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, uintptr_t *stack, uintptr_t rval) 53 { 54 struct trapframe *frame = (struct trapframe *)stack; 55 solaris_cpu_t *cpu = &solaris_cpu[curcpu]; 56 fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)]; 57 register_t fifthparam; 58 59 for (; fbt != NULL; fbt = fbt->fbtp_hashnext) { 60 if ((uintptr_t)fbt->fbtp_patchpoint == addr) { 61 cpu->cpu_dtrace_caller = addr; 62 63 /* Get 5th parameter from stack */ 64 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 65 fifthparam = *(register_t *)frame->tf_usr_sp; 66 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR); 67 68 dtrace_probe(fbt->fbtp_id, frame->tf_r0, 69 frame->tf_r1, frame->tf_r2, 70 frame->tf_r3, fifthparam); 71 72 cpu->cpu_dtrace_caller = 0; 73 74 return (fbt->fbtp_rval | (fbt->fbtp_savedval << DTRACE_INVOP_SHIFT)); 75 } 76 } 77 78 return (0); 79 } 80 81 void 82 fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val) 83 { 84 85 *fbt->fbtp_patchpoint = val; 86 icache_sync((vm_offset_t)fbt->fbtp_patchpoint, sizeof(val)); 87 } 88 89 int 90 fbt_provide_module_function(linker_file_t lf, int symindx, 91 linker_symval_t *symval, void *opaque) 92 { 93 char *modname = opaque; 94 const char *name = symval->name; 95 fbt_probe_t *fbt, *retfbt; 96 uint32_t *instr, *limit; 97 int popm; 98 99 if (strncmp(name, "dtrace_", 7) == 0 && 100 strncmp(name, "dtrace_safe_", 12) != 0) { 101 /* 102 * Anything beginning with "dtrace_" may be called 103 * from probe context unless it explicitly indicates 104 * that it won't be called from probe context by 105 * using the prefix "dtrace_safe_". 106 */ 107 return (0); 108 } 109 110 if (name[0] == '_' && name[1] == '_') 111 return (0); 112 113 instr = (uint32_t *)symval->value; 114 limit = (uint32_t *)(symval->value + symval->size); 115 116 /* 117 * va_arg functions has first instruction of 118 * sub sp, sp, #? 119 */ 120 if ((*instr & 0xfffff000) == FBT_SUBSP) 121 instr++; 122 123 /* 124 * check if insn is a pushm with LR 125 */ 126 if ((*instr & 0xffff0000) != FBT_PUSHM || 127 (*instr & (1 << LR)) == 0) 128 return (0); 129 130 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 131 fbt->fbtp_name = name; 132 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 133 name, FBT_ENTRY, 2, fbt); 134 fbt->fbtp_patchpoint = instr; 135 fbt->fbtp_ctl = lf; 136 fbt->fbtp_loadcnt = lf->loadcnt; 137 fbt->fbtp_savedval = *instr; 138 fbt->fbtp_patchval = FBT_BREAKPOINT; 139 fbt->fbtp_rval = DTRACE_INVOP_PUSHM; 140 fbt->fbtp_symindx = symindx; 141 142 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 143 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 144 145 lf->fbt_nentries++; 146 147 popm = FBT_POPM | ((*instr) & 0x3FFF) | 0x8000; 148 149 retfbt = NULL; 150 again: 151 for (; instr < limit; instr++) { 152 if (*instr == popm) 153 break; 154 else if ((*instr & 0xff000000) == FBT_JUMP) { 155 uint32_t *target, *start; 156 int offset; 157 158 offset = (*instr & 0xffffff); 159 offset <<= 8; 160 offset /= 64; 161 target = instr + (2 + offset); 162 start = (uint32_t *)symval->value; 163 if (target >= limit || target < start) 164 break; 165 } 166 } 167 168 if (instr >= limit) 169 return (0); 170 171 /* 172 * We have a winner! 173 */ 174 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); 175 fbt->fbtp_name = name; 176 if (retfbt == NULL) { 177 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, 178 name, FBT_RETURN, 2, fbt); 179 } else { 180 retfbt->fbtp_next = fbt; 181 fbt->fbtp_id = retfbt->fbtp_id; 182 } 183 retfbt = fbt; 184 185 fbt->fbtp_patchpoint = instr; 186 fbt->fbtp_ctl = lf; 187 fbt->fbtp_loadcnt = lf->loadcnt; 188 fbt->fbtp_symindx = symindx; 189 if ((*instr & 0xff000000) == FBT_JUMP) 190 fbt->fbtp_rval = DTRACE_INVOP_B; 191 else 192 fbt->fbtp_rval = DTRACE_INVOP_POPM; 193 fbt->fbtp_savedval = *instr; 194 fbt->fbtp_patchval = FBT_BREAKPOINT; 195 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; 196 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; 197 198 lf->fbt_nentries++; 199 200 instr++; 201 goto again; 202 } 203