powerpc-fbsd.c revision 192025
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 192025 2009-05-12 20:42:12Z dds $"; 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 /* Account for a 64-bit argument with corresponding alignment. */ 122 nargs += 2; 123 124 cpid = trussinfo->curthread->tid; 125 126 clear_fsc(); 127 if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0) { 128 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 129 return; 130 } 131 132 /* 133 * FreeBSD has two special kinds of system call redirctions -- 134 * SYS_syscall, and SYS___syscall. The former is the old syscall() 135 * routine, basicly; the latter is for quad-aligned arguments. 136 */ 137 regargs = NARGREG; 138 syscall_num = regs.fixreg[0]; 139 args = ®s.fixreg[3]; 140 if (syscall_num == SYS_syscall) { 141 args = ®s.fixreg[4]; 142 regargs -= 1; 143 syscall_num = regs.fixreg[3]; 144 } else if (syscall_num == SYS___syscall) { 145 args = ®s.fixreg[5]; 146 regargs -= 2; 147 syscall_num = regs.fixreg[4]; 148 } 149 150 fsc.number = syscall_num; 151 fsc.name = 152 (syscall_num < 0 || syscall_num > nsyscalls) ? NULL : syscallnames[syscall_num]; 153 if (!fsc.name) { 154 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", syscall_num); 155 } 156 157 if (fsc.name && (trussinfo->flags & FOLLOWFORKS) 158 && ((!strcmp(fsc.name, "fork") 159 || !strcmp(fsc.name, "rfork") 160 || !strcmp(fsc.name, "vfork")))) 161 { 162 trussinfo->curthread->in_fork = 1; 163 } 164 165 if (nargs == 0) 166 return; 167 168 fsc.args = malloc((1+nargs) * sizeof(unsigned long)); 169 170 if (nargs > regargs) { 171 struct ptrace_io_desc iorequest; 172 memmove(&fsc.args[0], args, regargs * sizeof(fsc.args[0])); 173 174 iorequest.piod_op = PIOD_READ_D; 175 iorequest.piod_offs = (void *)(regs.fixreg[1] + 8); 176 iorequest.piod_addr = &fsc.args[regargs]; 177 iorequest.piod_len = (nargs - regargs) * sizeof(fsc.args[0]); 178 ptrace(PT_IO, cpid, (caddr_t)&iorequest, 0); 179 if (iorequest.piod_len == 0) 180 return; 181 } else { 182 memmove(&fsc.args[0], args, nargs * sizeof(fsc.args[0])); 183 } 184 185 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 args to %d\n", 191 fsc.name, nargs); 192#endif 193 fsc.nargs = nargs; 194 } 195 196 fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*)); 197 memset(fsc.s_args, 0, fsc.nargs * sizeof(char*)); 198 fsc.sc = sc; 199 200 /* 201 * At this point, we set up the system call arguments. 202 * We ignore any OUT ones, however -- those are arguments that 203 * are set by the system call, and so are probably meaningless 204 * now. This doesn't currently support arguments that are 205 * passed in *and* out, however. 206 */ 207 208 if (fsc.name) { 209 210#if DEBUG 211 fprintf(stderr, "syscall %s(", fsc.name); 212#endif 213 for (i = 0; i < fsc.nargs; i++) { 214#if DEBUG 215 fprintf(stderr, "0x%x%s", 216 sc 217 ? fsc.args[sc->args[i].offset] 218 : fsc.args[i], 219 i < (fsc.nargs - 1) ? "," : ""); 220#endif 221 if (sc && !(sc->args[i].type & OUT)) { 222 fsc.s_args[i] = print_arg(&sc->args[i], fsc.args, 0, trussinfo); 223 } 224 } 225#if DEBUG 226 fprintf(stderr, ")\n"); 227#endif 228 } 229 230#if DEBUG 231 fprintf(trussinfo->outfile, "\n"); 232#endif 233 234 if (fsc.name && (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit"))) { 235 236 /* XXX 237 * This could be done in a more general 238 * manner but it still wouldn't be very pretty. 239 */ 240 if (!strcmp(fsc.name, "execve")) { 241 if ((trussinfo->flags & EXECVEARGS) == 0) 242 if (fsc.s_args[1]) { 243 free(fsc.s_args[1]); 244 fsc.s_args[1] = NULL; 245 } 246 if ((trussinfo->flags & EXECVEENVS) == 0) 247 if (fsc.s_args[2]) { 248 free(fsc.s_args[2]); 249 fsc.s_args[2] = NULL; 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 sytem call number instead of, say, an error status). 262 */ 263 264long 265powerpc_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused) 266{ 267 struct reg regs; 268 long retval; 269 int i; 270 int errorp; 271 struct syscall *sc; 272 273 if (fsc.name == NULL) 274 return (-1); 275 276 cpid = trussinfo->curthread->tid; 277 278 if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0) { 279 fprintf(trussinfo->outfile, "\n"); 280 return (-1); 281 } 282 retval = regs.fixreg[3]; 283 errorp = !!(regs.cr & 0x10000000); 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 * On 32-bit big-endian, the low word of a 64-bit return is 297 * in the greater address. Switch to this. XXX note that 298 * print_syscall_ret can't handle 64-bit return values (llseek) 299 */ 300 if (sc->ret_type == 2) 301 retval = regs.fixreg[4]; 302 303 /* 304 * Here, we only look for arguments that have OUT masked in -- 305 * otherwise, they were handled in the syscall_entry function. 306 */ 307 for (i = 0; i < sc->nargs; i++) { 308 char *temp; 309 if (sc->args[i].type & OUT) { 310 /* 311 * If an error occurred, than don't bothe getting the data; 312 * it may not be valid. 313 */ 314 if (errorp) 315 asprintf(&temp, "0x%lx", fsc.args[sc->args[i].offset]); 316 else 317 temp = print_arg(&sc->args[i], fsc.args, retval, trussinfo); 318 fsc.s_args[i] = temp; 319 } 320 } 321 } 322 323 if (fsc.name != NULL && 324 (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit"))) { 325 trussinfo->curthread->in_syscall = 1; 326 } 327 328 329 /* 330 * It would probably be a good idea to merge the error handling, 331 * but that complicates things considerably. 332 */ 333 334 print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp, 335 retval, fsc.sc); 336 clear_fsc(); 337 338 return (retval); 339} 340