1 /*
2 * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 #include <mach_kdp.h>
30 #include <mach/mach_types.h>
31 #include <mach/machine.h>
32 #include <mach/exception_types.h>
33 #include <kern/cpu_data.h>
34 #include <i386/trap.h>
35 #include <i386/mp.h>
36 #include <kdp/kdp_internal.h>
37 #include <mach-o/loader.h>
38 #include <mach-o/nlist.h>
39 #include <IOKit/IOPlatformExpert.h> /* for PE_halt_restart */
40 #include <kern/machine.h> /* for halt_all_cpus */
41 #include <libkern/OSAtomic.h>
42
43 #include <kern/thread.h>
44 #include <i386/thread.h>
45 #include <vm/vm_map.h>
46 #include <i386/pmap.h>
47
48 #define KDP_TEST_HARNESS 0
49 #if KDP_TEST_HARNESS
50 #define dprintf(x) printf x
51 #else
52 #define dprintf(x)
53 #endif
54
55 extern cpu_type_t cpuid_cputype(void);
56 extern cpu_subtype_t cpuid_cpusubtype(void);
57
58 void print_saved_state(void *);
59 void kdp_call(void);
60 int kdp_getc(void);
61 void kdp_getstate(x86_thread_state64_t *);
62 void kdp_setstate(x86_thread_state64_t *);
63 unsigned machine_read64(addr64_t srcaddr, caddr_t dstaddr, uint32_t len);
64 int machine_trace_thread64(thread_t thread, char * tracepos, char * tracebound,
65 int nframes, uint32_t * thread_trace_flags);
66
67 void
kdp_exception(unsigned char * pkt,int * len,unsigned short * remote_port,unsigned int exception,unsigned int code,unsigned int subcode)68 kdp_exception(
69 unsigned char *pkt,
70 int *len,
71 unsigned short *remote_port,
72 unsigned int exception,
73 unsigned int code,
74 unsigned int subcode
75 )
76 {
77 kdp_exception_t *rq = (kdp_exception_t *)pkt;
78
79 rq->hdr.request = KDP_EXCEPTION;
80 rq->hdr.is_reply = 0;
81 rq->hdr.seq = kdp.exception_seq;
82 rq->hdr.key = 0;
83 rq->hdr.len = sizeof(*rq);
84
85 rq->n_exc_info = 1;
86 rq->exc_info[0].cpu = 0;
87 rq->exc_info[0].exception = exception;
88 rq->exc_info[0].code = code;
89 rq->exc_info[0].subcode = subcode;
90
91 rq->hdr.len += rq->n_exc_info * sizeof(kdp_exc_info_t);
92
93 bcopy((char *)rq, (char *)pkt, rq->hdr.len);
94
95 kdp.exception_ack_needed = TRUE;
96
97 *remote_port = kdp.exception_port;
98 *len = rq->hdr.len;
99 }
100
101 boolean_t
kdp_exception_ack(unsigned char * pkt,int len)102 kdp_exception_ack(
103 unsigned char *pkt,
104 int len
105 )
106 {
107 kdp_exception_ack_t *rq = (kdp_exception_ack_t *)pkt;
108
109 if (((unsigned int) len) < sizeof(*rq)) {
110 return FALSE;
111 }
112
113 if (!rq->hdr.is_reply || rq->hdr.request != KDP_EXCEPTION) {
114 return FALSE;
115 }
116
117 dprintf(("kdp_exception_ack seq %x %x\n", rq->hdr.seq, kdp.exception_seq));
118
119 if (rq->hdr.seq == kdp.exception_seq) {
120 kdp.exception_ack_needed = FALSE;
121 kdp.exception_seq++;
122 }
123 return TRUE;
124 }
125
126 void
kdp_getstate(x86_thread_state64_t * state)127 kdp_getstate(
128 x86_thread_state64_t *state
129 )
130 {
131 x86_saved_state64_t *saved_state;
132
133 saved_state = (x86_saved_state64_t *)kdp.saved_state;
134
135 state->rax = saved_state->rax;
136 state->rbx = saved_state->rbx;
137 state->rcx = saved_state->rcx;
138 state->rdx = saved_state->rdx;
139 state->rdi = saved_state->rdi;
140 state->rsi = saved_state->rsi;
141 state->rbp = saved_state->rbp;
142
143 state->r8 = saved_state->r8;
144 state->r9 = saved_state->r9;
145 state->r10 = saved_state->r10;
146 state->r11 = saved_state->r11;
147 state->r12 = saved_state->r12;
148 state->r13 = saved_state->r13;
149 state->r14 = saved_state->r14;
150 state->r15 = saved_state->r15;
151
152 state->rsp = saved_state->isf.rsp;
153 state->rflags = saved_state->isf.rflags;
154 state->rip = saved_state->isf.rip;
155
156 state->cs = saved_state->isf.cs;
157 state->fs = saved_state->fs;
158 state->gs = saved_state->gs;
159 }
160
161
162 void
kdp_setstate(x86_thread_state64_t * state)163 kdp_setstate(
164 x86_thread_state64_t *state
165 )
166 {
167 x86_saved_state64_t *saved_state;
168
169 saved_state = (x86_saved_state64_t *)kdp.saved_state;
170 saved_state->rax = state->rax;
171 saved_state->rbx = state->rbx;
172 saved_state->rcx = state->rcx;
173 saved_state->rdx = state->rdx;
174 saved_state->rdi = state->rdi;
175 saved_state->rsi = state->rsi;
176 saved_state->rbp = state->rbp;
177 saved_state->r8 = state->r8;
178 saved_state->r9 = state->r9;
179 saved_state->r10 = state->r10;
180 saved_state->r11 = state->r11;
181 saved_state->r12 = state->r12;
182 saved_state->r13 = state->r13;
183 saved_state->r14 = state->r14;
184 saved_state->r15 = state->r15;
185
186 saved_state->isf.rflags = state->rflags;
187 saved_state->isf.rsp = state->rsp;
188 saved_state->isf.rip = state->rip;
189
190 saved_state->fs = (uint32_t)state->fs;
191 saved_state->gs = (uint32_t)state->gs;
192 }
193
194
195 kdp_error_t
kdp_machine_read_regs(__unused unsigned int cpu,unsigned int flavor,char * data,int * size)196 kdp_machine_read_regs(
197 __unused unsigned int cpu,
198 unsigned int flavor,
199 char *data,
200 int *size
201 )
202 {
203 static x86_float_state64_t null_fpstate;
204
205 switch (flavor) {
206 case x86_THREAD_STATE64:
207 dprintf(("kdp_readregs THREAD_STATE64\n"));
208 kdp_getstate((x86_thread_state64_t *)data);
209 *size = sizeof(x86_thread_state64_t);
210 return KDPERR_NO_ERROR;
211
212 case x86_FLOAT_STATE64:
213 dprintf(("kdp_readregs THREAD_FPSTATE64\n"));
214 *(x86_float_state64_t *)data = null_fpstate;
215 *size = sizeof(x86_float_state64_t);
216 return KDPERR_NO_ERROR;
217
218 default:
219 dprintf(("kdp_readregs bad flavor %d\n", flavor));
220 *size = 0;
221 return KDPERR_BADFLAVOR;
222 }
223 }
224
225 kdp_error_t
kdp_machine_write_regs(__unused unsigned int cpu,unsigned int flavor,char * data,__unused int * size)226 kdp_machine_write_regs(
227 __unused unsigned int cpu,
228 unsigned int flavor,
229 char *data,
230 __unused int *size
231 )
232 {
233 switch (flavor) {
234 case x86_THREAD_STATE64:
235 dprintf(("kdp_writeregs THREAD_STATE64\n"));
236 kdp_setstate((x86_thread_state64_t *)data);
237 return KDPERR_NO_ERROR;
238
239 case x86_FLOAT_STATE64:
240 dprintf(("kdp_writeregs THREAD_FPSTATE64\n"));
241 return KDPERR_NO_ERROR;
242
243 default:
244 dprintf(("kdp_writeregs bad flavor %d\n", flavor));
245 return KDPERR_BADFLAVOR;
246 }
247 }
248
249
250
251 void
kdp_machine_hostinfo(kdp_hostinfo_t * hostinfo)252 kdp_machine_hostinfo(
253 kdp_hostinfo_t *hostinfo
254 )
255 {
256 int i;
257
258 hostinfo->cpus_mask = 0;
259
260 for (i = 0; i < machine_info.max_cpus; i++) {
261 if (cpu_data_ptr[i] == NULL) {
262 continue;
263 }
264
265 hostinfo->cpus_mask |= (1 << i);
266 }
267
268 hostinfo->cpu_type = cpuid_cputype() | CPU_ARCH_ABI64;
269 hostinfo->cpu_subtype = cpuid_cpusubtype();
270 }
271
272 void
kdp_panic(const char * fmt,...)273 kdp_panic(
274 const char *fmt,
275 ...
276 )
277 {
278 #pragma clang diagnostic push
279 #pragma clang diagnostic ignored "-Wformat-nonliteral"
280 char kdp_fmt[256];
281 va_list args;
282
283 va_start(args, fmt);
284 (void) snprintf(kdp_fmt, sizeof(kdp_fmt), "kdp panic: %s", fmt);
285 vprintf(kdp_fmt, args);
286 va_end(args);
287
288 __asm__ volatile ("hlt");
289 #pragma clang diagnostic pop
290 }
291
292 int
kdp_intr_disbl(void)293 kdp_intr_disbl(void)
294 {
295 return splhigh();
296 }
297
298 void
kdp_intr_enbl(int s)299 kdp_intr_enbl(int s)
300 {
301 splx(s);
302 }
303
304 int
kdp_getc(void)305 kdp_getc(void)
306 {
307 return console_try_read_char();
308 }
309
310 void
kdp_us_spin(int usec)311 kdp_us_spin(int usec)
312 {
313 delay(usec / 100);
314 }
315
316 void
print_saved_state(void * state)317 print_saved_state(void *state)
318 {
319 x86_saved_state64_t *saved_state;
320
321 saved_state = state;
322
323 kprintf("pc = 0x%llx\n", saved_state->isf.rip);
324 kprintf("cr2= 0x%llx\n", saved_state->cr2);
325 kprintf("rp = TODO FIXME\n");
326 kprintf("sp = %p\n", saved_state);
327 }
328
329 void
kdp_sync_cache(void)330 kdp_sync_cache(void)
331 {
332 return; /* No op here. */
333 }
334
335 void
kdp_call(void)336 kdp_call(void)
337 {
338 __asm__ volatile ("int $3"); /* Let the processor do the work */
339 }
340
341
342 typedef struct _cframe_t {
343 struct _cframe_t *prev;
344 unsigned caller;
345 unsigned args[0];
346 } cframe_t;
347
348 boolean_t
kdp_i386_trap(unsigned int trapno,x86_saved_state64_t * saved_state,kern_return_t result,vm_offset_t va)349 kdp_i386_trap(
350 unsigned int trapno,
351 x86_saved_state64_t *saved_state,
352 kern_return_t result,
353 vm_offset_t va
354 )
355 {
356 unsigned int exception, code, subcode = 0;
357 boolean_t prev_interrupts_state;
358
359 if (trapno != T_INT3 && trapno != T_DEBUG) {
360 kprintf("Debugger: Unexpected kernel trap number: "
361 "0x%x, RIP: 0x%llx, CR2: 0x%llx\n",
362 trapno, saved_state->isf.rip, saved_state->cr2);
363 if (!kdp.is_conn) {
364 return FALSE;
365 }
366 }
367
368 prev_interrupts_state = ml_set_interrupts_enabled(FALSE);
369 disable_preemption();
370
371 if (saved_state->isf.rflags & EFL_TF) {
372 enable_preemption_no_check();
373 }
374
375 switch (trapno) {
376 case T_DIVIDE_ERROR:
377 exception = EXC_ARITHMETIC;
378 code = EXC_I386_DIVERR;
379 break;
380
381 case T_OVERFLOW:
382 exception = EXC_SOFTWARE;
383 code = EXC_I386_INTOFLT;
384 break;
385
386 case T_OUT_OF_BOUNDS:
387 exception = EXC_ARITHMETIC;
388 code = EXC_I386_BOUNDFLT;
389 break;
390
391 case T_INVALID_OPCODE:
392 exception = EXC_BAD_INSTRUCTION;
393 code = EXC_I386_INVOPFLT;
394 break;
395
396 case T_SEGMENT_NOT_PRESENT:
397 exception = EXC_BAD_INSTRUCTION;
398 code = EXC_I386_SEGNPFLT;
399 subcode = (unsigned int)saved_state->isf.err;
400 break;
401
402 case T_STACK_FAULT:
403 exception = EXC_BAD_INSTRUCTION;
404 code = EXC_I386_STKFLT;
405 subcode = (unsigned int)saved_state->isf.err;
406 break;
407
408 case T_GENERAL_PROTECTION:
409 exception = EXC_BAD_INSTRUCTION;
410 code = EXC_I386_GPFLT;
411 subcode = (unsigned int)saved_state->isf.err;
412 break;
413
414 case T_PAGE_FAULT:
415 exception = EXC_BAD_ACCESS;
416 code = result;
417 subcode = (unsigned int)va;
418 break;
419
420 case T_WATCHPOINT:
421 exception = EXC_SOFTWARE;
422 code = EXC_I386_ALIGNFLT;
423 break;
424
425 case T_DEBUG:
426 case T_INT3:
427 exception = EXC_BREAKPOINT;
428 code = EXC_I386_BPTFLT;
429 break;
430
431 default:
432 exception = EXC_BAD_INSTRUCTION;
433 code = trapno;
434 break;
435 }
436
437 if (current_cpu_datap()->cpu_fatal_trap_state) {
438 current_cpu_datap()->cpu_post_fatal_trap_state = saved_state;
439 saved_state = current_cpu_datap()->cpu_fatal_trap_state;
440 }
441
442 handle_debugger_trap(exception, code, subcode, saved_state);
443
444 enable_preemption();
445 ml_set_interrupts_enabled(prev_interrupts_state);
446
447 /* If the instruction single step bit is set, disable kernel preemption
448 */
449 if (saved_state->isf.rflags & EFL_TF) {
450 disable_preemption();
451 }
452
453 return TRUE;
454 }
455
456 void
kdp_machine_get_breakinsn(uint8_t * bytes,uint32_t * size)457 kdp_machine_get_breakinsn(
458 uint8_t *bytes,
459 uint32_t *size
460 )
461 {
462 bytes[0] = 0xcc;
463 *size = 1;
464 }
465
466 #define RETURN_OFFSET64 8
467 /* Routine to encapsulate the 64-bit address read hack*/
468 unsigned
machine_read64(addr64_t srcaddr,caddr_t dstaddr,uint32_t len)469 machine_read64(addr64_t srcaddr, caddr_t dstaddr, uint32_t len)
470 {
471 return (unsigned)kdp_machine_vm_read(srcaddr, dstaddr, len);
472 }
473
474 int
machine_trace_thread64(thread_t thread,char * tracepos,char * tracebound,int nframes,uint32_t * thread_trace_flags)475 machine_trace_thread64(thread_t thread,
476 char * tracepos,
477 char * tracebound,
478 int nframes,
479 uint32_t * thread_trace_flags)
480 {
481 extern bool machine_trace_thread_validate_kva(vm_offset_t addr);
482
483 uint64_t * tracebuf = (uint64_t *)tracepos;
484 unsigned framesize = sizeof(addr64_t);
485
486 uint32_t fence = 0;
487 int framecount = 0;
488 addr64_t prev_rip = 0;
489 addr64_t prevsp = 0;
490 vm_offset_t kern_virt_addr = 0;
491
492 nframes = (tracebound > tracepos) ? MIN(nframes, (int)((tracebound - tracepos) / framesize)) : 0;
493
494 addr64_t stackptr = STACK_IKS(thread->kernel_stack)->k_rbp;
495 prev_rip = STACK_IKS(thread->kernel_stack)->k_rip;
496 prev_rip = VM_KERNEL_UNSLIDE(prev_rip);
497
498 for (framecount = 0; framecount < nframes; framecount++) {
499 *tracebuf++ = prev_rip;
500
501 if (!stackptr || (stackptr == fence)) {
502 break;
503 }
504 if (stackptr & 0x0000007) {
505 break;
506 }
507 if (stackptr <= prevsp) {
508 break;
509 }
510
511 kern_virt_addr = stackptr + RETURN_OFFSET64;
512 bool ok = machine_trace_thread_validate_kva(kern_virt_addr);
513 if (!ok) {
514 if (thread_trace_flags) {
515 *thread_trace_flags |= kThreadTruncatedBT;
516 }
517 break;
518 }
519
520 prev_rip = VM_KERNEL_UNSLIDE(*(uint64_t *)kern_virt_addr);
521 prevsp = stackptr;
522
523 kern_virt_addr = stackptr;
524 ok = machine_trace_thread_validate_kva(kern_virt_addr);
525 if (!ok) {
526 if (thread_trace_flags) {
527 *thread_trace_flags |= kThreadTruncatedBT;
528 }
529 break;
530 }
531 stackptr = *(uint64_t *)kern_virt_addr;
532 }
533
534 return (uint32_t) (((char *) tracebuf) - tracepos);
535 }
536
537 void
kdp_ml_enter_debugger(void)538 kdp_ml_enter_debugger(void)
539 {
540 __asm__ __volatile__ ("int3");
541 }
542