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 * 25 * $FreeBSD$ 26 * 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 #include <machine/stack.h> 39 #include <machine/trap.h> 40 41 #include "fbt.h" 42 43 #define FBT_PUSHM 0xe92d0000 44 #define FBT_POPM 0xe8bd0000 45 #define FBT_JUMP 0xea000000 46 #define FBT_SUBSP 0xe24dd000 47 48 #define FBT_ENTRY "entry" 49 #define FBT_RETURN "return" 50 51 int 52 fbt_invop(uintptr_t addr, struct trapframe *frame, uintptr_t rval) 53 { 54 solaris_cpu_t *cpu = &solaris_cpu[curcpu]; 55 fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)]; 56 register_t fifthparam; 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 /* Get 5th parameter from stack */ 63 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 64 fifthparam = *(register_t *)frame->tf_usr_sp; 65 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR); 66 67 dtrace_probe(fbt->fbtp_id, frame->tf_r0, 68 frame->tf_r1, frame->tf_r2, 69 frame->tf_r3, fifthparam); 70 71 cpu->cpu_dtrace_caller = 0; 72 73 return (fbt->fbtp_rval | (fbt->fbtp_savedval << DTRACE_INVOP_SHIFT)); 74 } 75 } 76 77 return (0); 78 } 79 80 void 81 fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val) 82 { 83 84 *fbt->fbtp_patchpoint = val; 85 icache_sync((vm_offset_t)fbt->fbtp_patchpoint, sizeof(val)); 86 } 87 88 int 89 fbt_provide_module_function(linker_file_t lf, int symindx, 90 linker_symval_t *symval, void *opaque) 91 { 92 char *modname = opaque; 93 const char *name = symval->name; 94 fbt_probe_t *fbt, *retfbt; 95 uint32_t *instr, *limit; 96 int popm; 97 98 if (strncmp(name, "dtrace_", 7) == 0 && 99 strncmp(name, "dtrace_safe_", 12) != 0) { 100 /* 101 * Anything beginning with "dtrace_" may be called 102 * from probe context unless it explicitly indicates 103 * that it won't be called from probe context by 104 * using the prefix "dtrace_safe_". 105 */ 106 return (0); 107 } 108 109 instr = (uint32_t *)symval->value; 110 limit = (uint32_t *)(symval->value + symval->size); 111 112 /* 113 * va_arg functions has first instruction of 114 * sub sp, sp, #? 115 */ 116 if ((*instr & 0xfffff000) == FBT_SUBSP) 117 instr++; 118 119 /* 120 * check if insn is a pushm with LR 121 */ 122 if ((*instr & 0xffff0000) != FBT_PUSHM || 123 (*instr & (1 << LR)) == 0) 124 return (0); 125 126 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 127 fbt->fbtp_name = name; 128 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 129 name, FBT_ENTRY, 2, fbt); 130 fbt->fbtp_patchpoint = instr; 131 fbt->fbtp_ctl = lf; 132 fbt->fbtp_loadcnt = lf->loadcnt; 133 fbt->fbtp_savedval = *instr; 134 fbt->fbtp_patchval = FBT_BREAKPOINT; 135 fbt->fbtp_rval = DTRACE_INVOP_PUSHM; 136 fbt->fbtp_symindx = symindx; 137 138 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 139 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 140 141 lf->fbt_nentries++; 142 143 popm = FBT_POPM | ((*instr) & 0x3FFF) | 0x8000; 144 145 retfbt = NULL; 146 again: 147 for (; instr < limit; instr++) { 148 if (*instr == popm) 149 break; 150 else if ((*instr & 0xff000000) == FBT_JUMP) { 151 uint32_t *target, *start; 152 int offset; 153 154 offset = (*instr & 0xffffff); 155 offset <<= 8; 156 offset /= 64; 157 target = instr + (2 + offset); 158 start = (uint32_t *)symval->value; 159 if (target >= limit || target < start) 160 break; 161 } 162 } 163 164 if (instr >= limit) 165 return (0); 166 167 /* 168 * We have a winner! 169 */ 170 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 171 fbt->fbtp_name = name; 172 if (retfbt == NULL) { 173 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 174 name, FBT_RETURN, 2, fbt); 175 } else { 176 retfbt->fbtp_next = fbt; 177 fbt->fbtp_id = retfbt->fbtp_id; 178 } 179 retfbt = fbt; 180 181 fbt->fbtp_patchpoint = instr; 182 fbt->fbtp_ctl = lf; 183 fbt->fbtp_loadcnt = lf->loadcnt; 184 fbt->fbtp_symindx = symindx; 185 if ((*instr & 0xff000000) == FBT_JUMP) 186 fbt->fbtp_rval = DTRACE_INVOP_B; 187 else 188 fbt->fbtp_rval = DTRACE_INVOP_POPM; 189 fbt->fbtp_savedval = *instr; 190 fbt->fbtp_patchval = FBT_BREAKPOINT; 191 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 192 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 193 194 lf->fbt_nentries++; 195 196 instr++; 197 goto again; 198 } 199