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 vm_offset_t addr; 78 79 if (!arm64_get_writable_addr((vm_offset_t)fbt->fbtp_patchpoint, &addr)) 80 panic("%s: Unable to write new instruction", __func__); 81 82 *(fbt_patchval_t *)addr = val; 83 cpu_icache_sync_range((vm_offset_t)fbt->fbtp_patchpoint, 4); 84 } 85 86 int 87 fbt_provide_module_function(linker_file_t lf, int symindx, 88 linker_symval_t *symval, void *opaque) 89 { 90 fbt_probe_t *fbt, *retfbt; 91 uint32_t *target, *start; 92 uint32_t *instr, *limit; 93 const char *name; 94 char *modname; 95 bool found; 96 int offs; 97 98 modname = opaque; 99 name = symval->name; 100 101 /* Check if function is excluded from instrumentation */ 102 if (fbt_excluded(name)) 103 return (0); 104 105 /* 106 * Instrumenting certain exception handling functions can lead to FBT 107 * recursion, so exclude from instrumentation. 108 */ 109 if (strcmp(name, "handle_el1h_sync") == 0 || 110 strcmp(name, "do_el1h_sync") == 0) 111 return (1); 112 113 instr = (uint32_t *)(symval->value); 114 limit = (uint32_t *)(symval->value + symval->size); 115 116 /* Look for stp (pre-indexed) operation */ 117 found = false; 118 /* 119 * If the first instruction is a nop it's a specially marked 120 * asm function. We only support a nop first as it's not a normal 121 * part of the function prologue. 122 */ 123 if (*instr == NOP_INSTR) 124 found = true; 125 if (!found) { 126 for (; instr < limit; instr++) { 127 /* 128 * Some functions start with 129 * "stp xt1, xt2, [xn, <const>]!" 130 */ 131 if ((*instr & LDP_STP_MASK) == STP_64) { 132 /* 133 * Assume any other store of this type means we 134 * are past the function prolog. 135 */ 136 if (((*instr >> ADDR_SHIFT) & ADDR_MASK) == 31) 137 found = true; 138 break; 139 } 140 141 /* 142 * Some functions start with a "sub sp, sp, <const>" 143 * Sometimes the compiler will have a sub instruction 144 * that is not of the above type so don't stop if we 145 * see one. 146 */ 147 if ((*instr & SUB_MASK) == SUB_INSTR && 148 ((*instr >> SUB_RD_SHIFT) & SUB_R_MASK) == 31 && 149 ((*instr >> SUB_RN_SHIFT) & SUB_R_MASK) == 31) { 150 found = true; 151 break; 152 } 153 } 154 } 155 156 if (!found) 157 return (0); 158 159 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 160 fbt->fbtp_name = name; 161 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 162 name, FBT_ENTRY, FBT_AFRAMES, fbt); 163 fbt->fbtp_patchpoint = instr; 164 fbt->fbtp_ctl = lf; 165 fbt->fbtp_loadcnt = lf->loadcnt; 166 fbt->fbtp_savedval = *instr; 167 fbt->fbtp_patchval = FBT_PATCHVAL; 168 if ((*instr & SUB_MASK) == SUB_INSTR) 169 fbt->fbtp_rval = DTRACE_INVOP_SUB; 170 else 171 fbt->fbtp_rval = DTRACE_INVOP_STP; 172 fbt->fbtp_symindx = symindx; 173 174 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 175 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 176 177 lf->fbt_nentries++; 178 179 retfbt = NULL; 180 again: 181 for (; instr < limit; instr++) { 182 if (*instr == RET_INSTR) 183 break; 184 else if ((*instr & B_MASK) == B_INSTR) { 185 offs = (*instr & B_DATA_MASK); 186 offs *= 4; 187 target = (instr + offs); 188 start = (uint32_t *)symval->value; 189 if (target >= limit || target < start) 190 break; 191 } 192 } 193 194 if (instr >= limit) 195 return (0); 196 197 /* 198 * We have a winner! 199 */ 200 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 201 fbt->fbtp_name = name; 202 if (retfbt == NULL) { 203 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 204 name, FBT_RETURN, FBT_AFRAMES, fbt); 205 } else { 206 retfbt->fbtp_probenext = fbt; 207 fbt->fbtp_id = retfbt->fbtp_id; 208 } 209 retfbt = fbt; 210 211 fbt->fbtp_patchpoint = instr; 212 fbt->fbtp_ctl = lf; 213 fbt->fbtp_loadcnt = lf->loadcnt; 214 fbt->fbtp_symindx = symindx; 215 if ((*instr & B_MASK) == B_INSTR) 216 fbt->fbtp_rval = DTRACE_INVOP_B; 217 else 218 fbt->fbtp_rval = DTRACE_INVOP_RET; 219 fbt->fbtp_savedval = *instr; 220 fbt->fbtp_patchval = FBT_PATCHVAL; 221 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 222 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 223 224 lf->fbt_nentries++; 225 226 instr++; 227 goto again; 228 } 229