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 <i386/trap_internal.h>
46 #include <vm/vm_map.h>
47 #include <i386/pmap.h>
48
49 #define KDP_TEST_HARNESS 0
50 #if KDP_TEST_HARNESS
51 #define dprintf(x) printf x
52 #else
53 #define dprintf(x)
54 #endif
55
56 extern cpu_type_t cpuid_cputype(void);
57 extern cpu_subtype_t cpuid_cpusubtype(void);
58
59 void print_saved_state(void *);
60 void kdp_call(void);
61 int kdp_getc(void);
62 void kdp_getstate(x86_thread_state64_t *);
63 void kdp_setstate(x86_thread_state64_t *);
64 unsigned machine_read64(addr64_t srcaddr, caddr_t dstaddr, uint32_t len);
65 int machine_trace_thread64(thread_t thread, char * tracepos, char * tracebound,
66 int nframes, uint32_t * thread_trace_flags);
67
68 void
kdp_exception(unsigned char * pkt,int * len,unsigned short * remote_port,unsigned int exception,unsigned int code,unsigned int subcode)69 kdp_exception(
70 unsigned char *pkt,
71 int *len,
72 unsigned short *remote_port,
73 unsigned int exception,
74 unsigned int code,
75 unsigned int subcode
76 )
77 {
78 kdp_exception_t *rq = (kdp_exception_t *)pkt;
79
80 rq->hdr.request = KDP_EXCEPTION;
81 rq->hdr.is_reply = 0;
82 rq->hdr.seq = kdp.exception_seq;
83 rq->hdr.key = 0;
84 rq->hdr.len = sizeof(*rq);
85
86 rq->n_exc_info = 1;
87 rq->exc_info[0].cpu = 0;
88 rq->exc_info[0].exception = exception;
89 rq->exc_info[0].code = code;
90 rq->exc_info[0].subcode = subcode;
91
92 rq->hdr.len += rq->n_exc_info * sizeof(kdp_exc_info_t);
93
94 bcopy((char *)rq, (char *)pkt, rq->hdr.len);
95
96 kdp.exception_ack_needed = TRUE;
97
98 *remote_port = kdp.exception_port;
99 *len = rq->hdr.len;
100 }
101
102 boolean_t
kdp_exception_ack(unsigned char * pkt,int len)103 kdp_exception_ack(
104 unsigned char *pkt,
105 int len
106 )
107 {
108 kdp_exception_ack_t *rq = (kdp_exception_ack_t *)pkt;
109
110 if (((unsigned int) len) < sizeof(*rq)) {
111 return FALSE;
112 }
113
114 if (!rq->hdr.is_reply || rq->hdr.request != KDP_EXCEPTION) {
115 return FALSE;
116 }
117
118 dprintf(("kdp_exception_ack seq %x %x\n", rq->hdr.seq, kdp.exception_seq));
119
120 if (rq->hdr.seq == kdp.exception_seq) {
121 kdp.exception_ack_needed = FALSE;
122 kdp.exception_seq++;
123 }
124 return TRUE;
125 }
126
127 void
kdp_getstate(x86_thread_state64_t * state)128 kdp_getstate(
129 x86_thread_state64_t *state
130 )
131 {
132 x86_saved_state64_t *saved_state;
133
134 saved_state = (x86_saved_state64_t *)kdp.saved_state;
135
136 state->rax = saved_state->rax;
137 state->rbx = saved_state->rbx;
138 state->rcx = saved_state->rcx;
139 state->rdx = saved_state->rdx;
140 state->rdi = saved_state->rdi;
141 state->rsi = saved_state->rsi;
142 state->rbp = saved_state->rbp;
143
144 state->r8 = saved_state->r8;
145 state->r9 = saved_state->r9;
146 state->r10 = saved_state->r10;
147 state->r11 = saved_state->r11;
148 state->r12 = saved_state->r12;
149 state->r13 = saved_state->r13;
150 state->r14 = saved_state->r14;
151 state->r15 = saved_state->r15;
152
153 state->rsp = saved_state->isf.rsp;
154 state->rflags = saved_state->isf.rflags;
155 state->rip = saved_state->isf.rip;
156
157 state->cs = saved_state->isf.cs;
158 state->fs = saved_state->fs;
159 state->gs = saved_state->gs;
160 }
161
162
163 void
kdp_setstate(x86_thread_state64_t * state)164 kdp_setstate(
165 x86_thread_state64_t *state
166 )
167 {
168 x86_saved_state64_t *saved_state;
169
170 saved_state = (x86_saved_state64_t *)kdp.saved_state;
171 saved_state->rax = state->rax;
172 saved_state->rbx = state->rbx;
173 saved_state->rcx = state->rcx;
174 saved_state->rdx = state->rdx;
175 saved_state->rdi = state->rdi;
176 saved_state->rsi = state->rsi;
177 saved_state->rbp = state->rbp;
178 saved_state->r8 = state->r8;
179 saved_state->r9 = state->r9;
180 saved_state->r10 = state->r10;
181 saved_state->r11 = state->r11;
182 saved_state->r12 = state->r12;
183 saved_state->r13 = state->r13;
184 saved_state->r14 = state->r14;
185 saved_state->r15 = state->r15;
186
187 saved_state->isf.rflags = state->rflags;
188 saved_state->isf.rsp = state->rsp;
189 saved_state->isf.rip = state->rip;
190
191 saved_state->fs = (uint32_t)state->fs;
192 saved_state->gs = (uint32_t)state->gs;
193 }
194
195
196 kdp_error_t
kdp_machine_read_regs(__unused unsigned int cpu,unsigned int flavor,char * data,int * size)197 kdp_machine_read_regs(
198 __unused unsigned int cpu,
199 unsigned int flavor,
200 char *data,
201 int *size
202 )
203 {
204 static x86_float_state64_t null_fpstate;
205
206 switch (flavor) {
207 case x86_THREAD_STATE64:
208 dprintf(("kdp_readregs THREAD_STATE64\n"));
209 kdp_getstate((x86_thread_state64_t *)data);
210 *size = sizeof(x86_thread_state64_t);
211 return KDPERR_NO_ERROR;
212
213 case x86_FLOAT_STATE64:
214 dprintf(("kdp_readregs THREAD_FPSTATE64\n"));
215 *(x86_float_state64_t *)data = null_fpstate;
216 *size = sizeof(x86_float_state64_t);
217 return KDPERR_NO_ERROR;
218
219 default:
220 dprintf(("kdp_readregs bad flavor %d\n", flavor));
221 *size = 0;
222 return KDPERR_BADFLAVOR;
223 }
224 }
225
226 kdp_error_t
kdp_machine_write_regs(__unused unsigned int cpu,unsigned int flavor,char * data,__unused int * size)227 kdp_machine_write_regs(
228 __unused unsigned int cpu,
229 unsigned int flavor,
230 char *data,
231 __unused int *size
232 )
233 {
234 switch (flavor) {
235 case x86_THREAD_STATE64:
236 dprintf(("kdp_writeregs THREAD_STATE64\n"));
237 kdp_setstate((x86_thread_state64_t *)data);
238 return KDPERR_NO_ERROR;
239
240 case x86_FLOAT_STATE64:
241 dprintf(("kdp_writeregs THREAD_FPSTATE64\n"));
242 return KDPERR_NO_ERROR;
243
244 default:
245 dprintf(("kdp_writeregs bad flavor %d\n", flavor));
246 return KDPERR_BADFLAVOR;
247 }
248 }
249
250
251
252 void
kdp_machine_hostinfo(kdp_hostinfo_t * hostinfo)253 kdp_machine_hostinfo(
254 kdp_hostinfo_t *hostinfo
255 )
256 {
257 int i;
258
259 hostinfo->cpus_mask = 0;
260
261 for (i = 0; i < machine_info.max_cpus; i++) {
262 if (cpu_data_ptr[i] == NULL) {
263 continue;
264 }
265
266 hostinfo->cpus_mask |= (1 << i);
267 }
268
269 hostinfo->cpu_type = cpuid_cputype() | CPU_ARCH_ABI64;
270 hostinfo->cpu_subtype = cpuid_cpusubtype();
271 }
272
273 void
kdp_panic(const char * fmt,...)274 kdp_panic(
275 const char *fmt,
276 ...
277 )
278 {
279 #pragma clang diagnostic push
280 #pragma clang diagnostic ignored "-Wformat-nonliteral"
281 char kdp_fmt[256];
282 va_list args;
283
284 va_start(args, fmt);
285 (void) snprintf(kdp_fmt, sizeof(kdp_fmt), "kdp panic: %s", fmt);
286 vprintf(kdp_fmt, args);
287 va_end(args);
288
289 __asm__ volatile ("hlt");
290 #pragma clang diagnostic pop
291 }
292
293 int
kdp_intr_disbl(void)294 kdp_intr_disbl(void)
295 {
296 return splhigh();
297 }
298
299 void
kdp_intr_enbl(int s)300 kdp_intr_enbl(int s)
301 {
302 splx(s);
303 }
304
305 int
kdp_getc(void)306 kdp_getc(void)
307 {
308 return console_try_read_char();
309 }
310
311 void
kdp_us_spin(int usec)312 kdp_us_spin(int usec)
313 {
314 delay(usec / 100);
315 }
316
317 void
print_saved_state(void * state)318 print_saved_state(void *state)
319 {
320 x86_saved_state64_t *saved_state;
321
322 saved_state = state;
323
324 kprintf("pc = 0x%llx\n", saved_state->isf.rip);
325 kprintf("cr2= 0x%llx\n", saved_state->cr2);
326 kprintf("rp = TODO FIXME\n");
327 kprintf("sp = %p\n", saved_state);
328 }
329
330 void
kdp_sync_cache(void)331 kdp_sync_cache(void)
332 {
333 return; /* No op here. */
334 }
335
336 void
kdp_call(void)337 kdp_call(void)
338 {
339 __asm__ volatile ("int $3"); /* Let the processor do the work */
340 }
341
342
343 typedef struct _cframe_t {
344 struct _cframe_t *prev;
345 unsigned caller;
346 unsigned args[0];
347 } cframe_t;
348
349 boolean_t
kdp_i386_trap(unsigned int trapno,x86_saved_state64_t * saved_state,kern_return_t result,vm_offset_t va)350 kdp_i386_trap(
351 unsigned int trapno,
352 x86_saved_state64_t *saved_state,
353 kern_return_t result,
354 vm_offset_t va
355 )
356 {
357 unsigned int exception, code, subcode = 0;
358 boolean_t prev_interrupts_state;
359
360 if (trapno != T_INT3 && trapno != T_DEBUG) {
361 kprintf("Debugger: Unexpected kernel trap number: "
362 "0x%x, RIP: 0x%llx, CR2: 0x%llx\n",
363 trapno, saved_state->isf.rip, saved_state->cr2);
364 if (!kdp.is_conn) {
365 return FALSE;
366 }
367 }
368
369 prev_interrupts_state = ml_set_interrupts_enabled(FALSE);
370 disable_preemption();
371
372 if (saved_state->isf.rflags & EFL_TF) {
373 enable_preemption_no_check();
374 }
375
376 switch (trapno) {
377 case T_DIVIDE_ERROR:
378 exception = EXC_ARITHMETIC;
379 code = EXC_I386_DIVERR;
380 break;
381
382 case T_OVERFLOW:
383 exception = EXC_SOFTWARE;
384 code = EXC_I386_INTOFLT;
385 break;
386
387 case T_OUT_OF_BOUNDS:
388 exception = EXC_ARITHMETIC;
389 code = EXC_I386_BOUNDFLT;
390 break;
391
392 case T_INVALID_OPCODE:
393 exception = EXC_BAD_INSTRUCTION;
394 code = EXC_I386_INVOPFLT;
395 break;
396
397 case T_SEGMENT_NOT_PRESENT:
398 exception = EXC_BAD_INSTRUCTION;
399 code = EXC_I386_SEGNPFLT;
400 subcode = (unsigned int)saved_state->isf.err;
401 break;
402
403 case T_STACK_FAULT:
404 exception = EXC_BAD_INSTRUCTION;
405 code = EXC_I386_STKFLT;
406 subcode = (unsigned int)saved_state->isf.err;
407 break;
408
409 case T_GENERAL_PROTECTION:
410 exception = EXC_BAD_INSTRUCTION;
411 code = EXC_I386_GPFLT;
412 subcode = (unsigned int)saved_state->isf.err;
413 break;
414
415 case T_PAGE_FAULT:
416 exception = EXC_BAD_ACCESS;
417 code = result;
418 subcode = (unsigned int)va;
419 break;
420
421 case T_WATCHPOINT:
422 exception = EXC_SOFTWARE;
423 code = EXC_I386_ALIGNFLT;
424 break;
425
426 case T_DEBUG:
427 case T_INT3:
428 exception = EXC_BREAKPOINT;
429 code = EXC_I386_BPTFLT;
430 break;
431
432 default:
433 exception = EXC_BAD_INSTRUCTION;
434 code = trapno;
435 break;
436 }
437
438 if (current_cpu_datap()->cpu_fatal_trap_state) {
439 current_cpu_datap()->cpu_post_fatal_trap_state = saved_state;
440 saved_state = current_cpu_datap()->cpu_fatal_trap_state;
441 }
442
443 handle_debugger_trap(exception, code, subcode, saved_state);
444
445 enable_preemption();
446 ml_set_interrupts_enabled(prev_interrupts_state);
447
448 /* If the instruction single step bit is set, disable kernel preemption
449 */
450 if (saved_state->isf.rflags & EFL_TF) {
451 disable_preemption();
452 }
453
454 return TRUE;
455 }
456
457 void
kdp_machine_get_breakinsn(uint8_t * bytes,uint32_t * size)458 kdp_machine_get_breakinsn(
459 uint8_t *bytes,
460 uint32_t *size
461 )
462 {
463 bytes[0] = 0xcc;
464 *size = 1;
465 }
466
467 #define RETURN_OFFSET64 8
468 /* Routine to encapsulate the 64-bit address read hack*/
469 unsigned
machine_read64(addr64_t srcaddr,caddr_t dstaddr,uint32_t len)470 machine_read64(addr64_t srcaddr, caddr_t dstaddr, uint32_t len)
471 {
472 return (unsigned)kdp_machine_vm_read(srcaddr, dstaddr, len);
473 }
474
475 int
machine_trace_thread64(thread_t thread,char * tracepos,char * tracebound,int nframes,uint32_t * thread_trace_flags)476 machine_trace_thread64(thread_t thread,
477 char * tracepos,
478 char * tracebound,
479 int nframes,
480 uint32_t * thread_trace_flags)
481 {
482 extern bool machine_trace_thread_validate_kva(vm_offset_t addr);
483
484 uint64_t * tracebuf = (uint64_t *)tracepos;
485 unsigned framesize = sizeof(addr64_t);
486
487 uint32_t fence = 0;
488 int framecount = 0;
489 addr64_t prev_rip = 0;
490 addr64_t prevsp = 0;
491 vm_offset_t kern_virt_addr = 0;
492
493 nframes = (tracebound > tracepos) ? MIN(nframes, (int)((tracebound - tracepos) / framesize)) : 0;
494
495 addr64_t stackptr = STACK_IKS(thread->kernel_stack)->k_rbp;
496 prev_rip = STACK_IKS(thread->kernel_stack)->k_rip;
497 prev_rip = VM_KERNEL_UNSLIDE(prev_rip);
498
499 for (framecount = 0; framecount < nframes; framecount++) {
500 *tracebuf++ = prev_rip;
501
502 if (!stackptr || (stackptr == fence)) {
503 break;
504 }
505 if (stackptr & 0x0000007) {
506 break;
507 }
508 if (stackptr <= prevsp) {
509 break;
510 }
511
512 kern_virt_addr = stackptr + RETURN_OFFSET64;
513 bool ok = machine_trace_thread_validate_kva(kern_virt_addr);
514 if (!ok) {
515 if (thread_trace_flags) {
516 *thread_trace_flags |= kThreadTruncatedBT;
517 }
518 break;
519 }
520
521 prev_rip = VM_KERNEL_UNSLIDE(*(uint64_t *)kern_virt_addr);
522 prevsp = stackptr;
523
524 kern_virt_addr = stackptr;
525 ok = machine_trace_thread_validate_kva(kern_virt_addr);
526 if (!ok) {
527 if (thread_trace_flags) {
528 *thread_trace_flags |= kThreadTruncatedBT;
529 }
530 break;
531 }
532 stackptr = *(uint64_t *)kern_virt_addr;
533 }
534
535 return (uint32_t) (((char *) tracebuf) - tracepos);
536 }
537
538 void
kdp_ml_enter_debugger(void)539 kdp_ml_enter_debugger(void)
540 {
541 __asm__ __volatile__ ("int3");
542 }
543