amd64-freebsd32.c revision 32275
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 "$Id$"; 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 <errno.h> 46#include <fcntl.h> 47#include <signal.h> 48#include <stdio.h> 49#include <stdlib.h> 50#include <string.h> 51#include <unistd.h> 52#include <sys/ioctl.h> 53#include <sys/pioctl.h> 54#include <machine/reg.h> 55#include <machine/psl.h> 56#include <sys/syscall.h> 57 58#include "syscall.h" 59 60static int fd = -1; 61static int cpid = -1; 62extern int Procfd; 63 64extern FILE *outfile; 65#include "syscalls.h" 66 67static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]); 68 69/* 70 * This is what this particular file uses to keep track of a system call. 71 * It is probably not quite sufficient -- I can probably use the same 72 * structure for the various syscall personalities, and I also probably 73 * need to nest system calls (for signal handlers). 74 * 75 * 'struct syscall' describes the system call; it may be NULL, however, 76 * if we don't know about this particular system call yet. 77 */ 78static struct freebsd_syscall { 79 struct syscall *sc; 80 char *name; 81 int number; 82 unsigned long *args; 83 int nargs; /* number of arguments -- *not* number of words! */ 84 char **s_args; /* the printable arguments */ 85} fsc; 86 87/* Clear up and free parts of the fsc structure. */ 88static inline void 89clear_fsc() { 90 if (fsc.args) { 91 free(fsc.args); 92 } 93 if (fsc.s_args) { 94 int i; 95 for (i = 0; i < fsc.nargs; i++) 96 if (fsc.s_args[i]) 97 free(fsc.s_args[i]); 98 free(fsc.s_args); 99 } 100 memset(&fsc, 0, sizeof(fsc)); 101} 102 103/* 104 * Called when a process has entered a system call. nargs is the 105 * number of words, not number of arguments (a necessary distinction 106 * in some cases). Note that if the STOPEVENT() code in i386/i386/trap.c 107 * is ever changed these functions need to keep up. 108 */ 109 110void 111i386_syscall_entry(int pid, int nargs) { 112 char buf[32]; 113 struct reg regs = { 0 }; 114 int syscall; 115 int i; 116 unsigned int parm_offset; 117 struct syscall *sc; 118 119 if (fd == -1 || pid != cpid) { 120 sprintf(buf, "/proc/%d/regs", pid); 121 fd = open(buf, O_RDWR); 122 if (fd == -1) { 123 fprintf(outfile, "-- CANNOT READ REGISTERS --\n"); 124 return; 125 } 126 cpid = pid; 127 } 128 129 clear_fsc(); 130 lseek(fd, 0L, 0); 131 i = read(fd, ®s, sizeof(regs)); 132 parm_offset = regs.r_esp + sizeof(int); 133 134 /* 135 * FreeBSD has two special kinds of system call redirctions -- 136 * SYS_syscall, and SYS___syscall. The former is the old syscall() 137 * routine, basicly; the latter is for quad-aligned arguments. 138 */ 139 syscall = regs.r_eax; 140 switch (syscall) { 141 case SYS_syscall: 142 lseek(Procfd, parm_offset, SEEK_SET); 143 read(Procfd, &syscall, sizeof(int)); 144 parm_offset += sizeof(int); 145 break; 146 case SYS___syscall: 147 lseek(Procfd, parm_offset, SEEK_SET); 148 read(Procfd, &syscall, sizeof(int)); 149 parm_offset += sizeof(quad_t); 150 break; 151 } 152 153 fsc.number = syscall; 154 fsc.name = 155 (syscall < 0 || syscall > nsyscalls) ? NULL : syscallnames[syscall]; 156 if (!fsc.name) { 157 fprintf(outfile, "-- UNKNOWN SYSCALL %d --\n", syscall); 158 } 159 160 if (nargs == 0) 161 return; 162 163 fsc.args = malloc((1+nargs) * sizeof(unsigned long)); 164 lseek(Procfd, parm_offset, SEEK_SET); 165 if (read(Procfd, fsc.args, nargs * sizeof(unsigned long)) == -1) 166 return; 167 168 sc = get_syscall(fsc.name); 169 if (sc) { 170 fsc.nargs = sc->nargs; 171 } else { 172#if DEBUG 173 fprintf(outfile, "unknown syscall %s -- setting args to %d\n", 174 fsc.name, nargs); 175#endif 176 fsc.nargs = nargs; 177 } 178 179 fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*)); 180 memset(fsc.s_args, 0, fsc.nargs * sizeof(char*)); 181 fsc.sc = sc; 182 183 /* 184 * At this point, we set up the system call arguments. 185 * We ignore any OUT ones, however -- those are arguments that 186 * are set by the system call, and so are probably meaningless 187 * now. This doesn't currently support arguments that are 188 * passed in *and* out, however. 189 */ 190 191 if (fsc.name) { 192 193#if DEBUG 194 fprintf(stderr, "syscall %s(", fsc.name); 195#endif 196 for (i = 0; i < fsc.nargs; i++) { 197#if DEBUG 198 fprintf(stderr, "0x%x%s", 199 sc 200 ? fsc.args[sc->args[i].offset] 201 : fsc.args[i], 202 i < (fsc.nargs -1) ? "," : ""); 203#endif 204 if (sc && !(sc->args[i].type & OUT)) { 205 fsc.s_args[i] = print_arg(Procfd, &sc->args[i], fsc.args); 206 } 207 } 208#if DEBUG 209 fprintf(stderr, ")\n"); 210#endif 211 } 212 213#if DEBUG 214 fprintf(outfile, "\n"); 215#endif 216 217 /* 218 * Some system calls should be printed out before they are done -- 219 * execve() and exit(), for example, never return. Possibly change 220 * this to work for any system call that doesn't have an OUT 221 * parameter? 222 */ 223 224 if (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit")) { 225 print_syscall(outfile, fsc.name, fsc.nargs, fsc.s_args); 226 } 227 228 return; 229} 230 231/* 232 * And when the system call is done, we handle it here. 233 * Currently, no attempt is made to ensure that the system calls 234 * match -- this needs to be fixed (and is, in fact, why S_SCX includes 235 * the sytem call number instead of, say, an error status). 236 */ 237 238void 239i386_syscall_exit(int pid, int syscall) { 240 char buf[32]; 241 struct reg regs; 242 int retval; 243 int i; 244 int errorp; 245 struct syscall *sc; 246 247 if (fd == -1 || pid != cpid) { 248 sprintf(buf, "/proc/%d/regs", pid); 249 fd = open(buf, O_RDONLY); 250 if (fd == -1) { 251 fprintf(outfile, "-- CANNOT READ REGISTERS --\n"); 252 return; 253 } 254 cpid = pid; 255 } 256 257 lseek(fd, 0L, 0); 258 if (read(fd, ®s, sizeof(regs)) != sizeof(regs)) 259 return; 260 retval = regs.r_eax; 261 errorp = !!(regs.r_eflags & PSL_C); 262 263 /* 264 * This code, while simpler than the initial versions I used, could 265 * stand some significant cleaning. 266 */ 267 268 sc = fsc.sc; 269 if (!sc) { 270 for (i = 0; i < fsc.nargs; i++) { 271 fsc.s_args[i] = malloc(12); 272 sprintf(fsc.s_args[i], "0x%x", fsc.args[i]); 273 } 274 } else { 275 /* 276 * Here, we only look for arguments that have OUT masked in -- 277 * otherwise, they were handled in the syscall_entry function. 278 */ 279 for (i = 0; i < sc->nargs; i++) { 280 char *temp; 281 if (sc->args[i].type & OUT) { 282 /* 283 * If an error occurred, than don't bothe getting the data; 284 * it may not be valid. 285 */ 286 if (errorp) { 287 temp = malloc(12); 288 sprintf(temp, "0x%x", fsc.args[sc->args[i].offset]); 289 } else { 290 temp = print_arg(Procfd, &sc->args[i], fsc.args); 291 } 292 fsc.s_args[i] = temp; 293 } 294 } 295 } 296 297 /* 298 * It would probably be a good idea to merge the error handling, 299 * but that complicates things considerably. 300 */ 301 302 print_syscall(outfile, fsc.name, fsc.nargs, fsc.s_args); 303 if (errorp) { 304 fprintf(outfile, "errno %d '%s'\n", retval, strerror(retval)); 305 } else { 306 fprintf(outfile, "returns %d (0x%x)\n", retval, retval); 307 } 308 clear_fsc(); 309 310 return; 311} 312