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 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 #include <sys/cdefs.h> 27 28 #include <sys/param.h> 29 #include <sys/systm.h> 30 #include <sys/dtrace_impl.h> 31 #include <sys/kernel.h> 32 #include <sys/stack.h> 33 #include <sys/pcpu.h> 34 35 #include <machine/frame.h> 36 #include <machine/md_var.h> 37 38 #include <vm/vm.h> 39 #include <vm/vm_param.h> 40 #include <vm/pmap.h> 41 42 #include <machine/atomic.h> 43 #include <machine/db_machdep.h> 44 #include <machine/md_var.h> 45 #include <machine/stack.h> 46 #include <ddb/db_sym.h> 47 #include <ddb/ddb.h> 48 #include <sys/kdb.h> 49 50 #include <cddl/dev/dtrace/dtrace_cddl.h> 51 52 #include "regset.h" 53 54 #define MAX_USTACK_DEPTH 2048 55 56 uint8_t dtrace_fuword8_nocheck(void *); 57 uint16_t dtrace_fuword16_nocheck(void *); 58 uint32_t dtrace_fuword32_nocheck(void *); 59 uint64_t dtrace_fuword64_nocheck(void *); 60 61 void 62 dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes, 63 uint32_t *intrpc) 64 { 65 struct unwind_state state; 66 int scp_offset; 67 int depth; 68 69 depth = 0; 70 71 if (intrpc != 0) { 72 pcstack[depth++] = (pc_t) intrpc; 73 } 74 75 aframes++; 76 77 state.fp = (uintptr_t)__builtin_frame_address(0); 78 state.pc = (uintptr_t)dtrace_getpcstack; 79 80 while (depth < pcstack_limit) { 81 if (!unwind_frame(curthread, &state)) 82 break; 83 if (!INKERNEL(state.pc)) 84 break; 85 86 /* 87 * NB: Unlike some other architectures, we don't need to 88 * explicitly insert cpu_dtrace_caller as it appears in the 89 * normal kernel stack trace rather than a special trap frame. 90 */ 91 if (aframes > 0) { 92 aframes--; 93 } else { 94 pcstack[depth++] = state.pc; 95 } 96 97 } 98 99 for (; depth < pcstack_limit; depth++) { 100 pcstack[depth] = 0; 101 } 102 } 103 104 static int 105 dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t pc, 106 uintptr_t fp) 107 { 108 volatile uint16_t *flags = 109 (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags; 110 int ret = 0; 111 uintptr_t oldfp = fp; 112 113 ASSERT(pcstack == NULL || pcstack_limit > 0); 114 115 while (pc != 0) { 116 /* 117 * We limit the number of times we can go around this 118 * loop to account for a circular stack. 119 */ 120 if (ret++ >= MAX_USTACK_DEPTH) { 121 *flags |= CPU_DTRACE_BADSTACK; 122 cpu_core[curcpu].cpuc_dtrace_illval = fp; 123 break; 124 } 125 126 if (pcstack != NULL) { 127 *pcstack++ = (uint64_t)pc; 128 pcstack_limit--; 129 if (pcstack_limit <= 0) 130 break; 131 } 132 133 if (fp == 0) 134 break; 135 136 pc = dtrace_fuword64((void *)(fp + 137 offsetof(struct unwind_state, pc))); 138 fp = dtrace_fuword64((void *)fp); 139 140 if (fp == oldfp) { 141 *flags |= CPU_DTRACE_BADSTACK; 142 cpu_core[curcpu].cpuc_dtrace_illval = fp; 143 break; 144 } 145 146 /* 147 * ARM64TODO: 148 * This workaround might not be necessary. It needs to be 149 * revised and removed from all architectures if found 150 * unwanted. Leaving the original x86 comment for reference. 151 * 152 * This is totally bogus: if we faulted, we're going to clear 153 * the fault and break. This is to deal with the apparently 154 * broken Java stacks on x86. 155 */ 156 if (*flags & CPU_DTRACE_FAULT) { 157 *flags &= ~CPU_DTRACE_FAULT; 158 break; 159 } 160 161 oldfp = fp; 162 } 163 164 return (ret); 165 } 166 167 void 168 dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit) 169 { 170 proc_t *p = curproc; 171 struct trapframe *tf; 172 uintptr_t pc, fp; 173 volatile uint16_t *flags = 174 (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags; 175 int n; 176 177 if (*flags & CPU_DTRACE_FAULT) 178 return; 179 180 if (pcstack_limit <= 0) 181 return; 182 183 /* 184 * If there's no user context we still need to zero the stack. 185 */ 186 if (p == NULL || (tf = curthread->td_frame) == NULL) 187 goto zero; 188 189 *pcstack++ = (uint64_t)p->p_pid; 190 pcstack_limit--; 191 192 if (pcstack_limit <= 0) 193 return; 194 195 pc = tf->tf_elr; 196 fp = tf->tf_x[29]; 197 198 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) { 199 /* 200 * In an entry probe. The frame pointer has not yet been 201 * pushed (that happens in the function prologue). The 202 * best approach is to add the current pc as a missing top 203 * of stack and back the pc up to the caller, which is stored 204 * at the current stack pointer address since the call 205 * instruction puts it there right before the branch. 206 */ 207 208 *pcstack++ = (uint64_t)pc; 209 pcstack_limit--; 210 if (pcstack_limit <= 0) 211 return; 212 213 pc = tf->tf_lr; 214 } 215 216 n = dtrace_getustack_common(pcstack, pcstack_limit, pc, fp); 217 ASSERT(n >= 0); 218 ASSERT(n <= pcstack_limit); 219 220 pcstack += n; 221 pcstack_limit -= n; 222 223 zero: 224 while (pcstack_limit-- > 0) 225 *pcstack++ = 0; 226 } 227 228 int 229 dtrace_getustackdepth(void) 230 { 231 232 printf("IMPLEMENT ME: %s\n", __func__); 233 234 return (0); 235 } 236 237 void 238 dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit) 239 { 240 241 printf("IMPLEMENT ME: %s\n", __func__); 242 } 243 244 uint64_t 245 dtrace_getarg(int arg, int aframes __unused) 246 { 247 struct trapframe *tf; 248 249 /* 250 * We only handle invop providers here. 251 */ 252 if ((tf = curthread->t_dtrace_trapframe) == NULL) { 253 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP); 254 return (0); 255 } else if (arg < 8) { 256 return (tf->tf_x[arg]); 257 } else { 258 uintptr_t p; 259 uint64_t val; 260 261 p = (tf->tf_sp + (arg - 8) * sizeof(uint64_t)); 262 if ((p & 7) != 0) { 263 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADALIGN); 264 cpu_core[curcpu].cpuc_dtrace_illval = p; 265 return (0); 266 } 267 if (!kstack_contains(curthread, p, sizeof(uint64_t))) { 268 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 269 cpu_core[curcpu].cpuc_dtrace_illval = p; 270 return (0); 271 } 272 memcpy(&val, (void *)p, sizeof(uint64_t)); 273 return (val); 274 } 275 } 276 277 int 278 dtrace_getstackdepth(int aframes) 279 { 280 struct unwind_state state; 281 int scp_offset; 282 int depth; 283 bool done; 284 285 depth = 1; 286 done = false; 287 288 state.fp = (uintptr_t)__builtin_frame_address(0); 289 state.pc = (uintptr_t)dtrace_getstackdepth; 290 291 do { 292 done = !unwind_frame(curthread, &state); 293 if (!INKERNEL(state.pc) || !INKERNEL(state.fp)) 294 break; 295 depth++; 296 } while (!done); 297 298 if (depth < aframes) 299 return (0); 300 else 301 return (depth - aframes); 302 } 303 304 ulong_t 305 dtrace_getreg(struct trapframe *frame, uint_t reg) 306 { 307 switch (reg) { 308 case REG_X0 ... REG_X29: 309 return (frame->tf_x[reg]); 310 case REG_LR: 311 return (frame->tf_lr); 312 case REG_SP: 313 return (frame->tf_sp); 314 case REG_PC: 315 return (frame->tf_elr); 316 default: 317 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP); 318 return (0); 319 } 320 /* NOTREACHED */ 321 } 322 323 static int 324 dtrace_copycheck(uintptr_t uaddr, uintptr_t kaddr, size_t size) 325 { 326 327 if (uaddr + size > VM_MAXUSER_ADDRESS || uaddr + size < uaddr) { 328 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 329 cpu_core[curcpu].cpuc_dtrace_illval = uaddr; 330 return (0); 331 } 332 333 return (1); 334 } 335 336 void 337 dtrace_copyin(uintptr_t uaddr, uintptr_t kaddr, size_t size, 338 volatile uint16_t *flags) 339 { 340 341 if (dtrace_copycheck(uaddr, kaddr, size)) 342 dtrace_copy(uaddr, kaddr, size); 343 } 344 345 void 346 dtrace_copyout(uintptr_t kaddr, uintptr_t uaddr, size_t size, 347 volatile uint16_t *flags) 348 { 349 350 if (dtrace_copycheck(uaddr, kaddr, size)) 351 dtrace_copy(kaddr, uaddr, size); 352 } 353 354 void 355 dtrace_copyinstr(uintptr_t uaddr, uintptr_t kaddr, size_t size, 356 volatile uint16_t *flags) 357 { 358 359 if (dtrace_copycheck(uaddr, kaddr, size)) 360 dtrace_copystr(uaddr, kaddr, size, flags); 361 } 362 363 void 364 dtrace_copyoutstr(uintptr_t kaddr, uintptr_t uaddr, size_t size, 365 volatile uint16_t *flags) 366 { 367 368 if (dtrace_copycheck(uaddr, kaddr, size)) 369 dtrace_copystr(kaddr, uaddr, size, flags); 370 } 371 372 uint8_t 373 dtrace_fuword8(void *uaddr) 374 { 375 376 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 377 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 378 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 379 return (0); 380 } 381 382 return (dtrace_fuword8_nocheck(uaddr)); 383 } 384 385 uint16_t 386 dtrace_fuword16(void *uaddr) 387 { 388 389 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 390 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 391 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 392 return (0); 393 } 394 395 return (dtrace_fuword16_nocheck(uaddr)); 396 } 397 398 uint32_t 399 dtrace_fuword32(void *uaddr) 400 { 401 402 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 403 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 404 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 405 return (0); 406 } 407 408 return (dtrace_fuword32_nocheck(uaddr)); 409 } 410 411 uint64_t 412 dtrace_fuword64(void *uaddr) 413 { 414 415 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 416 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 417 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 418 return (0); 419 } 420 421 return (dtrace_fuword64_nocheck(uaddr)); 422 } 423