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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 * Copyright (c) 2016 by Delphix. All rights reserved. 26 */ 27 28 #pragma ident "%Z%%M% %I% %E% SMI" 29 30 #include "misc.h" 31 #include <ucontext.h> 32 #include <sys/frame.h> 33 #include <sys/stack.h> 34 #include <stdio.h> 35 36 #if defined(__sparc) || defined(__sparcv9) 37 extern void flush_windows(void); 38 #define UMEM_FRAMESIZE MINFRAME 39 40 #elif defined(__i386) || defined(__amd64) 41 /* 42 * On x86, MINFRAME is defined to be 0, but we want to be sure we can 43 * dereference the entire frame structure. 44 */ 45 #define UMEM_FRAMESIZE (sizeof (struct frame)) 46 47 #else 48 #error needs update for new architecture 49 #endif 50 51 /* 52 * Get a pc-only stacktrace. Used for kmem_alloc() buffer ownership tracking. 53 * Returns MIN(current stack depth, pcstack_limit). 54 */ 55 /*ARGSUSED*/ 56 int 57 getpcstack(uintptr_t *pcstack, int pcstack_limit, int check_signal) 58 { 59 struct frame *fp; 60 struct frame *nextfp, *minfp; 61 int depth = 0; 62 uintptr_t base = 0; 63 size_t size = 0; 64 #ifndef UMEM_STANDALONE 65 int on_altstack = 0; 66 uintptr_t sigbase = 0; 67 size_t sigsize = 0; 68 69 stack_t st; 70 71 if (stack_getbounds(&st) != 0) { 72 if (thr_stksegment(&st) != 0 || 73 (uintptr_t)st.ss_sp < st.ss_size) { 74 return (0); /* unable to get stack bounds */ 75 } 76 /* 77 * thr_stksegment(3C) has a slightly different interface than 78 * stack_getbounds(3C) -- correct it 79 */ 80 st.ss_sp = (void *)(((uintptr_t)st.ss_sp) - st.ss_size); 81 st.ss_flags = 0; /* can't be on-stack */ 82 } 83 on_altstack = (st.ss_flags & SS_ONSTACK); 84 85 if (st.ss_size != 0) { 86 base = (uintptr_t)st.ss_sp; 87 size = st.ss_size; 88 } else { 89 /* 90 * If size == 0, then ss_sp is the *top* of the stack. 91 * 92 * Since we only allow increasing frame pointers, and we 93 * know our caller set its up correctly, we can treat ss_sp 94 * as an upper bound safely. 95 */ 96 base = 0; 97 size = (uintptr_t)st.ss_sp; 98 } 99 100 if (check_signal != 0) { 101 void (*sigfunc)() = NULL; 102 int sigfuncsize = 0; 103 extern void thr_sighndlrinfo(void (**)(), int *); 104 105 thr_sighndlrinfo(&sigfunc, &sigfuncsize); 106 sigbase = (uintptr_t)sigfunc; 107 sigsize = sigfuncsize; 108 } 109 #else /* UMEM_STANDALONE */ 110 base = (uintptr_t)umem_min_stack; 111 size = umem_max_stack - umem_min_stack; 112 #endif 113 114 /* 115 * shorten size so that fr_savfp and fr_savpc will be within the stack 116 * bounds. 117 */ 118 if (size >= UMEM_FRAMESIZE - 1) 119 size -= (UMEM_FRAMESIZE - 1); 120 else 121 size = 0; 122 123 #if defined(__sparc) || defined(__sparcv9) 124 flush_windows(); 125 #endif 126 127 /* LINTED alignment */ 128 fp = (struct frame *)((caddr_t)getfp() + STACK_BIAS); 129 130 minfp = fp; 131 132 if (((uintptr_t)fp - base) >= size) 133 return (0); /* the frame pointer isn't in our stack */ 134 135 while (depth < pcstack_limit) { 136 uintptr_t tmp; 137 138 /* LINTED alignment */ 139 nextfp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS); 140 tmp = (uintptr_t)nextfp; 141 142 /* 143 * Check nextfp for validity. It must be properly aligned, 144 * increasing compared to the last %fp (or the top of the 145 * stack we just switched to), and it must be inside 146 * [base, base + size). 147 */ 148 if (tmp != SA(tmp)) 149 break; 150 else if (nextfp <= minfp || (tmp - base) >= size) { 151 #ifndef UMEM_STANDALONE 152 if (tmp == NULL || !on_altstack) 153 break; 154 /* 155 * If we're on an alternate signal stack, try jumping 156 * to the main thread stack. 157 * 158 * If the main thread stack has an unlimited size, we 159 * punt, since we don't know where the frame pointer's 160 * been. 161 * 162 * (thr_stksegment() returns the *top of stack* 163 * in ss_sp, not the bottom) 164 */ 165 if (thr_stksegment(&st) == 0) { 166 if (st.ss_size >= (uintptr_t)st.ss_sp || 167 st.ss_size < UMEM_FRAMESIZE - 1) 168 break; 169 170 on_altstack = 0; 171 base = (uintptr_t)st.ss_sp - st.ss_size; 172 size = st.ss_size - (UMEM_FRAMESIZE - 1); 173 minfp = (struct frame *)base; 174 continue; /* try again */ 175 } 176 #endif 177 break; 178 } 179 180 #ifndef UMEM_STANDALONE 181 if (check_signal && (fp->fr_savpc - sigbase) <= sigsize) 182 umem_panic("called from signal handler"); 183 #endif 184 pcstack[depth++] = fp->fr_savpc; 185 fp = nextfp; 186 minfp = fp; 187 } 188 return (depth); 189 } 190