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 #define FBT_AFRAMES 4 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_x[0], 63 frame->tf_x[1], frame->tf_x[2], 64 frame->tf_x[3], frame->tf_x[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 *fbt->fbtp_patchpoint = val; 79 cpu_icache_sync_range((vm_offset_t)fbt->fbtp_patchpoint, 4); 80 } 81 82 int 83 fbt_provide_module_function(linker_file_t lf, int symindx, 84 linker_symval_t *symval, void *opaque) 85 { 86 fbt_probe_t *fbt, *retfbt; 87 uint32_t *target, *start; 88 uint32_t *instr, *limit; 89 const char *name; 90 char *modname; 91 bool found; 92 int offs; 93 94 modname = opaque; 95 name = symval->name; 96 97 /* Check if function is excluded from instrumentation */ 98 if (fbt_excluded(name)) 99 return (0); 100 101 /* 102 * Instrumenting certain exception handling functions can lead to FBT 103 * recursion, so exclude from instrumentation. 104 */ 105 if (strcmp(name, "handle_el1h_sync") == 0 || 106 strcmp(name, "do_el1h_sync") == 0) 107 return (1); 108 109 instr = (uint32_t *)(symval->value); 110 limit = (uint32_t *)(symval->value + symval->size); 111 112 /* Look for stp (pre-indexed) operation */ 113 found = false; 114 /* 115 * If the first instruction is a nop it's a specially marked 116 * asm function. We only support a nop first as it's not a normal 117 * part of the function prologue. 118 */ 119 if (*instr == NOP_INSTR) 120 found = true; 121 if (!found) { 122 for (; instr < limit; instr++) { 123 /* 124 * Some functions start with 125 * "stp xt1, xt2, [xn, <const>]!" 126 */ 127 if ((*instr & LDP_STP_MASK) == STP_64) { 128 /* 129 * Assume any other store of this type means we 130 * are past the function prolog. 131 */ 132 if (((*instr >> ADDR_SHIFT) & ADDR_MASK) == 31) 133 found = true; 134 break; 135 } 136 137 /* 138 * Some functions start with a "sub sp, sp, <const>" 139 * Sometimes the compiler will have a sub instruction 140 * that is not of the above type so don't stop if we 141 * see one. 142 */ 143 if ((*instr & SUB_MASK) == SUB_INSTR && 144 ((*instr >> SUB_RD_SHIFT) & SUB_R_MASK) == 31 && 145 ((*instr >> SUB_RN_SHIFT) & SUB_R_MASK) == 31) { 146 found = true; 147 break; 148 } 149 } 150 } 151 152 if (!found) 153 return (0); 154 155 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 156 fbt->fbtp_name = name; 157 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 158 name, FBT_ENTRY, FBT_AFRAMES, fbt); 159 fbt->fbtp_patchpoint = instr; 160 fbt->fbtp_ctl = lf; 161 fbt->fbtp_loadcnt = lf->loadcnt; 162 fbt->fbtp_savedval = *instr; 163 fbt->fbtp_patchval = FBT_PATCHVAL; 164 if ((*instr & SUB_MASK) == SUB_INSTR) 165 fbt->fbtp_rval = DTRACE_INVOP_SUB; 166 else 167 fbt->fbtp_rval = DTRACE_INVOP_STP; 168 fbt->fbtp_symindx = symindx; 169 170 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 171 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 172 173 lf->fbt_nentries++; 174 175 retfbt = NULL; 176 again: 177 for (; instr < limit; instr++) { 178 if (*instr == RET_INSTR) 179 break; 180 else if ((*instr & B_MASK) == B_INSTR) { 181 offs = (*instr & B_DATA_MASK); 182 offs *= 4; 183 target = (instr + offs); 184 start = (uint32_t *)symval->value; 185 if (target >= limit || target < start) 186 break; 187 } 188 } 189 190 if (instr >= limit) 191 return (0); 192 193 /* 194 * We have a winner! 195 */ 196 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 197 fbt->fbtp_name = name; 198 if (retfbt == NULL) { 199 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 200 name, FBT_RETURN, FBT_AFRAMES, fbt); 201 } else { 202 retfbt->fbtp_probenext = fbt; 203 fbt->fbtp_id = retfbt->fbtp_id; 204 } 205 retfbt = fbt; 206 207 fbt->fbtp_patchpoint = instr; 208 fbt->fbtp_ctl = lf; 209 fbt->fbtp_loadcnt = lf->loadcnt; 210 fbt->fbtp_symindx = symindx; 211 if ((*instr & B_MASK) == B_INSTR) 212 fbt->fbtp_rval = DTRACE_INVOP_B; 213 else 214 fbt->fbtp_rval = DTRACE_INVOP_RET; 215 fbt->fbtp_savedval = *instr; 216 fbt->fbtp_patchval = FBT_PATCHVAL; 217 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 218 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 219 220 lf->fbt_nentries++; 221 222 instr++; 223 goto again; 224 } 225