powerpc-fbsd.c revision 267654
1/* 2 * Copyright 2006 Peter Grehan <grehan@freebsd.org> 3 * Copyright 2005 Orlando Bassotto <orlando@break.net> 4 * Copyright 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: releng/9.3/usr.bin/truss/powerpc-fbsd.c 241162 2012-10-03 14:28:55Z zont $"; 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/ptrace.h> 45#include <sys/syscall.h> 46 47#include <machine/reg.h> 48#include <machine/frame.h> 49 50#include <err.h> 51#include <errno.h> 52#include <fcntl.h> 53#include <signal.h> 54#include <stdio.h> 55#include <stdlib.h> 56#include <string.h> 57#include <time.h> 58#include <unistd.h> 59 60#include "truss.h" 61#include "syscall.h" 62#include "extern.h" 63 64#ifdef __powerpc64__ /* 32-bit compatibility */ 65#include "freebsd32_syscalls.h" 66#define syscallnames freebsd32_syscallnames 67#else /* native 32-bit */ 68#include "syscalls.h" 69#endif 70 71static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]); 72 73/* 74 * This is what this particular file uses to keep track of a system call. 75 * It is probably not quite sufficient -- I can probably use the same 76 * structure for the various syscall personalities, and I also probably 77 * need to nest system calls (for signal handlers). 78 * 79 * 'struct syscall' describes the system call; it may be NULL, however, 80 * if we don't know about this particular system call yet. 81 */ 82struct freebsd_syscall { 83 struct syscall *sc; 84 const char *name; 85 int number; 86 unsigned long *args; 87 int nargs; /* number of arguments -- *not* number of words! */ 88 char **s_args; /* the printable arguments */ 89}; 90 91static struct freebsd_syscall * 92alloc_fsc(void) 93{ 94 95 return (malloc(sizeof(struct freebsd_syscall))); 96} 97 98/* Clear up and free parts of the fsc structure. */ 99static void 100free_fsc(struct freebsd_syscall *fsc) 101{ 102 int i; 103 104 free(fsc->args); 105 if (fsc->s_args) { 106 for (i = 0; i < fsc->nargs; i++) 107 free(fsc->s_args[i]); 108 free(fsc->s_args); 109 } 110 free(fsc); 111} 112 113/* 114 * Called when a process has entered a system call. nargs is the 115 * number of words, not number of arguments (a necessary distinction 116 * in some cases). Note that if the STOPEVENT() code in powerpc/powerpc/trap.c 117 * is ever changed these functions need to keep up. 118 */ 119 120void 121powerpc_syscall_entry(struct trussinfo *trussinfo, int nargs) 122{ 123 struct ptrace_io_desc iorequest; 124 struct reg regs; 125 struct freebsd_syscall *fsc; 126 struct syscall *sc; 127 void *args; 128 lwpid_t tid; 129 int i, regargs, syscall_num; 130 131 /* Account for a 64-bit argument with corresponding alignment. */ 132 nargs += 2; 133 134 tid = trussinfo->curthread->tid; 135 136 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) { 137 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 138 return; 139 } 140 141 /* 142 * FreeBSD has two special kinds of system call redirctions -- 143 * SYS_syscall, and SYS___syscall. The former is the old syscall() 144 * routine, basically; the latter is for quad-aligned arguments. 145 */ 146 regargs = NARGREG; 147 syscall_num = regs.fixreg[0]; 148 args = ®s.fixreg[3]; 149 if (syscall_num == SYS_syscall) { 150 args = ®s.fixreg[4]; 151 regargs -= 1; 152 syscall_num = regs.fixreg[3]; 153 } else if (syscall_num == SYS___syscall) { 154 args = ®s.fixreg[5]; 155 regargs -= 2; 156 syscall_num = regs.fixreg[4]; 157 } 158 159 fsc = alloc_fsc(); 160 if (fsc == NULL) 161 return; 162 fsc->number = syscall_num; 163 fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ? 164 NULL : syscallnames[syscall_num]; 165 if (!fsc->name) { 166 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", 167 syscall_num); 168 } 169 170 if (fsc->name && (trussinfo->flags & FOLLOWFORKS) && 171 (strcmp(fsc->name, "fork") == 0 || 172 strcmp(fsc->name, "rfork") == 0 || 173 strcmp(fsc->name, "vfork") == 0)) 174 trussinfo->curthread->in_fork = 1; 175 176 if (nargs == 0) 177 return; 178 179 fsc->args = malloc((1 + nargs) * sizeof(unsigned long)); 180 181 if (nargs > regargs) { 182 memmove(&fsc->args[0], args, regargs * sizeof(fsc->args[0])); 183 184 iorequest.piod_op = PIOD_READ_D; 185 iorequest.piod_offs = (void *)(regs.fixreg[1] + 8); 186 iorequest.piod_addr = &fsc->args[regargs]; 187 iorequest.piod_len = (nargs - regargs) * sizeof(fsc->args[0]); 188 ptrace(PT_IO, tid, (caddr_t)&iorequest, 0); 189 if (iorequest.piod_len == 0) 190 return; 191 } else 192 memmove(&fsc->args[0], args, nargs * sizeof(fsc->args[0])); 193 194 sc = get_syscall(fsc->name); 195 if (sc) 196 fsc->nargs = sc->nargs; 197 else { 198#if DEBUG 199 fprintf(trussinfo->outfile, "unknown syscall %s -- setting " 200 "args to %d\n", fsc->name, nargs); 201#endif 202 fsc->nargs = nargs; 203 } 204 205 fsc->s_args = calloc(1, (1 + fsc->nargs) * sizeof(char *)); 206 fsc->sc = sc; 207 208 /* 209 * At this point, we set up the system call arguments. 210 * We ignore any OUT ones, however -- those are arguments that 211 * are set by the system call, and so are probably meaningless 212 * now. This doesn't currently support arguments that are 213 * passed in *and* out, however. 214 */ 215 216 if (fsc->name) { 217#if DEBUG 218 fprintf(stderr, "syscall %s(", fsc->name); 219#endif 220 for (i = 0; i < fsc->nargs; i++) { 221#if DEBUG 222 fprintf(stderr, "0x%x%s", sc ? 223 fsc->args[sc->args[i].offset] : fsc->args[i], 224 i < (fsc->nargs - 1) ? "," : ""); 225#endif 226 if (sc && !(sc->args[i].type & OUT)) { 227 fsc->s_args[i] = print_arg(&sc->args[i], 228 fsc->args, 0, trussinfo); 229 } 230 } 231#if DEBUG 232 fprintf(stderr, ")\n"); 233#endif 234 } 235 236#if DEBUG 237 fprintf(trussinfo->outfile, "\n"); 238#endif 239 240 if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 || 241 strcmp(fsc->name, "exit") == 0)) { 242 /* 243 * XXX 244 * This could be done in a more general 245 * manner but it still wouldn't be very pretty. 246 */ 247 if (strcmp(fsc->name, "execve") == 0) { 248 if ((trussinfo->flags & EXECVEARGS) == 0) { 249 if (fsc->s_args[1]) { 250 free(fsc->s_args[1]); 251 fsc->s_args[1] = NULL; 252 } 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 } 262 trussinfo->curthread->fsc = fsc; 263} 264 265/* 266 * And when the system call is done, we handle it here. 267 * Currently, no attempt is made to ensure that the system calls 268 * match -- this needs to be fixed (and is, in fact, why S_SCX includes 269 * the system call number instead of, say, an error status). 270 */ 271 272long 273powerpc_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused) 274{ 275 struct reg regs; 276 struct freebsd_syscall *fsc; 277 struct syscall *sc; 278 lwpid_t tid; 279 long retval; 280 int errorp, i; 281 282 if (trussinfo->curthread->fsc == NULL) 283 return (-1); 284 285 tid = trussinfo->curthread->tid; 286 287 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) { 288 fprintf(trussinfo->outfile, "\n"); 289 return (-1); 290 } 291 292 retval = regs.fixreg[3]; 293 errorp = !!(regs.cr & 0x10000000); 294 295 /* 296 * This code, while simpler than the initial versions I used, could 297 * stand some significant cleaning. 298 */ 299 300 fsc = trussinfo->curthread->fsc; 301 sc = fsc->sc; 302 if (!sc) { 303 for (i = 0; i < fsc->nargs; i++) 304 asprintf(&fsc->s_args[i], "0x%lx", fsc->args[i]); 305 } else { 306 /* 307 * On 32-bit big-endian, the low word of a 64-bit return is 308 * in the greater address. Switch to this. XXX note that 309 * print_syscall_ret can't handle 64-bit return values (llseek) 310 */ 311 if (sc->ret_type == 2) 312 retval = regs.fixreg[4]; 313 314 /* 315 * Here, we only look for arguments that have OUT masked in -- 316 * otherwise, they were handled in the syscall_entry function. 317 */ 318 for (i = 0; i < sc->nargs; i++) { 319 char *temp; 320 if (sc->args[i].type & OUT) { 321 /* 322 * If an error occurred, then don't bother 323 * getting the data; it may not be valid. 324 */ 325 if (errorp) { 326 asprintf(&temp, "0x%lx", 327 fsc->args[sc->args[i].offset]); 328 } else { 329 temp = print_arg(&sc->args[i], 330 fsc->args, retval, trussinfo); 331 } 332 fsc->s_args[i] = temp; 333 } 334 } 335 } 336 337 if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 || 338 strcmp(fsc->name, "exit") == 0)) 339 trussinfo->curthread->in_syscall = 1; 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, 347 retval, fsc->sc); 348 free_fsc(fsc); 349 350 return (retval); 351} 352