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 27 /* 28 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 29 * Use is subject to license terms. 30 */ 31 32 #include <sys/cdefs.h> 33 #include <sys/param.h> 34 35 #include <sys/dtrace.h> 36 37 #include "fbt.h" 38 39 #define FBT_PATCHVAL DTRACE_PATCHVAL 40 #define FBT_AFRAMES 4 41 42 int 43 fbt_invop(uintptr_t addr, struct trapframe *frame, uintptr_t rval) 44 { 45 solaris_cpu_t *cpu; 46 fbt_probe_t *fbt; 47 48 cpu = &solaris_cpu[curcpu]; 49 fbt = fbt_probetab[FBT_ADDR2NDX(addr)]; 50 51 for (; fbt != NULL; fbt = fbt->fbtp_hashnext) { 52 if ((uintptr_t)fbt->fbtp_patchpoint != addr) 53 continue; 54 55 cpu->cpu_dtrace_caller = addr; 56 57 if (fbt->fbtp_roffset == 0) { 58 dtrace_probe(fbt->fbtp_id, frame->tf_x[0], 59 frame->tf_x[1], frame->tf_x[2], 60 frame->tf_x[3], frame->tf_x[4]); 61 } else { 62 dtrace_probe(fbt->fbtp_id, fbt->fbtp_roffset, rval, 63 0, 0, 0); 64 } 65 cpu->cpu_dtrace_caller = 0; 66 return (fbt->fbtp_savedval); 67 } 68 69 return (0); 70 } 71 72 void 73 fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val) 74 { 75 vm_offset_t addr; 76 77 if (!arm64_get_writable_addr((vm_offset_t)fbt->fbtp_patchpoint, &addr)) 78 panic("%s: Unable to write new instruction", __func__); 79 80 *(fbt_patchval_t *)addr = val; 81 cpu_icache_sync_range((vm_offset_t)fbt->fbtp_patchpoint, 4); 82 } 83 84 int 85 fbt_provide_module_function(linker_file_t lf, int symindx, 86 linker_symval_t *symval, void *opaque) 87 { 88 fbt_probe_t *fbt, *retfbt; 89 uint32_t *target, *start; 90 uint32_t *instr, *limit; 91 const char *name; 92 char *modname; 93 int offs; 94 95 modname = opaque; 96 name = symval->name; 97 98 /* Check if function is excluded from instrumentation */ 99 if (fbt_excluded(name)) 100 return (0); 101 102 /* 103 * Instrumenting certain exception handling functions can lead to FBT 104 * recursion, so exclude from instrumentation. 105 */ 106 if (strcmp(name, "handle_el1h_sync") == 0 || 107 strcmp(name, "do_el1h_sync") == 0) 108 return (1); 109 110 instr = (uint32_t *)(symval->value); 111 limit = (uint32_t *)(symval->value + symval->size); 112 113 /* 114 * Ignore any bti instruction at the start of the function 115 * we need to keep it there for any indirect branches calling 116 * the function on Armv8.5+ 117 */ 118 if ((*instr & BTI_MASK) == BTI_INSTR) 119 instr++; 120 121 /* 122 * If the first instruction is a nop it's a specially marked 123 * asm function. We only support a nop first as it's not a normal 124 * part of the function prologue. 125 */ 126 if (*instr == NOP_INSTR) 127 goto found; 128 129 /* Look for stp (pre-indexed) or sub operation */ 130 for (; instr < limit; instr++) { 131 /* 132 * Functions start with "stp xt1, xt2, [xn, <const>]!" or 133 * "sub sp, sp, <const>". 134 * 135 * Sometimes the compiler will have a sub instruction that is 136 * not of the above type so don't stop if we see one. 137 */ 138 if ((*instr & LDP_STP_MASK) == STP_64) { 139 /* 140 * Assume any other store of this type means we are 141 * past the function prologue. 142 */ 143 if (((*instr >> ADDR_SHIFT) & ADDR_MASK) == 31) 144 break; 145 } else if ((*instr & SUB_MASK) == SUB_INSTR && 146 ((*instr >> SUB_RD_SHIFT) & SUB_R_MASK) == 31 && 147 ((*instr >> SUB_RN_SHIFT) & SUB_R_MASK) == 31) 148 break; 149 } 150 found: 151 if (instr >= limit) 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, FBT_AFRAMES, 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, FBT_AFRAMES, 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_roffset = (uintptr_t)instr - (uintptr_t)symval->value; 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