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 /*
24 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
25 * Use is subject to license terms.
26 */
27
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/kernel.h>
31 #include <sys/malloc.h>
32 #include <sys/kmem.h>
33 #include <sys/proc.h>
34 #include <sys/smp.h>
35 #include <sys/dtrace_impl.h>
36 #include <sys/dtrace_bsd.h>
37 #include <cddl/dev/dtrace/dtrace_cddl.h>
38 #include <machine/armreg.h>
39 #include <machine/clock.h>
40 #include <machine/frame.h>
41 #include <machine/trap.h>
42 #include <machine/vmparam.h>
43 #include <vm/pmap.h>
44
45 extern dtrace_id_t dtrace_probeid_error;
46 extern int (*dtrace_invop_jump_addr)(struct trapframe *);
47 extern void dtrace_getnanotime(struct timespec *tsp);
48 extern void dtrace_getnanouptime(struct timespec *tsp);
49
50 int dtrace_invop(uintptr_t, struct trapframe *, uintptr_t);
51 void dtrace_invop_init(void);
52 void dtrace_invop_uninit(void);
53
54 typedef struct dtrace_invop_hdlr {
55 int (*dtih_func)(uintptr_t, struct trapframe *, uintptr_t);
56 struct dtrace_invop_hdlr *dtih_next;
57 } dtrace_invop_hdlr_t;
58
59 dtrace_invop_hdlr_t *dtrace_invop_hdlr;
60
61 int
dtrace_invop(uintptr_t addr,struct trapframe * frame,uintptr_t eax)62 dtrace_invop(uintptr_t addr, struct trapframe *frame, uintptr_t eax)
63 {
64 struct thread *td;
65 dtrace_invop_hdlr_t *hdlr;
66 int rval;
67
68 rval = 0;
69 td = curthread;
70 td->t_dtrace_trapframe = frame;
71 for (hdlr = dtrace_invop_hdlr; hdlr != NULL; hdlr = hdlr->dtih_next)
72 if ((rval = hdlr->dtih_func(addr, frame, eax)) != 0)
73 break;
74 td->t_dtrace_trapframe = NULL;
75 return (rval);
76 }
77
78 void
dtrace_invop_add(int (* func)(uintptr_t,struct trapframe *,uintptr_t))79 dtrace_invop_add(int (*func)(uintptr_t, struct trapframe *, uintptr_t))
80 {
81 dtrace_invop_hdlr_t *hdlr;
82
83 hdlr = kmem_alloc(sizeof (dtrace_invop_hdlr_t), KM_SLEEP);
84 hdlr->dtih_func = func;
85 hdlr->dtih_next = dtrace_invop_hdlr;
86 dtrace_invop_hdlr = hdlr;
87 }
88
89 void
dtrace_invop_remove(int (* func)(uintptr_t,struct trapframe *,uintptr_t))90 dtrace_invop_remove(int (*func)(uintptr_t, struct trapframe *, uintptr_t))
91 {
92 dtrace_invop_hdlr_t *hdlr, *prev;
93
94 hdlr = dtrace_invop_hdlr;
95 prev = NULL;
96
97 for (;;) {
98 if (hdlr == NULL)
99 panic("attempt to remove non-existent invop handler");
100
101 if (hdlr->dtih_func == func)
102 break;
103
104 prev = hdlr;
105 hdlr = hdlr->dtih_next;
106 }
107
108 if (prev == NULL) {
109 ASSERT(dtrace_invop_hdlr == hdlr);
110 dtrace_invop_hdlr = hdlr->dtih_next;
111 } else {
112 ASSERT(dtrace_invop_hdlr != hdlr);
113 prev->dtih_next = hdlr->dtih_next;
114 }
115
116 kmem_free(hdlr, 0);
117 }
118
119 /*ARGSUSED*/
120 void
dtrace_toxic_ranges(void (* func)(uintptr_t base,uintptr_t limit))121 dtrace_toxic_ranges(void (*func)(uintptr_t base, uintptr_t limit))
122 {
123
124 (*func)(0, (uintptr_t)VM_MIN_KERNEL_ADDRESS);
125 }
126
127 static uint64_t nsec_scale;
128
129 #define SCALE_SHIFT 25
130
131 /*
132 * Choose scaling factors which let us convert a cntvct_el0 value to nanoseconds
133 * without overflow, as in the amd64 implementation.
134 *
135 * Documentation for the ARM generic timer states that typical counter
136 * frequencies are in the range 1Mhz-50Mhz; in ARMv9 the frequency is fixed at
137 * 1GHz. The lower bound of 1MHz forces the shift to be at most 25 bits. At
138 * that frequency, the calculation (hi * scale) << (32 - shift) will not
139 * overflow for over 100 years, assuming that the counter value starts at 0 upon
140 * boot.
141 */
142 static void
dtrace_gethrtime_init(void * arg __unused)143 dtrace_gethrtime_init(void *arg __unused)
144 {
145 uint64_t freq;
146
147 freq = READ_SPECIALREG(cntfrq_el0);
148 nsec_scale = ((uint64_t)NANOSEC << SCALE_SHIFT) / freq;
149 }
150 SYSINIT(dtrace_gethrtime_init, SI_SUB_DTRACE, SI_ORDER_ANY,
151 dtrace_gethrtime_init, NULL);
152
153 /*
154 * DTrace needs a high resolution time function which can be called from a
155 * probe context and guaranteed not to have instrumented with probes itself.
156 *
157 * Returns nanoseconds since some arbitrary point in time (likely SoC reset?).
158 */
159 uint64_t
dtrace_gethrtime(void)160 dtrace_gethrtime(void)
161 {
162 uint64_t count, freq;
163 uint32_t lo, hi;
164
165 count = READ_SPECIALREG(cntvct_el0);
166 lo = count;
167 hi = count >> 32;
168 return (((lo * nsec_scale) >> SCALE_SHIFT) +
169 ((hi * nsec_scale) << (32 - SCALE_SHIFT)));
170 }
171
172 /*
173 * Return a much lower resolution wallclock time based on the system clock
174 * updated by the timer. If needed, we could add a version interpolated from
175 * the system clock as is the case with dtrace_gethrtime().
176 */
177 uint64_t
dtrace_gethrestime(void)178 dtrace_gethrestime(void)
179 {
180 struct timespec current_time;
181
182 dtrace_getnanotime(¤t_time);
183
184 return (current_time.tv_sec * 1000000000UL + current_time.tv_nsec);
185 }
186
187 /* Function to handle DTrace traps during probes. See arm64/arm64/trap.c */
188 int
dtrace_trap(struct trapframe * frame,u_int type)189 dtrace_trap(struct trapframe *frame, u_int type)
190 {
191 /*
192 * A trap can occur while DTrace executes a probe. Before
193 * executing the probe, DTrace blocks re-scheduling and sets
194 * a flag in its per-cpu flags to indicate that it doesn't
195 * want to fault. On returning from the probe, the no-fault
196 * flag is cleared and finally re-scheduling is enabled.
197 *
198 * Check if DTrace has enabled 'no-fault' mode:
199 *
200 */
201
202 if ((cpu_core[curcpu].cpuc_dtrace_flags & CPU_DTRACE_NOFAULT) != 0) {
203 /*
204 * There are only a couple of trap types that are expected.
205 * All the rest will be handled in the usual way.
206 */
207 switch (type) {
208 case EXCP_DATA_ABORT:
209 /* Flag a bad address. */
210 cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_BADADDR;
211 cpu_core[curcpu].cpuc_dtrace_illval = frame->tf_far;
212
213 /*
214 * Offset the instruction pointer to the instruction
215 * following the one causing the fault.
216 */
217 frame->tf_elr += 4;
218 return (1);
219 default:
220 /* Handle all other traps in the usual way. */
221 break;
222 }
223 }
224
225 /* Handle the trap in the usual way. */
226 return (0);
227 }
228
229 void
dtrace_probe_error(dtrace_state_t * state,dtrace_epid_t epid,int which,int fault,int fltoffs,uintptr_t illval)230 dtrace_probe_error(dtrace_state_t *state, dtrace_epid_t epid, int which,
231 int fault, int fltoffs, uintptr_t illval)
232 {
233
234 dtrace_probe(dtrace_probeid_error, (uint64_t)(uintptr_t)state,
235 (uintptr_t)epid,
236 (uintptr_t)which, (uintptr_t)fault, (uintptr_t)fltoffs);
237 }
238
239 static void
dtrace_load64(uint64_t * addr,struct trapframe * frame,u_int reg)240 dtrace_load64(uint64_t *addr, struct trapframe *frame, u_int reg)
241 {
242
243 KASSERT(reg <= 31, ("dtrace_load64: Invalid register %u", reg));
244 if (reg < nitems(frame->tf_x))
245 frame->tf_x[reg] = *addr;
246 else if (reg == 30) /* lr */
247 frame->tf_lr = *addr;
248 /* Nothing to do for load to xzr */
249 }
250
251 static void
dtrace_store64(uint64_t * addr,struct trapframe * frame,u_int reg)252 dtrace_store64(uint64_t *addr, struct trapframe *frame, u_int reg)
253 {
254
255 KASSERT(reg <= 31, ("dtrace_store64: Invalid register %u", reg));
256 if (reg < nitems(frame->tf_x))
257 *addr = frame->tf_x[reg];
258 else if (reg == 30) /* lr */
259 *addr = frame->tf_lr;
260 else if (reg == 31) /* xzr */
261 *addr = 0;
262 }
263
264 static int
dtrace_invop_start(struct trapframe * frame)265 dtrace_invop_start(struct trapframe *frame)
266 {
267 int data, invop, tmp;
268
269 invop = dtrace_invop(frame->tf_elr, frame, frame->tf_x[0]);
270
271 tmp = (invop & LDP_STP_MASK);
272 if (tmp == STP_64 || tmp == LDP_64) {
273 register_t arg1, arg2, *sp;
274 int offs;
275
276 sp = (register_t *)frame->tf_sp;
277 data = invop;
278 arg1 = (data >> ARG1_SHIFT) & ARG1_MASK;
279 arg2 = (data >> ARG2_SHIFT) & ARG2_MASK;
280
281 offs = (data >> OFFSET_SHIFT) & OFFSET_MASK;
282
283 switch (tmp) {
284 case STP_64:
285 if (offs >> (OFFSET_SIZE - 1))
286 sp -= (~offs & OFFSET_MASK) + 1;
287 else
288 sp += (offs);
289 dtrace_store64(sp + 0, frame, arg1);
290 dtrace_store64(sp + 1, frame, arg2);
291 break;
292 case LDP_64:
293 dtrace_load64(sp + 0, frame, arg1);
294 dtrace_load64(sp + 1, frame, arg2);
295 if (offs >> (OFFSET_SIZE - 1))
296 sp -= (~offs & OFFSET_MASK) + 1;
297 else
298 sp += (offs);
299 break;
300 default:
301 break;
302 }
303
304 /* Update the stack pointer and program counter to continue */
305 frame->tf_sp = (register_t)sp;
306 frame->tf_elr += INSN_SIZE;
307 return (0);
308 }
309
310 if ((invop & SUB_MASK) == SUB_INSTR) {
311 frame->tf_sp -= (invop >> SUB_IMM_SHIFT) & SUB_IMM_MASK;
312 frame->tf_elr += INSN_SIZE;
313 return (0);
314 }
315
316 if (invop == NOP_INSTR) {
317 frame->tf_elr += INSN_SIZE;
318 return (0);
319 }
320
321 if ((invop & B_MASK) == B_INSTR) {
322 data = (invop & B_DATA_MASK);
323 /* The data is the number of 4-byte words to change the pc */
324 data *= 4;
325 frame->tf_elr += data;
326 return (0);
327 }
328
329 if (invop == RET_INSTR) {
330 frame->tf_elr = frame->tf_lr;
331 return (0);
332 }
333
334 return (-1);
335 }
336
337 void
dtrace_invop_init(void)338 dtrace_invop_init(void)
339 {
340
341 dtrace_invop_jump_addr = dtrace_invop_start;
342 }
343
344 void
dtrace_invop_uninit(void)345 dtrace_invop_uninit(void)
346 {
347
348 dtrace_invop_jump_addr = 0;
349 }
350