1 /* $NetBSD: systrace.c,v 1.7 2015/03/10 12:17:50 christos Exp $ */ 2 3 /* 4 * CDDL HEADER START 5 * 6 * The contents of this file are subject to the terms of the 7 * Common Development and Distribution License (the "License"). 8 * You may not use this file except in compliance with the License. 9 * 10 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 11 * or http://www.opensolaris.org/os/licensing. 12 * See the License for the specific language governing permissions 13 * and limitations under the License. 14 * 15 * When distributing Covered Code, include this CDDL HEADER in each 16 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 17 * If applicable, add the following below this CDDL HEADER, with the 18 * fields enclosed by brackets "[]" replaced with your own identifying 19 * information: Portions Copyright [yyyy] [name of copyright owner] 20 * 21 * CDDL HEADER END 22 * 23 * Portions Copyright 2006-2008 John Birrell jb@freebsd.org 24 * 25 * $FreeBSD: src/sys/cddl/dev/systrace/systrace.c,v 1.2.2.1 2009/08/03 08:13:06 kensmith Exp $ 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 #include <sys/systm.h> 37 #include <sys/conf.h> 38 #include <sys/cpuvar.h> 39 #include <sys/fcntl.h> 40 #include <sys/filio.h> 41 #include <sys/kernel.h> 42 #include <sys/kmem.h> 43 #include <sys/kthread.h> 44 #include <sys/limits.h> 45 #include <sys/linker.h> 46 #include <sys/lock.h> 47 #include <sys/malloc.h> 48 #include <sys/module.h> 49 #include <sys/mutex.h> 50 #include <sys/poll.h> 51 #include <sys/proc.h> 52 #include <sys/selinfo.h> 53 #include <sys/syscallargs.h> 54 #include <sys/uio.h> 55 #include <sys/unistd.h> 56 57 #include <sys/dtrace.h> 58 59 #include "emultrace.h" 60 61 #define CONCAT(x,y) __CONCAT(x,y) 62 #define STRING(s) __STRING(s) 63 64 #ifndef NATIVE 65 extern const char * const CONCAT(emulname,_syscallnames)[]; 66 extern struct sysent CONCAT(emulname,_sysent)[]; 67 #define MODNAME CONCAT(dtrace_syscall_,emulname) 68 #define MODDEP "dtrace_syscall,compat_" STRING(emulname) 69 #define MAXSYSCALL CONCAT(EMULNAME,_SYS_MAXSYSCALL) 70 #define SYSCALLNAMES CONCAT(emulname,_syscallnames) 71 #define SYSENT CONCAT(emulname,_sysent) 72 #define PROVNAME STRING(emulname) "_syscall" 73 #else 74 extern const char * const syscallnames[]; 75 #define MODNAME dtrace_syscall 76 #define MODDEP "dtrace" 77 #define MAXSYSCALL SYS_MAXSYSCALL 78 #define SYSCALLNAMES syscallnames 79 #define SYSENT sysent 80 #define PROVNAME "syscall" 81 #endif 82 83 #define MODCMD CONCAT(MODNAME,_modcmd) 84 #define EMUL CONCAT(emul_,emulname) 85 extern struct emul EMUL; 86 87 #define SYSTRACE_ARTIFICIAL_FRAMES 1 88 89 #define SYSTRACE_SHIFT 16 90 #define SYSTRACE_ISENTRY(x) ((int)(x) >> SYSTRACE_SHIFT) 91 #define SYSTRACE_SYSNUM(x) ((int)(x) & ((1 << SYSTRACE_SHIFT) - 1)) 92 #define SYSTRACE_ENTRY(id) ((1 << SYSTRACE_SHIFT) | (id)) 93 #define SYSTRACE_RETURN(id) (id) 94 95 #if ((1 << SYSTRACE_SHIFT) <= MAXSYSCALL) 96 #error 1 << SYSTRACE_SHIFT must exceed number of system calls 97 #endif 98 99 static int systrace_unload(void); 100 static void systrace_getargdesc(void *, dtrace_id_t, void *, dtrace_argdesc_t *); 101 static void systrace_provide(void *, const dtrace_probedesc_t *); 102 static void systrace_destroy(void *, dtrace_id_t, void *); 103 static int systrace_enable(void *, dtrace_id_t, void *); 104 static void systrace_disable(void *, dtrace_id_t, void *); 105 static void systrace_load(void *); 106 107 static dtrace_pattr_t systrace_attr = { 108 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON }, 109 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN }, 110 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA }, 111 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON }, 112 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA }, 113 }; 114 115 static dtrace_pops_t systrace_pops = { 116 systrace_provide, 117 NULL, 118 systrace_enable, 119 systrace_disable, 120 NULL, 121 NULL, 122 systrace_getargdesc, 123 NULL, 124 NULL, 125 systrace_destroy 126 }; 127 128 static dtrace_provider_id_t systrace_id; 129 130 /* 131 * Probe callback function. 132 * 133 * Note: This function is called for _all_ syscalls, regardless of which sysent 134 * array the syscall comes from. It could be a standard syscall or a 135 * compat syscall from something like Linux. 136 */ 137 static void 138 systrace_probe(uint32_t id, register_t sysnum, const struct sysent *se, 139 const void *params, const register_t *ret, int error) 140 { 141 size_t n_args = 0; 142 uintptr_t uargs[SYS_MAXSYSARGS + 3]; 143 144 memset(uargs, 0, sizeof(uargs)); 145 if (ret == NULL) { 146 /* entry syscall, convert params */ 147 systrace_args(sysnum, params, uargs, &n_args); 148 } else { 149 /* return syscall, set values and params: */ 150 uargs[0] = ret[0]; 151 uargs[1] = ret[1]; 152 uargs[2] = error; 153 systrace_args(sysnum, params, uargs + 3, &n_args); 154 } 155 /* Process the probe using the converted argments. */ 156 /* XXX: fix for more arguments! */ 157 dtrace_probe(id, uargs[0], uargs[1], uargs[2], uargs[3], uargs[4]); 158 } 159 160 static void 161 systrace_getargdesc(void *arg, dtrace_id_t id, void *parg, dtrace_argdesc_t *desc) 162 { 163 int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg); 164 if (SYSTRACE_ISENTRY((uintptr_t)parg)) 165 systrace_entry_setargdesc(sysnum, desc->dtargd_ndx, 166 desc->dtargd_native, sizeof(desc->dtargd_native)); 167 else 168 systrace_return_setargdesc(sysnum, desc->dtargd_ndx, 169 desc->dtargd_native, sizeof(desc->dtargd_native)); 170 171 if (desc->dtargd_native[0] == '\0') 172 desc->dtargd_ndx = DTRACE_ARGNONE; 173 } 174 175 static void 176 systrace_provide(void *arg, const dtrace_probedesc_t *desc) 177 { 178 int i; 179 180 if (desc != NULL) 181 return; 182 183 for (i = 0; i < MAXSYSCALL; i++) { 184 if (dtrace_probe_lookup(systrace_id, NULL, 185 SYSCALLNAMES[i], "entry") != 0) 186 continue; 187 188 (void) dtrace_probe_create(systrace_id, NULL, 189 SYSCALLNAMES[i], "entry", SYSTRACE_ARTIFICIAL_FRAMES, 190 (void *)(intptr_t)SYSTRACE_ENTRY(i)); 191 (void) dtrace_probe_create(systrace_id, NULL, 192 SYSCALLNAMES[i], "return", SYSTRACE_ARTIFICIAL_FRAMES, 193 (void *)(intptr_t)SYSTRACE_RETURN(i)); 194 } 195 } 196 197 static void 198 systrace_destroy(void *arg, dtrace_id_t id, void *parg) 199 { 200 #ifdef DEBUG 201 int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg); 202 203 /* 204 * There's nothing to do here but assert that we have actually been 205 * disabled. 206 */ 207 if (SYSTRACE_ISENTRY((uintptr_t)parg)) { 208 ASSERT(sysent[sysnum].sy_entry == 0); 209 } else { 210 ASSERT(sysent[sysnum].sy_return == 0); 211 } 212 #endif 213 } 214 215 static int 216 systrace_enable(void *arg, dtrace_id_t id, void *parg) 217 { 218 int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg); 219 220 if (SYSTRACE_ISENTRY((uintptr_t)parg)) 221 SYSENT[sysnum].sy_entry = id; 222 else 223 SYSENT[sysnum].sy_return = id; 224 return 0; 225 } 226 227 static void 228 systrace_disable(void *arg, dtrace_id_t id, void *parg) 229 { 230 int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg); 231 232 SYSENT[sysnum].sy_entry = 0; 233 SYSENT[sysnum].sy_return = 0; 234 } 235 236 static void 237 systrace_load(void *dummy) 238 { 239 if (dtrace_register(PROVNAME, &systrace_attr, DTRACE_PRIV_USER, 240 NULL, &systrace_pops, NULL, &systrace_id) != 0) 241 return; 242 243 EMUL.e_dtrace_syscall = systrace_probe; 244 } 245 246 247 static int 248 systrace_unload() 249 { 250 int error; 251 252 if ((error = dtrace_unregister(systrace_id)) != 0) 253 return (error); 254 255 EMUL.e_dtrace_syscall = NULL; 256 257 return error; 258 } 259 260 static int 261 MODCMD(modcmd_t cmd, void *data) 262 { 263 switch (cmd) { 264 case MODULE_CMD_INIT: 265 systrace_load(NULL); 266 return 0; 267 268 case MODULE_CMD_FINI: 269 return systrace_unload(); 270 271 case MODULE_CMD_AUTOUNLOAD: 272 return EBUSY; 273 274 default: 275 return ENOTTY; 276 } 277 } 278 279 MODULE(MODULE_CLASS_MISC, MODNAME, MODDEP) 280