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 * Portions Copyright 2013 Howard Su howardsu@freebsd.org 24 * 25 * $FreeBSD$ 26 * 27 */ 28 29 /* 30 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 31 * Use is subject to license terms. 32 */ 33 34 #include <sys/cdefs.h> 35 #include <sys/param.h> 36 37 #include <sys/dtrace.h> 38 39 #include "fbt.h" 40 41 #define FBT_PATCHVAL 0xe7f000f0 /* Specified undefined instruction */ 42 43 #define FBT_PUSHM 0xe92d0000 44 #define FBT_POPM 0xe8bd0000 45 #define FBT_JUMP 0xea000000 46 47 #define FBT_ENTRY "entry" 48 #define FBT_RETURN "return" 49 50 int 51 fbt_invop(uintptr_t addr, uintptr_t *stack, uintptr_t rval) 52 { 53 struct trapframe *frame = (struct trapframe *)stack; 54 solaris_cpu_t *cpu = &solaris_cpu[curcpu]; 55 fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)]; 56 57 for (; fbt != NULL; fbt = fbt->fbtp_hashnext) { 58 if ((uintptr_t)fbt->fbtp_patchpoint == addr) { 59 cpu->cpu_dtrace_caller = addr; 60 61 /* TODO: Need 5th parameter from stack */ 62 dtrace_probe(fbt->fbtp_id, frame->tf_r0, 63 frame->tf_r1, frame->tf_r2, 64 frame->tf_r3, 0); 65 66 cpu->cpu_dtrace_caller = 0; 67 68 return (fbt->fbtp_rval | (fbt->fbtp_savedval << DTRACE_INVOP_SHIFT)); 69 } 70 } 71 72 return (0); 73 } 74 75 void 76 fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val) 77 { 78 79 *fbt->fbtp_patchpoint = val; 80 cpu_icache_sync_range((vm_offset_t)fbt->fbtp_patchpoint, 4); 81 } 82 83 int 84 fbt_provide_module_function(linker_file_t lf, int symindx, 85 linker_symval_t *symval, void *opaque) 86 { 87 char *modname = opaque; 88 const char *name = symval->name; 89 fbt_probe_t *fbt, *retfbt; 90 uint32_t *instr, *limit; 91 int popm; 92 93 if (strncmp(name, "dtrace_", 7) == 0 && 94 strncmp(name, "dtrace_safe_", 12) != 0) { 95 /* 96 * Anything beginning with "dtrace_" may be called 97 * from probe context unless it explicitly indicates 98 * that it won't be called from probe context by 99 * using the prefix "dtrace_safe_". 100 */ 101 return (0); 102 } 103 104 if (name[0] == '_' && name[1] == '_') 105 return (0); 106 107 /* 108 * Architecture-specific exclusion list, largely to do with FBT trap 109 * processing, to prevent reentrance. 110 */ 111 if (strcmp(name, "undefinedinstruction") == 0) 112 return (0); 113 114 instr = (uint32_t *)symval->value; 115 limit = (uint32_t *)(symval->value + symval->size); 116 117 for (; instr < limit; instr++) 118 if ((*instr & 0xffff0000) == FBT_PUSHM && 119 (*instr & 0x4000) != 0) 120 break; 121 122 if (instr >= limit) 123 return (0); 124 125 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 126 fbt->fbtp_name = name; 127 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 128 name, FBT_ENTRY, 3, fbt); 129 fbt->fbtp_patchpoint = instr; 130 fbt->fbtp_ctl = lf; 131 fbt->fbtp_loadcnt = lf->loadcnt; 132 fbt->fbtp_savedval = *instr; 133 fbt->fbtp_patchval = FBT_PATCHVAL; 134 fbt->fbtp_rval = DTRACE_INVOP_PUSHM; 135 fbt->fbtp_symindx = symindx; 136 137 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 138 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 139 140 lf->fbt_nentries++; 141 142 popm = FBT_POPM | ((*instr) & 0x3FFF) | 0x8000; 143 144 retfbt = NULL; 145 again: 146 for (; instr < limit; instr++) { 147 if (*instr == popm) 148 break; 149 else if ((*instr & 0xff000000) == FBT_JUMP) { 150 uint32_t *target, *start; 151 int offset; 152 153 offset = (*instr & 0xffffff); 154 offset <<= 8; 155 offset /= 64; 156 target = instr + (2 + offset); 157 start = (uint32_t *)symval->value; 158 if (target >= limit || target < start) 159 break; 160 instr++; /* skip delay slot */ 161 } 162 } 163 164 if (instr >= limit) 165 return (0); 166 167 /* 168 * We have a winner! 169 */ 170 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 171 fbt->fbtp_name = name; 172 if (retfbt == NULL) { 173 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 174 name, FBT_RETURN, 3, fbt); 175 } else { 176 retfbt->fbtp_next = fbt; 177 fbt->fbtp_id = retfbt->fbtp_id; 178 } 179 retfbt = fbt; 180 181 fbt->fbtp_patchpoint = instr; 182 fbt->fbtp_ctl = lf; 183 fbt->fbtp_loadcnt = lf->loadcnt; 184 fbt->fbtp_symindx = symindx; 185 if ((*instr & 0xff000000) == FBT_JUMP) 186 fbt->fbtp_rval = DTRACE_INVOP_B; 187 else 188 fbt->fbtp_rval = DTRACE_INVOP_POPM; 189 fbt->fbtp_savedval = *instr; 190 fbt->fbtp_patchval = FBT_PATCHVAL; 191 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 192 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 193 194 lf->fbt_nentries++; 195 196 instr++; 197 goto again; 198 } 199