1/* 2 * Copyright 1997 Sean Eric Fagan 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. All advertising materials mentioning features or use of this software 13 * must display the following acknowledgement: 14 * This product includes software developed by Sean Eric Fagan 15 * 4. Neither the name of the author may be used to endorse or promote 16 * products derived from this software without specific prior written 17 * permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32#ifndef lint 33static const char rcsid[] = 34 "$FreeBSD$"; 35#endif /* not lint */ 36 37/* 38 * FreeBSD/i386-specific system call handling. This is probably the most 39 * complex part of the entire truss program, although I've got lots of 40 * it handled relatively cleanly now. The system call names are generated 41 * automatically, thanks to /usr/src/sys/kern/syscalls.master. The 42 * names used for the various structures are confusing, I sadly admit. 43 */ 44 45#include <sys/types.h> 46#include <sys/ptrace.h> 47#include <sys/syscall.h> 48 49#include <machine/reg.h> 50#include <machine/psl.h> 51 52#include <errno.h> 53#include <fcntl.h> 54#include <signal.h> 55#include <stdio.h> 56#include <stdlib.h> 57#include <string.h> 58#include <time.h> 59#include <unistd.h> 60 61#include "truss.h" 62#include "syscall.h" 63#include "extern.h" 64 65#include "freebsd32_syscalls.h" 66 67static int nsyscalls = sizeof(freebsd32_syscallnames) / 68 sizeof(freebsd32_syscallnames[0]); 69 70/* 71 * This is what this particular file uses to keep track of a system call. 72 * It is probably not quite sufficient -- I can probably use the same 73 * structure for the various syscall personalities, and I also probably 74 * need to nest system calls (for signal handlers). 75 * 76 * 'struct syscall' describes the system call; it may be NULL, however, 77 * if we don't know about this particular system call yet. 78 */ 79struct freebsd32_syscall { 80 struct syscall *sc; 81 const char *name; 82 int number; 83 unsigned long *args; 84 unsigned int *args32; 85 int nargs; /* number of arguments -- *not* number of words! */ 86 char **s_args; /* the printable arguments */ 87}; 88 89static struct freebsd32_syscall * 90alloc_fsc(void) 91{ 92 93 return (malloc(sizeof(struct freebsd32_syscall))); 94} 95 96/* Clear up and free parts of the fsc structure. */ 97static void 98free_fsc(struct freebsd32_syscall *fsc) 99{ 100 int i; 101 102 free(fsc->args); 103 free(fsc->args32); 104 if (fsc->s_args) { 105 for (i = 0; i < fsc->nargs; i++) 106 free(fsc->s_args[i]); 107 free(fsc->s_args); 108 } 109 free(fsc); 110} 111 112/* 113 * Called when a process has entered a system call. nargs is the 114 * number of words, not number of arguments (a necessary distinction 115 * in some cases). Note that if the STOPEVENT() code in i386/i386/trap.c 116 * is ever changed these functions need to keep up. 117 */ 118 119void 120amd64_fbsd32_syscall_entry(struct trussinfo *trussinfo, int nargs) 121{ 122 struct ptrace_io_desc iorequest; 123 struct reg regs; 124 struct freebsd32_syscall *fsc; 125 struct syscall *sc; 126 lwpid_t tid; 127 unsigned long parm_offset; 128 int i, syscall_num; 129 130 tid = trussinfo->curthread->tid; 131 132 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) { 133 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 134 return; 135 } 136 parm_offset = regs.r_rsp + sizeof(int); 137 138 /* 139 * FreeBSD has two special kinds of system call redirctions -- 140 * SYS_syscall, and SYS___syscall. The former is the old syscall() 141 * routine, basically; the latter is for quad-aligned arguments. 142 */ 143 syscall_num = regs.r_rax; 144 switch (syscall_num) { 145 case SYS_syscall: 146 syscall_num = ptrace(PT_READ_D, tid, (caddr_t)parm_offset, 0); 147 parm_offset += sizeof(int); 148 break; 149 case SYS___syscall: 150 syscall_num = ptrace(PT_READ_D, tid, (caddr_t)parm_offset, 0); 151 parm_offset += sizeof(quad_t); 152 break; 153 } 154 155 fsc = alloc_fsc(); 156 if (fsc == NULL) 157 return; 158 fsc->number = syscall_num; 159 fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ? 160 NULL : freebsd32_syscallnames[syscall_num]; 161 if (!fsc->name) { 162 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", 163 syscall_num); 164 } 165 166 if (fsc->name && (trussinfo->flags & FOLLOWFORKS) && 167 (strcmp(fsc->name, "fork") == 0 || 168 strcmp(fsc->name, "rfork") == 0 || 169 strcmp(fsc->name, "vfork") == 0)) 170 trussinfo->curthread->in_fork = 1; 171 172 if (nargs == 0) 173 return; 174 175 fsc->args32 = malloc((1 + nargs) * sizeof(unsigned int)); 176 iorequest.piod_op = PIOD_READ_D; 177 iorequest.piod_offs = (void *)parm_offset; 178 iorequest.piod_addr = fsc->args32; 179 iorequest.piod_len = (1 + nargs) * sizeof(unsigned int); 180 ptrace(PT_IO, tid, (caddr_t)&iorequest, 0); 181 if (iorequest.piod_len == 0) 182 return; 183 184 fsc->args = malloc((1 + nargs) * sizeof(unsigned long)); 185 for (i = 0; i < nargs + 1; i++) 186 fsc->args[i] = fsc->args32[i]; 187 188 sc = NULL; 189 if (fsc->name) 190 sc = get_syscall(fsc->name); 191 if (sc) 192 fsc->nargs = sc->nargs; 193 else { 194#if DEBUG 195 fprintf(trussinfo->outfile, "unknown syscall %s -- setting " 196 "args to %d\n", fsc->name, nargs); 197#endif 198 fsc->nargs = nargs; 199 } 200 201 fsc->s_args = calloc(1, (1 + fsc->nargs) * sizeof(char *)); 202 fsc->sc = sc; 203 204 /* 205 * At this point, we set up the system call arguments. 206 * We ignore any OUT ones, however -- those are arguments that 207 * are set by the system call, and so are probably meaningless 208 * now. This doesn't currently support arguments that are 209 * passed in *and* out, however. 210 */ 211 212 if (fsc->name) { 213#if DEBUG 214 fprintf(stderr, "syscall %s(", fsc->name); 215#endif 216 for (i = 0; i < fsc->nargs; i++) { 217#if DEBUG 218 fprintf(stderr, "0x%x%s", sc ? 219 fsc->args[sc->args[i].offset] : fsc->args[i], 220 i < (fsc->nargs - 1) ? "," : ""); 221#endif 222 if (sc && !(sc->args[i].type & OUT)) { 223 fsc->s_args[i] = print_arg(&sc->args[i], 224 fsc->args, 0, trussinfo); 225 } 226 } 227#if DEBUG 228 fprintf(stderr, ")\n"); 229#endif 230 } 231 232#if DEBUG 233 fprintf(trussinfo->outfile, "\n"); 234#endif 235 236 if (fsc->name != NULL && (strcmp(fsc->name, "freebsd32_execve") == 0 || 237 strcmp(fsc->name, "exit") == 0)) { 238 /* 239 * XXX 240 * This could be done in a more general 241 * manner but it still wouldn't be very pretty. 242 */ 243 if (strcmp(fsc->name, "freebsd32_execve") == 0) { 244 if ((trussinfo->flags & EXECVEARGS) == 0) { 245 if (fsc->s_args[1]) { 246 free(fsc->s_args[1]); 247 fsc->s_args[1] = NULL; 248 } 249 } 250 if ((trussinfo->flags & EXECVEENVS) == 0) { 251 if (fsc->s_args[2]) { 252 free(fsc->s_args[2]); 253 fsc->s_args[2] = NULL; 254 } 255 } 256 } 257 } 258 trussinfo->curthread->fsc = fsc; 259} 260 261/* 262 * And when the system call is done, we handle it here. 263 * Currently, no attempt is made to ensure that the system calls 264 * match -- this needs to be fixed (and is, in fact, why S_SCX includes 265 * the system call number instead of, say, an error status). 266 */ 267 268long 269amd64_fbsd32_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused) 270{ 271 struct reg regs; 272 struct freebsd32_syscall *fsc; 273 struct syscall *sc; 274 lwpid_t tid; 275 long retval; 276 int errorp, i; 277 278 if (trussinfo->curthread->fsc == NULL) 279 return (-1); 280 281 tid = trussinfo->curthread->tid; 282 283 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) { 284 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 285 return (-1); 286 } 287 288 retval = regs.r_rax; 289 errorp = !!(regs.r_rflags & PSL_C); 290 291 /* 292 * This code, while simpler than the initial versions I used, could 293 * stand some significant cleaning. 294 */ 295 296 fsc = trussinfo->curthread->fsc; 297 sc = fsc->sc; 298 if (!sc) { 299 for (i = 0; i < fsc->nargs; i++) 300 asprintf(&fsc->s_args[i], "0x%lx", fsc->args[i]); 301 } else { 302 /* 303 * Here, we only look for arguments that have OUT masked in -- 304 * otherwise, they were handled in the syscall_entry function. 305 */ 306 for (i = 0; i < sc->nargs; i++) { 307 char *temp; 308 if (sc->args[i].type & OUT) { 309 /* 310 * If an error occurred, then don't bother 311 * getting the data; it may not be valid. 312 */ 313 if (errorp) { 314 asprintf(&temp, "0x%lx", 315 fsc->args[sc->args[i].offset]); 316 } else { 317 temp = print_arg(&sc->args[i], 318 fsc->args, retval, trussinfo); 319 } 320 fsc->s_args[i] = temp; 321 } 322 } 323 } 324 325 if (fsc->name != NULL && (strcmp(fsc->name, "freebsd32_execve") == 0 || 326 strcmp(fsc->name, "exit") == 0)) 327 trussinfo->curthread->in_syscall = 1; 328 329 /* 330 * It would probably be a good idea to merge the error handling, 331 * but that complicates things considerably. 332 */ 333 334 print_syscall_ret(trussinfo, fsc->name, fsc->nargs, fsc->s_args, errorp, 335 retval, fsc->sc); 336 free_fsc(fsc); 337 338 return (retval); 339} 340