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 * Portions Copyright 2006-2008 John Birrell jb@freebsd.org 22 * Portions Copyright 2013 Justin Hibbits jhibbits@freebsd.org 23 * 24 */ 25 26 /* 27 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 28 * Use is subject to license terms. 29 */ 30 31 #include <sys/param.h> 32 #include <sys/dtrace.h> 33 #include <machine/md_var.h> 34 35 #include "fbt.h" 36 37 #define FBT_PATCHVAL 0x7ffff808 38 #define FBT_MFLR_R0 0x7c0802a6 39 #define FBT_MTLR_R0 0x7c0803a6 40 #define FBT_BLR 0x4e800020 41 #define FBT_BCTR 0x4e800030 42 #define FBT_BRANCH 0x48000000 43 #define FBT_BR_MASK 0x03fffffc 44 #define FBT_IS_JUMP(instr) ((instr & ~FBT_BR_MASK) == FBT_BRANCH) 45 46 #define FBT_AFRAMES 5 47 48 int 49 fbt_invop(uintptr_t addr, struct trapframe *frame, uintptr_t rval) 50 { 51 solaris_cpu_t *cpu = &solaris_cpu[curcpu]; 52 fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)]; 53 uintptr_t tmp; 54 55 for (; fbt != NULL; fbt = fbt->fbtp_hashnext) { 56 if ((uintptr_t)fbt->fbtp_patchpoint == addr) { 57 if (fbt->fbtp_roffset == 0) { 58 cpu->cpu_dtrace_caller = addr; 59 60 dtrace_probe(fbt->fbtp_id, frame->fixreg[3], 61 frame->fixreg[4], frame->fixreg[5], 62 frame->fixreg[6], frame->fixreg[7]); 63 64 cpu->cpu_dtrace_caller = 0; 65 } else { 66 67 dtrace_probe(fbt->fbtp_id, fbt->fbtp_roffset, 68 rval, 0, 0, 0); 69 /* 70 * The caller doesn't have the fbt item, so 71 * fixup tail calls here. 72 */ 73 if (fbt->fbtp_rval == DTRACE_INVOP_JUMP) { 74 frame->srr0 = (uintptr_t)fbt->fbtp_patchpoint; 75 tmp = fbt->fbtp_savedval & FBT_BR_MASK; 76 /* Sign extend. */ 77 if (tmp & 0x02000000) 78 #ifdef __powerpc64__ 79 tmp |= 0xfffffffffc000000ULL; 80 #else 81 tmp |= 0xfc000000UL; 82 #endif 83 frame->srr0 += tmp; 84 } 85 cpu->cpu_dtrace_caller = 0; 86 } 87 88 return (fbt->fbtp_rval); 89 } 90 } 91 92 return (0); 93 } 94 95 void 96 fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val) 97 { 98 99 *fbt->fbtp_patchpoint = val; 100 __syncicache(fbt->fbtp_patchpoint, 4); 101 } 102 103 int 104 fbt_provide_module_function(linker_file_t lf, int symindx, 105 linker_symval_t *symval, void *opaque) 106 { 107 char *modname = opaque; 108 const char *name = symval->name; 109 fbt_probe_t *fbt, *retfbt; 110 int j; 111 uint32_t *instr, *limit; 112 113 #ifdef __powerpc64__ 114 #if !defined(_CALL_ELF) || _CALL_ELF == 1 115 /* 116 * PowerPC64 uses '.' prefixes on symbol names, ignore it, but only 117 * allow symbols with the '.' prefix, so that we don't get the function 118 * descriptor instead. 119 */ 120 if (name[0] == '.') 121 name++; 122 else 123 return (0); 124 #endif 125 #endif 126 127 if (fbt_excluded(name)) 128 return (0); 129 130 instr = (uint32_t *) symval->value; 131 limit = (uint32_t *) (symval->value + symval->size); 132 133 for (; instr < limit; instr++) 134 if (*instr == FBT_MFLR_R0) 135 break; 136 137 if (*instr != FBT_MFLR_R0) 138 return (0); 139 140 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 141 fbt->fbtp_name = name; 142 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 143 name, FBT_ENTRY, FBT_AFRAMES, fbt); 144 fbt->fbtp_patchpoint = instr; 145 fbt->fbtp_ctl = lf; 146 fbt->fbtp_loadcnt = lf->loadcnt; 147 fbt->fbtp_savedval = *instr; 148 fbt->fbtp_patchval = FBT_PATCHVAL; 149 fbt->fbtp_rval = DTRACE_INVOP_MFLR_R0; 150 fbt->fbtp_symindx = symindx; 151 152 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 153 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 154 155 lf->fbt_nentries++; 156 157 retfbt = NULL; 158 again: 159 if (instr >= limit) 160 return (0); 161 162 /* 163 * We (desperately) want to avoid erroneously instrumenting a 164 * jump table. To determine if we're looking at a true instruction 165 * sequence or an inline jump table that happens to contain the same 166 * byte sequences, we resort to some heuristic sleeze: we treat this 167 * instruction as being contained within a pointer, and see if that 168 * pointer points to within the body of the function. If it does, we 169 * refuse to instrument it. 170 */ 171 { 172 uint32_t *ptr; 173 174 ptr = *(uint32_t **)instr; 175 176 if (ptr >= (uint32_t *) symval->value && ptr < limit) { 177 instr++; 178 goto again; 179 } 180 } 181 182 if (*instr != FBT_MTLR_R0) { 183 instr++; 184 goto again; 185 } 186 187 instr++; 188 189 for (j = 0; j < 12 && instr < limit; j++, instr++) { 190 if ((*instr == FBT_BCTR) || (*instr == FBT_BLR) || 191 FBT_IS_JUMP(*instr)) 192 break; 193 } 194 195 if (!(*instr == FBT_BCTR || *instr == FBT_BLR || FBT_IS_JUMP(*instr))) 196 goto again; 197 198 /* 199 * We have a winner! 200 */ 201 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 202 fbt->fbtp_name = name; 203 204 if (retfbt == NULL) { 205 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 206 name, FBT_RETURN, FBT_AFRAMES, fbt); 207 } else { 208 retfbt->fbtp_probenext = fbt; 209 fbt->fbtp_id = retfbt->fbtp_id; 210 } 211 212 retfbt = fbt; 213 fbt->fbtp_patchpoint = instr; 214 fbt->fbtp_ctl = lf; 215 fbt->fbtp_loadcnt = lf->loadcnt; 216 fbt->fbtp_symindx = symindx; 217 218 if (*instr == FBT_BCTR) 219 fbt->fbtp_rval = DTRACE_INVOP_BCTR; 220 else if (*instr == FBT_BLR) 221 fbt->fbtp_rval = DTRACE_INVOP_BLR; 222 else 223 fbt->fbtp_rval = DTRACE_INVOP_JUMP; 224 225 fbt->fbtp_roffset = 226 (uintptr_t)((uint8_t *)instr - (uint8_t *)symval->value); 227 228 fbt->fbtp_savedval = *instr; 229 fbt->fbtp_patchval = FBT_PATCHVAL; 230 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 231 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 232 233 lf->fbt_nentries++; 234 235 instr += 4; 236 goto again; 237 } 238