xref: /freebsd/sys/cddl/dev/dtrace/aarch64/dtrace_subr.c (revision fed1ca4b719c56c930f2259d80663cd34be812bb)
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 /*
26  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/types.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/kmem.h>
39 #include <sys/smp.h>
40 #include <sys/dtrace_impl.h>
41 #include <sys/dtrace_bsd.h>
42 #include <machine/armreg.h>
43 #include <machine/clock.h>
44 #include <machine/frame.h>
45 #include <machine/trap.h>
46 #include <vm/pmap.h>
47 
48 extern dtrace_id_t	dtrace_probeid_error;
49 extern int (*dtrace_invop_jump_addr)(struct trapframe *);
50 extern void dtrace_getnanotime(struct timespec *tsp);
51 
52 int dtrace_invop(uintptr_t, struct trapframe *, uintptr_t);
53 void dtrace_invop_init(void);
54 void dtrace_invop_uninit(void);
55 
56 typedef struct dtrace_invop_hdlr {
57 	int (*dtih_func)(uintptr_t, struct trapframe *, uintptr_t);
58 	struct dtrace_invop_hdlr *dtih_next;
59 } dtrace_invop_hdlr_t;
60 
61 dtrace_invop_hdlr_t *dtrace_invop_hdlr;
62 
63 int
64 dtrace_invop(uintptr_t addr, struct trapframe *frame, uintptr_t eax)
65 {
66 	dtrace_invop_hdlr_t *hdlr;
67 	int rval;
68 
69 	for (hdlr = dtrace_invop_hdlr; hdlr != NULL; hdlr = hdlr->dtih_next)
70 		if ((rval = hdlr->dtih_func(addr, frame, eax)) != 0)
71 			return (rval);
72 
73 	return (0);
74 }
75 
76 
77 void
78 dtrace_invop_add(int (*func)(uintptr_t, struct trapframe *, uintptr_t))
79 {
80 	dtrace_invop_hdlr_t *hdlr;
81 
82 	hdlr = kmem_alloc(sizeof (dtrace_invop_hdlr_t), KM_SLEEP);
83 	hdlr->dtih_func = func;
84 	hdlr->dtih_next = dtrace_invop_hdlr;
85 	dtrace_invop_hdlr = hdlr;
86 }
87 
88 void
89 dtrace_invop_remove(int (*func)(uintptr_t, struct trapframe *, uintptr_t))
90 {
91 	dtrace_invop_hdlr_t *hdlr, *prev;
92 
93 	hdlr = dtrace_invop_hdlr;
94 	prev = NULL;
95 
96 	for (;;) {
97 		if (hdlr == NULL)
98 			panic("attempt to remove non-existent invop handler");
99 
100 		if (hdlr->dtih_func == func)
101 			break;
102 
103 		prev = hdlr;
104 		hdlr = hdlr->dtih_next;
105 	}
106 
107 	if (prev == NULL) {
108 		ASSERT(dtrace_invop_hdlr == hdlr);
109 		dtrace_invop_hdlr = hdlr->dtih_next;
110 	} else {
111 		ASSERT(dtrace_invop_hdlr != hdlr);
112 		prev->dtih_next = hdlr->dtih_next;
113 	}
114 
115 	kmem_free(hdlr, 0);
116 }
117 
118 /*ARGSUSED*/
119 void
120 dtrace_toxic_ranges(void (*func)(uintptr_t base, uintptr_t limit))
121 {
122 
123 	(*func)(0, (uintptr_t)VM_MIN_KERNEL_ADDRESS);
124 }
125 
126 void
127 dtrace_xcall(processorid_t cpu, dtrace_xcall_t func, void *arg)
128 {
129 	cpuset_t cpus;
130 
131 	if (cpu == DTRACE_CPUALL)
132 		cpus = all_cpus;
133 	else
134 		CPU_SETOF(cpu, &cpus);
135 
136 	smp_rendezvous_cpus(cpus, smp_no_rendevous_barrier, func,
137 	    smp_no_rendevous_barrier, arg);
138 }
139 
140 static void
141 dtrace_sync_func(void)
142 {
143 
144 }
145 
146 void
147 dtrace_sync(void)
148 {
149 
150 	dtrace_xcall(DTRACE_CPUALL, (dtrace_xcall_t)dtrace_sync_func, NULL);
151 }
152 
153 /*
154  * DTrace needs a high resolution time function which can
155  * be called from a probe context and guaranteed not to have
156  * instrumented with probes itself.
157  *
158  * Returns nanoseconds since boot.
159  */
160 uint64_t
161 dtrace_gethrtime()
162 {
163 	struct timespec curtime;
164 
165 	nanouptime(&curtime);
166 
167 	return (curtime.tv_sec * 1000000000UL + curtime.tv_nsec);
168 
169 }
170 
171 uint64_t
172 dtrace_gethrestime(void)
173 {
174 	struct timespec current_time;
175 
176 	dtrace_getnanotime(&current_time);
177 
178 	return (current_time.tv_sec * 1000000000UL + current_time.tv_nsec);
179 }
180 
181 /* Function to handle DTrace traps during probes. See arm64/arm64/trap.c */
182 int
183 dtrace_trap(struct trapframe *frame, u_int type)
184 {
185 	/*
186 	 * A trap can occur while DTrace executes a probe. Before
187 	 * executing the probe, DTrace blocks re-scheduling and sets
188 	 * a flag in it's per-cpu flags to indicate that it doesn't
189 	 * want to fault. On returning from the probe, the no-fault
190 	 * flag is cleared and finally re-scheduling is enabled.
191 	 *
192 	 * Check if DTrace has enabled 'no-fault' mode:
193 	 *
194 	 */
195 
196 	if ((cpu_core[curcpu].cpuc_dtrace_flags & CPU_DTRACE_NOFAULT) != 0) {
197 		/*
198 		 * There are only a couple of trap types that are expected.
199 		 * All the rest will be handled in the usual way.
200 		 */
201 		switch (type) {
202 		case EXCP_DATA_ABORT:
203 			/* Flag a bad address. */
204 			cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_BADADDR;
205 			cpu_core[curcpu].cpuc_dtrace_illval = 0;
206 
207 			/*
208 			 * Offset the instruction pointer to the instruction
209 			 * following the one causing the fault.
210 			 */
211 			frame->tf_elr += 4;
212 			return (1);
213 		default:
214 			/* Handle all other traps in the usual way. */
215 			break;
216 		}
217 	}
218 
219 	/* Handle the trap in the usual way. */
220 	return (0);
221 }
222 
223 void
224 dtrace_probe_error(dtrace_state_t *state, dtrace_epid_t epid, int which,
225     int fault, int fltoffs, uintptr_t illval)
226 {
227 
228 	dtrace_probe(dtrace_probeid_error, (uint64_t)(uintptr_t)state,
229 	    (uintptr_t)epid,
230 	    (uintptr_t)which, (uintptr_t)fault, (uintptr_t)fltoffs);
231 }
232 
233 static int
234 dtrace_invop_start(struct trapframe *frame)
235 {
236 	int data, invop, reg, update_sp;
237 	register_t arg1, arg2;
238 	register_t *sp;
239 	int offs;
240 	int tmp;
241 	int i;
242 
243 	invop = dtrace_invop(frame->tf_elr, frame, frame->tf_elr);
244 
245 	tmp = (invop & LDP_STP_MASK);
246 	if (tmp == STP_64 || tmp == LDP_64) {
247 		sp = (register_t *)frame->tf_sp;
248 		data = invop;
249 		arg1 = (data >> ARG1_SHIFT) & ARG1_MASK;
250 		arg2 = (data >> ARG2_SHIFT) & ARG2_MASK;
251 
252 		offs = (data >> OFFSET_SHIFT) & OFFSET_MASK;
253 
254 		switch (tmp) {
255 		case STP_64:
256 			if (offs >> (OFFSET_SIZE - 1))
257 				sp -= (~offs & OFFSET_MASK) + 1;
258 			else
259 				sp += (offs);
260 			*(sp + 0) = frame->tf_x[arg1];
261 			*(sp + 1) = frame->tf_x[arg2];
262 			break;
263 		case LDP_64:
264 			frame->tf_x[arg1] = *(sp + 0);
265 			frame->tf_x[arg2] = *(sp + 1);
266 			if (offs >> (OFFSET_SIZE - 1))
267 				sp -= (~offs & OFFSET_MASK) + 1;
268 			else
269 				sp += (offs);
270 			break;
271 		default:
272 			break;
273 		}
274 
275 		/* Update the stack pointer and program counter to continue */
276 		frame->tf_sp = (register_t)sp;
277 		frame->tf_elr += INSN_SIZE;
278 		return (0);
279 	}
280 
281 	if ((invop & B_MASK) == B_INSTR) {
282 		data = (invop & B_DATA_MASK);
283 		/* The data is the number of 4-byte words to change the pc */
284 		data *= 4;
285 		frame->tf_elr += data;
286 		return (0);
287 	}
288 
289 	if (invop == RET_INSTR) {
290 		frame->tf_elr = frame->tf_lr;
291 		return (0);
292 	}
293 
294 	return (-1);
295 }
296 
297 void
298 dtrace_invop_init(void)
299 {
300 
301 	dtrace_invop_jump_addr = dtrace_invop_start;
302 }
303 
304 void
305 dtrace_invop_uninit(void)
306 {
307 
308 	dtrace_invop_jump_addr = 0;
309 }
310