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 for (; instr < limit; instr++) { 114 /* Some functions start with "stp xt1, xt2, [xn, <const>]!" */ 115 if ((*instr & LDP_STP_MASK) == STP_64) { 116 /* 117 * Assume any other store of this type means we 118 * are past the function prolog. 119 */ 120 if (((*instr >> ADDR_SHIFT) & ADDR_MASK) == 31) 121 found = true; 122 break; 123 } 124 125 /* 126 * Some functions start with a "sub sp, sp, <const>" 127 * Sometimes the compiler will have a sub instruction that 128 * is not of the above type so don't stop if we see one. 129 */ 130 if ((*instr & SUB_MASK) == SUB_INSTR && 131 ((*instr >> SUB_RD_SHIFT) & SUB_R_MASK) == 31 && 132 ((*instr >> SUB_RN_SHIFT) & SUB_R_MASK) == 31) { 133 found = true; 134 break; 135 } 136 } 137 138 if (!found) 139 return (0); 140 141 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 142 fbt->fbtp_name = name; 143 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 144 name, FBT_ENTRY, 3, fbt); 145 fbt->fbtp_patchpoint = instr; 146 fbt->fbtp_ctl = lf; 147 fbt->fbtp_loadcnt = lf->loadcnt; 148 fbt->fbtp_savedval = *instr; 149 fbt->fbtp_patchval = FBT_PATCHVAL; 150 if ((*instr & SUB_MASK) == SUB_INSTR) 151 fbt->fbtp_rval = DTRACE_INVOP_SUB; 152 else 153 fbt->fbtp_rval = DTRACE_INVOP_STP; 154 fbt->fbtp_symindx = symindx; 155 156 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 157 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 158 159 lf->fbt_nentries++; 160 161 retfbt = NULL; 162 again: 163 for (; instr < limit; instr++) { 164 if (*instr == RET_INSTR) 165 break; 166 else if ((*instr & B_MASK) == B_INSTR) { 167 offs = (*instr & B_DATA_MASK); 168 offs *= 4; 169 target = (instr + offs); 170 start = (uint32_t *)symval->value; 171 if (target >= limit || target < start) 172 break; 173 } 174 } 175 176 if (instr >= limit) 177 return (0); 178 179 /* 180 * We have a winner! 181 */ 182 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 183 fbt->fbtp_name = name; 184 if (retfbt == NULL) { 185 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 186 name, FBT_RETURN, 3, fbt); 187 } else { 188 retfbt->fbtp_probenext = fbt; 189 fbt->fbtp_id = retfbt->fbtp_id; 190 } 191 retfbt = fbt; 192 193 fbt->fbtp_patchpoint = instr; 194 fbt->fbtp_ctl = lf; 195 fbt->fbtp_loadcnt = lf->loadcnt; 196 fbt->fbtp_symindx = symindx; 197 if ((*instr & B_MASK) == B_INSTR) 198 fbt->fbtp_rval = DTRACE_INVOP_B; 199 else 200 fbt->fbtp_rval = DTRACE_INVOP_RET; 201 fbt->fbtp_savedval = *instr; 202 fbt->fbtp_patchval = FBT_PATCHVAL; 203 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 204 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 205 206 lf->fbt_nentries++; 207 208 instr++; 209 goto again; 210 } 211