powerpc-fbsd.c revision 225736
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: stable/9/usr.bin/truss/powerpc-fbsd.c 222103 2011-05-19 20:35:40Z bcr $"; 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#ifdef __powerpc64__ /* 32-bit compatibility */ 67#include "freebsd32_syscalls.h" 68#define syscallnames freebsd32_syscallnames 69#else /* native 32-bit */ 70#include "syscalls.h" 71#endif 72 73static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]); 74 75/* 76 * This is what this particular file uses to keep track of a system call. 77 * It is probably not quite sufficient -- I can probably use the same 78 * structure for the various syscall personalities, and I also probably 79 * need to nest system calls (for signal handlers). 80 * 81 * 'struct syscall' describes the system call; it may be NULL, however, 82 * if we don't know about this particular system call yet. 83 */ 84static struct freebsd_syscall { 85 struct syscall *sc; 86 const char *name; 87 int number; 88 unsigned long *args; 89 int nargs; /* number of arguments -- *not* number of words! */ 90 char **s_args; /* the printable arguments */ 91} fsc; 92 93/* Clear up and free parts of the fsc structure. */ 94static __inline void 95clear_fsc(void) { 96 if (fsc.args) { 97 free(fsc.args); 98 } 99 if (fsc.s_args) { 100 int i; 101 for (i = 0; i < fsc.nargs; i++) 102 if (fsc.s_args[i]) 103 free(fsc.s_args[i]); 104 free(fsc.s_args); 105 } 106 memset(&fsc, 0, sizeof(fsc)); 107} 108 109/* 110 * Called when a process has entered a system call. nargs is the 111 * number of words, not number of arguments (a necessary distinction 112 * in some cases). Note that if the STOPEVENT() code in powerpc/powerpc/trap.c 113 * is ever changed these functions need to keep up. 114 */ 115 116void 117powerpc_syscall_entry(struct trussinfo *trussinfo, int nargs) { 118 char buf[32]; 119 struct reg regs; 120 void *args; 121 int syscall_num; 122 int i; 123 unsigned int regargs; 124 struct syscall *sc; 125 126 /* Account for a 64-bit argument with corresponding alignment. */ 127 nargs += 2; 128 129 cpid = trussinfo->curthread->tid; 130 131 clear_fsc(); 132 if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0) { 133 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 134 return; 135 } 136 137 /* 138 * FreeBSD has two special kinds of system call redirctions -- 139 * SYS_syscall, and SYS___syscall. The former is the old syscall() 140 * routine, basically; the latter is for quad-aligned arguments. 141 */ 142 regargs = NARGREG; 143 syscall_num = regs.fixreg[0]; 144 args = ®s.fixreg[3]; 145 if (syscall_num == SYS_syscall) { 146 args = ®s.fixreg[4]; 147 regargs -= 1; 148 syscall_num = regs.fixreg[3]; 149 } else if (syscall_num == SYS___syscall) { 150 args = ®s.fixreg[5]; 151 regargs -= 2; 152 syscall_num = regs.fixreg[4]; 153 } 154 155 fsc.number = syscall_num; 156 fsc.name = 157 (syscall_num < 0 || syscall_num >= nsyscalls) ? NULL : syscallnames[syscall_num]; 158 if (!fsc.name) { 159 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", syscall_num); 160 } 161 162 if (fsc.name && (trussinfo->flags & FOLLOWFORKS) 163 && ((!strcmp(fsc.name, "fork") 164 || !strcmp(fsc.name, "rfork") 165 || !strcmp(fsc.name, "vfork")))) 166 { 167 trussinfo->curthread->in_fork = 1; 168 } 169 170 if (nargs == 0) 171 return; 172 173 fsc.args = malloc((1+nargs) * sizeof(unsigned long)); 174 175 if (nargs > regargs) { 176 struct ptrace_io_desc iorequest; 177 memmove(&fsc.args[0], args, regargs * sizeof(fsc.args[0])); 178 179 iorequest.piod_op = PIOD_READ_D; 180 iorequest.piod_offs = (void *)(regs.fixreg[1] + 8); 181 iorequest.piod_addr = &fsc.args[regargs]; 182 iorequest.piod_len = (nargs - regargs) * sizeof(fsc.args[0]); 183 ptrace(PT_IO, cpid, (caddr_t)&iorequest, 0); 184 if (iorequest.piod_len == 0) 185 return; 186 } else { 187 memmove(&fsc.args[0], args, nargs * sizeof(fsc.args[0])); 188 } 189 190 sc = get_syscall(fsc.name); 191 if (sc) { 192 fsc.nargs = sc->nargs; 193 } else { 194#if DEBUG 195 fprintf(trussinfo->outfile, "unknown syscall %s -- setting args to %d\n", 196 fsc.name, nargs); 197#endif 198 fsc.nargs = nargs; 199 } 200 201 fsc.s_args = calloc(1, (1+fsc.nargs) * sizeof(char*)); 202 fsc.sc = sc; 203 204 /* 205 * At this point, we set up the system call arguments. 206 * We ignore any OUT ones, however -- those are arguments that 207 * are set by the system call, and so are probably meaningless 208 * now. This doesn't currently support arguments that are 209 * passed in *and* out, however. 210 */ 211 212 if (fsc.name) { 213 214#if DEBUG 215 fprintf(stderr, "syscall %s(", fsc.name); 216#endif 217 for (i = 0; i < fsc.nargs; i++) { 218#if DEBUG 219 fprintf(stderr, "0x%x%s", 220 sc 221 ? fsc.args[sc->args[i].offset] 222 : fsc.args[i], 223 i < (fsc.nargs - 1) ? "," : ""); 224#endif 225 if (sc && !(sc->args[i].type & OUT)) { 226 fsc.s_args[i] = print_arg(&sc->args[i], fsc.args, 0, trussinfo); 227 } 228 } 229#if DEBUG 230 fprintf(stderr, ")\n"); 231#endif 232 } 233 234#if DEBUG 235 fprintf(trussinfo->outfile, "\n"); 236#endif 237 238 if (fsc.name && (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit"))) { 239 240 /* XXX 241 * This could be done in a more general 242 * manner but it still wouldn't be very pretty. 243 */ 244 if (!strcmp(fsc.name, "execve")) { 245 if ((trussinfo->flags & EXECVEARGS) == 0) 246 if (fsc.s_args[1]) { 247 free(fsc.s_args[1]); 248 fsc.s_args[1] = NULL; 249 } 250 if ((trussinfo->flags & EXECVEENVS) == 0) 251 if (fsc.s_args[2]) { 252 free(fsc.s_args[2]); 253 fsc.s_args[2] = NULL; 254 } 255 } 256 } 257 258 return; 259} 260 261/* 262 * And when the system call is done, we handle it here. 263 * Currently, no attempt is made to ensure that the system calls 264 * match -- this needs to be fixed (and is, in fact, why S_SCX includes 265 * the system call number instead of, say, an error status). 266 */ 267 268long 269powerpc_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused) 270{ 271 struct reg regs; 272 long retval; 273 int i; 274 int errorp; 275 struct syscall *sc; 276 277 if (fsc.name == NULL) 278 return (-1); 279 280 cpid = trussinfo->curthread->tid; 281 282 if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0) { 283 fprintf(trussinfo->outfile, "\n"); 284 return (-1); 285 } 286 retval = regs.fixreg[3]; 287 errorp = !!(regs.cr & 0x10000000); 288 289 /* 290 * This code, while simpler than the initial versions I used, could 291 * stand some significant cleaning. 292 */ 293 294 sc = fsc.sc; 295 if (!sc) { 296 for (i = 0; i < fsc.nargs; i++) 297 asprintf(&fsc.s_args[i], "0x%lx", fsc.args[i]); 298 } else { 299 /* 300 * On 32-bit big-endian, the low word of a 64-bit return is 301 * in the greater address. Switch to this. XXX note that 302 * print_syscall_ret can't handle 64-bit return values (llseek) 303 */ 304 if (sc->ret_type == 2) 305 retval = regs.fixreg[4]; 306 307 /* 308 * Here, we only look for arguments that have OUT masked in -- 309 * otherwise, they were handled in the syscall_entry function. 310 */ 311 for (i = 0; i < sc->nargs; i++) { 312 char *temp; 313 if (sc->args[i].type & OUT) { 314 /* 315 * If an error occurred, than don't bothe getting the data; 316 * it may not be valid. 317 */ 318 if (errorp) 319 asprintf(&temp, "0x%lx", fsc.args[sc->args[i].offset]); 320 else 321 temp = print_arg(&sc->args[i], fsc.args, retval, trussinfo); 322 fsc.s_args[i] = temp; 323 } 324 } 325 } 326 327 if (fsc.name != NULL && 328 (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit"))) { 329 trussinfo->curthread->in_syscall = 1; 330 } 331 332 333 /* 334 * It would probably be a good idea to merge the error handling, 335 * but that complicates things considerably. 336 */ 337 338 print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp, 339 retval, fsc.sc); 340 clear_fsc(); 341 342 return (retval); 343} 344