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 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 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 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 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 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 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 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 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 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 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 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 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 338 dtrace_invop_init(void) 339 { 340 341 dtrace_invop_jump_addr = dtrace_invop_start; 342 } 343 344 void 345 dtrace_invop_uninit(void) 346 { 347 348 dtrace_invop_jump_addr = 0; 349 } 350