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 * Portions Copyright 2016-2018 Ruslan Bukin <br@bsdpad.com> 25 * 26 * $FreeBSD$ 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 <machine/riscvreg.h> 40 #include <machine/encoding.h> 41 42 #include "fbt.h" 43 44 #define FBT_C_PATCHVAL MATCH_C_EBREAK 45 #define FBT_PATCHVAL MATCH_EBREAK 46 #define FBT_ENTRY "entry" 47 #define FBT_RETURN "return" 48 49 int 50 fbt_invop(uintptr_t addr, struct trapframe *frame, uintptr_t rval) 51 { 52 solaris_cpu_t *cpu; 53 fbt_probe_t *fbt; 54 55 cpu = &solaris_cpu[curcpu]; 56 fbt = fbt_probetab[FBT_ADDR2NDX(addr)]; 57 58 for (; fbt != NULL; fbt = fbt->fbtp_hashnext) { 59 if ((uintptr_t)fbt->fbtp_patchpoint == addr) { 60 cpu->cpu_dtrace_caller = addr; 61 62 dtrace_probe(fbt->fbtp_id, frame->tf_a[0], 63 frame->tf_a[1], frame->tf_a[2], 64 frame->tf_a[3], frame->tf_a[4]); 65 66 cpu->cpu_dtrace_caller = 0; 67 return (fbt->fbtp_savedval); 68 } 69 } 70 71 return (0); 72 } 73 74 void 75 fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val) 76 { 77 78 switch(fbt->fbtp_patchval) { 79 case FBT_C_PATCHVAL: 80 *(uint16_t *)fbt->fbtp_patchpoint = (uint16_t)val; 81 fence_i(); 82 break; 83 case FBT_PATCHVAL: 84 *fbt->fbtp_patchpoint = val; 85 fence_i(); 86 break; 87 }; 88 } 89 90 static int 91 match_opcode(uint32_t insn, int match, int mask) 92 { 93 94 if (((insn ^ match) & mask) == 0) 95 return (1); 96 97 return (0); 98 } 99 100 static int 101 check_c_ret(uint32_t **instr) 102 { 103 uint16_t *instr1; 104 int i; 105 106 for (i = 0; i < 2; i++) { 107 instr1 = (uint16_t *)(*instr) + i; 108 if (match_opcode(*instr1, (MATCH_C_JR | (X_RA << RD_SHIFT)), 109 (MASK_C_JR | RD_MASK))) { 110 *instr = (uint32_t *)instr1; 111 return (1); 112 } 113 } 114 115 return (0); 116 } 117 118 static int 119 check_c_sdsp(uint32_t **instr) 120 { 121 uint16_t *instr1; 122 int i; 123 124 for (i = 0; i < 2; i++) { 125 instr1 = (uint16_t *)(*instr) + i; 126 if (match_opcode(*instr1, (MATCH_C_SDSP | RS2_C_RA), 127 (MASK_C_SDSP | RS2_C_MASK))) { 128 *instr = (uint32_t *)instr1; 129 return (1); 130 } 131 } 132 133 return (0); 134 } 135 136 int 137 fbt_provide_module_function(linker_file_t lf, int symindx, 138 linker_symval_t *symval, void *opaque) 139 { 140 fbt_probe_t *fbt, *retfbt; 141 uint32_t *instr, *limit; 142 const char *name; 143 char *modname; 144 int patchval; 145 int rval; 146 147 modname = opaque; 148 name = symval->name; 149 150 /* Check if function is excluded from instrumentation */ 151 if (fbt_excluded(name)) 152 return (0); 153 154 instr = (uint32_t *)(symval->value); 155 limit = (uint32_t *)(symval->value + symval->size); 156 157 /* Look for sd operation */ 158 for (; instr < limit; instr++) { 159 /* Look for a non-compressed store of ra to sp */ 160 if (match_opcode(*instr, (MATCH_SD | RS2_RA | RS1_SP), 161 (MASK_SD | RS2_MASK | RS1_MASK))) { 162 rval = DTRACE_INVOP_SD; 163 patchval = FBT_PATCHVAL; 164 break; 165 } 166 167 /* Look for a 'C'-compressed store of ra to sp. */ 168 if (check_c_sdsp(&instr)) { 169 rval = DTRACE_INVOP_C_SDSP; 170 patchval = FBT_C_PATCHVAL; 171 break; 172 } 173 } 174 175 if (instr >= limit) 176 return (0); 177 178 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 179 fbt->fbtp_name = name; 180 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 181 name, FBT_ENTRY, 3, fbt); 182 fbt->fbtp_patchpoint = instr; 183 fbt->fbtp_ctl = lf; 184 fbt->fbtp_loadcnt = lf->loadcnt; 185 fbt->fbtp_savedval = *instr; 186 fbt->fbtp_patchval = patchval; 187 fbt->fbtp_rval = rval; 188 fbt->fbtp_symindx = symindx; 189 190 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 191 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 192 193 lf->fbt_nentries++; 194 195 retfbt = NULL; 196 again: 197 for (; instr < limit; instr++) { 198 /* Look for non-compressed return */ 199 if (match_opcode(*instr, (MATCH_JALR | (X_RA << RS1_SHIFT)), 200 (MASK_JALR | RD_MASK | RS1_MASK | IMM_MASK))) { 201 rval = DTRACE_INVOP_RET; 202 patchval = FBT_PATCHVAL; 203 break; 204 } 205 206 /* Look for 'C'-compressed return */ 207 if (check_c_ret(&instr)) { 208 rval = DTRACE_INVOP_C_RET; 209 patchval = FBT_C_PATCHVAL; 210 break; 211 } 212 } 213 214 if (instr >= limit) 215 return (0); 216 217 /* 218 * We have a winner! 219 */ 220 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 221 fbt->fbtp_name = name; 222 if (retfbt == NULL) { 223 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 224 name, FBT_RETURN, 3, fbt); 225 } else { 226 retfbt->fbtp_probenext = fbt; 227 fbt->fbtp_id = retfbt->fbtp_id; 228 } 229 retfbt = fbt; 230 231 fbt->fbtp_patchpoint = instr; 232 fbt->fbtp_ctl = lf; 233 fbt->fbtp_loadcnt = lf->loadcnt; 234 fbt->fbtp_symindx = symindx; 235 fbt->fbtp_rval = rval; 236 fbt->fbtp_savedval = *instr; 237 fbt->fbtp_patchval = patchval; 238 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 239 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 240 241 lf->fbt_nentries++; 242 243 instr++; 244 goto again; 245 } 246