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;
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 = (uintptr_t)__builtin_frame_address(0);
87	state.sp = sp;
88	state.pc = (uintptr_t)dtrace_getpcstack;
89
90	while (depth < pcstack_limit) {
91		if (!unwind_frame(curthread, &state))
92			break;
93		if (!INKERNEL(state.pc))
94			break;
95
96		/*
97		 * NB: Unlike some other architectures, we don't need to
98		 * explicitly insert cpu_dtrace_caller as it appears in the
99		 * normal kernel stack trace rather than a special trap frame.
100		 */
101		if (aframes > 0) {
102			aframes--;
103		} else {
104			pcstack[depth++] = state.pc;
105		}
106
107	}
108
109	for (; depth < pcstack_limit; depth++) {
110		pcstack[depth] = 0;
111	}
112}
113
114static int
115dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t pc,
116    uintptr_t fp)
117{
118	volatile uint16_t *flags =
119	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
120	int ret = 0;
121	uintptr_t oldfp = fp;
122
123	ASSERT(pcstack == NULL || pcstack_limit > 0);
124
125	while (pc != 0) {
126		/*
127		 * We limit the number of times we can go around this
128		 * loop to account for a circular stack.
129		 */
130		if (ret++ >= MAX_USTACK_DEPTH) {
131			*flags |= CPU_DTRACE_BADSTACK;
132			cpu_core[curcpu].cpuc_dtrace_illval = fp;
133			break;
134		}
135
136		if (pcstack != NULL) {
137			*pcstack++ = (uint64_t)pc;
138			pcstack_limit--;
139			if (pcstack_limit <= 0)
140				break;
141		}
142
143		if (fp == 0)
144			break;
145
146		pc = dtrace_fuword64((void *)(fp +
147		    offsetof(struct arm64_frame, f_retaddr)));
148		fp = dtrace_fuword64((void *)fp);
149
150		if (fp == oldfp) {
151			*flags |= CPU_DTRACE_BADSTACK;
152			cpu_core[curcpu].cpuc_dtrace_illval = fp;
153			break;
154		}
155
156		/*
157		 * ARM64TODO:
158		 *     This workaround might not be necessary. It needs to be
159		 *     revised and removed from all architectures if found
160		 *     unwanted. Leaving the original x86 comment for reference.
161		 *
162		 * This is totally bogus:  if we faulted, we're going to clear
163		 * the fault and break.  This is to deal with the apparently
164		 * broken Java stacks on x86.
165		 */
166		if (*flags & CPU_DTRACE_FAULT) {
167			*flags &= ~CPU_DTRACE_FAULT;
168			break;
169		}
170
171		oldfp = fp;
172	}
173
174	return (ret);
175}
176
177void
178dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit)
179{
180	proc_t *p = curproc;
181	struct trapframe *tf;
182	uintptr_t pc, sp, fp;
183	volatile uint16_t *flags =
184	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
185	int n;
186
187	if (*flags & CPU_DTRACE_FAULT)
188		return;
189
190	if (pcstack_limit <= 0)
191		return;
192
193	/*
194	 * If there's no user context we still need to zero the stack.
195	 */
196	if (p == NULL || (tf = curthread->td_frame) == NULL)
197		goto zero;
198
199	*pcstack++ = (uint64_t)p->p_pid;
200	pcstack_limit--;
201
202	if (pcstack_limit <= 0)
203		return;
204
205	pc = tf->tf_elr;
206	sp = tf->tf_sp;
207	fp = tf->tf_x[29];
208
209	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
210		/*
211		 * In an entry probe.  The frame pointer has not yet been
212		 * pushed (that happens in the function prologue).  The
213		 * best approach is to add the current pc as a missing top
214		 * of stack and back the pc up to the caller, which is stored
215		 * at the current stack pointer address since the call
216		 * instruction puts it there right before the branch.
217		 */
218
219		*pcstack++ = (uint64_t)pc;
220		pcstack_limit--;
221		if (pcstack_limit <= 0)
222			return;
223
224		pc = tf->tf_lr;
225	}
226
227	n = dtrace_getustack_common(pcstack, pcstack_limit, pc, fp);
228	ASSERT(n >= 0);
229	ASSERT(n <= pcstack_limit);
230
231	pcstack += n;
232	pcstack_limit -= n;
233
234zero:
235	while (pcstack_limit-- > 0)
236		*pcstack++ = 0;
237}
238
239int
240dtrace_getustackdepth(void)
241{
242
243	printf("IMPLEMENT ME: %s\n", __func__);
244
245	return (0);
246}
247
248void
249dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit)
250{
251
252	printf("IMPLEMENT ME: %s\n", __func__);
253}
254
255/*ARGSUSED*/
256uint64_t
257dtrace_getarg(int arg, int aframes)
258{
259
260	printf("IMPLEMENT ME: %s\n", __func__);
261
262	return (0);
263}
264
265int
266dtrace_getstackdepth(int aframes)
267{
268	struct unwind_state state;
269	int scp_offset;
270	register_t sp;
271	int depth;
272	bool done;
273
274	depth = 1;
275	done = false;
276
277	__asm __volatile("mov %0, sp" : "=&r" (sp));
278
279	state.fp = (uintptr_t)__builtin_frame_address(0);
280	state.sp = sp;
281	state.pc = (uintptr_t)dtrace_getstackdepth;
282
283	do {
284		done = !unwind_frame(curthread, &state);
285		if (!INKERNEL(state.pc) || !INKERNEL(state.fp))
286			break;
287		depth++;
288	} while (!done);
289
290	if (depth < aframes)
291		return (0);
292	else
293		return (depth - aframes);
294}
295
296ulong_t
297dtrace_getreg(struct trapframe *rp, uint_t reg)
298{
299
300	printf("IMPLEMENT ME: %s\n", __func__);
301
302	return (0);
303}
304
305static int
306dtrace_copycheck(uintptr_t uaddr, uintptr_t kaddr, size_t size)
307{
308
309	if (uaddr + size > VM_MAXUSER_ADDRESS || uaddr + size < uaddr) {
310		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
311		cpu_core[curcpu].cpuc_dtrace_illval = uaddr;
312		return (0);
313	}
314
315	return (1);
316}
317
318void
319dtrace_copyin(uintptr_t uaddr, uintptr_t kaddr, size_t size,
320    volatile uint16_t *flags)
321{
322
323	if (dtrace_copycheck(uaddr, kaddr, size))
324		dtrace_copy(uaddr, kaddr, size);
325}
326
327void
328dtrace_copyout(uintptr_t kaddr, uintptr_t uaddr, size_t size,
329    volatile uint16_t *flags)
330{
331
332	if (dtrace_copycheck(uaddr, kaddr, size))
333		dtrace_copy(kaddr, uaddr, size);
334}
335
336void
337dtrace_copyinstr(uintptr_t uaddr, uintptr_t kaddr, size_t size,
338    volatile uint16_t *flags)
339{
340
341	if (dtrace_copycheck(uaddr, kaddr, size))
342		dtrace_copystr(uaddr, kaddr, size, flags);
343}
344
345void
346dtrace_copyoutstr(uintptr_t kaddr, uintptr_t uaddr, size_t size,
347    volatile uint16_t *flags)
348{
349
350	if (dtrace_copycheck(uaddr, kaddr, size))
351		dtrace_copystr(kaddr, uaddr, size, flags);
352}
353
354uint8_t
355dtrace_fuword8(void *uaddr)
356{
357
358	if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) {
359		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
360		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
361		return (0);
362	}
363
364	return (dtrace_fuword8_nocheck(uaddr));
365}
366
367uint16_t
368dtrace_fuword16(void *uaddr)
369{
370
371	if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) {
372		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
373		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
374		return (0);
375	}
376
377	return (dtrace_fuword16_nocheck(uaddr));
378}
379
380uint32_t
381dtrace_fuword32(void *uaddr)
382{
383
384	if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) {
385		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
386		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
387		return (0);
388	}
389
390	return (dtrace_fuword32_nocheck(uaddr));
391}
392
393uint64_t
394dtrace_fuword64(void *uaddr)
395{
396
397	if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) {
398		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
399		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
400		return (0);
401	}
402
403	return (dtrace_fuword64_nocheck(uaddr));
404}
405