powerpc-fbsd.c revision 171055
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 171055 2007-06-26 22:42:37Z delphij $"; 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 64static int cpid = -1; 65 66#include "syscalls.h" 67 68static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]); 69 70/* 71 * This is what this particular file uses to keep track of a system call. 72 * It is probably not quite sufficient -- I can probably use the same 73 * structure for the various syscall personalities, and I also probably 74 * need to nest system calls (for signal handlers). 75 * 76 * 'struct syscall' describes the system call; it may be NULL, however, 77 * if we don't know about this particular system call yet. 78 */ 79static struct freebsd_syscall { 80 struct syscall *sc; 81 const char *name; 82 int number; 83 unsigned long *args; 84 int nargs; /* number of arguments -- *not* number of words! */ 85 char **s_args; /* the printable arguments */ 86} fsc; 87 88/* Clear up and free parts of the fsc structure. */ 89static __inline void 90clear_fsc(void) { 91 if (fsc.args) { 92 free(fsc.args); 93 } 94 if (fsc.s_args) { 95 int i; 96 for (i = 0; i < fsc.nargs; i++) 97 if (fsc.s_args[i]) 98 free(fsc.s_args[i]); 99 free(fsc.s_args); 100 } 101 memset(&fsc, 0, sizeof(fsc)); 102} 103 104/* 105 * Called when a process has entered a system call. nargs is the 106 * number of words, not number of arguments (a necessary distinction 107 * in some cases). Note that if the STOPEVENT() code in powerpc/powerpc/trap.c 108 * is ever changed these functions need to keep up. 109 */ 110 111void 112powerpc_syscall_entry(struct trussinfo *trussinfo, int nargs) { 113 char buf[32]; 114 struct reg regs; 115 void *args; 116 int syscall_num; 117 int i; 118 unsigned int regargs; 119 struct syscall *sc; 120 121 cpid = trussinfo->curthread->tid; 122 123 clear_fsc(); 124 if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0) { 125 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 126 return; 127 } 128 129 /* 130 * FreeBSD has two special kinds of system call redirctions -- 131 * SYS_syscall, and SYS___syscall. The former is the old syscall() 132 * routine, basicly; the latter is for quad-aligned arguments. 133 */ 134 regargs = NARGREG; 135 syscall_num = regs.fixreg[0]; 136 args = ®s.fixreg[3]; 137 if (syscall_num == SYS_syscall) { 138 args = ®s.fixreg[4]; 139 regargs -= 1; 140 syscall_num = regs.fixreg[3]; 141 } else if (syscall_num == SYS___syscall) { 142 args = ®s.fixreg[5]; 143 regargs -= 2; 144 syscall_num = regs.fixreg[4]; 145 } 146 147 fsc.number = syscall_num; 148 fsc.name = 149 (syscall_num < 0 || syscall_num > nsyscalls) ? NULL : syscallnames[syscall_num]; 150 if (!fsc.name) { 151 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", syscall_num); 152 } 153 154 if (fsc.name && (trussinfo->flags & FOLLOWFORKS) 155 && ((!strcmp(fsc.name, "fork") 156 || !strcmp(fsc.name, "rfork") 157 || !strcmp(fsc.name, "vfork")))) 158 { 159 trussinfo->curthread->in_fork = 1; 160 } 161 162 if (nargs == 0) 163 return; 164 165 fsc.args = malloc((1+nargs) * sizeof(unsigned long)); 166 167 if (nargs > regargs) { 168 struct ptrace_io_desc iorequest; 169 memmove(&fsc.args[0], args, regargs * sizeof(fsc.args[0])); 170 171 iorequest.piod_op = PIOD_READ_D; 172 iorequest.piod_offs = (void *)(regs.fixreg[1] + 8); 173 iorequest.piod_addr = &fsc.args[regargs]; 174 iorequest.piod_len = (nargs - regargs) * sizeof(fsc.args[0]); 175 ptrace(PT_IO, cpid, (caddr_t)&iorequest, 0); 176 if (iorequest.piod_len == 0) 177 return; 178 } else { 179 memmove(&fsc.args[0], args, nargs * sizeof(fsc.args[0])); 180 } 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 args to %d\n", 188 fsc.name, nargs); 189#endif 190 fsc.nargs = nargs; 191 } 192 193 fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*)); 194 memset(fsc.s_args, 0, fsc.nargs * sizeof(char*)); 195 fsc.sc = sc; 196 197 /* 198 * At this point, we set up the system call arguments. 199 * We ignore any OUT ones, however -- those are arguments that 200 * are set by the system call, and so are probably meaningless 201 * now. This doesn't currently support arguments that are 202 * passed in *and* out, however. 203 */ 204 205 if (fsc.name) { 206 207#if DEBUG 208 fprintf(stderr, "syscall %s(", fsc.name); 209#endif 210 for (i = 0; i < fsc.nargs; i++) { 211#if DEBUG 212 fprintf(stderr, "0x%x%s", 213 sc 214 ? fsc.args[sc->args[i].offset] 215 : fsc.args[i], 216 i < (fsc.nargs - 1) ? "," : ""); 217#endif 218 if (sc && !(sc->args[i].type & OUT)) { 219 fsc.s_args[i] = print_arg(&sc->args[i], 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 && (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit"))) { 232 233 /* XXX 234 * This could be done in a more general 235 * manner but it still wouldn't be very pretty. 236 */ 237 if (!strcmp(fsc.name, "execve")) { 238 if ((trussinfo->flags & EXECVEARGS) == 0) 239 if (fsc.s_args[1]) { 240 free(fsc.s_args[1]); 241 fsc.s_args[1] = NULL; 242 } 243 if ((trussinfo->flags & EXECVEENVS) == 0) 244 if (fsc.s_args[2]) { 245 free(fsc.s_args[2]); 246 fsc.s_args[2] = NULL; 247 } 248 } 249 } 250 251 return; 252} 253 254/* 255 * And when the system call is done, we handle it here. 256 * Currently, no attempt is made to ensure that the system calls 257 * match -- this needs to be fixed (and is, in fact, why S_SCX includes 258 * the sytem call number instead of, say, an error status). 259 */ 260 261long 262powerpc_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused) 263{ 264 struct reg regs; 265 long retval; 266 int i; 267 int errorp; 268 struct syscall *sc; 269 270 if (fsc.name == NULL) 271 return (-1); 272 273 cpid = trussinfo->curthread->tid; 274 275 if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0) { 276 fprintf(trussinfo->outfile, "\n"); 277 return (-1); 278 } 279 retval = regs.fixreg[3]; 280 errorp = !!(regs.cr & 0x10000000); 281 282 /* 283 * This code, while simpler than the initial versions I used, could 284 * stand some significant cleaning. 285 */ 286 287 sc = fsc.sc; 288 if (!sc) { 289 for (i = 0; i < fsc.nargs; i++) 290 asprintf(&fsc.s_args[i], "0x%lx", fsc.args[i]); 291 } else { 292 /* 293 * On 32-bit big-endian, the low word of a 64-bit return is 294 * in the greater address. Switch to this. XXX note that 295 * print_syscall_ret can't handle 64-bit return values (llseek) 296 */ 297 if (sc->ret_type == 2) 298 retval = regs.fixreg[4]; 299 300 /* 301 * Here, we only look for arguments that have OUT masked in -- 302 * otherwise, they were handled in the syscall_entry function. 303 */ 304 for (i = 0; i < sc->nargs; i++) { 305 char *temp; 306 if (sc->args[i].type & OUT) { 307 /* 308 * If an error occurred, than don't bothe getting the data; 309 * it may not be valid. 310 */ 311 if (errorp) 312 asprintf(&temp, "0x%lx", fsc.args[sc->args[i].offset]); 313 else 314 temp = print_arg(&sc->args[i], fsc.args, retval, trussinfo); 315 fsc.s_args[i] = temp; 316 } 317 } 318 } 319 320 if (fsc.name != NULL && 321 (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit"))) { 322 trussinfo->curthread->in_syscall = 1; 323 } 324 325 326 /* 327 * It would probably be a good idea to merge the error handling, 328 * but that complicates things considerably. 329 */ 330 331 print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp, retval); 332 clear_fsc(); 333 334 return (retval); 335} 336