i386-fbsd.c revision 101286
1/* 2 * Copryight 1997 Sean Eric Fagan 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. All advertising materials mentioning features or use of this software 13 * must display the following acknowledgement: 14 * This product includes software developed by Sean Eric Fagan 15 * 4. Neither the name of the author may be used to endorse or promote 16 * products derived from this software without specific prior written 17 * permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32#ifndef lint 33static const char rcsid[] = 34 "$FreeBSD: head/usr.bin/truss/i386-fbsd.c 101286 2002-08-04 01:28:13Z mdodd $"; 35#endif /* not lint */ 36 37/* 38 * FreeBSD/386-specific system call handling. This is probably the most 39 * complex part of the entire truss program, although I've got lots of 40 * it handled relatively cleanly now. The system call names are generated 41 * automatically, thanks to /usr/src/sys/kern/syscalls.master. The 42 * names used for the various structures are confusing, I sadly admit. 43 */ 44 45#include <sys/types.h> 46#include <sys/ioctl.h> 47#include <sys/pioctl.h> 48#include <sys/syscall.h> 49 50#include <machine/reg.h> 51#include <machine/psl.h> 52 53#include <errno.h> 54#include <fcntl.h> 55#include <signal.h> 56#include <stdio.h> 57#include <stdlib.h> 58#include <string.h> 59#include <unistd.h> 60 61#include "truss.h" 62#include "syscall.h" 63 64static int fd = -1; 65static int cpid = -1; 66extern int Procfd; 67 68#include "syscalls.h" 69 70static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]); 71 72/* 73 * This is what this particular file uses to keep track of a system call. 74 * It is probably not quite sufficient -- I can probably use the same 75 * structure for the various syscall personalities, and I also probably 76 * need to nest system calls (for signal handlers). 77 * 78 * 'struct syscall' describes the system call; it may be NULL, however, 79 * if we don't know about this particular system call yet. 80 */ 81static struct freebsd_syscall { 82 struct syscall *sc; 83 char *name; 84 int number; 85 unsigned long *args; 86 int nargs; /* number of arguments -- *not* number of words! */ 87 char **s_args; /* the printable arguments */ 88} fsc; 89 90/* Clear up and free parts of the fsc structure. */ 91static __inline void 92clear_fsc() { 93 if (fsc.args) { 94 free(fsc.args); 95 } 96 if (fsc.s_args) { 97 int i; 98 for (i = 0; i < fsc.nargs; i++) 99 if (fsc.s_args[i]) 100 free(fsc.s_args[i]); 101 free(fsc.s_args); 102 } 103 memset(&fsc, 0, sizeof(fsc)); 104} 105 106/* 107 * Called when a process has entered a system call. nargs is the 108 * number of words, not number of arguments (a necessary distinction 109 * in some cases). Note that if the STOPEVENT() code in i386/i386/trap.c 110 * is ever changed these functions need to keep up. 111 */ 112 113void 114i386_syscall_entry(struct trussinfo *trussinfo, int nargs) { 115 char buf[32]; 116 struct reg regs = { 0 }; 117 int syscall; 118 int i; 119 unsigned int parm_offset; 120 struct syscall *sc; 121 122 if (fd == -1 || trussinfo->pid != cpid) { 123 sprintf(buf, "/proc/%d/regs", trussinfo->pid); 124 fd = open(buf, O_RDWR); 125 if (fd == -1) { 126 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 127 return; 128 } 129 cpid = trussinfo->pid; 130 } 131 132 clear_fsc(); 133 lseek(fd, 0L, 0); 134 i = read(fd, ®s, sizeof(regs)); 135 parm_offset = regs.r_esp + sizeof(int); 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, basicly; the latter is for quad-aligned arguments. 141 */ 142 syscall = regs.r_eax; 143 switch (syscall) { 144 case SYS_syscall: 145 lseek(Procfd, parm_offset, SEEK_SET); 146 read(Procfd, &syscall, sizeof(int)); 147 parm_offset += sizeof(int); 148 break; 149 case SYS___syscall: 150 lseek(Procfd, parm_offset, SEEK_SET); 151 read(Procfd, &syscall, sizeof(int)); 152 parm_offset += sizeof(quad_t); 153 break; 154 } 155 156 fsc.number = syscall; 157 fsc.name = 158 (syscall < 0 || syscall > nsyscalls) ? NULL : syscallnames[syscall]; 159 if (!fsc.name) { 160 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", syscall); 161 } 162 163 if (fsc.name && (trussinfo->flags & FOLLOWFORKS) 164 && ((!strcmp(fsc.name, "fork") 165 || !strcmp(fsc.name, "rfork") 166 || !strcmp(fsc.name, "vfork")))) 167 { 168 trussinfo->in_fork = 1; 169 } 170 171 if (nargs == 0) 172 return; 173 174 fsc.args = malloc((1+nargs) * sizeof(unsigned long)); 175 lseek(Procfd, parm_offset, SEEK_SET); 176 if (read(Procfd, fsc.args, nargs * sizeof(unsigned long)) == -1) 177 return; 178 179 sc = get_syscall(fsc.name); 180 if (sc) { 181 fsc.nargs = sc->nargs; 182 } else { 183#if DEBUG 184 fprintf(trussinfo->outfile, "unknown syscall %s -- setting args to %d\n", 185 fsc.name, nargs); 186#endif 187 fsc.nargs = nargs; 188 } 189 190 fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*)); 191 memset(fsc.s_args, 0, fsc.nargs * sizeof(char*)); 192 fsc.sc = sc; 193 194 /* 195 * At this point, we set up the system call arguments. 196 * We ignore any OUT ones, however -- those are arguments that 197 * are set by the system call, and so are probably meaningless 198 * now. This doesn't currently support arguments that are 199 * passed in *and* out, however. 200 */ 201 202 if (fsc.name) { 203 204#if DEBUG 205 fprintf(stderr, "syscall %s(", fsc.name); 206#endif 207 for (i = 0; i < fsc.nargs; i++) { 208#if DEBUG 209 fprintf(stderr, "0x%x%s", 210 sc 211 ? fsc.args[sc->args[i].offset] 212 : fsc.args[i], 213 i < (fsc.nargs -1) ? "," : ""); 214#endif 215 if (sc && !(sc->args[i].type & OUT)) { 216 fsc.s_args[i] = print_arg(Procfd, &sc->args[i], fsc.args); 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 /* 229 * Some system calls should be printed out before they are done -- 230 * execve() and exit(), for example, never return. Possibly change 231 * this to work for any system call that doesn't have an OUT 232 * parameter? 233 */ 234 235 if (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit")) { 236 print_syscall(trussinfo, fsc.name, fsc.nargs, fsc.s_args); 237 fprintf(trussinfo->outfile, "\n"); 238 } 239 240 return; 241} 242 243/* 244 * And when the system call is done, we handle it here. 245 * Currently, no attempt is made to ensure that the system calls 246 * match -- this needs to be fixed (and is, in fact, why S_SCX includes 247 * the sytem call number instead of, say, an error status). 248 */ 249 250int 251i386_syscall_exit(struct trussinfo *trussinfo, int syscall) { 252 char buf[32]; 253 struct reg regs; 254 int retval; 255 int i; 256 int errorp; 257 struct syscall *sc; 258 259 if (fd == -1 || trussinfo->pid != cpid) { 260 sprintf(buf, "/proc/%d/regs", trussinfo->pid); 261 fd = open(buf, O_RDONLY); 262 if (fd == -1) { 263 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 264 return; 265 } 266 cpid = trussinfo->pid; 267 } 268 269 lseek(fd, 0L, 0); 270 if (read(fd, ®s, sizeof(regs)) != sizeof(regs)) { 271 fprintf(trussinfo->outfile, "\n"); 272 return; 273 } 274 retval = regs.r_eax; 275 errorp = !!(regs.r_eflags & PSL_C); 276 277 /* 278 * This code, while simpler than the initial versions I used, could 279 * stand some significant cleaning. 280 */ 281 282 sc = fsc.sc; 283 if (!sc) { 284 for (i = 0; i < fsc.nargs; i++) { 285 fsc.s_args[i] = malloc(12); 286 sprintf(fsc.s_args[i], "0x%lx", fsc.args[i]); 287 } 288 } else { 289 /* 290 * Here, we only look for arguments that have OUT masked in -- 291 * otherwise, they were handled in the syscall_entry function. 292 */ 293 for (i = 0; i < sc->nargs; i++) { 294 char *temp; 295 if (sc->args[i].type & OUT) { 296 /* 297 * If an error occurred, than don't bothe getting the data; 298 * it may not be valid. 299 */ 300 if (errorp) { 301 temp = malloc(12); 302 sprintf(temp, "0x%lx", fsc.args[sc->args[i].offset]); 303 } else { 304 temp = print_arg(Procfd, &sc->args[i], fsc.args); 305 } 306 fsc.s_args[i] = temp; 307 } 308 } 309 } 310 311 /* 312 * It would probably be a good idea to merge the error handling, 313 * but that complicates things considerably. 314 */ 315 316 print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp, retval); 317 clear_fsc(); 318 319 return (retval); 320} 321