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 if (fbt->fbtp_roffset == 0) { 63 dtrace_probe(fbt->fbtp_id, frame->tf_a[0], 64 frame->tf_a[1], frame->tf_a[2], 65 frame->tf_a[3], frame->tf_a[4]); 66 } else { 67 dtrace_probe(fbt->fbtp_id, fbt->fbtp_roffset, 68 frame->tf_a[0], frame->tf_a[1], 0, 0); 69 } 70 71 cpu->cpu_dtrace_caller = 0; 72 return (fbt->fbtp_savedval); 73 } 74 } 75 76 return (0); 77 } 78 79 void 80 fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val) 81 { 82 83 switch(fbt->fbtp_patchval) { 84 case FBT_C_PATCHVAL: 85 *(uint16_t *)fbt->fbtp_patchpoint = (uint16_t)val; 86 fence_i(); 87 break; 88 case FBT_PATCHVAL: 89 *fbt->fbtp_patchpoint = val; 90 fence_i(); 91 break; 92 }; 93 } 94 95 static int 96 match_opcode(uint32_t insn, int match, int mask) 97 { 98 99 if (((insn ^ match) & mask) == 0) 100 return (1); 101 102 return (0); 103 } 104 105 static int 106 check_c_ret(uint32_t **instr) 107 { 108 uint16_t *instr1; 109 int i; 110 111 for (i = 0; i < 2; i++) { 112 instr1 = (uint16_t *)(*instr) + i; 113 if (match_opcode(*instr1, (MATCH_C_JR | (X_RA << RD_SHIFT)), 114 (MASK_C_JR | RD_MASK))) { 115 *instr = (uint32_t *)instr1; 116 return (1); 117 } 118 } 119 120 return (0); 121 } 122 123 static int 124 check_c_sdsp(uint32_t **instr) 125 { 126 uint16_t *instr1; 127 int i; 128 129 for (i = 0; i < 2; i++) { 130 instr1 = (uint16_t *)(*instr) + i; 131 if (match_opcode(*instr1, (MATCH_C_SDSP | RS2_C_RA), 132 (MASK_C_SDSP | RS2_C_MASK))) { 133 *instr = (uint32_t *)instr1; 134 return (1); 135 } 136 } 137 138 return (0); 139 } 140 141 int 142 fbt_provide_module_function(linker_file_t lf, int symindx, 143 linker_symval_t *symval, void *opaque) 144 { 145 fbt_probe_t *fbt, *retfbt; 146 uint32_t *instr, *limit; 147 const char *name; 148 char *modname; 149 int patchval; 150 int rval; 151 152 modname = opaque; 153 name = symval->name; 154 155 /* Check if function is excluded from instrumentation */ 156 if (fbt_excluded(name)) 157 return (0); 158 159 /* 160 * Some assembly-language exception handlers are not suitable for 161 * instrumentation. 162 */ 163 if (strcmp(name, "cpu_exception_handler") == 0) 164 return (0); 165 if (strcmp(name, "cpu_exception_handler_user") == 0) 166 return (0); 167 if (strcmp(name, "cpu_exception_handler_supervisor") == 0) 168 return (0); 169 if (strcmp(name, "do_trap_supervisor") == 0) 170 return (0); 171 172 instr = (uint32_t *)(symval->value); 173 limit = (uint32_t *)(symval->value + symval->size); 174 175 /* Look for sd operation */ 176 for (; instr < limit; instr++) { 177 /* Look for a non-compressed store of ra to sp */ 178 if (match_opcode(*instr, (MATCH_SD | RS2_RA | RS1_SP), 179 (MASK_SD | RS2_MASK | RS1_MASK))) { 180 rval = DTRACE_INVOP_SD; 181 patchval = FBT_PATCHVAL; 182 break; 183 } 184 185 /* Look for a 'C'-compressed store of ra to sp. */ 186 if (check_c_sdsp(&instr)) { 187 rval = DTRACE_INVOP_C_SDSP; 188 patchval = FBT_C_PATCHVAL; 189 break; 190 } 191 } 192 193 if (instr >= limit) 194 return (0); 195 196 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 197 fbt->fbtp_name = name; 198 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 199 name, FBT_ENTRY, 3, fbt); 200 fbt->fbtp_patchpoint = instr; 201 fbt->fbtp_ctl = lf; 202 fbt->fbtp_loadcnt = lf->loadcnt; 203 fbt->fbtp_savedval = *instr; 204 fbt->fbtp_patchval = patchval; 205 fbt->fbtp_rval = rval; 206 fbt->fbtp_symindx = symindx; 207 208 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 209 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 210 211 lf->fbt_nentries++; 212 213 retfbt = NULL; 214 again: 215 for (; instr < limit; instr++) { 216 /* Look for non-compressed return */ 217 if (match_opcode(*instr, (MATCH_JALR | (X_RA << RS1_SHIFT)), 218 (MASK_JALR | RD_MASK | RS1_MASK | IMM_MASK))) { 219 rval = DTRACE_INVOP_RET; 220 patchval = FBT_PATCHVAL; 221 break; 222 } 223 224 /* Look for 'C'-compressed return */ 225 if (check_c_ret(&instr)) { 226 rval = DTRACE_INVOP_C_RET; 227 patchval = FBT_C_PATCHVAL; 228 break; 229 } 230 } 231 232 if (instr >= limit) 233 return (0); 234 235 /* 236 * We have a winner! 237 */ 238 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 239 fbt->fbtp_name = name; 240 if (retfbt == NULL) { 241 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 242 name, FBT_RETURN, 3, fbt); 243 } else { 244 retfbt->fbtp_probenext = fbt; 245 fbt->fbtp_id = retfbt->fbtp_id; 246 } 247 retfbt = fbt; 248 249 fbt->fbtp_patchpoint = instr; 250 fbt->fbtp_ctl = lf; 251 fbt->fbtp_loadcnt = lf->loadcnt; 252 fbt->fbtp_symindx = symindx; 253 fbt->fbtp_rval = rval; 254 fbt->fbtp_roffset = (uintptr_t)instr - (uintptr_t)symval->value; 255 fbt->fbtp_savedval = *instr; 256 fbt->fbtp_patchval = patchval; 257 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 258 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 259 260 lf->fbt_nentries++; 261 262 instr++; 263 goto again; 264 } 265