return gdb_get_reg32(mem_buf, env->fpuc);
  94         case IDX_FP_REGS + 9:
  95             return gdb_get_reg32(mem_buf, (env->fpus & ~0x3800) |
  96                                           (env->fpstt & 0x7) << 11);
  97         case IDX_FP_REGS + 10:
  98             return gdb_get_reg32(mem_buf, 0); /* ftag */
  99         case IDX_FP_REGS + 11:
 100             return gdb_get_reg32(mem_buf, 0); /* fiseg */
 101         case IDX_FP_REGS + 12:
 102             return gdb_get_reg32(mem_buf, 0); /* fioff */
 103         case IDX_FP_REGS + 13:
 104             return gdb_get_reg32(mem_buf, 0); /* foseg */
 105         case IDX_FP_REGS + 14:
 106             return gdb_get_reg32(mem_buf, 0); /* fooff */
 107         case IDX_FP_REGS + 15:
 108             return gdb_get_reg32(mem_buf, 0); /* fop */
 109
 110         case IDX_MXCSR_REG:
 111             return gdb_get_reg32(mem_buf, env->mxcsr);
 112         }
 113     }
 114     return 0;
 115 }
 116
 117 static int x86_cpu_gdb_load_seg(X86CPU *cpu, int sreg, uint8_t *mem_buf)
 118 {
 119     CPUX86State *env = &cpu->env;
 120     uint16_t selector = ldl_p(mem_buf);
 121
 122     if (selector != env->segs[sreg].selector) {
 123 #if defined(CONFIG_USER_ONLY)
 124         cpu_x86_load_seg(env, sreg, selector);
 125 #else
 126         unsigned int limit, flags;
 127         target_ulong base;
 128
 129         if (!(env->cr[0] & CR0_PE_MASK) || (env->eflags & VM_MASK)) {
 130             int dpl = (env->eflags & VM_MASK) ? 3 : 0;
 131             base = selector << 4;
 132             limit = 0xffff;
 133             flags = DESC_P_MASK | DESC_S_MASK | DESC_W_MASK |
 134                     DESC_A_MASK | (dpl << DESC_DPL_SHIFT);
 135         } else {
 136             if (!cpu_x86_get_descr_debug(env, selector, &base, &limit,
 137                                          &flags)) {
 138                 return 4;
 139             }
 140         }
 141         cpu_x86_load_seg_cache(env, sreg, selector, base, limit, flags);
 142 #endif
 143     }
 144     return 4;
 145 }
 146
 147 int x86_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
 148 {
 149     X86CPU *cpu = X86_CPU(cs);
 150     CPUX86State *env = &cpu->env;
 151     uint32_t tmp;
 152
 153     if (n < CPU_NB_REGS) {
 154         if (TARGET_LONG_BITS == 64 && env->hflags & HF_CS64_MASK) {
 155             env->regs[gpr_map[n]] = ldtul_p(mem_buf);
 156             return sizeof(target_ulong);
 157         } else if (n < CPU_NB_REGS32) {
 158             n = gpr_map32[n];
 159             env->regs[n] &= ~0xffffffffUL;
 160             env->regs[n] |= (uint32_t)ldl_p(mem_buf);
 161             return 4;
 162         }
 163     } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) {
 164 #ifdef USE_X86LDOUBLE
 165         /* FIXME: byteswap float values - after fixing fpregs layout. */
 166         memcpy(&env->fpregs[n - IDX_FP_REGS], mem_buf, 10);
 167 #endif
 168         return 10;
 169     } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) {
 170         n -= IDX_XMM_REGS;
 171         if (n < CPU_NB_REGS32 ||
 172             (TARGET_LONG_BITS == 64 && env->hflags & HF_CS64_MASK)) {
 173             env->xmm_regs[n].XMM_Q(0) = ldq_p(mem_buf);
 174             env->xmm_regs[n].XMM_Q(1) = ldq_p(mem_buf + 8);
 175             return 16;
 176         }
 177     } else {
 178         switch (n) {
 179         case IDX_IP_REG:
 180             if (TARGET_LONG_BITS == 64 && env->hflags & HF_CS64_MASK) {
 181                 env->eip = ldq_p(mem_buf);
 182                 return 8;
 183             } else {
 184                 env->eip &= ~0xffffffffUL;
 185                 env->eip |= (uint32_t)ldl_p(mem_buf);
 186                 return 4;
 187             }
 188         case IDX_FLAGS_REG:
 189             env->eflags = ldl_p(mem_buf);
 190             return 4;
 191
 192         case IDX_SEG_REGS:
 193             return x86_cpu_gdb_load_seg(cpu, R_CS, mem_buf);
 194         case IDX_SEG_REGS + 1:
 195             return x86_cpu_gdb_load_seg(cpu, R_SS, mem_buf);
 196         case IDX_SEG_REGS + 2:
 197             return x86_cpu_gdb_load_seg(cpu, R_DS, mem_buf);
 198         case IDX_SEG_REGS + 3:
 199             return x86_cpu_gdb_load_seg(cpu, R_ES, mem_buf);
 200         case IDX_SEG_REGS + 4:
 201             return x86_cpu_gdb_load_seg(cpu, R_FS, mem_buf);
 202         case IDX_SEG_REGS + 5:
 203             return x86_cpu_gdb_load_seg(cpu, R_GS, mem_buf);
 204
 205         case IDX_FP_REGS + 8:
 206             cpu_set_fpuc(env, ldl_p(mem_buf));
 207             return 4;
 208         case IDX_FP_REGS + 9:
 209             tmp = ldl_p(mem_buf);
 210             env->fpstt = (tmp >> 11) & 7;
 211             env->fpus = tmp & ~0x3800;
 212             return 4;
 213         case IDX_FP_REGS + 10: /* ftag */
 214             return 4;
 215         case IDX_FP_REGS + 11: /* fiseg */
 216             return 4;
 217         case IDX_FP_REGS + 12: /* fioff */
 218             return 4;
 219         case IDX_FP_REGS + 13: /* foseg */
 220             return 4;
 221         case IDX_FP_REGS + 14: /* fooff */
 222             return 4;
 223         case IDX_FP_REGS + 15: /* fop */
 224             return 4;
 225
 226         case IDX_MXCSR_REG:
 227             cpu_set_mxcsr(env, ldl_p(mem_buf));
 228             return 4;
 229         }
 230     }
 231     /* Unrecognised register.  */
 232     return 0;
 233 }