amd64-freebsd32.c revision 240005
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: head/usr.bin/truss/amd64-fbsd32.c 240005 2012-09-02 11:03:18Z zont $"; 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 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{ 95 int i; 96 97 if (fsc.args) 98 free(fsc.args); 99 if (fsc.args32) 100 free(fsc.args32); 101 if (fsc.s_args) { 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{ 120 struct ptrace_io_desc iorequest; 121 struct reg regs; 122 struct syscall *sc; 123 unsigned long parm_offset; 124 int i, syscall_num; 125 126 clear_fsc(); 127 128 cpid = trussinfo->curthread->tid; 129 130 if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0) { 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, basically; 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 = (syscall_num < 0 || syscall_num >= nsyscalls) ? 155 NULL : freebsd32_syscallnames[syscall_num]; 156 if (!fsc.name) { 157 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", 158 syscall_num); 159 } 160 161 if (fsc.name && (trussinfo->flags & FOLLOWFORKS) && 162 (strcmp(fsc.name, "fork") == 0 || 163 strcmp(fsc.name, "rfork") == 0|| 164 strcmp(fsc.name, "vfork") == 0)) 165 trussinfo->curthread->in_fork = 1; 166 167 if (nargs == 0) 168 return; 169 170 fsc.args32 = malloc((1 + nargs) * sizeof(unsigned int)); 171 iorequest.piod_op = PIOD_READ_D; 172 iorequest.piod_offs = (void *)parm_offset; 173 iorequest.piod_addr = fsc.args32; 174 iorequest.piod_len = (1 + nargs) * sizeof(unsigned int); 175 ptrace(PT_IO, cpid, (caddr_t)&iorequest, 0); 176 if (iorequest.piod_len == 0) 177 return; 178 179 fsc.args = malloc((1 + nargs) * sizeof(unsigned long)); 180 for (i = 0; i < nargs + 1; i++) 181 fsc.args[i] = fsc.args32[i]; 182 183 sc = NULL; 184 if (fsc.name) 185 sc = get_syscall(fsc.name); 186 if (sc) 187 fsc.nargs = sc->nargs; 188 else { 189#if DEBUG 190 fprintf(trussinfo->outfile, "unknown syscall %s -- setting " 191 "args to %d\n", fsc.name, nargs); 192#endif 193 fsc.nargs = nargs; 194 } 195 196 fsc.s_args = calloc(1, (1 + fsc.nargs) * sizeof(char *)); 197 fsc.sc = sc; 198 199 /* 200 * At this point, we set up the system call arguments. 201 * We ignore any OUT ones, however -- those are arguments that 202 * are set by the system call, and so are probably meaningless 203 * now. This doesn't currently support arguments that are 204 * passed in *and* out, however. 205 */ 206 207 if (fsc.name) { 208#if DEBUG 209 fprintf(stderr, "syscall %s(", fsc.name); 210#endif 211 for (i = 0; i < fsc.nargs; i++) { 212#if DEBUG 213 fprintf(stderr, "0x%x%s", sc ? 214 fsc.args[sc->args[i].offset] : fsc.args[i], 215 i < (fsc.nargs - 1) ? "," : ""); 216#endif 217 if (sc && !(sc->args[i].type & OUT)) { 218 fsc.s_args[i] = print_arg(&sc->args[i], 219 fsc.args, 0, trussinfo); 220 } 221 } 222#if DEBUG 223 fprintf(stderr, ")\n"); 224#endif 225 } 226 227#if DEBUG 228 fprintf(trussinfo->outfile, "\n"); 229#endif 230 231 if (fsc.name != NULL && (strcmp(fsc.name, "freebsd32_execve") == 0|| 232 strcmp(fsc.name, "exit") == 0)) { 233 /* 234 * XXX 235 * This could be done in a more general 236 * manner but it still wouldn't be very pretty. 237 */ 238 if (strcmp(fsc.name, "freebsd32_execve") == 0) { 239 if ((trussinfo->flags & EXECVEARGS) == 0) { 240 if (fsc.s_args[1]) { 241 free(fsc.s_args[1]); 242 fsc.s_args[1] = NULL; 243 } 244 } 245 if ((trussinfo->flags & EXECVEENVS) == 0) { 246 if (fsc.s_args[2]) { 247 free(fsc.s_args[2]); 248 fsc.s_args[2] = NULL; 249 } 250 } 251 } 252 } 253 254 return; 255} 256 257/* 258 * And when the system call is done, we handle it here. 259 * Currently, no attempt is made to ensure that the system calls 260 * match -- this needs to be fixed (and is, in fact, why S_SCX includes 261 * the system call number instead of, say, an error status). 262 */ 263 264long 265amd64_fbsd32_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused) 266{ 267 struct reg regs; 268 struct syscall *sc; 269 long retval; 270 int errorp, i; 271 272 if (fsc.name == NULL) 273 return (-1); 274 275 cpid = trussinfo->curthread->tid; 276 277 if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0) { 278 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 279 return (-1); 280 } 281 282 retval = regs.r_rax; 283 errorp = !!(regs.r_rflags & PSL_C); 284 285 /* 286 * This code, while simpler than the initial versions I used, could 287 * stand some significant cleaning. 288 */ 289 290 sc = fsc.sc; 291 if (!sc) { 292 for (i = 0; i < fsc.nargs; i++) 293 asprintf(&fsc.s_args[i], "0x%lx", fsc.args[i]); 294 } else { 295 /* 296 * Here, we only look for arguments that have OUT masked in -- 297 * otherwise, they were handled in the syscall_entry function. 298 */ 299 for (i = 0; i < sc->nargs; i++) { 300 char *temp; 301 if (sc->args[i].type & OUT) { 302 /* 303 * If an error occurred, then don't bother 304 * getting the data; it may not be valid. 305 */ 306 if (errorp) { 307 asprintf(&temp, "0x%lx", 308 fsc.args[sc->args[i].offset]); 309 } else { 310 temp = print_arg(&sc->args[i], 311 fsc.args, retval, trussinfo); 312 } 313 fsc.s_args[i] = temp; 314 } 315 } 316 } 317 318 if (fsc.name != NULL && (strcmp(fsc.name, "freebsd32_execve") == 0 || 319 strcmp(fsc.name, "exit") == 0)) 320 trussinfo->curthread->in_syscall = 1; 321 322 /* 323 * It would probably be a good idea to merge the error handling, 324 * but that complicates things considerably. 325 */ 326 327 print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp, 328 retval, fsc.sc); 329 clear_fsc(); 330 331 return (retval); 332} 333