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__KERNEL_RCSID(0, "$NetBSD: dtrace_subr.c,v 1.6 2023/04/17 06:57:02 skrll Exp $");
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/xcall.h>
40#include <sys/cpu.h>
41#include <sys/cpuvar.h>
42#include <sys/dtrace_impl.h>
43#include <sys/dtrace_bsd.h>
44#include <machine/cpu.h>
45#include <machine/frame.h>
46#include <machine/vmparam.h>
47#include <uvm/uvm_pglist.h>
48#include <uvm/uvm_prot.h>
49#include <uvm/uvm_pmap.h>
50
51#define	CURRENT_CPU	cpu_index(curcpu())
52#define	OFFSET_MASK	((1 << OFFSET_SIZE) - 1)
53
54extern dtrace_id_t	dtrace_probeid_error;
55extern int (*dtrace_invop_jump_addr)(struct trapframe *);
56extern void dtrace_getnanotime(struct timespec *tsp);
57
58int dtrace_invop(uintptr_t, struct trapframe *, uintptr_t);
59void dtrace_invop_init(void);
60void dtrace_invop_uninit(void);
61
62void dtrace_gethrtime_init(void);
63
64typedef struct dtrace_invop_hdlr {
65	int (*dtih_func)(uintptr_t, struct trapframe *, uintptr_t);
66	struct dtrace_invop_hdlr *dtih_next;
67} dtrace_invop_hdlr_t;
68
69dtrace_invop_hdlr_t *dtrace_invop_hdlr;
70
71int
72dtrace_invop(uintptr_t addr, struct trapframe *frame, uintptr_t r0)
73{
74	dtrace_invop_hdlr_t *hdlr;
75	int rval;
76
77	for (hdlr = dtrace_invop_hdlr; hdlr != NULL; hdlr = hdlr->dtih_next)
78		if ((rval = hdlr->dtih_func(addr, frame, r0)) != 0)
79			return (rval);
80
81	return (0);
82}
83
84
85void
86dtrace_invop_add(int (*func)(uintptr_t, struct trapframe *, uintptr_t))
87{
88	dtrace_invop_hdlr_t *hdlr;
89
90	hdlr = kmem_alloc(sizeof(*hdlr), KM_SLEEP);
91	hdlr->dtih_func = func;
92	hdlr->dtih_next = dtrace_invop_hdlr;
93	dtrace_invop_hdlr = hdlr;
94}
95
96void
97dtrace_invop_remove(int (*func)(uintptr_t, struct trapframe *, uintptr_t))
98{
99	dtrace_invop_hdlr_t *hdlr, *prev;
100
101	hdlr = dtrace_invop_hdlr;
102	prev = NULL;
103
104	for (;;) {
105		if (hdlr == NULL)
106			panic("attempt to remove non-existent invop handler");
107
108		if (hdlr->dtih_func == func)
109			break;
110
111		prev = hdlr;
112		hdlr = hdlr->dtih_next;
113	}
114
115	if (prev == NULL) {
116		ASSERT(dtrace_invop_hdlr == hdlr);
117		dtrace_invop_hdlr = hdlr->dtih_next;
118	} else {
119		ASSERT(dtrace_invop_hdlr != hdlr);
120		prev->dtih_next = hdlr->dtih_next;
121	}
122
123	kmem_free(hdlr, sizeof(*hdlr));
124}
125
126/*ARGSUSED*/
127void
128dtrace_toxic_ranges(void (*func)(uintptr_t base, uintptr_t limit))
129{
130
131	(*func)(0, (uintptr_t)AARCH64_DIRECTMAP_START);
132	(*func)((uintptr_t)VM_KERNEL_IO_BASE, ~(uintptr_t)0);
133}
134
135static void
136xcall_func(void *arg0, void *arg1)
137{
138	dtrace_xcall_t func = arg0;
139
140	(*func)(arg1);
141}
142
143void
144dtrace_xcall(processorid_t cpu, dtrace_xcall_t func, void *arg)
145{
146	uint64_t where;
147
148	if (cpu == DTRACE_CPUALL) {
149		where = xc_broadcast(0, xcall_func, func, arg);
150	} else {
151		struct cpu_info *ci = cpu_lookup(cpu);
152
153		KASSERT(ci != NULL);
154		where = xc_unicast(0, xcall_func, func, arg, ci);
155	}
156	xc_wait(where);
157}
158
159static void
160dtrace_sync_func(void)
161{
162
163}
164
165void
166dtrace_sync(void)
167{
168
169	dtrace_xcall(DTRACE_CPUALL, (dtrace_xcall_t)dtrace_sync_func, NULL);
170}
171
172/*
173 * DTrace needs a high resolution time function which can
174 * be called from a probe context and guaranteed not to have
175 * instrumented with probes itself.
176 *
177 * Returns nanoseconds since boot.
178 */
179uint64_t
180dtrace_gethrtime()
181{
182	struct timespec curtime;
183
184	nanouptime(&curtime);
185
186	return (curtime.tv_sec * 1000000000UL + curtime.tv_nsec);
187
188}
189
190void
191dtrace_gethrtime_init(void)
192{
193}
194
195uint64_t
196dtrace_gethrestime(void)
197{
198	struct timespec current_time;
199
200	dtrace_getnanotime(&current_time);
201
202	return (current_time.tv_sec * 1000000000UL + current_time.tv_nsec);
203}
204
205/* Function to handle DTrace traps during probes. See arm64/arm64/trap.c */
206int
207dtrace_trap(struct trapframe *frame, u_int type)
208{
209	/*
210	 * A trap can occur while DTrace executes a probe. Before
211	 * executing the probe, DTrace blocks re-scheduling and sets
212	 * a flag in its per-cpu flags to indicate that it doesn't
213	 * want to fault. On returning from the probe, the no-fault
214	 * flag is cleared and finally re-scheduling is enabled.
215	 *
216	 * Check if DTrace has enabled 'no-fault' mode:
217	 *
218	 */
219
220	if ((cpu_core[CURRENT_CPU].cpuc_dtrace_flags & CPU_DTRACE_NOFAULT) != 0) {
221		/*
222		 * There are only a couple of trap types that are expected.
223		 * All the rest will be handled in the usual way.
224		 */
225		switch (type) {
226		case ESR_EC_DATA_ABT_EL1:
227			/* Flag a bad address. */
228			cpu_core[CURRENT_CPU].cpuc_dtrace_flags |= CPU_DTRACE_BADADDR;
229			cpu_core[CURRENT_CPU].cpuc_dtrace_illval = 0;
230
231			/*
232			 * Offset the instruction pointer to the instruction
233			 * following the one causing the fault.
234			 */
235			frame->tf_pc += 4;
236			return (1);
237		default:
238			/* Handle all other traps in the usual way. */
239			break;
240		}
241	}
242
243	/* Handle the trap in the usual way. */
244	return (0);
245}
246
247void
248dtrace_probe_error(dtrace_state_t *state, dtrace_epid_t epid, int which,
249    int fault, int fltoffs, uintptr_t illval)
250{
251
252	dtrace_probe(dtrace_probeid_error, (uint64_t)(uintptr_t)state,
253	    (uintptr_t)epid,
254	    (uintptr_t)which, (uintptr_t)fault, (uintptr_t)fltoffs);
255}
256
257static int
258dtrace_invop_start(struct trapframe *frame)
259{
260	int data, invop, reg, update_sp;
261	register_t arg1, arg2;
262	register_t *sp;
263	int offs;
264	int tmp;
265	int i;
266
267	invop = dtrace_invop(frame->tf_pc, frame, frame->tf_regs.r_reg[0]);
268
269	tmp = (invop & LDP_STP_MASK);
270	if (tmp == STP_64 || tmp == LDP_64) {
271		sp = (register_t *)frame->tf_sp;
272		data = invop;
273		arg1 = (data >> ARG1_SHIFT) & ARG1_MASK;
274		arg2 = (data >> ARG2_SHIFT) & ARG2_MASK;
275
276		offs = (data >> OFFSET_SHIFT) & OFFSET_MASK;
277
278		switch (tmp) {
279		case STP_64:
280			if (offs >> (OFFSET_SIZE - 1))
281				sp -= (~offs & OFFSET_MASK) + 1;
282			else
283				sp += (offs);
284			*(sp + 0) = frame->tf_regs.r_reg[arg1];
285			*(sp + 1) = frame->tf_regs.r_reg[arg2];
286			break;
287		case LDP_64:
288			frame->tf_regs.r_reg[arg1] = *(sp + 0);
289			frame->tf_regs.r_reg[arg2] = *(sp + 1);
290			if (offs >> (OFFSET_SIZE - 1))
291				sp -= (~offs & OFFSET_MASK) + 1;
292			else
293				sp += (offs);
294			break;
295		default:
296			break;
297		}
298
299		/* Update the stack pointer and program counter to continue */
300		frame->tf_sp = (register_t)sp;
301		frame->tf_pc += INSN_SIZE;
302		return (0);
303	}
304
305	if ((invop & B_MASK) == B_INSTR) {
306		data = (invop & B_DATA_MASK);
307		/* The data is the number of 4-byte words to change the pc */
308		data *= 4;
309		frame->tf_pc += data;
310		return (0);
311	}
312
313	if (invop == RET_INSTR) {
314		frame->tf_pc = frame->tf_lr;
315		return (0);
316	}
317
318	return (-1);
319}
320
321void
322dtrace_invop_init(void)
323{
324
325	dtrace_invop_jump_addr = dtrace_invop_start;
326}
327
328void
329dtrace_invop_uninit(void)
330{
331
332	dtrace_invop_jump_addr = 0;
333}
334