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 "$FreeBSD$"; 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#include "syscalls.h" 65 66static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]); 67 68/* 69 * This is what this particular file uses to keep track of a system call. 70 * It is probably not quite sufficient -- I can probably use the same 71 * structure for the various syscall personalities, and I also probably 72 * need to nest system calls (for signal handlers). 73 * 74 * 'struct syscall' describes the system call; it may be NULL, however, 75 * if we don't know about this particular system call yet. 76 */ 77struct freebsd_syscall { 78 struct syscall *sc; 79 const char *name; 80 int number; 81 unsigned long *args; 82 int nargs; /* number of arguments -- *not* number of words! */ 83 char **s_args; /* the printable arguments */ 84}; 85 86static struct freebsd_syscall * 87alloc_fsc(void) 88{ 89 90 return (malloc(sizeof(struct freebsd_syscall))); 91} 92 93/* Clear up and free parts of the fsc structure. */ 94static void 95free_fsc(struct freebsd_syscall *fsc) 96{ 97 int i; 98 99 free(fsc->args); 100 if (fsc->s_args) { 101 for (i = 0; i < fsc->nargs; i++) 102 free(fsc->s_args[i]); 103 free(fsc->s_args); 104 } 105 free(fsc); 106} 107 108/* 109 * Called when a process has entered a system call. nargs is the 110 * number of words, not number of arguments (a necessary distinction 111 * in some cases). Note that if the STOPEVENT() code in powerpc/powerpc/trap.c 112 * is ever changed these functions need to keep up. 113 */ 114 115void 116powerpc64_syscall_entry(struct trussinfo *trussinfo, int nargs) 117{ 118 struct ptrace_io_desc iorequest; 119 struct reg regs; 120 struct freebsd_syscall *fsc; 121 struct syscall *sc; 122 void *args; 123 lwpid_t tid; 124 int i, regargs, syscall_num; 125 126 tid = trussinfo->curthread->tid; 127 128 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) { 129 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 130 return; 131 } 132 133 /* 134 * FreeBSD has two special kinds of system call redirctions -- 135 * SYS_syscall, and SYS___syscall. The former is the old syscall() 136 * routine, basically; the latter is for quad-aligned arguments. 137 */ 138 regargs = NARGREG; 139 syscall_num = regs.fixreg[0]; 140 args = ®s.fixreg[3]; 141 if (syscall_num == SYS_syscall || syscall_num == SYS___syscall) { 142 args = ®s.fixreg[4]; 143 regargs -= 1; 144 syscall_num = regs.fixreg[3]; 145 } 146 147 fsc = alloc_fsc(); 148 if (fsc == NULL) 149 return; 150 fsc->number = syscall_num; 151 fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ? 152 NULL : syscallnames[syscall_num]; 153 if (!fsc->name) { 154 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", 155 syscall_num); 156 } 157 158 if (fsc->name && (trussinfo->flags & FOLLOWFORKS) && 159 (strcmp(fsc->name, "fork") == 0 || 160 strcmp(fsc->name, "rfork") == 0 || 161 strcmp(fsc->name, "vfork") == 0)) 162 trussinfo->curthread->in_fork = 1; 163 164 if (nargs == 0) 165 return; 166 167 fsc->args = malloc((1 + nargs) * sizeof(unsigned long)); 168 169 if (nargs > regargs) { 170 memmove(&fsc->args[0], args, regargs * sizeof(fsc->args[0])); 171 172 iorequest.piod_op = PIOD_READ_D; 173 iorequest.piod_offs = (void *)(regs.fixreg[1] + 48); 174 iorequest.piod_addr = &fsc->args[regargs]; 175 iorequest.piod_len = (nargs - regargs) * sizeof(fsc->args[0]); 176 ptrace(PT_IO, tid, (caddr_t)&iorequest, 0); 177 if (iorequest.piod_len == 0) 178 return; 179 } else 180 memmove(&fsc->args[0], args, nargs * sizeof(fsc->args[0])); 181 182 sc = get_syscall(fsc->name); 183 if (sc) 184 fsc->nargs = sc->nargs; 185 else { 186#if DEBUG 187 fprintf(trussinfo->outfile, "unknown syscall %s -- setting " 188 "args to %d\n", fsc->name, nargs); 189#endif 190 fsc->nargs = nargs; 191 } 192 193 fsc->s_args = calloc(1, (1 + fsc->nargs) * sizeof(char *)); 194 fsc->sc = sc; 195 196 /* 197 * At this point, we set up the system call arguments. 198 * We ignore any OUT ones, however -- those are arguments that 199 * are set by the system call, and so are probably meaningless 200 * now. This doesn't currently support arguments that are 201 * passed in *and* out, however. 202 */ 203 204 if (fsc->name) { 205#if DEBUG 206 fprintf(stderr, "syscall %s(", fsc->name); 207#endif 208 for (i = 0; i < fsc->nargs; i++) { 209#if DEBUG 210 fprintf(stderr, "0x%x%s", sc ? 211 fsc->args[sc->args[i].offset] : fsc->args[i], 212 i < (fsc->nargs - 1) ? "," : ""); 213#endif 214 if (sc && !(sc->args[i].type & OUT)) { 215 fsc->s_args[i] = print_arg(&sc->args[i], 216 fsc->args, 0, trussinfo); 217 } 218 } 219#if DEBUG 220 fprintf(stderr, ")\n"); 221#endif 222 } 223 224#if DEBUG 225 fprintf(trussinfo->outfile, "\n"); 226#endif 227 228 if (fsc->name && (strcmp(fsc->name, "execve") == 0 || 229 strcmp(fsc->name, "exit") == 0)) { 230 /* 231 * XXX 232 * This could be done in a more general 233 * manner but it still wouldn't be very pretty. 234 */ 235 if (strcmp(fsc->name, "execve") == 0) { 236 if ((trussinfo->flags & EXECVEARGS) == 0) { 237 if (fsc->s_args[1]) { 238 free(fsc->s_args[1]); 239 fsc->s_args[1] = NULL; 240 } 241 } 242 if ((trussinfo->flags & EXECVEENVS) == 0) { 243 if (fsc->s_args[2]) { 244 free(fsc->s_args[2]); 245 fsc->s_args[2] = NULL; 246 } 247 } 248 } 249 } 250 trussinfo->curthread->fsc = fsc; 251} 252 253/* 254 * And when the system call is done, we handle it here. 255 * Currently, no attempt is made to ensure that the system calls 256 * match -- this needs to be fixed (and is, in fact, why S_SCX includes 257 * the system call number instead of, say, an error status). 258 */ 259 260long 261powerpc64_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused) 262{ 263 struct reg regs; 264 struct freebsd_syscall *fsc; 265 struct syscall *sc; 266 lwpid_t tid; 267 long retval; 268 int errorp, i; 269 270 if (trussinfo->curthread->fsc == NULL) 271 return (-1); 272 273 tid = trussinfo->curthread->tid; 274 275 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) { 276 fprintf(trussinfo->outfile, "\n"); 277 return (-1); 278 } 279 280 retval = regs.fixreg[3]; 281 errorp = !!(regs.cr & 0x10000000); 282 283 /* 284 * This code, while simpler than the initial versions I used, could 285 * stand some significant cleaning. 286 */ 287 288 fsc = trussinfo->curthread->fsc; 289 sc = fsc->sc; 290 if (!sc) { 291 for (i = 0; i < fsc->nargs; i++) 292 asprintf(&fsc->s_args[i], "0x%lx", fsc->args[i]); 293 } else { 294 /* 295 * Here, we only look for arguments that have OUT masked in -- 296 * otherwise, they were handled in the syscall_entry function. 297 */ 298 for (i = 0; i < sc->nargs; i++) { 299 char *temp; 300 if (sc->args[i].type & OUT) { 301 /* 302 * If an error occurred, then don't bother 303 * getting the data; it may not be valid. 304 */ 305 if (errorp) { 306 asprintf(&temp, "0x%lx", 307 fsc->args[sc->args[i].offset]); 308 } else { 309 temp = print_arg(&sc->args[i], 310 fsc->args, retval, trussinfo); 311 } 312 fsc->s_args[i] = temp; 313 } 314 } 315 } 316 317 if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 || 318 strcmp(fsc->name, "exit") == 0)) 319 trussinfo->curthread->in_syscall = 1; 320 321 /* 322 * It would probably be a good idea to merge the error handling, 323 * but that complicates things considerably. 324 */ 325 326 print_syscall_ret(trussinfo, fsc->name, fsc->nargs, fsc->s_args, errorp, 327 retval, fsc->sc); 328 free_fsc(fsc); 329 330 return (retval); 331} 332