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 2015 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 "fbt.h" 40 41 #define AARCH64_BRK 0xd4200000 42 #define AARCH64_BRK_IMM16_SHIFT 5 43 #define AARCH64_BRK_IMM16_VAL (0x40d << AARCH64_BRK_IMM16_SHIFT) 44 #define FBT_PATCHVAL (AARCH64_BRK | AARCH64_BRK_IMM16_VAL) 45 #define FBT_ENTRY "entry" 46 #define FBT_RETURN "return" 47 48 int 49 fbt_invop(uintptr_t addr, struct trapframe *frame, uintptr_t rval) 50 { 51 solaris_cpu_t *cpu; 52 fbt_probe_t *fbt; 53 54 cpu = &solaris_cpu[curcpu]; 55 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 dtrace_probe(fbt->fbtp_id, frame->tf_x[0], 62 frame->tf_x[1], frame->tf_x[2], 63 frame->tf_x[3], frame->tf_x[4]); 64 65 cpu->cpu_dtrace_caller = 0; 66 return (fbt->fbtp_savedval); 67 } 68 } 69 70 return (0); 71 } 72 73 void 74 fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val) 75 { 76 77 *fbt->fbtp_patchpoint = val; 78 cpu_icache_sync_range((vm_offset_t)fbt->fbtp_patchpoint, 4); 79 } 80 81 int 82 fbt_provide_module_function(linker_file_t lf, int symindx, 83 linker_symval_t *symval, void *opaque) 84 { 85 fbt_probe_t *fbt, *retfbt; 86 uint32_t *target, *start; 87 uint32_t *instr, *limit; 88 const char *name; 89 char *modname; 90 bool found; 91 int offs; 92 93 modname = opaque; 94 name = symval->name; 95 96 /* Check if function is excluded from instrumentation */ 97 if (fbt_excluded(name)) 98 return (0); 99 100 /* 101 * Instrumenting certain exception handling functions can lead to FBT 102 * recursion, so exclude from instrumentation. 103 */ 104 if (strcmp(name, "handle_el1h_sync") == 0 || 105 strcmp(name, "do_el1h_sync") == 0) 106 return (1); 107 108 instr = (uint32_t *)(symval->value); 109 limit = (uint32_t *)(symval->value + symval->size); 110 111 /* Look for stp (pre-indexed) operation */ 112 found = false; 113 /* 114 * If the first instruction is a nop it's a specially marked 115 * asm function. We only support a nop first as it's not a normal 116 * part of the function prologue. 117 */ 118 if (*instr == NOP_INSTR) 119 found = true; 120 if (!found) { 121 for (; instr < limit; instr++) { 122 /* 123 * Some functions start with 124 * "stp xt1, xt2, [xn, <const>]!" 125 */ 126 if ((*instr & LDP_STP_MASK) == STP_64) { 127 /* 128 * Assume any other store of this type means we 129 * are past the function prolog. 130 */ 131 if (((*instr >> ADDR_SHIFT) & ADDR_MASK) == 31) 132 found = true; 133 break; 134 } 135 136 /* 137 * Some functions start with a "sub sp, sp, <const>" 138 * Sometimes the compiler will have a sub instruction 139 * that is not of the above type so don't stop if we 140 * see one. 141 */ 142 if ((*instr & SUB_MASK) == SUB_INSTR && 143 ((*instr >> SUB_RD_SHIFT) & SUB_R_MASK) == 31 && 144 ((*instr >> SUB_RN_SHIFT) & SUB_R_MASK) == 31) { 145 found = true; 146 break; 147 } 148 } 149 } 150 151 if (!found) 152 return (0); 153 154 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 155 fbt->fbtp_name = name; 156 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 157 name, FBT_ENTRY, 3, fbt); 158 fbt->fbtp_patchpoint = instr; 159 fbt->fbtp_ctl = lf; 160 fbt->fbtp_loadcnt = lf->loadcnt; 161 fbt->fbtp_savedval = *instr; 162 fbt->fbtp_patchval = FBT_PATCHVAL; 163 if ((*instr & SUB_MASK) == SUB_INSTR) 164 fbt->fbtp_rval = DTRACE_INVOP_SUB; 165 else 166 fbt->fbtp_rval = DTRACE_INVOP_STP; 167 fbt->fbtp_symindx = symindx; 168 169 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 170 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 171 172 lf->fbt_nentries++; 173 174 retfbt = NULL; 175 again: 176 for (; instr < limit; instr++) { 177 if (*instr == RET_INSTR) 178 break; 179 else if ((*instr & B_MASK) == B_INSTR) { 180 offs = (*instr & B_DATA_MASK); 181 offs *= 4; 182 target = (instr + offs); 183 start = (uint32_t *)symval->value; 184 if (target >= limit || target < start) 185 break; 186 } 187 } 188 189 if (instr >= limit) 190 return (0); 191 192 /* 193 * We have a winner! 194 */ 195 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 196 fbt->fbtp_name = name; 197 if (retfbt == NULL) { 198 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 199 name, FBT_RETURN, 3, fbt); 200 } else { 201 retfbt->fbtp_probenext = fbt; 202 fbt->fbtp_id = retfbt->fbtp_id; 203 } 204 retfbt = fbt; 205 206 fbt->fbtp_patchpoint = instr; 207 fbt->fbtp_ctl = lf; 208 fbt->fbtp_loadcnt = lf->loadcnt; 209 fbt->fbtp_symindx = symindx; 210 if ((*instr & B_MASK) == B_INSTR) 211 fbt->fbtp_rval = DTRACE_INVOP_B; 212 else 213 fbt->fbtp_rval = DTRACE_INVOP_RET; 214 fbt->fbtp_savedval = *instr; 215 fbt->fbtp_patchval = FBT_PATCHVAL; 216 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 217 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 218 219 lf->fbt_nentries++; 220 221 instr++; 222 goto again; 223 } 224