1/* 2 * Copyright 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 "$FreeBSD$"; 35#endif /* not lint */ 36 37/* 38 * Linux/i386-specific system call handling. Given how much of this code 39 * is taken from the freebsd equivalent, I can probably put even more of 40 * it in support routines that can be used by any personality support. 41 */ 42 43#include <sys/types.h> 44#include <sys/ptrace.h> 45 46#include <machine/reg.h> 47#include <machine/psl.h> 48 49#include <errno.h> 50#include <fcntl.h> 51#include <signal.h> 52#include <stdio.h> 53#include <stdlib.h> 54#include <string.h> 55#include <time.h> 56#include <unistd.h> 57 58#include "truss.h" 59#include "syscall.h" 60#include "extern.h" 61 62#include "linux32_syscalls.h" 63 64static int nsyscalls = 65 sizeof(linux32_syscallnames) / sizeof(linux32_syscallnames[0]); 66 67/* 68 * This is what this particular file uses to keep track of a system call. 69 * It is probably not quite sufficient -- I can probably use the same 70 * structure for the various syscall personalities, and I also probably 71 * need to nest system calls (for signal handlers). 72 * 73 * 'struct syscall' describes the system call; it may be NULL, however, 74 * if we don't know about this particular system call yet. 75 */ 76struct linux_syscall { 77 struct syscall *sc; 78 const char *name; 79 int number; 80 unsigned long args[5]; 81 int nargs; /* number of arguments -- *not* number of words! */ 82 char **s_args; /* the printable arguments */ 83}; 84 85static struct linux_syscall * 86alloc_fsc(void) 87{ 88 89 return (malloc(sizeof(struct linux_syscall))); 90} 91 92/* Clear up and free parts of the fsc structure. */ 93static void 94free_fsc(struct linux_syscall *fsc) 95{ 96 int i; 97 98 if (fsc->s_args) { 99 for (i = 0; i < fsc->nargs; i++) 100 free(fsc->s_args[i]); 101 free(fsc->s_args); 102 } 103 free(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 114amd64_linux32_syscall_entry(struct trussinfo *trussinfo, int nargs) 115{ 116 struct reg regs; 117 struct linux_syscall *fsc; 118 struct syscall *sc; 119 lwpid_t tid; 120 int i, syscall_num; 121 122 tid = trussinfo->curthread->tid; 123 124 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) { 125 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 126 return; 127 } 128 129 syscall_num = regs.r_rax; 130 131 fsc = alloc_fsc(); 132 if (fsc == NULL) 133 return; 134 fsc->number = syscall_num; 135 fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ? 136 NULL : linux32_syscallnames[syscall_num]; 137 if (!fsc->name) { 138 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", 139 syscall_num); 140 } 141 142 if (fsc->name && (trussinfo->flags & FOLLOWFORKS) && 143 (strcmp(fsc->name, "linux_fork") == 0 || 144 strcmp(fsc->name, "linux_vfork") == 0)) 145 trussinfo->curthread->in_fork = 1; 146 147 if (nargs == 0) 148 return; 149 150 /* 151 * Linux passes syscall arguments in registers, not 152 * on the stack. Fortunately, we've got access to the 153 * register set. Note that we don't bother checking the 154 * number of arguments. And what does linux do for syscalls 155 * that have more than five arguments? 156 */ 157 158 fsc->args[0] = regs.r_rbx; 159 fsc->args[1] = regs.r_rcx; 160 fsc->args[2] = regs.r_rdx; 161 fsc->args[3] = regs.r_rsi; 162 fsc->args[4] = regs.r_rdi; 163 164 sc = get_syscall(fsc->name); 165 if (sc) 166 fsc->nargs = sc->nargs; 167 else { 168#if DEBUG 169 fprintf(trussinfo->outfile, "unknown syscall %s -- setting " 170 "args to %d\n", fsc->name, nargs); 171#endif 172 fsc->nargs = nargs; 173 } 174 175 fsc->s_args = calloc(1, (1 + fsc->nargs) * sizeof(char *)); 176 fsc->sc = sc; 177 178 /* 179 * At this point, we set up the system call arguments. 180 * We ignore any OUT ones, however -- those are arguments that 181 * are set by the system call, and so are probably meaningless 182 * now. This doesn't currently support arguments that are 183 * passed in *and* out, however. 184 */ 185 186 if (fsc->name) { 187#if DEBUG 188 fprintf(stderr, "syscall %s(", fsc->name); 189#endif 190 for (i = 0; i < fsc->nargs; i++) { 191#if DEBUG 192 fprintf(stderr, "0x%x%s", sc ? 193 fsc->args[sc->args[i].offset] : fsc->args[i], 194 i < (fsc->nargs - 1) ? "," : ""); 195#endif 196 if (sc && !(sc->args[i].type & OUT)) { 197 fsc->s_args[i] = print_arg(&sc->args[i], 198 fsc->args, 0, trussinfo); 199 } 200 } 201#if DEBUG 202 fprintf(stderr, ")\n"); 203#endif 204 } 205 206#if DEBUG 207 fprintf(trussinfo->outfile, "\n"); 208#endif 209 210 if (fsc->name != NULL && (strcmp(fsc->name, "linux_execve") == 0 || 211 strcmp(fsc->name, "exit") == 0)) { 212 /* 213 * XXX 214 * This could be done in a more general 215 * manner but it still wouldn't be very pretty. 216 */ 217 if (strcmp(fsc->name, "linux_execve") == 0) { 218 if ((trussinfo->flags & EXECVEARGS) == 0) { 219 if (fsc->s_args[1]) { 220 free(fsc->s_args[1]); 221 fsc->s_args[1] = NULL; 222 } 223 } 224 if ((trussinfo->flags & EXECVEENVS) == 0) { 225 if (fsc->s_args[2]) { 226 free(fsc->s_args[2]); 227 fsc->s_args[2] = NULL; 228 } 229 } 230 } 231 } 232 trussinfo->curthread->fsc = fsc; 233} 234 235/* 236 * Linux syscalls return negative errno's, we do positive and map them 237 */ 238const int bsd_to_linux_errno[] = { 239 -0, -1, -2, -3, -4, -5, -6, -7, -8, -9, 240 -10, -35, -12, -13, -14, -15, -16, -17, -18, -19, 241 -20, -21, -22, -23, -24, -25, -26, -27, -28, -29, 242 -30, -31, -32, -33, -34, -11,-115,-114, -88, -89, 243 -90, -91, -92, -93, -94, -95, -96, -97, -98, -99, 244 -100,-101,-102,-103,-104,-105,-106,-107,-108,-109, 245 -110,-111, -40, -36,-112,-113, -39, -11, -87,-122, 246 -116, -66, -6, -6, -6, -6, -6, -37, -38, -9, 247 -6, 248}; 249 250long 251amd64_linux32_syscall_exit(struct trussinfo *trussinfo, 252 int syscall_num __unused) 253{ 254 struct reg regs; 255 struct linux_syscall *fsc; 256 struct syscall *sc; 257 lwpid_t tid; 258 long retval; 259 int errorp, i; 260 261 if (trussinfo->curthread->fsc == NULL) 262 return (-1); 263 264 tid = trussinfo->curthread->tid; 265 266 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) { 267 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 268 return (-1); 269 } 270 271 retval = regs.r_rax; 272 errorp = !!(regs.r_rflags & PSL_C); 273 274 /* 275 * This code, while simpler than the initial versions I used, could 276 * stand some significant cleaning. 277 */ 278 279 fsc = trussinfo->curthread->fsc; 280 sc = fsc->sc; 281 if (!sc) { 282 for (i = 0; i < fsc->nargs; i++) 283 asprintf(&fsc->s_args[i], "0x%lx", fsc->args[i]); 284 } else { 285 /* 286 * Here, we only look for arguments that have OUT masked in -- 287 * otherwise, they were handled in the syscall_entry function. 288 */ 289 for (i = 0; i < sc->nargs; i++) { 290 char *temp; 291 if (sc->args[i].type & OUT) { 292 /* 293 * If an error occurred, then don't bother 294 * getting the data; it may not be valid. 295 */ 296 if (errorp) { 297 asprintf(&temp, "0x%lx", 298 fsc->args[sc->args[i].offset]); 299 } else { 300 temp = print_arg(&sc->args[i], 301 fsc->args, retval, trussinfo); 302 } 303 fsc->s_args[i] = temp; 304 } 305 } 306 } 307 308 /* 309 * It would probably be a good idea to merge the error handling, 310 * but that complicates things considerably. 311 */ 312 if (errorp) { 313 for (i = 0; 314 (size_t)i < sizeof(bsd_to_linux_errno) / sizeof(int); i++) { 315 if (retval == bsd_to_linux_errno[i]) 316 break; 317 } 318 } 319 320 if (fsc->name != NULL && (strcmp(fsc->name, "linux_execve") == 0 || 321 strcmp(fsc->name, "exit") == 0)) 322 trussinfo->curthread->in_syscall = 1; 323 324 print_syscall_ret(trussinfo, fsc->name, fsc->nargs, fsc->s_args, errorp, 325 errorp ? i : retval, fsc->sc); 326 free_fsc(fsc); 327 328 return (retval); 329} 330