1 /* General "disassemble this chunk" code.  Used for debugging. */
2 #include "qemu/osdep.h"
3 #include "disas/dis-asm.h"
4 #include "elf.h"
5 #include "qemu/qemu-print.h"
6 
7 #include "disas/disas.h"
8 #include "disas/capstone.h"
9 
10 typedef struct CPUDebug {
11     struct disassemble_info info;
12     CPUState *cpu;
13 } CPUDebug;
14 
15 /* Filled in by elfload.c.  Simplistic, but will do for now. */
16 struct syminfo *syminfos = NULL;
17 
18 /*
19  * Get LENGTH bytes from info's buffer, at host address memaddr.
20  * Transfer them to myaddr.
21  */
host_read_memory(bfd_vma memaddr,bfd_byte * myaddr,int length,struct disassemble_info * info)22 static int host_read_memory(bfd_vma memaddr, bfd_byte *myaddr, int length,
23                             struct disassemble_info *info)
24 {
25     if (memaddr < info->buffer_vma
26         || memaddr + length > info->buffer_vma + info->buffer_length) {
27         /* Out of bounds.  Use EIO because GDB uses it.  */
28         return EIO;
29     }
30     memcpy (myaddr, info->buffer + (memaddr - info->buffer_vma), length);
31     return 0;
32 }
33 
34 /*
35  * Get LENGTH bytes from info's buffer, at target address memaddr.
36  * Transfer them to myaddr.
37  */
target_read_memory(bfd_vma memaddr,bfd_byte * myaddr,int length,struct disassemble_info * info)38 static int target_read_memory(bfd_vma memaddr, bfd_byte *myaddr, int length,
39                               struct disassemble_info *info)
40 {
41     CPUDebug *s = container_of(info, CPUDebug, info);
42     int r = cpu_memory_rw_debug(s->cpu, memaddr, myaddr, length, 0);
43     return r ? EIO : 0;
44 }
45 
46 /*
47  * Print an error message.  We can assume that this is in response to
48  * an error return from {host,target}_read_memory.
49  */
perror_memory(int status,bfd_vma memaddr,struct disassemble_info * info)50 static void perror_memory(int status, bfd_vma memaddr,
51                           struct disassemble_info *info)
52 {
53     if (status != EIO) {
54         /* Can't happen.  */
55         info->fprintf_func(info->stream, "Unknown error %d\n", status);
56     } else {
57         /* Address between memaddr and memaddr + len was out of bounds.  */
58         info->fprintf_func(info->stream,
59                            "Address 0x%" PRIx64 " is out of bounds.\n",
60                            memaddr);
61     }
62 }
63 
64 /* Print address in hex. */
print_address(bfd_vma addr,struct disassemble_info * info)65 static void print_address(bfd_vma addr, struct disassemble_info *info)
66 {
67     info->fprintf_func(info->stream, "0x%" PRIx64, addr);
68 }
69 
70 /* Print address in hex, truncated to the width of a host virtual address. */
host_print_address(bfd_vma addr,struct disassemble_info * info)71 static void host_print_address(bfd_vma addr, struct disassemble_info *info)
72 {
73     print_address((uintptr_t)addr, info);
74 }
75 
76 /* Stub prevents some fruitless earching in optabs disassemblers. */
symbol_at_address(bfd_vma addr,struct disassemble_info * info)77 static int symbol_at_address(bfd_vma addr, struct disassemble_info *info)
78 {
79     return 1;
80 }
81 
print_insn_objdump(bfd_vma pc,disassemble_info * info,const char * prefix)82 static int print_insn_objdump(bfd_vma pc, disassemble_info *info,
83                               const char *prefix)
84 {
85     int i, n = info->buffer_length;
86     uint8_t *buf = g_malloc(n);
87 
88     info->read_memory_func(pc, buf, n, info);
89 
90     for (i = 0; i < n; ++i) {
91         if (i % 32 == 0) {
92             info->fprintf_func(info->stream, "\n%s: ", prefix);
93         }
94         info->fprintf_func(info->stream, "%02x", buf[i]);
95     }
96 
97     g_free(buf);
98     return n;
99 }
100 
print_insn_od_host(bfd_vma pc,disassemble_info * info)101 static int print_insn_od_host(bfd_vma pc, disassemble_info *info)
102 {
103     return print_insn_objdump(pc, info, "OBJD-H");
104 }
105 
print_insn_od_target(bfd_vma pc,disassemble_info * info)106 static int print_insn_od_target(bfd_vma pc, disassemble_info *info)
107 {
108     return print_insn_objdump(pc, info, "OBJD-T");
109 }
110 
initialize_debug(CPUDebug * s)111 static void initialize_debug(CPUDebug *s)
112 {
113     memset(s, 0, sizeof(*s));
114     s->info.arch = bfd_arch_unknown;
115     s->info.cap_arch = -1;
116     s->info.cap_insn_unit = 4;
117     s->info.cap_insn_split = 4;
118     s->info.memory_error_func = perror_memory;
119     s->info.symbol_at_address_func = symbol_at_address;
120 }
121 
initialize_debug_target(CPUDebug * s,CPUState * cpu)122 static void initialize_debug_target(CPUDebug *s, CPUState *cpu)
123 {
124     initialize_debug(s);
125 
126     s->cpu = cpu;
127     s->info.read_memory_func = target_read_memory;
128     s->info.print_address_func = print_address;
129 #ifdef TARGET_WORDS_BIGENDIAN
130     s->info.endian = BFD_ENDIAN_BIG;
131 #else
132     s->info.endian = BFD_ENDIAN_LITTLE;
133 #endif
134 
135     CPUClass *cc = CPU_GET_CLASS(cpu);
136     if (cc->disas_set_info) {
137         cc->disas_set_info(cpu, &s->info);
138     }
139 }
140 
initialize_debug_host(CPUDebug * s)141 static void initialize_debug_host(CPUDebug *s)
142 {
143     initialize_debug(s);
144 
145     s->info.read_memory_func = host_read_memory;
146     s->info.print_address_func = host_print_address;
147 #ifdef HOST_WORDS_BIGENDIAN
148     s->info.endian = BFD_ENDIAN_BIG;
149 #else
150     s->info.endian = BFD_ENDIAN_LITTLE;
151 #endif
152 #if defined(CONFIG_TCG_INTERPRETER)
153     s->info.print_insn = print_insn_tci;
154 #elif defined(__i386__)
155     s->info.mach = bfd_mach_i386_i386;
156     s->info.print_insn = print_insn_i386;
157     s->info.cap_arch = CS_ARCH_X86;
158     s->info.cap_mode = CS_MODE_32;
159     s->info.cap_insn_unit = 1;
160     s->info.cap_insn_split = 8;
161 #elif defined(__x86_64__)
162     s->info.mach = bfd_mach_x86_64;
163     s->info.print_insn = print_insn_i386;
164     s->info.cap_arch = CS_ARCH_X86;
165     s->info.cap_mode = CS_MODE_64;
166     s->info.cap_insn_unit = 1;
167     s->info.cap_insn_split = 8;
168 #elif defined(_ARCH_PPC)
169     s->info.disassembler_options = (char *)"any";
170     s->info.print_insn = print_insn_ppc;
171     s->info.cap_arch = CS_ARCH_PPC;
172 # ifdef _ARCH_PPC64
173     s->info.cap_mode = CS_MODE_64;
174 # endif
175 #elif defined(__riscv) && defined(CONFIG_RISCV_DIS)
176 #if defined(_ILP32) || (__riscv_xlen == 32)
177     s->info.print_insn = print_insn_riscv32;
178 #elif defined(_LP64)
179     s->info.print_insn = print_insn_riscv64;
180 #else
181 #error unsupported RISC-V ABI
182 #endif
183 #elif defined(__aarch64__)
184     s->info.cap_arch = CS_ARCH_ARM64;
185 # ifdef CONFIG_ARM_A64_DIS
186     s->info.print_insn = print_insn_arm_a64;
187 # endif
188 #elif defined(__alpha__)
189     s->info.print_insn = print_insn_alpha;
190 #elif defined(__sparc__)
191     s->info.print_insn = print_insn_sparc;
192     s->info.mach = bfd_mach_sparc_v9b;
193 #elif defined(__arm__)
194     /* TCG only generates code for arm mode.  */
195     s->info.print_insn = print_insn_arm;
196     s->info.cap_arch = CS_ARCH_ARM;
197 #elif defined(__MIPSEB__)
198     s->info.print_insn = print_insn_big_mips;
199 #elif defined(__MIPSEL__)
200     s->info.print_insn = print_insn_little_mips;
201 #elif defined(__m68k__)
202     s->info.print_insn = print_insn_m68k;
203 #elif defined(__s390__)
204     s->info.print_insn = print_insn_s390;
205     s->info.cap_arch = CS_ARCH_SYSZ;
206     s->info.cap_insn_unit = 2;
207     s->info.cap_insn_split = 6;
208 #elif defined(__hppa__)
209     s->info.print_insn = print_insn_hppa;
210 #endif
211 }
212 
213 /* Disassemble this for me please... (debugging).  */
target_disas(FILE * out,CPUState * cpu,target_ulong code,target_ulong size)214 void target_disas(FILE *out, CPUState *cpu, target_ulong code,
215                   target_ulong size)
216 {
217     target_ulong pc;
218     int count;
219     CPUDebug s;
220 
221     initialize_debug_target(&s, cpu);
222     s.info.fprintf_func = fprintf;
223     s.info.stream = out;
224     s.info.buffer_vma = code;
225     s.info.buffer_length = size;
226 
227     if (s.info.cap_arch >= 0 && cap_disas_target(&s.info, code, size)) {
228         return;
229     }
230 
231     if (s.info.print_insn == NULL) {
232         s.info.print_insn = print_insn_od_target;
233     }
234 
235     for (pc = code; size > 0; pc += count, size -= count) {
236 	fprintf(out, "0x" TARGET_FMT_lx ":  ", pc);
237 	count = s.info.print_insn(pc, &s.info);
238 	fprintf(out, "\n");
239 	if (count < 0)
240 	    break;
241         if (size < count) {
242             fprintf(out,
243                     "Disassembler disagrees with translator over instruction "
244                     "decoding\n"
245                     "Please report this to qemu-devel@nongnu.org\n");
246             break;
247         }
248     }
249 }
250 
plugin_printf(FILE * stream,const char * fmt,...)251 static int plugin_printf(FILE *stream, const char *fmt, ...)
252 {
253     /* We abuse the FILE parameter to pass a GString. */
254     GString *s = (GString *)stream;
255     int initial_len = s->len;
256     va_list va;
257 
258     va_start(va, fmt);
259     g_string_append_vprintf(s, fmt, va);
260     va_end(va);
261 
262     return s->len - initial_len;
263 }
264 
plugin_print_address(bfd_vma addr,struct disassemble_info * info)265 static void plugin_print_address(bfd_vma addr, struct disassemble_info *info)
266 {
267     /* does nothing */
268 }
269 
270 
271 /*
272  * We should only be dissembling one instruction at a time here. If
273  * there is left over it usually indicates the front end has read more
274  * bytes than it needed.
275  */
plugin_disas(CPUState * cpu,uint64_t addr,size_t size)276 char *plugin_disas(CPUState *cpu, uint64_t addr, size_t size)
277 {
278     CPUDebug s;
279     GString *ds = g_string_new(NULL);
280 
281     initialize_debug_target(&s, cpu);
282     s.info.fprintf_func = plugin_printf;
283     s.info.stream = (FILE *)ds;  /* abuse this slot */
284     s.info.buffer_vma = addr;
285     s.info.buffer_length = size;
286     s.info.print_address_func = plugin_print_address;
287 
288     if (s.info.cap_arch >= 0 && cap_disas_plugin(&s.info, addr, size)) {
289         ; /* done */
290     } else if (s.info.print_insn) {
291         s.info.print_insn(addr, &s.info);
292     } else {
293         ; /* cannot disassemble -- return empty string */
294     }
295 
296     /* Return the buffer, freeing the GString container.  */
297     return g_string_free(ds, false);
298 }
299 
300 /* Disassemble this for me please... (debugging). */
disas(FILE * out,const void * code,unsigned long size)301 void disas(FILE *out, const void *code, unsigned long size)
302 {
303     uintptr_t pc;
304     int count;
305     CPUDebug s;
306 
307     initialize_debug_host(&s);
308     s.info.fprintf_func = fprintf;
309     s.info.stream = out;
310     s.info.buffer = code;
311     s.info.buffer_vma = (uintptr_t)code;
312     s.info.buffer_length = size;
313 
314     if (s.info.cap_arch >= 0 && cap_disas_host(&s.info, code, size)) {
315         return;
316     }
317 
318     if (s.info.print_insn == NULL) {
319         s.info.print_insn = print_insn_od_host;
320     }
321     for (pc = (uintptr_t)code; size > 0; pc += count, size -= count) {
322         fprintf(out, "0x%08" PRIxPTR ":  ", pc);
323         count = s.info.print_insn(pc, &s.info);
324         fprintf(out, "\n");
325         if (count < 0) {
326             break;
327         }
328     }
329 
330 }
331 
332 /* Look up symbol for debugging purpose.  Returns "" if unknown. */
lookup_symbol(target_ulong orig_addr)333 const char *lookup_symbol(target_ulong orig_addr)
334 {
335     const char *symbol = "";
336     struct syminfo *s;
337 
338     for (s = syminfos; s; s = s->next) {
339         symbol = s->lookup_symbol(s, orig_addr);
340         if (symbol[0] != '\0') {
341             break;
342         }
343     }
344 
345     return symbol;
346 }
347 
348 #if !defined(CONFIG_USER_ONLY)
349 
350 #include "monitor/monitor.h"
351 
352 static int
physical_read_memory(bfd_vma memaddr,bfd_byte * myaddr,int length,struct disassemble_info * info)353 physical_read_memory(bfd_vma memaddr, bfd_byte *myaddr, int length,
354                      struct disassemble_info *info)
355 {
356     CPUDebug *s = container_of(info, CPUDebug, info);
357     MemTxResult res;
358 
359     res = address_space_read(s->cpu->as, memaddr, MEMTXATTRS_UNSPECIFIED,
360                              myaddr, length);
361     return res == MEMTX_OK ? 0 : EIO;
362 }
363 
364 /* Disassembler for the monitor.  */
monitor_disas(Monitor * mon,CPUState * cpu,target_ulong pc,int nb_insn,int is_physical)365 void monitor_disas(Monitor *mon, CPUState *cpu,
366                    target_ulong pc, int nb_insn, int is_physical)
367 {
368     int count, i;
369     CPUDebug s;
370 
371     initialize_debug_target(&s, cpu);
372     s.info.fprintf_func = qemu_fprintf;
373     if (is_physical) {
374         s.info.read_memory_func = physical_read_memory;
375     }
376     s.info.buffer_vma = pc;
377 
378     if (s.info.cap_arch >= 0 && cap_disas_monitor(&s.info, pc, nb_insn)) {
379         return;
380     }
381 
382     if (!s.info.print_insn) {
383         monitor_printf(mon, "0x" TARGET_FMT_lx
384                        ": Asm output not supported on this arch\n", pc);
385         return;
386     }
387 
388     for(i = 0; i < nb_insn; i++) {
389 	monitor_printf(mon, "0x" TARGET_FMT_lx ":  ", pc);
390         count = s.info.print_insn(pc, &s.info);
391 	monitor_printf(mon, "\n");
392 	if (count < 0)
393 	    break;
394         pc += count;
395     }
396 }
397 #endif
398