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 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 26 * Use is subject to license terms. 27 */ 28 #include <sys/cdefs.h> 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/kernel.h> 33 #include <sys/stack.h> 34 #include <sys/pcpu.h> 35 36 #include <machine/frame.h> 37 #include <machine/md_var.h> 38 #include <machine/reg.h> 39 40 #include <vm/vm.h> 41 #include <vm/vm_param.h> 42 #include <vm/pmap.h> 43 44 #include <machine/atomic.h> 45 #include <machine/db_machdep.h> 46 #include <machine/md_var.h> 47 #include <machine/stack.h> 48 #include <ddb/db_sym.h> 49 #include <ddb/ddb.h> 50 #include <sys/kdb.h> 51 52 #include "regset.h" 53 54 /* 55 * Wee need some reasonable default to prevent backtrace code 56 * from wandering too far 57 */ 58 #define MAX_FUNCTION_SIZE 0x10000 59 #define MAX_PROLOGUE_SIZE 0x100 60 #define MAX_USTACK_DEPTH 2048 61 62 uint8_t dtrace_fuword8_nocheck(void *); 63 uint16_t dtrace_fuword16_nocheck(void *); 64 uint32_t dtrace_fuword32_nocheck(void *); 65 uint64_t dtrace_fuword64_nocheck(void *); 66 67 void 68 dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes, 69 uint32_t *intrpc) 70 { 71 struct unwind_state state; 72 int scp_offset; 73 int depth; 74 75 depth = 0; 76 77 if (intrpc != 0) { 78 pcstack[depth++] = (pc_t) intrpc; 79 } 80 81 aframes++; 82 83 state.fp = (uintptr_t)__builtin_frame_address(0); 84 state.pc = (uintptr_t)dtrace_getpcstack; 85 86 while (depth < pcstack_limit) { 87 if (!unwind_frame(curthread, &state)) 88 break; 89 if (!INKERNEL(state.pc)) 90 break; 91 92 /* 93 * NB: Unlike some other architectures, we don't need to 94 * explicitly insert cpu_dtrace_caller as it appears in the 95 * normal kernel stack trace rather than a special trap frame. 96 */ 97 if (aframes > 0) { 98 aframes--; 99 } else { 100 pcstack[depth++] = state.pc; 101 } 102 103 } 104 105 for (; depth < pcstack_limit; depth++) { 106 pcstack[depth] = 0; 107 } 108 } 109 110 static int 111 dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t pc, 112 uintptr_t fp) 113 { 114 volatile uint16_t *flags = 115 (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags; 116 int ret = 0; 117 uintptr_t oldfp = fp; 118 119 ASSERT(pcstack == NULL || pcstack_limit > 0); 120 121 while (pc != 0) { 122 /* 123 * We limit the number of times we can go around this 124 * loop to account for a circular stack. 125 */ 126 if (ret++ >= MAX_USTACK_DEPTH) { 127 *flags |= CPU_DTRACE_BADSTACK; 128 cpu_core[curcpu].cpuc_dtrace_illval = fp; 129 break; 130 } 131 132 if (pcstack != NULL) { 133 *pcstack++ = (uint64_t)pc; 134 pcstack_limit--; 135 if (pcstack_limit <= 0) 136 break; 137 } 138 139 if (fp == 0) 140 break; 141 142 pc = dtrace_fuword64((void *)(fp + 143 offsetof(struct arm64_frame, f_retaddr))); 144 fp = dtrace_fuword64((void *)fp); 145 146 if (fp == oldfp) { 147 *flags |= CPU_DTRACE_BADSTACK; 148 cpu_core[curcpu].cpuc_dtrace_illval = fp; 149 break; 150 } 151 152 /* 153 * ARM64TODO: 154 * This workaround might not be necessary. It needs to be 155 * revised and removed from all architectures if found 156 * unwanted. Leaving the original x86 comment for reference. 157 * 158 * This is totally bogus: if we faulted, we're going to clear 159 * the fault and break. This is to deal with the apparently 160 * broken Java stacks on x86. 161 */ 162 if (*flags & CPU_DTRACE_FAULT) { 163 *flags &= ~CPU_DTRACE_FAULT; 164 break; 165 } 166 167 oldfp = fp; 168 } 169 170 return (ret); 171 } 172 173 void 174 dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit) 175 { 176 proc_t *p = curproc; 177 struct trapframe *tf; 178 uintptr_t pc, fp; 179 volatile uint16_t *flags = 180 (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags; 181 int n; 182 183 if (*flags & CPU_DTRACE_FAULT) 184 return; 185 186 if (pcstack_limit <= 0) 187 return; 188 189 /* 190 * If there's no user context we still need to zero the stack. 191 */ 192 if (p == NULL || (tf = curthread->td_frame) == NULL) 193 goto zero; 194 195 *pcstack++ = (uint64_t)p->p_pid; 196 pcstack_limit--; 197 198 if (pcstack_limit <= 0) 199 return; 200 201 pc = tf->tf_elr; 202 fp = tf->tf_x[29]; 203 204 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) { 205 /* 206 * In an entry probe. The frame pointer has not yet been 207 * pushed (that happens in the function prologue). The 208 * best approach is to add the current pc as a missing top 209 * of stack and back the pc up to the caller, which is stored 210 * at the current stack pointer address since the call 211 * instruction puts it there right before the branch. 212 */ 213 214 *pcstack++ = (uint64_t)pc; 215 pcstack_limit--; 216 if (pcstack_limit <= 0) 217 return; 218 219 pc = tf->tf_lr; 220 } 221 222 n = dtrace_getustack_common(pcstack, pcstack_limit, pc, fp); 223 ASSERT(n >= 0); 224 ASSERT(n <= pcstack_limit); 225 226 pcstack += n; 227 pcstack_limit -= n; 228 229 zero: 230 while (pcstack_limit-- > 0) 231 *pcstack++ = 0; 232 } 233 234 int 235 dtrace_getustackdepth(void) 236 { 237 238 printf("IMPLEMENT ME: %s\n", __func__); 239 240 return (0); 241 } 242 243 void 244 dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit) 245 { 246 247 printf("IMPLEMENT ME: %s\n", __func__); 248 } 249 250 /*ARGSUSED*/ 251 uint64_t 252 dtrace_getarg(int arg, int aframes) 253 { 254 255 printf("IMPLEMENT ME: %s\n", __func__); 256 257 return (0); 258 } 259 260 int 261 dtrace_getstackdepth(int aframes) 262 { 263 struct unwind_state state; 264 int scp_offset; 265 int depth; 266 bool done; 267 268 depth = 1; 269 done = false; 270 271 state.fp = (uintptr_t)__builtin_frame_address(0); 272 state.pc = (uintptr_t)dtrace_getstackdepth; 273 274 do { 275 done = !unwind_frame(curthread, &state); 276 if (!INKERNEL(state.pc) || !INKERNEL(state.fp)) 277 break; 278 depth++; 279 } while (!done); 280 281 if (depth < aframes) 282 return (0); 283 else 284 return (depth - aframes); 285 } 286 287 ulong_t 288 dtrace_getreg(struct trapframe *rp, uint_t reg) 289 { 290 291 printf("IMPLEMENT ME: %s\n", __func__); 292 293 return (0); 294 } 295 296 static int 297 dtrace_copycheck(uintptr_t uaddr, uintptr_t kaddr, size_t size) 298 { 299 300 if (uaddr + size > VM_MAXUSER_ADDRESS || uaddr + size < uaddr) { 301 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 302 cpu_core[curcpu].cpuc_dtrace_illval = uaddr; 303 return (0); 304 } 305 306 return (1); 307 } 308 309 void 310 dtrace_copyin(uintptr_t uaddr, uintptr_t kaddr, size_t size, 311 volatile uint16_t *flags) 312 { 313 314 if (dtrace_copycheck(uaddr, kaddr, size)) 315 dtrace_copy(uaddr, kaddr, size); 316 } 317 318 void 319 dtrace_copyout(uintptr_t kaddr, uintptr_t uaddr, size_t size, 320 volatile uint16_t *flags) 321 { 322 323 if (dtrace_copycheck(uaddr, kaddr, size)) 324 dtrace_copy(kaddr, uaddr, size); 325 } 326 327 void 328 dtrace_copyinstr(uintptr_t uaddr, uintptr_t kaddr, size_t size, 329 volatile uint16_t *flags) 330 { 331 332 if (dtrace_copycheck(uaddr, kaddr, size)) 333 dtrace_copystr(uaddr, kaddr, size, flags); 334 } 335 336 void 337 dtrace_copyoutstr(uintptr_t kaddr, uintptr_t uaddr, size_t size, 338 volatile uint16_t *flags) 339 { 340 341 if (dtrace_copycheck(uaddr, kaddr, size)) 342 dtrace_copystr(kaddr, uaddr, size, flags); 343 } 344 345 uint8_t 346 dtrace_fuword8(void *uaddr) 347 { 348 349 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 350 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 351 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 352 return (0); 353 } 354 355 return (dtrace_fuword8_nocheck(uaddr)); 356 } 357 358 uint16_t 359 dtrace_fuword16(void *uaddr) 360 { 361 362 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 363 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 364 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 365 return (0); 366 } 367 368 return (dtrace_fuword16_nocheck(uaddr)); 369 } 370 371 uint32_t 372 dtrace_fuword32(void *uaddr) 373 { 374 375 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 376 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 377 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 378 return (0); 379 } 380 381 return (dtrace_fuword32_nocheck(uaddr)); 382 } 383 384 uint64_t 385 dtrace_fuword64(void *uaddr) 386 { 387 388 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 389 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 390 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 391 return (0); 392 } 393 394 return (dtrace_fuword64_nocheck(uaddr)); 395 } 396