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gdbstub.c (13345B)


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