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/kernel.h> 31 #include <sys/stack.h> 32 #include <sys/pcpu.h> 33 34 #include <machine/frame.h> 35 #include <machine/md_var.h> 36 37 #include <vm/vm.h> 38 #include <vm/vm_param.h> 39 #include <vm/pmap.h> 40 41 #include <machine/atomic.h> 42 #include <machine/db_machdep.h> 43 #include <machine/md_var.h> 44 #include <machine/stack.h> 45 #include <ddb/db_sym.h> 46 #include <ddb/ddb.h> 47 #include <sys/kdb.h> 48 49 #include "regset.h" 50 51 #define MAX_USTACK_DEPTH 2048 52 53 uint8_t dtrace_fuword8_nocheck(void *); 54 uint16_t dtrace_fuword16_nocheck(void *); 55 uint32_t dtrace_fuword32_nocheck(void *); 56 uint64_t dtrace_fuword64_nocheck(void *); 57 58 void 59 dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes, 60 uint32_t *intrpc) 61 { 62 struct unwind_state state; 63 int scp_offset; 64 int depth; 65 66 depth = 0; 67 68 if (intrpc != 0) { 69 pcstack[depth++] = (pc_t) intrpc; 70 } 71 72 aframes++; 73 74 state.fp = (uintptr_t)__builtin_frame_address(0); 75 state.pc = (uintptr_t)dtrace_getpcstack; 76 77 while (depth < pcstack_limit) { 78 if (!unwind_frame(curthread, &state)) 79 break; 80 if (!INKERNEL(state.pc)) 81 break; 82 83 /* 84 * NB: Unlike some other architectures, we don't need to 85 * explicitly insert cpu_dtrace_caller as it appears in the 86 * normal kernel stack trace rather than a special trap frame. 87 */ 88 if (aframes > 0) { 89 aframes--; 90 } else { 91 pcstack[depth++] = state.pc; 92 } 93 94 } 95 96 for (; depth < pcstack_limit; depth++) { 97 pcstack[depth] = 0; 98 } 99 } 100 101 static int 102 dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t pc, 103 uintptr_t fp) 104 { 105 volatile uint16_t *flags = 106 (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags; 107 int ret = 0; 108 uintptr_t oldfp = fp; 109 110 ASSERT(pcstack == NULL || pcstack_limit > 0); 111 112 while (pc != 0) { 113 /* 114 * We limit the number of times we can go around this 115 * loop to account for a circular stack. 116 */ 117 if (ret++ >= MAX_USTACK_DEPTH) { 118 *flags |= CPU_DTRACE_BADSTACK; 119 cpu_core[curcpu].cpuc_dtrace_illval = fp; 120 break; 121 } 122 123 if (pcstack != NULL) { 124 *pcstack++ = (uint64_t)pc; 125 pcstack_limit--; 126 if (pcstack_limit <= 0) 127 break; 128 } 129 130 if (fp == 0) 131 break; 132 133 pc = dtrace_fuword64((void *)(fp + 134 offsetof(struct unwind_state, pc))); 135 fp = dtrace_fuword64((void *)fp); 136 137 if (fp == oldfp) { 138 *flags |= CPU_DTRACE_BADSTACK; 139 cpu_core[curcpu].cpuc_dtrace_illval = fp; 140 break; 141 } 142 143 /* 144 * ARM64TODO: 145 * This workaround might not be necessary. It needs to be 146 * revised and removed from all architectures if found 147 * unwanted. Leaving the original x86 comment for reference. 148 * 149 * This is totally bogus: if we faulted, we're going to clear 150 * the fault and break. This is to deal with the apparently 151 * broken Java stacks on x86. 152 */ 153 if (*flags & CPU_DTRACE_FAULT) { 154 *flags &= ~CPU_DTRACE_FAULT; 155 break; 156 } 157 158 oldfp = fp; 159 } 160 161 return (ret); 162 } 163 164 void 165 dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit) 166 { 167 proc_t *p = curproc; 168 struct trapframe *tf; 169 uintptr_t pc, fp; 170 volatile uint16_t *flags = 171 (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags; 172 int n; 173 174 if (*flags & CPU_DTRACE_FAULT) 175 return; 176 177 if (pcstack_limit <= 0) 178 return; 179 180 /* 181 * If there's no user context we still need to zero the stack. 182 */ 183 if (p == NULL || (tf = curthread->td_frame) == NULL) 184 goto zero; 185 186 *pcstack++ = (uint64_t)p->p_pid; 187 pcstack_limit--; 188 189 if (pcstack_limit <= 0) 190 return; 191 192 pc = tf->tf_elr; 193 fp = tf->tf_x[29]; 194 195 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) { 196 /* 197 * In an entry probe. The frame pointer has not yet been 198 * pushed (that happens in the function prologue). The 199 * best approach is to add the current pc as a missing top 200 * of stack and back the pc up to the caller, which is stored 201 * at the current stack pointer address since the call 202 * instruction puts it there right before the branch. 203 */ 204 205 *pcstack++ = (uint64_t)pc; 206 pcstack_limit--; 207 if (pcstack_limit <= 0) 208 return; 209 210 pc = tf->tf_lr; 211 } 212 213 n = dtrace_getustack_common(pcstack, pcstack_limit, pc, fp); 214 ASSERT(n >= 0); 215 ASSERT(n <= pcstack_limit); 216 217 pcstack += n; 218 pcstack_limit -= n; 219 220 zero: 221 while (pcstack_limit-- > 0) 222 *pcstack++ = 0; 223 } 224 225 int 226 dtrace_getustackdepth(void) 227 { 228 229 printf("IMPLEMENT ME: %s\n", __func__); 230 231 return (0); 232 } 233 234 void 235 dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit) 236 { 237 238 printf("IMPLEMENT ME: %s\n", __func__); 239 } 240 241 /*ARGSUSED*/ 242 uint64_t 243 dtrace_getarg(int arg, int aframes) 244 { 245 246 printf("IMPLEMENT ME: %s\n", __func__); 247 248 return (0); 249 } 250 251 int 252 dtrace_getstackdepth(int aframes) 253 { 254 struct unwind_state state; 255 int scp_offset; 256 int depth; 257 bool done; 258 259 depth = 1; 260 done = false; 261 262 state.fp = (uintptr_t)__builtin_frame_address(0); 263 state.pc = (uintptr_t)dtrace_getstackdepth; 264 265 do { 266 done = !unwind_frame(curthread, &state); 267 if (!INKERNEL(state.pc) || !INKERNEL(state.fp)) 268 break; 269 depth++; 270 } while (!done); 271 272 if (depth < aframes) 273 return (0); 274 else 275 return (depth - aframes); 276 } 277 278 ulong_t 279 dtrace_getreg(struct trapframe *frame, uint_t reg) 280 { 281 switch (reg) { 282 case REG_X0 ... REG_X29: 283 return (frame->tf_x[reg]); 284 case REG_LR: 285 return (frame->tf_lr); 286 case REG_SP: 287 return (frame->tf_sp); 288 case REG_PC: 289 return (frame->tf_elr); 290 default: 291 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP); 292 return (0); 293 } 294 /* NOTREACHED */ 295 } 296 297 static int 298 dtrace_copycheck(uintptr_t uaddr, uintptr_t kaddr, size_t size) 299 { 300 301 if (uaddr + size > VM_MAXUSER_ADDRESS || uaddr + size < uaddr) { 302 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 303 cpu_core[curcpu].cpuc_dtrace_illval = uaddr; 304 return (0); 305 } 306 307 return (1); 308 } 309 310 void 311 dtrace_copyin(uintptr_t uaddr, uintptr_t kaddr, size_t size, 312 volatile uint16_t *flags) 313 { 314 315 if (dtrace_copycheck(uaddr, kaddr, size)) 316 dtrace_copy(uaddr, kaddr, size); 317 } 318 319 void 320 dtrace_copyout(uintptr_t kaddr, uintptr_t uaddr, size_t size, 321 volatile uint16_t *flags) 322 { 323 324 if (dtrace_copycheck(uaddr, kaddr, size)) 325 dtrace_copy(kaddr, uaddr, size); 326 } 327 328 void 329 dtrace_copyinstr(uintptr_t uaddr, uintptr_t kaddr, size_t size, 330 volatile uint16_t *flags) 331 { 332 333 if (dtrace_copycheck(uaddr, kaddr, size)) 334 dtrace_copystr(uaddr, kaddr, size, flags); 335 } 336 337 void 338 dtrace_copyoutstr(uintptr_t kaddr, uintptr_t uaddr, size_t size, 339 volatile uint16_t *flags) 340 { 341 342 if (dtrace_copycheck(uaddr, kaddr, size)) 343 dtrace_copystr(kaddr, uaddr, size, flags); 344 } 345 346 uint8_t 347 dtrace_fuword8(void *uaddr) 348 { 349 350 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 351 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 352 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 353 return (0); 354 } 355 356 return (dtrace_fuword8_nocheck(uaddr)); 357 } 358 359 uint16_t 360 dtrace_fuword16(void *uaddr) 361 { 362 363 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 364 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 365 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 366 return (0); 367 } 368 369 return (dtrace_fuword16_nocheck(uaddr)); 370 } 371 372 uint32_t 373 dtrace_fuword32(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_fuword32_nocheck(uaddr)); 383 } 384 385 uint64_t 386 dtrace_fuword64(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_fuword64_nocheck(uaddr)); 396 } 397