1 /* 2 * Copyright (c) 2005-2012 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 29 // NOTE: This file is only c++ so I can get static initialisers going 30 #include <libkern/OSDebug.h> 31 #include <IOKit/IOLib.h> 32 33 #include <sys/cdefs.h> 34 35 #include <stdarg.h> 36 #include <mach/mach_types.h> 37 #include <mach/kmod.h> 38 #include <kern/locks.h> 39 40 #include <libkern/libkern.h> // From bsd's libkern directory 41 #include <mach/vm_param.h> 42 43 #include <sys/kdebug.h> 44 #include <kern/thread.h> 45 46 extern int etext; 47 __BEGIN_DECLS 48 // From osmfk/kern/thread.h but considered to be private 49 extern vm_offset_t min_valid_stack_address(void); 50 extern vm_offset_t max_valid_stack_address(void); 51 52 // From osfmk/kmod.c 53 extern void kmod_dump_log(vm_offset_t *addr, unsigned int cnt); 54 55 extern addr64_t kvtophys(vm_offset_t va); 56 57 __END_DECLS 58 59 extern lck_grp_t *IOLockGroup; 60 61 static lck_mtx_t *sOSReportLock = lck_mtx_alloc_init(IOLockGroup, LCK_ATTR_NULL); 62 63 /* Use kernel_debug() to log a backtrace */ 64 void 65 trace_backtrace(uint32_t debugid, uint32_t debugid2, uintptr_t size, uintptr_t data) { 66 void *bt[16]; 67 const unsigned cnt = sizeof(bt) / sizeof(bt[0]); 68 unsigned i; 69 int found = 0; 70 71 OSBacktrace(bt, cnt); 72 73 /* find first non-kernel frame */ 74 for (i = 3; i < cnt && bt[i]; i++) { 75 if (bt[i] > (void*)&etext) { 76 found = 1; 77 break; 78 } 79 } 80 /* 81 * if there are non-kernel frames, only log these 82 * otherwise, log everything but the first two 83 */ 84 if (!found) i=2; 85 86 #define safe_bt(a) (uintptr_t)(a<cnt ? bt[a] : 0) 87 kernel_debug(debugid, data, size, safe_bt(i), safe_bt(i+1), 0); 88 kernel_debug(debugid2, safe_bt(i+2), safe_bt(i+3), safe_bt(i+4), safe_bt(i+5), 0); 89 } 90 91 /* Report a message with a 4 entry backtrace - very slow */ 92 void 93 OSReportWithBacktrace(const char *str, ...) 94 { 95 char buf[128]; 96 void *bt[9]; 97 const unsigned cnt = sizeof(bt) / sizeof(bt[0]); 98 va_list listp; 99 100 // Ignore the our and our callers stackframes, skipping frames 0 & 1 101 (void) OSBacktrace(bt, cnt); 102 103 va_start(listp, str); 104 vsnprintf(buf, sizeof(buf), str, listp); 105 va_end(listp); 106 107 lck_mtx_lock(sOSReportLock); 108 { 109 printf("%s\nBacktrace 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", buf, 110 (unsigned long) VM_KERNEL_UNSLIDE(bt[2]), (unsigned long) VM_KERNEL_UNSLIDE(bt[3]), 111 (unsigned long) VM_KERNEL_UNSLIDE(bt[4]), (unsigned long) VM_KERNEL_UNSLIDE(bt[5]), 112 (unsigned long) VM_KERNEL_UNSLIDE(bt[6]), (unsigned long) VM_KERNEL_UNSLIDE(bt[7]), 113 (unsigned long) VM_KERNEL_UNSLIDE(bt[8])); 114 kmod_dump_log((vm_offset_t *) &bt[2], cnt - 2); 115 } 116 lck_mtx_unlock(sOSReportLock); 117 } 118 119 static vm_offset_t minstackaddr = min_valid_stack_address(); 120 static vm_offset_t maxstackaddr = max_valid_stack_address(); 121 122 123 #if __x86_64__ 124 #define x86_64_RETURN_OFFSET 8 125 static unsigned int 126 x86_64_validate_raddr(vm_offset_t raddr) 127 { 128 return ((raddr > VM_MIN_KERNEL_AND_KEXT_ADDRESS) && 129 (raddr < VM_MAX_KERNEL_ADDRESS)); 130 } 131 static unsigned int 132 x86_64_validate_stackptr(vm_offset_t stackptr) 133 { 134 /* Existence and alignment check 135 */ 136 if (!stackptr || (stackptr & 0x7) || !x86_64_validate_raddr(stackptr)) 137 return 0; 138 139 /* Is a virtual->physical translation present? 140 */ 141 if (!kvtophys(stackptr)) 142 return 0; 143 144 /* Check if the return address lies on the same page; 145 * If not, verify that a translation exists. 146 */ 147 if (((PAGE_SIZE - (stackptr & PAGE_MASK)) < x86_64_RETURN_OFFSET) && 148 !kvtophys(stackptr + x86_64_RETURN_OFFSET)) 149 return 0; 150 return 1; 151 } 152 #endif 153 154 void 155 OSPrintBacktrace(void) 156 { 157 void * btbuf[20]; 158 int tmp = OSBacktrace(btbuf, 20); 159 int i; 160 for(i=0;i<tmp;i++) 161 { 162 kprintf("bt[%.2d] = %p\n", i, btbuf[i]); 163 } 164 } 165 166 unsigned OSBacktrace(void **bt, unsigned maxAddrs) 167 { 168 unsigned frame; 169 170 #if __x86_64__ 171 #define SANE_x86_64_FRAME_SIZE (kernel_stack_size >> 1) 172 vm_offset_t stackptr, stackptr_prev, raddr; 173 unsigned frame_index = 0; 174 /* Obtain current frame pointer */ 175 176 __asm__ volatile("movq %%rbp, %0" : "=m" (stackptr)); 177 178 if (!x86_64_validate_stackptr(stackptr)) 179 goto pad; 180 181 raddr = *((vm_offset_t *) (stackptr + x86_64_RETURN_OFFSET)); 182 183 if (!x86_64_validate_raddr(raddr)) 184 goto pad; 185 186 bt[frame_index++] = (void *) raddr; 187 188 for ( ; frame_index < maxAddrs; frame_index++) { 189 stackptr_prev = stackptr; 190 stackptr = *((vm_offset_t *) stackptr_prev); 191 192 if (!x86_64_validate_stackptr(stackptr)) 193 break; 194 /* Stack grows downwards */ 195 if (stackptr < stackptr_prev) 196 break; 197 198 if ((stackptr - stackptr_prev) > SANE_x86_64_FRAME_SIZE) 199 break; 200 201 raddr = *((vm_offset_t *) (stackptr + x86_64_RETURN_OFFSET)); 202 203 if (!x86_64_validate_raddr(raddr)) 204 break; 205 206 bt[frame_index] = (void *) raddr; 207 } 208 pad: 209 frame = frame_index; 210 211 for ( ; frame_index < maxAddrs; frame_index++) 212 bt[frame_index] = (void *) 0; 213 #else 214 #error arch 215 #endif 216 return frame; 217 } 218