amd64-freebsd32.c revision 179051
1/* 2 * Copryight 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: head/usr.bin/truss/amd64-fbsd32.c 179051 2008-05-16 15:34:06Z jhb $"; 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/syscall.h> 47#include <sys/ptrace.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 65static int cpid = -1; 66 67#include "freebsd32_syscalls.h" 68 69static int nsyscalls = sizeof(freebsd32_syscallnames) / 70 sizeof(freebsd32_syscallnames[0]); 71 72/* 73 * This is what this particular file uses to keep track of a system call. 74 * It is probably not quite sufficient -- I can probably use the same 75 * structure for the various syscall personalities, and I also probably 76 * need to nest system calls (for signal handlers). 77 * 78 * 'struct syscall' describes the system call; it may be NULL, however, 79 * if we don't know about this particular system call yet. 80 */ 81static struct freebsd32_syscall { 82 struct syscall *sc; 83 const char *name; 84 int number; 85 unsigned long *args; 86 unsigned int *args32; 87 int nargs; /* number of arguments -- *not* number of words! */ 88 char **s_args; /* the printable arguments */ 89} fsc; 90 91/* Clear up and free parts of the fsc structure. */ 92static __inline void 93clear_fsc(void) { 94 if (fsc.args) { 95 free(fsc.args); 96 } 97 if (fsc.args32) { 98 free(fsc.args32); 99 } 100 if (fsc.s_args) { 101 int i; 102 for (i = 0; i < fsc.nargs; i++) 103 if (fsc.s_args[i]) 104 free(fsc.s_args[i]); 105 free(fsc.s_args); 106 } 107 memset(&fsc, 0, sizeof(fsc)); 108} 109 110/* 111 * Called when a process has entered a system call. nargs is the 112 * number of words, not number of arguments (a necessary distinction 113 * in some cases). Note that if the STOPEVENT() code in i386/i386/trap.c 114 * is ever changed these functions need to keep up. 115 */ 116 117void 118amd64_fbsd32_syscall_entry(struct trussinfo *trussinfo, int nargs) { 119 struct reg regs; 120 int syscall_num; 121 int i; 122 unsigned long parm_offset; 123 struct syscall *sc = NULL; 124 struct ptrace_io_desc iorequest; 125 cpid = trussinfo->curthread->tid; 126 127 clear_fsc(); 128 129 if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0) 130 { 131 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 132 return; 133 } 134 parm_offset = regs.r_rsp + sizeof(int); 135 136 /* 137 * FreeBSD has two special kinds of system call redirctions -- 138 * SYS_syscall, and SYS___syscall. The former is the old syscall() 139 * routine, basicly; the latter is for quad-aligned arguments. 140 */ 141 syscall_num = regs.r_rax; 142 switch (syscall_num) { 143 case SYS_syscall: 144 syscall_num = ptrace(PT_READ_D, cpid, (caddr_t)parm_offset, 0); 145 parm_offset += sizeof(int); 146 break; 147 case SYS___syscall: 148 syscall_num = ptrace(PT_READ_D, cpid, (caddr_t)parm_offset, 0); 149 parm_offset += sizeof(quad_t); 150 break; 151 } 152 153 fsc.number = syscall_num; 154 fsc.name = 155 (syscall_num < 0 || syscall_num > nsyscalls) ? NULL : 156 freebsd32_syscallnames[syscall_num]; 157 if (!fsc.name) { 158 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", syscall_num); 159 } 160 161 if (fsc.name && (trussinfo->flags & FOLLOWFORKS) 162 && ((!strcmp(fsc.name, "fork") 163 || !strcmp(fsc.name, "rfork") 164 || !strcmp(fsc.name, "vfork")))) 165 { 166 trussinfo->curthread->in_fork = 1; 167 } 168 169 if (nargs == 0) 170 return; 171 172 fsc.args32 = malloc((1+nargs) * sizeof(unsigned int)); 173 iorequest.piod_op = PIOD_READ_D; 174 iorequest.piod_offs = (void *)parm_offset; 175 iorequest.piod_addr = fsc.args32; 176 iorequest.piod_len = (1+nargs) * sizeof(unsigned int); 177 ptrace(PT_IO, cpid, (caddr_t)&iorequest, 0); 178 if (iorequest.piod_len == 0) 179 return; 180 181 fsc.args = malloc((1+nargs) * sizeof(unsigned long)); 182 for (i = 0; i < nargs + 1; i++) 183 fsc.args[i] = fsc.args32[i]; 184 185 if (fsc.name) 186 sc = get_syscall(fsc.name); 187 if (sc) { 188 fsc.nargs = sc->nargs; 189 } else { 190#if DEBUG 191 fprintf(trussinfo->outfile, "unknown syscall %s -- setting args to %d\n", 192 fsc.name, nargs); 193#endif 194 fsc.nargs = nargs; 195 } 196 197 fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*)); 198 memset(fsc.s_args, 0, fsc.nargs * sizeof(char*)); 199 fsc.sc = sc; 200 201 /* 202 * At this point, we set up the system call arguments. 203 * We ignore any OUT ones, however -- those are arguments that 204 * are set by the system call, and so are probably meaningless 205 * now. This doesn't currently support arguments that are 206 * passed in *and* out, however. 207 */ 208 209 if (fsc.name) { 210 211#if DEBUG 212 fprintf(stderr, "syscall %s(", fsc.name); 213#endif 214 for (i = 0; i < fsc.nargs; i++) { 215#if DEBUG 216 fprintf(stderr, "0x%x%s", 217 sc 218 ? fsc.args[sc->args[i].offset] 219 : 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], fsc.args, 0, trussinfo); 224 } 225 } 226#if DEBUG 227 fprintf(stderr, ")\n"); 228#endif 229 } 230 231#if DEBUG 232 fprintf(trussinfo->outfile, "\n"); 233#endif 234 235 if (fsc.name != NULL && 236 (!strcmp(fsc.name, "freebsd32_execve") || !strcmp(fsc.name, "exit"))) { 237 238 /* XXX 239 * This could be done in a more general 240 * manner but it still wouldn't be very pretty. 241 */ 242 if (!strcmp(fsc.name, "freebsd32_execve")) { 243 if ((trussinfo->flags & EXECVEARGS) == 0) 244 if (fsc.s_args[1]) { 245 free(fsc.s_args[1]); 246 fsc.s_args[1] = NULL; 247 } 248 if ((trussinfo->flags & EXECVEENVS) == 0) 249 if (fsc.s_args[2]) { 250 free(fsc.s_args[2]); 251 fsc.s_args[2] = NULL; 252 } 253 } 254 255 } 256 257 return; 258} 259 260/* 261 * And when the system call is done, we handle it here. 262 * Currently, no attempt is made to ensure that the system calls 263 * match -- this needs to be fixed (and is, in fact, why S_SCX includes 264 * the sytem call number instead of, say, an error status). 265 */ 266 267long 268amd64_fbsd32_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused) 269{ 270 struct reg regs; 271 long retval; 272 int i; 273 int errorp; 274 struct syscall *sc; 275 276 if (fsc.name == NULL) 277 return (-1); 278 cpid = trussinfo->curthread->tid; 279 280 if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0) 281 { 282 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 283 return (-1); 284 } 285 286 retval = regs.r_rax; 287 errorp = !!(regs.r_rflags & PSL_C); 288 289 /* 290 * This code, while simpler than the initial versions I used, could 291 * stand some significant cleaning. 292 */ 293 294 sc = fsc.sc; 295 if (!sc) { 296 for (i = 0; i < fsc.nargs; i++) 297 asprintf(&fsc.s_args[i], "0x%lx", fsc.args[i]); 298 } else { 299 /* 300 * Here, we only look for arguments that have OUT masked in -- 301 * otherwise, they were handled in the syscall_entry function. 302 */ 303 for (i = 0; i < sc->nargs; i++) { 304 char *temp; 305 if (sc->args[i].type & OUT) { 306 /* 307 * If an error occurred, then don't bother getting the data; 308 * it may not be valid. 309 */ 310 if (errorp) 311 asprintf(&temp, "0x%lx", fsc.args[sc->args[i].offset]); 312 else 313 temp = print_arg(&sc->args[i], fsc.args, retval, trussinfo); 314 fsc.s_args[i] = temp; 315 } 316 } 317 } 318 319 /* 320 * The pipe syscall returns its fds in two registers and has assembly glue 321 * to provide the libc API, so it cannot be handled like regular syscalls. 322 * The nargs check is so we don't have to do yet another strcmp on every 323 * syscall. 324 */ 325 if (!errorp && fsc.nargs == 0 && fsc.name && strcmp(fsc.name, "pipe") == 0) { 326 fsc.nargs = 1; 327 fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*)); 328 asprintf(&fsc.s_args[0], "[%d,%d]", (int)retval, (int)regs.r_rdx); 329 retval = 0; 330 } 331 332 if (fsc.name != NULL && 333 (!strcmp(fsc.name, "freebsd32_execve") || !strcmp(fsc.name, "exit"))) { 334 trussinfo->curthread->in_syscall = 1; 335 } 336 337 /* 338 * It would probably be a good idea to merge the error handling, 339 * but that complicates things considerably. 340 */ 341 342 print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp, retval); 343 clear_fsc(); 344 345 return (retval); 346} 347