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
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.
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]
26 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
27 * Use is subject to license terms.
31 * Copyright (c) 2011, Joyent, Inc. All rights reserved.
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/types.h>
37 #include <sys/cpuset.h>
38 #include <sys/kernel.h>
39 #include <sys/malloc.h>
42 #include <sys/dtrace_impl.h>
43 #include <sys/dtrace_bsd.h>
44 #include <machine/clock.h>
45 #include <machine/cpufunc.h>
46 #include <machine/frame.h>
47 #include <machine/psl.h>
48 #include <machine/trap.h>
51 extern uintptr_t kernelbase;
53 extern void dtrace_getnanotime(struct timespec *tsp);
55 int dtrace_invop(uintptr_t, struct trapframe *, uintptr_t);
57 typedef struct dtrace_invop_hdlr {
58 int (*dtih_func)(uintptr_t, struct trapframe *, uintptr_t);
59 struct dtrace_invop_hdlr *dtih_next;
60 } dtrace_invop_hdlr_t;
62 dtrace_invop_hdlr_t *dtrace_invop_hdlr;
65 dtrace_invop(uintptr_t addr, struct trapframe *frame, uintptr_t eax)
67 dtrace_invop_hdlr_t *hdlr;
70 for (hdlr = dtrace_invop_hdlr; hdlr != NULL; hdlr = hdlr->dtih_next)
71 if ((rval = hdlr->dtih_func(addr, frame, eax)) != 0)
78 dtrace_invop_add(int (*func)(uintptr_t, struct trapframe *, uintptr_t))
80 dtrace_invop_hdlr_t *hdlr;
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;
89 dtrace_invop_remove(int (*func)(uintptr_t, struct trapframe *, uintptr_t))
91 dtrace_invop_hdlr_t *hdlr = dtrace_invop_hdlr, *prev = NULL;
95 panic("attempt to remove non-existent invop handler");
97 if (hdlr->dtih_func == func)
101 hdlr = hdlr->dtih_next;
105 ASSERT(dtrace_invop_hdlr == hdlr);
106 dtrace_invop_hdlr = hdlr->dtih_next;
108 ASSERT(dtrace_invop_hdlr != hdlr);
109 prev->dtih_next = hdlr->dtih_next;
116 dtrace_toxic_ranges(void (*func)(uintptr_t base, uintptr_t limit))
118 (*func)(0, kernelbase);
122 dtrace_xcall(processorid_t cpu, dtrace_xcall_t func, void *arg)
126 if (cpu == DTRACE_CPUALL)
129 CPU_SETOF(cpu, &cpus);
131 smp_rendezvous_cpus(cpus, smp_no_rendezvous_barrier, func,
132 smp_no_rendezvous_barrier, arg);
136 dtrace_sync_func(void)
143 dtrace_xcall(DTRACE_CPUALL, (dtrace_xcall_t)dtrace_sync_func, NULL);
148 dtrace_safe_synchronous_signal(void)
150 kthread_t *t = curthread;
151 struct regs *rp = lwptoregs(ttolwp(t));
152 size_t isz = t->t_dtrace_npc - t->t_dtrace_pc;
154 ASSERT(t->t_dtrace_on);
157 * If we're not in the range of scratch addresses, we're not actually
158 * tracing user instructions so turn off the flags. If the instruction
159 * we copied out caused a synchonous trap, reset the pc back to its
160 * original value and turn off the flags.
162 if (rp->r_pc < t->t_dtrace_scrpc ||
163 rp->r_pc > t->t_dtrace_astpc + isz) {
165 } else if (rp->r_pc == t->t_dtrace_scrpc ||
166 rp->r_pc == t->t_dtrace_astpc) {
167 rp->r_pc = t->t_dtrace_pc;
173 dtrace_safe_defer_signal(void)
175 kthread_t *t = curthread;
176 struct regs *rp = lwptoregs(ttolwp(t));
177 size_t isz = t->t_dtrace_npc - t->t_dtrace_pc;
179 ASSERT(t->t_dtrace_on);
182 * If we're not in the range of scratch addresses, we're not actually
183 * tracing user instructions so turn off the flags.
185 if (rp->r_pc < t->t_dtrace_scrpc ||
186 rp->r_pc > t->t_dtrace_astpc + isz) {
192 * If we have executed the original instruction, but we have performed
193 * neither the jmp back to t->t_dtrace_npc nor the clean up of any
194 * registers used to emulate %rip-relative instructions in 64-bit mode,
195 * we'll save ourselves some effort by doing that here and taking the
196 * signal right away. We detect this condition by seeing if the program
197 * counter is the range [scrpc + isz, astpc).
199 if (rp->r_pc >= t->t_dtrace_scrpc + isz &&
200 rp->r_pc < t->t_dtrace_astpc) {
203 * If there is a scratch register and we're on the
204 * instruction immediately after the modified instruction,
205 * restore the value of that scratch register.
207 if (t->t_dtrace_reg != 0 &&
208 rp->r_pc == t->t_dtrace_scrpc + isz) {
209 switch (t->t_dtrace_reg) {
211 rp->r_rax = t->t_dtrace_regv;
214 rp->r_rcx = t->t_dtrace_regv;
217 rp->r_r8 = t->t_dtrace_regv;
220 rp->r_r9 = t->t_dtrace_regv;
225 rp->r_pc = t->t_dtrace_npc;
231 * Otherwise, make sure we'll return to the kernel after executing
232 * the copied out instruction and defer the signal.
234 if (!t->t_dtrace_step) {
235 ASSERT(rp->r_pc < t->t_dtrace_astpc);
236 rp->r_pc += t->t_dtrace_astpc - t->t_dtrace_scrpc;
237 t->t_dtrace_step = 1;
246 static int64_t tgt_cpu_tsc;
247 static int64_t hst_cpu_tsc;
248 static int64_t tsc_skew[MAXCPU];
249 static uint64_t nsec_scale;
251 /* See below for the explanation of this macro. */
252 #define SCALE_SHIFT 28
255 dtrace_gethrtime_init_cpu(void *arg)
257 uintptr_t cpu = (uintptr_t) arg;
260 tgt_cpu_tsc = rdtsc();
262 hst_cpu_tsc = rdtsc();
265 #ifdef EARLY_AP_STARTUP
267 dtrace_gethrtime_init(void *arg)
275 * Get the frequency and scale factor as early as possible so that they can be
276 * used for boot-time tracing.
279 dtrace_gethrtime_init_early(void *arg)
285 * Get TSC frequency known at this moment.
286 * This should be constant if TSC is invariant.
287 * Otherwise tick->time conversion will be inaccurate, but
288 * will preserve monotonic property of TSC.
290 tsc_f = atomic_load_acq_64(&tsc_freq);
293 * The following line checks that nsec_scale calculated below
294 * doesn't overflow 32-bit unsigned integer, so that it can multiply
295 * another 32-bit integer without overflowing 64-bit.
296 * Thus minimum supported TSC frequency is 62.5MHz.
298 KASSERT(tsc_f > (NANOSEC >> (32 - SCALE_SHIFT)),
299 ("TSC frequency is too low"));
302 * We scale up NANOSEC/tsc_f ratio to preserve as much precision
304 * 2^28 factor was chosen quite arbitrarily from practical
306 * - it supports TSC frequencies as low as 62.5MHz (see above);
307 * - it provides quite good precision (e < 0.01%) up to THz
308 * (terahertz) values;
310 nsec_scale = ((uint64_t)NANOSEC << SCALE_SHIFT) / tsc_f;
311 #ifndef EARLY_AP_STARTUP
313 SYSINIT(dtrace_gethrtime_init_early, SI_SUB_CPU, SI_ORDER_ANY,
314 dtrace_gethrtime_init_early, NULL);
317 dtrace_gethrtime_init(void *arg)
324 /* The current CPU is the reference one. */
326 tsc_skew[curcpu] = 0;
332 CPU_SETOF(PCPU_GET(cpuid), &map);
333 CPU_SET(pc->pc_cpuid, &map);
335 smp_rendezvous_cpus(map, NULL,
336 dtrace_gethrtime_init_cpu,
337 smp_no_rendezvous_barrier, (void *)(uintptr_t) i);
339 tsc_skew[i] = tgt_cpu_tsc - hst_cpu_tsc;
343 #ifdef EARLY_AP_STARTUP
344 SYSINIT(dtrace_gethrtime_init, SI_SUB_DTRACE, SI_ORDER_ANY,
345 dtrace_gethrtime_init, NULL);
347 SYSINIT(dtrace_gethrtime_init, SI_SUB_SMP, SI_ORDER_ANY, dtrace_gethrtime_init,
352 * DTrace needs a high resolution time function which can
353 * be called from a probe context and guaranteed not to have
354 * instrumented with probes itself.
356 * Returns nanoseconds since boot.
359 dtrace_gethrtime(void)
366 * We split TSC value into lower and higher 32-bit halves and separately
367 * scale them with nsec_scale, then we scale them down by 2^28
368 * (see nsec_scale calculations) taking into account 32-bit shift of
369 * the higher half and finally add.
371 eflags = intr_disable();
372 tsc = rdtsc() - tsc_skew[curcpu];
373 intr_restore(eflags);
377 return (((lo * nsec_scale) >> SCALE_SHIFT) +
378 ((hi * nsec_scale) << (32 - SCALE_SHIFT)));
382 dtrace_gethrestime(void)
384 struct timespec current_time;
386 dtrace_getnanotime(¤t_time);
388 return (current_time.tv_sec * 1000000000ULL + current_time.tv_nsec);
391 /* Function to handle DTrace traps during probes. See i386/i386/trap.c */
393 dtrace_trap(struct trapframe *frame, u_int type)
398 * A trap can occur while DTrace executes a probe. Before
399 * executing the probe, DTrace blocks re-scheduling and sets
400 * a flag in its per-cpu flags to indicate that it doesn't
401 * want to fault. On returning from the probe, the no-fault
402 * flag is cleared and finally re-scheduling is enabled.
404 * Check if DTrace has enabled 'no-fault' mode:
407 nofault = cpu_core[curcpu].cpuc_dtrace_flags & CPU_DTRACE_NOFAULT;
410 KASSERT((read_eflags() & PSL_I) == 0, ("interrupts enabled"));
413 * There are only a couple of trap types that are expected.
414 * All the rest will be handled in the usual way.
417 /* General protection fault. */
419 /* Flag an illegal operation. */
420 cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
423 * Offset the instruction pointer to the instruction
424 * following the one causing the fault.
426 frame->tf_eip += dtrace_instr_size((u_char *) frame->tf_eip);
430 /* Flag a bad address. */
431 cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_BADADDR;
432 cpu_core[curcpu].cpuc_dtrace_illval = rcr2();
435 * Offset the instruction pointer to the instruction
436 * following the one causing the fault.
438 frame->tf_eip += dtrace_instr_size((u_char *) frame->tf_eip);
441 /* Handle all other traps in the usual way. */
446 /* Handle the trap in the usual way. */