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
gdb_read_reg_cs64(uint32_t hflags,GByteArray * buf,target_ulong val)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
gdb_write_reg_cs64(uint32_t hflags,uint8_t * buf,target_ulong * val)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
x86_cpu_gdb_read_register(CPUState * cs,GByteArray * mem_buf,int n)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
x86_cpu_gdb_load_seg(X86CPU * cpu,X86Seg sreg,uint8_t * mem_buf)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
x86_cpu_gdb_write_register(CPUState * cs,uint8_t * mem_buf,int n)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