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/*
23 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26#include <sys/cdefs.h>
27
28#include <sys/param.h>
29#include <sys/systm.h>
30#include <sys/kernel.h>
31#include <sys/stack.h>
32#include <sys/pcpu.h>
33
34#include <machine/frame.h>
35#include <machine/md_var.h>
36
37#include <vm/vm.h>
38#include <vm/vm_param.h>
39#include <vm/pmap.h>
40
41#include <machine/atomic.h>
42#include <machine/db_machdep.h>
43#include <machine/md_var.h>
44#include <machine/stack.h>
45#include <ddb/db_sym.h>
46#include <ddb/ddb.h>
47#include <sys/kdb.h>
48
49#include "regset.h"
50
51#define	MAX_USTACK_DEPTH  2048
52
53uint8_t dtrace_fuword8_nocheck(void *);
54uint16_t dtrace_fuword16_nocheck(void *);
55uint32_t dtrace_fuword32_nocheck(void *);
56uint64_t dtrace_fuword64_nocheck(void *);
57
58void
59dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes,
60    uint32_t *intrpc)
61{
62	struct unwind_state state;
63	int scp_offset;
64	int depth;
65
66	depth = 0;
67
68	if (intrpc != 0) {
69		pcstack[depth++] = (pc_t) intrpc;
70	}
71
72	aframes++;
73
74	state.fp = (uintptr_t)__builtin_frame_address(0);
75	state.pc = (uintptr_t)dtrace_getpcstack;
76
77	while (depth < pcstack_limit) {
78		if (!unwind_frame(curthread, &state))
79			break;
80		if (!INKERNEL(state.pc))
81			break;
82
83		/*
84		 * NB: Unlike some other architectures, we don't need to
85		 * explicitly insert cpu_dtrace_caller as it appears in the
86		 * normal kernel stack trace rather than a special trap frame.
87		 */
88		if (aframes > 0) {
89			aframes--;
90		} else {
91			pcstack[depth++] = state.pc;
92		}
93
94	}
95
96	for (; depth < pcstack_limit; depth++) {
97		pcstack[depth] = 0;
98	}
99}
100
101static int
102dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t pc,
103    uintptr_t fp)
104{
105	volatile uint16_t *flags =
106	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
107	int ret = 0;
108	uintptr_t oldfp = fp;
109
110	ASSERT(pcstack == NULL || pcstack_limit > 0);
111
112	while (pc != 0) {
113		/*
114		 * We limit the number of times we can go around this
115		 * loop to account for a circular stack.
116		 */
117		if (ret++ >= MAX_USTACK_DEPTH) {
118			*flags |= CPU_DTRACE_BADSTACK;
119			cpu_core[curcpu].cpuc_dtrace_illval = fp;
120			break;
121		}
122
123		if (pcstack != NULL) {
124			*pcstack++ = (uint64_t)pc;
125			pcstack_limit--;
126			if (pcstack_limit <= 0)
127				break;
128		}
129
130		if (fp == 0)
131			break;
132
133		pc = dtrace_fuword64((void *)(fp +
134		    offsetof(struct unwind_state, pc)));
135		fp = dtrace_fuword64((void *)fp);
136
137		if (fp == oldfp) {
138			*flags |= CPU_DTRACE_BADSTACK;
139			cpu_core[curcpu].cpuc_dtrace_illval = fp;
140			break;
141		}
142
143		/*
144		 * ARM64TODO:
145		 *     This workaround might not be necessary. It needs to be
146		 *     revised and removed from all architectures if found
147		 *     unwanted. Leaving the original x86 comment for reference.
148		 *
149		 * This is totally bogus:  if we faulted, we're going to clear
150		 * the fault and break.  This is to deal with the apparently
151		 * broken Java stacks on x86.
152		 */
153		if (*flags & CPU_DTRACE_FAULT) {
154			*flags &= ~CPU_DTRACE_FAULT;
155			break;
156		}
157
158		oldfp = fp;
159	}
160
161	return (ret);
162}
163
164void
165dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit)
166{
167	proc_t *p = curproc;
168	struct trapframe *tf;
169	uintptr_t pc, fp;
170	volatile uint16_t *flags =
171	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
172	int n;
173
174	if (*flags & CPU_DTRACE_FAULT)
175		return;
176
177	if (pcstack_limit <= 0)
178		return;
179
180	/*
181	 * If there's no user context we still need to zero the stack.
182	 */
183	if (p == NULL || (tf = curthread->td_frame) == NULL)
184		goto zero;
185
186	*pcstack++ = (uint64_t)p->p_pid;
187	pcstack_limit--;
188
189	if (pcstack_limit <= 0)
190		return;
191
192	pc = tf->tf_elr;
193	fp = tf->tf_x[29];
194
195	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
196		/*
197		 * In an entry probe.  The frame pointer has not yet been
198		 * pushed (that happens in the function prologue).  The
199		 * best approach is to add the current pc as a missing top
200		 * of stack and back the pc up to the caller, which is stored
201		 * at the current stack pointer address since the call
202		 * instruction puts it there right before the branch.
203		 */
204
205		*pcstack++ = (uint64_t)pc;
206		pcstack_limit--;
207		if (pcstack_limit <= 0)
208			return;
209
210		pc = tf->tf_lr;
211	}
212
213	n = dtrace_getustack_common(pcstack, pcstack_limit, pc, fp);
214	ASSERT(n >= 0);
215	ASSERT(n <= pcstack_limit);
216
217	pcstack += n;
218	pcstack_limit -= n;
219
220zero:
221	while (pcstack_limit-- > 0)
222		*pcstack++ = 0;
223}
224
225int
226dtrace_getustackdepth(void)
227{
228
229	printf("IMPLEMENT ME: %s\n", __func__);
230
231	return (0);
232}
233
234void
235dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit)
236{
237
238	printf("IMPLEMENT ME: %s\n", __func__);
239}
240
241/*ARGSUSED*/
242uint64_t
243dtrace_getarg(int arg, int aframes)
244{
245
246	printf("IMPLEMENT ME: %s\n", __func__);
247
248	return (0);
249}
250
251int
252dtrace_getstackdepth(int aframes)
253{
254	struct unwind_state state;
255	int scp_offset;
256	int depth;
257	bool done;
258
259	depth = 1;
260	done = false;
261
262	state.fp = (uintptr_t)__builtin_frame_address(0);
263	state.pc = (uintptr_t)dtrace_getstackdepth;
264
265	do {
266		done = !unwind_frame(curthread, &state);
267		if (!INKERNEL(state.pc) || !INKERNEL(state.fp))
268			break;
269		depth++;
270	} while (!done);
271
272	if (depth < aframes)
273		return (0);
274	else
275		return (depth - aframes);
276}
277
278ulong_t
279dtrace_getreg(struct trapframe *frame, uint_t reg)
280{
281	switch (reg) {
282	case REG_X0 ... REG_X29:
283		return (frame->tf_x[reg]);
284	case REG_LR:
285		return (frame->tf_lr);
286	case REG_SP:
287		return (frame->tf_sp);
288	case REG_PC:
289		return (frame->tf_elr);
290	default:
291		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
292		return (0);
293	}
294	/* NOTREACHED */
295}
296
297static int
298dtrace_copycheck(uintptr_t uaddr, uintptr_t kaddr, size_t size)
299{
300
301	if (uaddr + size > VM_MAXUSER_ADDRESS || uaddr + size < uaddr) {
302		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
303		cpu_core[curcpu].cpuc_dtrace_illval = uaddr;
304		return (0);
305	}
306
307	return (1);
308}
309
310void
311dtrace_copyin(uintptr_t uaddr, uintptr_t kaddr, size_t size,
312    volatile uint16_t *flags)
313{
314
315	if (dtrace_copycheck(uaddr, kaddr, size))
316		dtrace_copy(uaddr, kaddr, size);
317}
318
319void
320dtrace_copyout(uintptr_t kaddr, uintptr_t uaddr, size_t size,
321    volatile uint16_t *flags)
322{
323
324	if (dtrace_copycheck(uaddr, kaddr, size))
325		dtrace_copy(kaddr, uaddr, size);
326}
327
328void
329dtrace_copyinstr(uintptr_t uaddr, uintptr_t kaddr, size_t size,
330    volatile uint16_t *flags)
331{
332
333	if (dtrace_copycheck(uaddr, kaddr, size))
334		dtrace_copystr(uaddr, kaddr, size, flags);
335}
336
337void
338dtrace_copyoutstr(uintptr_t kaddr, uintptr_t uaddr, size_t size,
339    volatile uint16_t *flags)
340{
341
342	if (dtrace_copycheck(uaddr, kaddr, size))
343		dtrace_copystr(kaddr, uaddr, size, flags);
344}
345
346uint8_t
347dtrace_fuword8(void *uaddr)
348{
349
350	if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) {
351		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
352		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
353		return (0);
354	}
355
356	return (dtrace_fuword8_nocheck(uaddr));
357}
358
359uint16_t
360dtrace_fuword16(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_fuword16_nocheck(uaddr));
370}
371
372uint32_t
373dtrace_fuword32(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_fuword32_nocheck(uaddr));
383}
384
385uint64_t
386dtrace_fuword64(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_fuword64_nocheck(uaddr));
396}
397