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 22 /* 23 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <sys/dtrace.h> 30 #include <sys/fasttrap.h> 31 #include <sys/x_call.h> 32 #include <sys/atomic.h> 33 #include <sys/machsystm.h> 34 35 static void 36 dtrace_xcall_func(uint64_t arg1, uint64_t arg2) 37 { 38 (*(dtrace_xcall_t)arg1)((void *)(arg2)); 39 } 40 41 void 42 dtrace_xcall(processorid_t cpu, dtrace_xcall_t func, void *arg) 43 { 44 if (cpu == DTRACE_CPUALL) { 45 xc_all(dtrace_xcall_func, (uint64_t)func, (uint64_t)arg); 46 } else { 47 xc_one(cpu, dtrace_xcall_func, (uint64_t)func, (uint64_t)arg); 48 } 49 } 50 51 /*ARGSUSED*/ 52 static void 53 dtrace_sync_func(uint64_t arg1, uint64_t arg2) 54 { 55 membar_consumer(); 56 } 57 58 void 59 dtrace_sync(void) 60 { 61 membar_producer(); 62 xc_all(dtrace_sync_func, 0, 0); 63 } 64 65 void 66 dtrace_toxic_ranges(void (*func)(uintptr_t base, uintptr_t limit)) 67 { 68 (*func)(PIOMAPBASE, PIOMAPBASE + PIOMAPSIZE); 69 (*func)(OFW_START_ADDR, OFW_END_ADDR); 70 71 if (hole_end > hole_start) 72 (*func)((uintptr_t)hole_start, (uintptr_t)hole_end); 73 } 74 75 int (*dtrace_pid_probe_ptr)(struct regs *); 76 77 void 78 dtrace_pid_probe(struct regs *rp) 79 { 80 krwlock_t *rwp = &CPU->cpu_ft_lock; 81 uint32_t instr; 82 83 /* 84 * This trap should only be invoked if there's a corresponding 85 * enabled dtrace probe. If there isn't, send SIGILL as though 86 * the process had executed an invalid trap instruction. 87 */ 88 rw_enter(rwp, RW_READER); 89 if (dtrace_pid_probe_ptr != NULL && (*dtrace_pid_probe_ptr)(rp) == 0) { 90 rw_exit(rwp); 91 return; 92 } 93 rw_exit(rwp); 94 95 /* 96 * It is possible that we were preempted after entering the kernel, 97 * and the tracepoint was removed. If it appears that the process hit 98 * our reserved trap instruction, we call send SIGILL just as though 99 * the user had executed an unused trap instruction. 100 */ 101 if (fuword32((void *)rp->r_pc, &instr) != 0 || 102 instr == FASTTRAP_INSTR) { 103 sigqueue_t *sqp = kmem_zalloc(sizeof (sigqueue_t), KM_SLEEP); 104 proc_t *p = curproc; 105 106 sqp->sq_info.si_signo = SIGILL; 107 sqp->sq_info.si_code = ILL_ILLTRP; 108 sqp->sq_info.si_addr = (caddr_t)rp->r_pc; 109 sqp->sq_info.si_trapno = 0x38; 110 111 mutex_enter(&p->p_lock); 112 sigaddqa(p, curthread, sqp); 113 mutex_exit(&p->p_lock); 114 aston(curthread); 115 } 116 } 117 118 int (*dtrace_return_probe_ptr)(struct regs *); 119 120 void 121 dtrace_return_probe(struct regs *rp) 122 { 123 krwlock_t *rwp; 124 uintptr_t npc = curthread->t_dtrace_npc; 125 uint8_t step = curthread->t_dtrace_step; 126 uint8_t ret = curthread->t_dtrace_ret; 127 128 if (curthread->t_dtrace_ast) { 129 aston(curthread); 130 curthread->t_sig_check = 1; 131 } 132 133 /* 134 * Clear all user tracing flags. 135 */ 136 curthread->t_dtrace_ft = 0; 137 138 /* 139 * If we weren't expecting to take a return probe trap, kill the 140 * process as though it had just executed an unassigned trap 141 * instruction. 142 */ 143 if (step == 0) { 144 tsignal(curthread, SIGILL); 145 return; 146 } 147 148 ASSERT(rp->r_npc == rp->r_pc + 4); 149 150 /* 151 * If we hit this trap unrelated to a return probe, we're just here 152 * to reset the AST flag since we deferred a signal until after we 153 * logically single-stepped the instruction we copied out. 154 */ 155 if (ret == 0) { 156 rp->r_pc = npc; 157 rp->r_npc = npc + 4; 158 return; 159 } 160 161 /* 162 * We need to wait until after we've called the dtrace_return_probe_ptr 163 * function pointer to set %pc and %npc. 164 */ 165 rwp = &CPU->cpu_ft_lock; 166 rw_enter(rwp, RW_READER); 167 if (dtrace_return_probe_ptr != NULL) 168 (void) (*dtrace_return_probe_ptr)(rp); 169 rw_exit(rwp); 170 rp->r_pc = npc; 171 rp->r_npc = npc + 4; 172 } 173 174 void 175 dtrace_safe_synchronous_signal(void) 176 { 177 kthread_t *t = curthread; 178 struct regs *rp = lwptoregs(ttolwp(t)); 179 180 ASSERT(t->t_dtrace_on); 181 182 /* 183 * If we're not actively tracing an instruction, turn off tracing 184 * flags. If the instruction we copied out caused a synchronous 185 * trap, reset the pc and npc back to their original values and turn 186 * off the flags. 187 */ 188 if (rp->r_pc != t->t_dtrace_scrpc && rp->r_pc != t->t_dtrace_astpc && 189 rp->r_npc != t->t_dtrace_astpc) { 190 t->t_dtrace_ft = 0; 191 } else if (rp->r_pc == t->t_dtrace_scrpc) { 192 rp->r_pc = t->t_dtrace_pc; 193 rp->r_npc = t->t_dtrace_npc; 194 t->t_dtrace_ft = 0; 195 } 196 } 197 198 int 199 dtrace_safe_defer_signal(void) 200 { 201 kthread_t *t = curthread; 202 struct regs *rp = lwptoregs(ttolwp(t)); 203 204 ASSERT(t->t_dtrace_on); 205 206 /* 207 * If we're not actively tracing an instruction, turn off tracing 208 * flags. 209 */ 210 if (rp->r_pc != t->t_dtrace_scrpc && rp->r_pc != t->t_dtrace_astpc && 211 rp->r_npc != t->t_dtrace_astpc) { 212 t->t_dtrace_ft = 0; 213 return (0); 214 } 215 216 /* 217 * Otherwise, make sure we'll return to the kernel after executing 218 * the instruction we copied out. 219 */ 220 if (!t->t_dtrace_step) { 221 ASSERT(rp->r_pc == t->t_dtrace_scrpc); 222 rp->r_npc = t->t_dtrace_astpc; 223 t->t_dtrace_step = 1; 224 } 225 226 t->t_dtrace_ast = 1; 227 228 return (1); 229 } 230