1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 *
22 * $FreeBSD$
23 */
24/*
25 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
26 * Use is subject to license terms.
27 */
28#include <sys/cdefs.h>
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/stack.h>
34#include <sys/pcpu.h>
35
36#include <machine/frame.h>
37#include <machine/md_var.h>
38#include <machine/reg.h>
39
40#include <vm/vm.h>
41#include <vm/vm_param.h>
42#include <vm/pmap.h>
43
44#include <machine/atomic.h>
45#include <machine/db_machdep.h>
46#include <machine/md_var.h>
47#include <machine/stack.h>
48#include <ddb/db_sym.h>
49#include <ddb/ddb.h>
50#include <sys/kdb.h>
51
52#include "regset.h"
53
54/*
55 * Wee need some reasonable default to prevent backtrace code
56 * from wandering too far
57 */
58#define	MAX_FUNCTION_SIZE 0x10000
59#define	MAX_PROLOGUE_SIZE 0x100
60#define	MAX_USTACK_DEPTH  2048
61
62uint8_t dtrace_fuword8_nocheck(void *);
63uint16_t dtrace_fuword16_nocheck(void *);
64uint32_t dtrace_fuword32_nocheck(void *);
65uint64_t dtrace_fuword64_nocheck(void *);
66
67void
68dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes,
69    uint32_t *intrpc)
70{
71	struct unwind_state state;
72	int scp_offset;
73	register_t sp, fp;
74	int depth;
75
76	depth = 0;
77
78	if (intrpc != 0) {
79		pcstack[depth++] = (pc_t) intrpc;
80	}
81
82	aframes++;
83
84	__asm __volatile("mov %0, sp" : "=&r" (sp));
85
86	state.fp = (uint64_t)__builtin_frame_address(0);
87	state.sp = sp;
88	state.pc = (uint64_t)dtrace_getpcstack;
89
90	while (depth < pcstack_limit) {
91		if (!INKERNEL(state.pc) || !INKERNEL(state.fp))
92			break;
93
94		fp = state.fp;
95		state.sp = fp + 0x10;
96		/* FP to previous frame (X29) */
97		state.fp = *(register_t *)(fp);
98		/* LR (X30) */
99		state.pc = *(register_t *)(fp + 8) - 4;
100
101		/*
102		 * NB: Unlike some other architectures, we don't need to
103		 * explicitly insert cpu_dtrace_caller as it appears in the
104		 * normal kernel stack trace rather than a special trap frame.
105		 */
106		if (aframes > 0) {
107			aframes--;
108		} else {
109			pcstack[depth++] = state.pc;
110		}
111
112	}
113
114	for (; depth < pcstack_limit; depth++) {
115		pcstack[depth] = 0;
116	}
117}
118
119static int
120dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t pc,
121    uintptr_t fp)
122{
123	volatile uint16_t *flags =
124	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
125	int ret = 0;
126	uintptr_t oldfp = fp;
127
128	ASSERT(pcstack == NULL || pcstack_limit > 0);
129
130	while (pc != 0) {
131		/*
132		 * We limit the number of times we can go around this
133		 * loop to account for a circular stack.
134		 */
135		if (ret++ >= MAX_USTACK_DEPTH) {
136			*flags |= CPU_DTRACE_BADSTACK;
137			cpu_core[curcpu].cpuc_dtrace_illval = fp;
138			break;
139		}
140
141		if (pcstack != NULL) {
142			*pcstack++ = (uint64_t)pc;
143			pcstack_limit--;
144			if (pcstack_limit <= 0)
145				break;
146		}
147
148		if (fp == 0)
149			break;
150
151		pc = dtrace_fuword64((void *)(fp +
152		    offsetof(struct arm64_frame, f_retaddr)));
153		fp = dtrace_fuword64((void *)fp);
154
155		if (fp == oldfp) {
156			*flags |= CPU_DTRACE_BADSTACK;
157			cpu_core[curcpu].cpuc_dtrace_illval = fp;
158			break;
159		}
160
161		/*
162		 * ARM64TODO:
163		 *     This workaround might not be necessary. It needs to be
164		 *     revised and removed from all architectures if found
165		 *     unwanted. Leaving the original x86 comment for reference.
166		 *
167		 * This is totally bogus:  if we faulted, we're going to clear
168		 * the fault and break.  This is to deal with the apparently
169		 * broken Java stacks on x86.
170		 */
171		if (*flags & CPU_DTRACE_FAULT) {
172			*flags &= ~CPU_DTRACE_FAULT;
173			break;
174		}
175
176		oldfp = fp;
177	}
178
179	return (ret);
180}
181
182void
183dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit)
184{
185	proc_t *p = curproc;
186	struct trapframe *tf;
187	uintptr_t pc, sp, fp;
188	volatile uint16_t *flags =
189	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
190	int n;
191
192	if (*flags & CPU_DTRACE_FAULT)
193		return;
194
195	if (pcstack_limit <= 0)
196		return;
197
198	/*
199	 * If there's no user context we still need to zero the stack.
200	 */
201	if (p == NULL || (tf = curthread->td_frame) == NULL)
202		goto zero;
203
204	*pcstack++ = (uint64_t)p->p_pid;
205	pcstack_limit--;
206
207	if (pcstack_limit <= 0)
208		return;
209
210	pc = tf->tf_elr;
211	sp = tf->tf_sp;
212	fp = tf->tf_x[29];
213
214	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
215		/*
216		 * In an entry probe.  The frame pointer has not yet been
217		 * pushed (that happens in the function prologue).  The
218		 * best approach is to add the current pc as a missing top
219		 * of stack and back the pc up to the caller, which is stored
220		 * at the current stack pointer address since the call
221		 * instruction puts it there right before the branch.
222		 */
223
224		*pcstack++ = (uint64_t)pc;
225		pcstack_limit--;
226		if (pcstack_limit <= 0)
227			return;
228
229		pc = tf->tf_lr;
230	}
231
232	n = dtrace_getustack_common(pcstack, pcstack_limit, pc, fp);
233	ASSERT(n >= 0);
234	ASSERT(n <= pcstack_limit);
235
236	pcstack += n;
237	pcstack_limit -= n;
238
239zero:
240	while (pcstack_limit-- > 0)
241		*pcstack++ = 0;
242}
243
244int
245dtrace_getustackdepth(void)
246{
247
248	printf("IMPLEMENT ME: %s\n", __func__);
249
250	return (0);
251}
252
253void
254dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit)
255{
256
257	printf("IMPLEMENT ME: %s\n", __func__);
258}
259
260/*ARGSUSED*/
261uint64_t
262dtrace_getarg(int arg, int aframes)
263{
264
265	printf("IMPLEMENT ME: %s\n", __func__);
266
267	return (0);
268}
269
270int
271dtrace_getstackdepth(int aframes)
272{
273	struct unwind_state state;
274	int scp_offset;
275	register_t sp;
276	int depth;
277	int done;
278
279	depth = 1;
280	done = 0;
281
282	__asm __volatile("mov %0, sp" : "=&r" (sp));
283
284	state.fp = (uint64_t)__builtin_frame_address(0);
285	state.sp = sp;
286	state.pc = (uint64_t)dtrace_getstackdepth;
287
288	do {
289		done = unwind_frame(&state);
290		if (!INKERNEL(state.pc) || !INKERNEL(state.fp))
291			break;
292		depth++;
293	} while (!done);
294
295	if (depth < aframes)
296		return (0);
297	else
298		return (depth - aframes);
299}
300
301ulong_t
302dtrace_getreg(struct trapframe *rp, uint_t reg)
303{
304
305	printf("IMPLEMENT ME: %s\n", __func__);
306
307	return (0);
308}
309
310static int
311dtrace_copycheck(uintptr_t uaddr, uintptr_t kaddr, size_t size)
312{
313
314	if (uaddr + size > VM_MAXUSER_ADDRESS || uaddr + size < uaddr) {
315		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
316		cpu_core[curcpu].cpuc_dtrace_illval = uaddr;
317		return (0);
318	}
319
320	return (1);
321}
322
323void
324dtrace_copyin(uintptr_t uaddr, uintptr_t kaddr, size_t size,
325    volatile uint16_t *flags)
326{
327
328	if (dtrace_copycheck(uaddr, kaddr, size))
329		dtrace_copy(uaddr, kaddr, size);
330}
331
332void
333dtrace_copyout(uintptr_t kaddr, uintptr_t uaddr, size_t size,
334    volatile uint16_t *flags)
335{
336
337	if (dtrace_copycheck(uaddr, kaddr, size))
338		dtrace_copy(kaddr, uaddr, size);
339}
340
341void
342dtrace_copyinstr(uintptr_t uaddr, uintptr_t kaddr, size_t size,
343    volatile uint16_t *flags)
344{
345
346	if (dtrace_copycheck(uaddr, kaddr, size))
347		dtrace_copystr(uaddr, kaddr, size, flags);
348}
349
350void
351dtrace_copyoutstr(uintptr_t kaddr, uintptr_t uaddr, size_t size,
352    volatile uint16_t *flags)
353{
354
355	if (dtrace_copycheck(uaddr, kaddr, size))
356		dtrace_copystr(kaddr, uaddr, size, flags);
357}
358
359uint8_t
360dtrace_fuword8(void *uaddr)
361{
362
363	if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) {
364		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
365		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
366		return (0);
367	}
368
369	return (dtrace_fuword8_nocheck(uaddr));
370}
371
372uint16_t
373dtrace_fuword16(void *uaddr)
374{
375
376	if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) {
377		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
378		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
379		return (0);
380	}
381
382	return (dtrace_fuword16_nocheck(uaddr));
383}
384
385uint32_t
386dtrace_fuword32(void *uaddr)
387{
388
389	if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) {
390		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
391		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
392		return (0);
393	}
394
395	return (dtrace_fuword32_nocheck(uaddr));
396}
397
398uint64_t
399dtrace_fuword64(void *uaddr)
400{
401
402	if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) {
403		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
404		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
405		return (0);
406	}
407
408	return (dtrace_fuword64_nocheck(uaddr));
409}
410