powerpc-fbsd.c revision 154047
1/* 2 * Copyright 2006 Peter Grehan <grehan@freebsd.org> 3 * Copryight 2005 Orlando Bassotto <orlando@break.net> 4 * Copryight 1998 Sean Eric Fagan 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#ifndef lint 29static const char rcsid[] = 30 "$FreeBSD: head/usr.bin/truss/powerpc-fbsd.c 154047 2006-01-05 05:57:47Z grehan $"; 31#endif /* not lint */ 32 33/* 34 * FreeBSD/powerpc-specific system call handling. This is probably the most 35 * complex part of the entire truss program, although I've got lots of 36 * it handled relatively cleanly now. The system call names are generated 37 * automatically, thanks to /usr/src/sys/kern/syscalls.master. The 38 * names used for the various structures are confusing, I sadly admit. 39 * 40 * This file is almost nothing more than a slightly-edited i386-fbsd.c. 41 */ 42 43#include <sys/types.h> 44#include <sys/ioctl.h> 45#include <sys/pioctl.h> 46#include <sys/syscall.h> 47 48#include <machine/reg.h> 49#include <machine/frame.h> 50 51#include <err.h> 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 fd = -1; 66static int cpid = -1; 67 68#include "syscalls.h" 69 70static int nsyscalls = sizeof(syscallnames) / sizeof(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 freebsd_syscall { 82 struct syscall *sc; 83 const char *name; 84 int number; 85 unsigned long *args; 86 int nargs; /* number of arguments -- *not* number of words! */ 87 char **s_args; /* the printable arguments */ 88} fsc; 89 90/* Clear up and free parts of the fsc structure. */ 91static __inline void 92clear_fsc(void) { 93 if (fsc.args) { 94 free(fsc.args); 95 } 96 if (fsc.s_args) { 97 int i; 98 for (i = 0; i < fsc.nargs; i++) 99 if (fsc.s_args[i]) 100 free(fsc.s_args[i]); 101 free(fsc.s_args); 102 } 103 memset(&fsc, 0, sizeof(fsc)); 104} 105 106/* 107 * Called when a process has entered a system call. nargs is the 108 * number of words, not number of arguments (a necessary distinction 109 * in some cases). Note that if the STOPEVENT() code in powerpc/powerpc/trap.c 110 * is ever changed these functions need to keep up. 111 */ 112 113void 114powerpc_syscall_entry(struct trussinfo *trussinfo, int nargs) { 115 char buf[32]; 116 struct reg regs; 117 void *args; 118 int syscall_num; 119 int i; 120 unsigned int regargs; 121 struct syscall *sc; 122 123 if (fd == -1 || trussinfo->pid != cpid) { 124 sprintf(buf, "/proc/%d/regs", trussinfo->pid); 125 fd = open(buf, O_RDWR); 126 if (fd == -1) { 127 fprintf(trussinfo->outfile, "-- CANNOT OPEN REGISTERS --\n"); 128 return; 129 } 130 cpid = trussinfo->pid; 131 } 132 133 clear_fsc(); 134 lseek(fd, 0L, 0); 135 if (read(fd, ®s, sizeof(regs)) != sizeof(regs)) { 136 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 137 return; 138 } 139 140 /* 141 * FreeBSD has two special kinds of system call redirctions -- 142 * SYS_syscall, and SYS___syscall. The former is the old syscall() 143 * routine, basicly; the latter is for quad-aligned arguments. 144 */ 145 regargs = NARGREG; 146 syscall_num = regs.fixreg[0]; 147 args = ®s.fixreg[3]; 148 if (syscall_num == SYS_syscall) { 149 args = ®s.fixreg[4]; 150 regargs -= 1; 151 syscall_num = regs.fixreg[3]; 152 } else if (syscall_num == SYS___syscall) { 153 args = ®s.fixreg[5]; 154 regargs -= 2; 155 syscall_num = regs.fixreg[4]; 156 } 157 158 fsc.number = syscall_num; 159 fsc.name = 160 (syscall_num < 0 || syscall_num > nsyscalls) ? NULL : syscallnames[syscall_num]; 161 if (!fsc.name) { 162 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", syscall_num); 163 } 164 165 if (fsc.name && (trussinfo->flags & FOLLOWFORKS) 166 && ((!strcmp(fsc.name, "fork") 167 || !strcmp(fsc.name, "rfork") 168 || !strcmp(fsc.name, "vfork")))) 169 { 170 trussinfo->in_fork = 1; 171 } 172 173 if (nargs == 0) 174 return; 175 176 fsc.args = malloc((1+nargs) * sizeof(unsigned long)); 177 178 if (nargs > regargs) { 179 memmove(&fsc.args[0], args, regargs * sizeof(fsc.args[0])); 180 lseek(Procfd, regs.fixreg[1] + 8, SEEK_SET); 181 read(Procfd, &fsc.args[regargs], (nargs - regargs) * sizeof(fsc.args[0])); 182 } else { 183 memmove(&fsc.args[0], args, nargs * sizeof(fsc.args[0])); 184 } 185 186 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(Procfd, &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 /* 236 * Some system calls should be printed out before they are done -- 237 * execve() and exit(), for example, never return. Possibly change 238 * this to work for any system call that doesn't have an OUT 239 * parameter? 240 */ 241 242 if (fsc.name && (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit"))) { 243 244 /* XXX 245 * This could be done in a more general 246 * manner but it still wouldn't be very pretty. 247 */ 248 if (!strcmp(fsc.name, "execve")) { 249 if ((trussinfo->flags & EXECVEARGS) == 0) 250 if (fsc.s_args[1]) { 251 free(fsc.s_args[1]); 252 fsc.s_args[1] = NULL; 253 } 254 if ((trussinfo->flags & EXECVEENVS) == 0) 255 if (fsc.s_args[2]) { 256 free(fsc.s_args[2]); 257 fsc.s_args[2] = NULL; 258 } 259 } 260 261 print_syscall(trussinfo, fsc.name, fsc.nargs, fsc.s_args); 262 fprintf(trussinfo->outfile, "\n"); 263 } 264 265 return; 266} 267 268/* 269 * And when the system call is done, we handle it here. 270 * Currently, no attempt is made to ensure that the system calls 271 * match -- this needs to be fixed (and is, in fact, why S_SCX includes 272 * the sytem call number instead of, say, an error status). 273 */ 274 275long 276powerpc_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused) 277{ 278 char buf[32]; 279 struct reg regs; 280 long retval; 281 int i; 282 int errorp; 283 struct syscall *sc; 284 285 if (fd == -1 || trussinfo->pid != cpid) { 286 sprintf(buf, "/proc/%d/regs", trussinfo->pid); 287 fd = open(buf, O_RDONLY); 288 if (fd == -1) { 289 fprintf(trussinfo->outfile, "-- CANNOT OPEN REGISTERS --\n"); 290 return (-1); 291 } 292 cpid = trussinfo->pid; 293 } 294 295 lseek(fd, 0L, 0); 296 if (read(fd, ®s, sizeof(regs)) != sizeof(regs)) { 297 fprintf(trussinfo->outfile, "\n"); 298 return (-1); 299 } 300 retval = regs.fixreg[3]; 301 errorp = !!(regs.cr & 0x10000000); 302 303 /* 304 * This code, while simpler than the initial versions I used, could 305 * stand some significant cleaning. 306 */ 307 308 sc = fsc.sc; 309 if (!sc) { 310 for (i = 0; i < fsc.nargs; i++) 311 asprintf(&fsc.s_args[i], "0x%lx", fsc.args[i]); 312 } else { 313 /* 314 * On 32-bit big-endian, the low word of a 64-bit return is 315 * in the greater address. Switch to this. XXX note that 316 * print_syscall_ret can't handle 64-bit return values (llseek) 317 */ 318 if (sc->ret_type == 2) 319 retval = regs.fixreg[4]; 320 321 /* 322 * Here, we only look for arguments that have OUT masked in -- 323 * otherwise, they were handled in the syscall_entry function. 324 */ 325 for (i = 0; i < sc->nargs; i++) { 326 char *temp; 327 if (sc->args[i].type & OUT) { 328 /* 329 * If an error occurred, than don't bothe getting the data; 330 * it may not be valid. 331 */ 332 if (errorp) 333 asprintf(&temp, "0x%lx", fsc.args[sc->args[i].offset]); 334 else 335 temp = print_arg(Procfd, &sc->args[i], fsc.args, retval, trussinfo); 336 fsc.s_args[i] = temp; 337 } 338 } 339 } 340 341 /* 342 * It would probably be a good idea to merge the error handling, 343 * but that complicates things considerably. 344 */ 345 346 print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp, retval); 347 clear_fsc(); 348 349 return (retval); 350} 351