1 /* $NetBSD: kern_scdebug.c,v 1.2 2019/03/14 19:51:49 palle Exp $ */ 2 3 /* 4 * Copyright (c) 2015 Matthew R. Green 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 /* 30 * Copyright (c) 1982, 1986, 1989, 1993 31 * The Regents of the University of California. All rights reserved. 32 * 33 * Redistribution and use in source and binary forms, with or without 34 * modification, are permitted provided that the following conditions 35 * are met: 36 * 1. Redistributions of source code must retain the above copyright 37 * notice, this list of conditions and the following disclaimer. 38 * 2. Redistributions in binary form must reproduce the above copyright 39 * notice, this list of conditions and the following disclaimer in the 40 * documentation and/or other materials provided with the distribution. 41 * 3. Neither the name of the University nor the names of its contributors 42 * may be used to endorse or promote products derived from this software 43 * without specific prior written permission. 44 * 45 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 48 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 55 * SUCH DAMAGE. 56 * 57 * @(#)kern_xxx.c 8.3 (Berkeley) 2/14/95 58 * from: NetBSD: kern_xxx.c,v 1.74 2017/10/28 00:37:11 pgoyette Exp 59 */ 60 61 #include <sys/cdefs.h> 62 __KERNEL_RCSID(0, "$NetBSD: kern_scdebug.c,v 1.2 2019/03/14 19:51:49 palle Exp $"); 63 64 #ifdef _KERNEL_OPT 65 #include "opt_syscall_debug.h" 66 #include "opt_kernhist.h" 67 #endif 68 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/kernel.h> 72 #include <sys/proc.h> 73 #include <sys/sysctl.h> 74 #include <sys/mount.h> 75 #include <sys/syscall.h> 76 #include <sys/syscallargs.h> 77 #include <sys/kernhist.h> 78 79 /* 80 * Pull in the indirect syscall functions here. 81 * They are only actually used if the ports syscall entry code 82 * doesn't special-case SYS_SYSCALL and SYS___SYSCALL 83 * 84 * In some cases the generated code for the two functions is identical, 85 * but there isn't a MI way of determining that - so we don't try. 86 */ 87 88 #define SYS_SYSCALL sys_syscall 89 #include "sys_syscall.c" 90 #undef SYS_SYSCALL 91 92 #define SYS_SYSCALL sys___syscall 93 #include "sys_syscall.c" 94 #undef SYS_SYSCALL 95 96 #ifdef SYSCALL_DEBUG 97 #define SCDEBUG_CALLS 0x0001 /* show calls */ 98 #define SCDEBUG_RETURNS 0x0002 /* show returns */ 99 #define SCDEBUG_ALL 0x0004 /* even syscalls that are not implemented */ 100 #define SCDEBUG_SHOWARGS 0x0008 /* show arguments to calls */ 101 #define SCDEBUG_KERNHIST 0x0010 /* use kernhist instead of printf */ 102 103 #ifndef SCDEBUG_DEFAULT 104 #define SCDEBUG_DEFAULT (SCDEBUG_CALLS|SCDEBUG_RETURNS|SCDEBUG_SHOWARGS) 105 #endif 106 107 int scdebug = SCDEBUG_DEFAULT; 108 109 #ifdef KERNHIST 110 KERNHIST_DEFINE(scdebughist); 111 #define SCDEBUG_KERNHIST_FUNC(a) KERNHIST_FUNC(a) 112 #define SCDEBUG_KERNHIST_CALLED(a) KERNHIST_CALLED(a) 113 #define SCDEBUG_KERNHIST_LOG(a,b,c,d,e,f) KERNHIST_LOG(a,b,c,d,e,f) 114 #else 115 #define SCDEBUG_KERNHIST_FUNC(a) {} /* nothing */ 116 #define SCDEBUG_KERNHIST_CALLED(a) {} /* nothing */ 117 #define SCDEBUG_KERNHIST_LOG(a,b,c,d,e,f) {} /* nothing */ 118 /* The non-kernhist support version can elide all this code easily. */ 119 #undef SCDEBUG_KERNHIST 120 #define SCDEBUG_KERNHIST 0 121 #endif 122 123 #ifdef __HAVE_MINIMAL_EMUL 124 #define CODE_NOT_OK(code, em) ((int)(code) < 0) 125 #else 126 #define CODE_NOT_OK(code, em) (((int)(code) < 0) || \ 127 ((int)(code) >= (em)->e_nsysent)) 128 #endif 129 130 void 131 scdebug_call(register_t code, const register_t args[]) 132 { 133 SCDEBUG_KERNHIST_FUNC("scdebug_call"); 134 struct lwp *l = curlwp; 135 struct proc *p = l->l_proc; 136 const struct sysent *sy; 137 const struct emul *em; 138 int i; 139 140 if ((scdebug & SCDEBUG_CALLS) == 0) 141 return; 142 143 if (scdebug & SCDEBUG_KERNHIST) 144 SCDEBUG_KERNHIST_CALLED(scdebughist); 145 146 em = p->p_emul; 147 sy = &em->e_sysent[code]; 148 149 if ((scdebug & SCDEBUG_ALL) == 0 && 150 (CODE_NOT_OK(code, em) || sy->sy_call == sys_nosys)) { 151 if (scdebug & SCDEBUG_KERNHIST) 152 SCDEBUG_KERNHIST_LOG(scdebughist, "", 0, 0, 0, 0); 153 return; 154 } 155 156 /* 157 * The kernhist version of scdebug needs to restrict the usage 158 * compared to the normal version. histories must avoid these 159 * sorts of usage: 160 * 161 * - the format string *must* be literal, as it is used 162 * at display time in the kernel or userland 163 * - strings in the format will cause vmstat -u to crash 164 * so avoid using %s formats 165 * 166 * to avoid these, we have a fairly long block to print args 167 * as the format needs to change for each, and we can't just 168 * call printf() on each argument until we're done. 169 */ 170 if (scdebug & SCDEBUG_KERNHIST) { 171 if (CODE_NOT_OK(code, em)) { 172 SCDEBUG_KERNHIST_LOG(scdebughist, 173 "pid %jd:%jd: OUT OF RANGE (%jd)", 174 p->p_pid, l->l_lid, code, 0); 175 } else { 176 SCDEBUG_KERNHIST_LOG(scdebughist, 177 "pid %jd:%jd: num %jd call %#jx", 178 p->p_pid, l->l_lid, code, (uintptr_t)sy->sy_call); 179 if ((scdebug & SCDEBUG_SHOWARGS) == 0) 180 return; 181 182 if (sy->sy_narg > 7) { 183 SCDEBUG_KERNHIST_LOG(scdebughist, 184 "args[4-7]: (%jx, %jx, %jx, %jx, ...)", 185 (long)args[4], (long)args[5], 186 (long)args[6], (long)args[7]); 187 } else if (sy->sy_narg > 6) { 188 SCDEBUG_KERNHIST_LOG(scdebughist, 189 "args[4-6]: (%jx, %jx, %jx)", 190 (long)args[4], (long)args[5], 191 (long)args[6], 0); 192 } else if (sy->sy_narg > 5) { 193 SCDEBUG_KERNHIST_LOG(scdebughist, 194 "args[4-5]: (%jx, %jx)", 195 (long)args[4], (long)args[5], 0, 0); 196 } else if (sy->sy_narg == 5) { 197 SCDEBUG_KERNHIST_LOG(scdebughist, 198 "args[4]: (%jx)", 199 (long)args[4], 0, 0, 0); 200 } 201 202 if (sy->sy_narg > 3) { 203 SCDEBUG_KERNHIST_LOG(scdebughist, 204 "args[0-3]: (%jx, %jx, %jx, %jx, ...)", 205 (long)args[0], (long)args[1], 206 (long)args[2], (long)args[3]); 207 } else if (sy->sy_narg > 2) { 208 SCDEBUG_KERNHIST_LOG(scdebughist, 209 "args[0-2]: (%jx, %jx, %jx)", 210 (long)args[0], (long)args[1], 211 (long)args[2], 0); 212 } else if (sy->sy_narg > 1) { 213 SCDEBUG_KERNHIST_LOG(scdebughist, 214 "args[0-1]: (%jx, %jx)", 215 (long)args[0], (long)args[1], 0, 0); 216 } else if (sy->sy_narg == 1) { 217 SCDEBUG_KERNHIST_LOG(scdebughist, 218 "args[0]: (%jx)", 219 (long)args[0], 0, 0, 0); 220 } 221 } 222 return; 223 } 224 225 printf("proc %d (%s): %s num ", p->p_pid, p->p_comm, em->e_name); 226 if (CODE_NOT_OK(code, em)) 227 printf("OUT OF RANGE (%ld)", (long)code); 228 else { 229 printf("%ld call: %s", (long)code, em->e_syscallnames[code]); 230 if (scdebug & SCDEBUG_SHOWARGS) { 231 printf("("); 232 for (i = 0; i < sy->sy_argsize/sizeof(register_t); i++) 233 printf("%s0x%lx", i == 0 ? "" : ", ", 234 (long)args[i]); 235 printf(")"); 236 } 237 } 238 printf("\n"); 239 } 240 241 void 242 scdebug_ret(register_t code, int error, const register_t retval[]) 243 { 244 SCDEBUG_KERNHIST_FUNC("scdebug_ret"); 245 struct lwp *l = curlwp; 246 struct proc *p = l->l_proc; 247 const struct sysent *sy; 248 const struct emul *em; 249 250 if ((scdebug & SCDEBUG_RETURNS) == 0) 251 return; 252 253 if (scdebug & SCDEBUG_KERNHIST) 254 SCDEBUG_KERNHIST_CALLED(scdebughist); 255 256 em = p->p_emul; 257 sy = &em->e_sysent[code]; 258 if ((scdebug & SCDEBUG_ALL) == 0 && 259 (CODE_NOT_OK(code, em) || sy->sy_call == sys_nosys)) { 260 if (scdebug & SCDEBUG_KERNHIST) 261 SCDEBUG_KERNHIST_LOG(scdebughist, "", 0, 0, 0, 0); 262 return; 263 } 264 265 if (scdebug & SCDEBUG_KERNHIST) { 266 if (CODE_NOT_OK(code, em)) { 267 SCDEBUG_KERNHIST_LOG(scdebughist, 268 "pid %jd:%jd: OUT OF RANGE (%jd)", 269 p->p_pid, l->l_lid, code, 0); 270 } else { 271 SCDEBUG_KERNHIST_LOG(scdebughist, 272 "pid %jd:%jd: num %jd", 273 p->p_pid, l->l_lid, code, 0); 274 SCDEBUG_KERNHIST_LOG(scdebughist, 275 "ret: err = %jd, rv = 0x%jx,0x%jx", 276 error, (long)retval[0], (long)retval[1], 0); 277 } 278 return; 279 } 280 281 printf("proc %d (%s): %s num ", p->p_pid, p->p_comm, em->e_name); 282 if (CODE_NOT_OK(code, em)) 283 printf("OUT OF RANGE (%ld)", (long)code); 284 else 285 printf("%ld ret %s: err = %d, rv = 0x%lx,0x%lx", (long)code, 286 em->e_syscallnames[code], error, 287 (long)retval[0], (long)retval[1]); 288 printf("\n"); 289 } 290 #endif /* SYSCALL_DEBUG */ 291 292 #ifndef SCDEBUG_KERNHIST_SIZE 293 #define SCDEBUG_KERNHIST_SIZE 500 294 #endif 295 296 void 297 scdebug_init(void) 298 { 299 #if defined(SYSCALL_DEBUG) && defined(KERNHIST) 300 /* Setup scdebughist kernel history */ 301 KERNHIST_INIT(scdebughist, SCDEBUG_KERNHIST_SIZE); 302 #endif 303 } 304