i386-fbsd.c revision 101283
1207753Smm/* 2207753Smm * Copryight 1997 Sean Eric Fagan 3207753Smm * 4207753Smm * Redistribution and use in source and binary forms, with or without 5207753Smm * modification, are permitted provided that the following conditions 6207753Smm * are met: 7207753Smm * 1. Redistributions of source code must retain the above copyright 8207753Smm * notice, this list of conditions and the following disclaimer. 9207753Smm * 2. Redistributions in binary form must reproduce the above copyright 10207753Smm * notice, this list of conditions and the following disclaimer in the 11207753Smm * documentation and/or other materials provided with the distribution. 12207753Smm * 3. All advertising materials mentioning features or use of this software 13207753Smm * must display the following acknowledgement: 14207753Smm * This product includes software developed by Sean Eric Fagan 15207753Smm * 4. Neither the name of the author may be used to endorse or promote 16207753Smm * products derived from this software without specific prior written 17207753Smm * permission. 18207753Smm * 19207753Smm * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20207753Smm * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21215187Smm * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22215187Smm * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23215187Smm * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24215187Smm * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25207753Smm * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26207753Smm * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27207753Smm * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28207753Smm * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29207753Smm * SUCH DAMAGE. 30207753Smm */ 31215187Smm 32215187Smm#ifndef lint 33215187Smmstatic const char rcsid[] = 34207753Smm "$FreeBSD: head/usr.bin/truss/i386-fbsd.c 101283 2002-08-04 01:02:52Z mdodd $"; 35215187Smm#endif /* not lint */ 36207753Smm 37207753Smm/* 38207753Smm * FreeBSD/386-specific system call handling. This is probably the most 39207753Smm * complex part of the entire truss program, although I've got lots of 40207753Smm * it handled relatively cleanly now. The system call names are generated 41207753Smm * automatically, thanks to /usr/src/sys/kern/syscalls.master. The 42207753Smm * names used for the various structures are confusing, I sadly admit. 43207753Smm */ 44207753Smm 45207753Smm#include <sys/types.h> 46207753Smm#include <sys/ioctl.h> 47207753Smm#include <sys/pioctl.h> 48207753Smm#include <sys/syscall.h> 49215187Smm 50215187Smm#include <machine/reg.h> 51215187Smm#include <machine/psl.h> 52207753Smm 53207753Smm#include <errno.h> 54207753Smm#include <fcntl.h> 55215187Smm#include <signal.h> 56207753Smm#include <stdio.h> 57207753Smm#include <stdlib.h> 58207753Smm#include <string.h> 59207753Smm#include <unistd.h> 60207753Smm 61207753Smm#include "truss.h" 62207753Smm#include "syscall.h" 63207753Smm 64207753Smmstatic int fd = -1; 65207753Smmstatic int cpid = -1; 66207753Smmextern int Procfd; 67207753Smm 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 } 238 239 return; 240} 241 242/* 243 * And when the system call is done, we handle it here. 244 * Currently, no attempt is made to ensure that the system calls 245 * match -- this needs to be fixed (and is, in fact, why S_SCX includes 246 * the sytem call number instead of, say, an error status). 247 */ 248 249int 250i386_syscall_exit(struct trussinfo *trussinfo, int syscall) { 251 char buf[32]; 252 struct reg regs; 253 int retval; 254 int i; 255 int errorp; 256 struct syscall *sc; 257 258 if (fd == -1 || trussinfo->pid != cpid) { 259 sprintf(buf, "/proc/%d/regs", trussinfo->pid); 260 fd = open(buf, O_RDONLY); 261 if (fd == -1) { 262 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 263 return; 264 } 265 cpid = trussinfo->pid; 266 } 267 268 lseek(fd, 0L, 0); 269 if (read(fd, ®s, sizeof(regs)) != sizeof(regs)) { 270 fprintf(trussinfo->outfile, "\n"); 271 return; 272 } 273 retval = regs.r_eax; 274 errorp = !!(regs.r_eflags & PSL_C); 275 276 /* 277 * This code, while simpler than the initial versions I used, could 278 * stand some significant cleaning. 279 */ 280 281 sc = fsc.sc; 282 if (!sc) { 283 for (i = 0; i < fsc.nargs; i++) { 284 fsc.s_args[i] = malloc(12); 285 sprintf(fsc.s_args[i], "0x%lx", fsc.args[i]); 286 } 287 } else { 288 /* 289 * Here, we only look for arguments that have OUT masked in -- 290 * otherwise, they were handled in the syscall_entry function. 291 */ 292 for (i = 0; i < sc->nargs; i++) { 293 char *temp; 294 if (sc->args[i].type & OUT) { 295 /* 296 * If an error occurred, than don't bothe getting the data; 297 * it may not be valid. 298 */ 299 if (errorp) { 300 temp = malloc(12); 301 sprintf(temp, "0x%lx", fsc.args[sc->args[i].offset]); 302 } else { 303 temp = print_arg(Procfd, &sc->args[i], fsc.args); 304 } 305 fsc.s_args[i] = temp; 306 } 307 } 308 } 309 310 /* 311 * It would probably be a good idea to merge the error handling, 312 * but that complicates things considerably. 313 */ 314 315 print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp, retval); 316 clear_fsc(); 317 318 return (retval); 319} 320