usr.bin/truss/i386-linux.c

   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  * $FreeBSD: src/usr.bin/truss/i386-linux.c,v 1.7.2.4 2002/02/15 11:43:51 des Exp $
  32  * $DragonFly: src/usr.bin/truss/i386-linux.c,v 1.4 2003/11/04 15:34:41 eirikn Exp $
  33  */
  34
  35 /*
  36  * Linux/i386-specific system call handling.  Given how much of this code
  37  * is taken from the freebsd equivalent, I can probably put even more of
  38  * it in support routines that can be used by any personality support.
  39  */
  40
  41 #include <sys/types.h>
  42 #include <sys/ioctl.h>
  43 #include <sys/pioctl.h>
  44
  45 #include <machine/reg.h>
  46 #include <machine/psl.h>
  47
  48 #include <errno.h>
  49 #include <fcntl.h>
  50 #include <signal.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <unistd.h>
  55
  56 #include "extern.h"
  57 #include "syscall.h"
  58
  59 static int fd = -1;
  60 static int cpid = -1;
  61 extern int Procfd;
  62
  63 extern FILE *outfile;
  64 #include "linux_syscalls.h"
  65
  66 static int nsyscalls =
  67         sizeof(linux_syscallnames) / sizeof(linux_syscallnames[0]);
  68
  69 /* See the comment in i386-fbsd.c about this structure. */
  70 static struct linux_syscall {
  71         struct syscall *sc;
  72         char *name;
  73         int number;
  74         unsigned long args[5];
  75         int nargs;      /* number of arguments -- *not* number of words! */
  76         char **s_args;  /* the printable arguments */
  77 } lsc;
  78
  79 static inline void
  80 clear_lsc(void) {
  81   if (lsc.s_args) {
  82     int i;
  83     for (i = 0; i < lsc.nargs; i++)
  84       if (lsc.s_args[i])
  85         free(lsc.s_args[i]);
  86     free(lsc.s_args);
  87   }
  88   memset(&lsc, 0, sizeof(lsc));
  89 }
  90
  91 void
  92 i386_linux_syscall_entry(int pid, int nargs) {
  93   char *buf;
  94   struct reg regs = { 0 };
  95   int syscall;
  96   int i;
  97   struct syscall *sc;
  98
  99   if (fd == -1 || pid != cpid) {
 100     asprintf(&buf, "%s/%d/regs", procfs_path, pid);
 101     if (buf == NULL)
 102       err(1, "Out of memory");
 103     fd = open(buf, O_RDWR);
 104     free(buf);
 105     if (fd == -1) {
 106       fprintf(outfile, "-- CANNOT READ REGISTERS --\n");
 107       return;
 108     }
 109     cpid = pid;
 110   }
 111
 112   clear_lsc();
 113   lseek(fd, 0L, 0);
 114   i = read(fd, &regs, sizeof(regs));
 115   syscall = regs.r_eax;
 116
 117   lsc.number = syscall;
 118   lsc.name =
 119     (syscall < 0 || syscall > nsyscalls) ? NULL : linux_syscallnames[syscall];
 120   if (!lsc.name) {
 121     fprintf (outfile, "-- UNKNOWN SYSCALL %d\n", syscall);
 122   }
 123
 124   if (nargs == 0)
 125     return;
 126
 127   /*
 128    * Linux passes syscall arguments in registers, not
 129    * on the stack.  Fortunately, we've got access to the
 130    * register set.  Note that we don't bother checking the
 131    * number of arguments.  And what does linux do for syscalls
 132    * that have more than five arguments?
 133    */
 134
 135   lsc.args[0] = regs.r_ebx;
 136   lsc.args[1] = regs.r_ecx;
 137   lsc.args[2] = regs.r_edx;
 138   lsc.args[3] = regs.r_esi;
 139   lsc.args[4] = regs.r_edi;
 140
 141   sc = get_syscall(lsc.name);
 142   if (sc) {
 143     lsc.nargs = sc->nargs;
 144   } else {
 145 #ifdef DEBUG
 146     fprintf(outfile, "unknown syscall %s -- setting args to %d\n",
 147             lsc.name, nargs);
 148 #endif
 149     lsc.nargs = nargs;
 150   }
 151
 152   lsc.s_args = malloc((1+lsc.nargs) * sizeof(char*));
 153   memset(lsc.s_args, 0, lsc.nargs * sizeof(char*));
 154   lsc.sc = sc;
 155
 156   if (lsc.name) {
 157
 158 #ifdef DEBUG
 159     fprintf(stderr, "syscall %s(", lsc.name);
 160 #endif
 161     for (i = 0; i < lsc.nargs ; i++) {
 162 #ifdef DEBUG
 163       fprintf(stderr, "0x%x%s",
 164               sc ?
 165               lsc.args[sc->args[i].offset]
 166               : lsc.args[i],
 167               i < (lsc.nargs - 1) ? "," : "");
 168 #endif
 169       if (sc && !(sc->args[i].type & OUT)) {
 170         lsc.s_args[i] = print_arg(Procfd, &sc->args[i], lsc.args);
 171       }
 172     }
 173 #ifdef DEBUG
 174     fprintf(stderr, ")\n");
 175 #endif
 176   }
 177
 178   if (!strcmp(lsc.name, "linux_execve") || !strcmp(lsc.name, "exit")) {
 179     print_syscall(outfile, lsc.name, lsc.nargs, lsc.s_args);
 180   }
 181
 182   return;
 183 }
 184
 185 /*
 186  * Linux syscalls return negative errno's, we do positive and map them
 187  */
 188 const int bsd_to_linux_errno[] = {
 189         -0,  -1,  -2,  -3,  -4,  -5,  -6,  -7,  -8,  -9,
 190         -10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
 191         -20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
 192         -30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
 193         -90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
 194         -100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
 195         -110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
 196         -116, -66,  -6,  -6,  -6,  -6,  -6, -37, -38,  -9,
 197         -6,
 198 };
 199
 200 void
 201 i386_linux_syscall_exit(int pid, int syscall) {
 202   char *buf;
 203   struct reg regs;
 204   int retval;
 205   int size, i;
 206   int errorp;
 207   struct syscall *sc;
 208
 209   if (fd == -1 || pid != cpid) {
 210     asprintf(&buf, "%s/%d/regs", procfs_path, pid);
 211     if (buf == NULL)
 212       err(1, "Out of memory");
 213     fd = open(buf, O_RDONLY);
 214     free(buf);
 215     if (fd == -1) {
 216       fprintf(outfile, "-- CANNOT READ REGISTERS --\n");
 217       return;
 218     }
 219     cpid = pid;
 220   }
 221
 222   lseek(fd, 0L, 0);
 223   if (read(fd, &regs, sizeof(regs)) != sizeof(regs))
 224     return;
 225
 226   retval = regs.r_eax;
 227   errorp = !!(regs.r_eflags & PSL_C);
 228
 229   sc = lsc.sc;
 230   if (!sc) {
 231     for (i = 0; i < lsc.nargs; i++) {
 232       lsc.s_args[i] = malloc(12);
 233       sprintf(lsc.s_args[i], "0x%lx", lsc.args[i]);
 234     }
 235   } else {
 236     for (i = 0; i < sc->nargs; i++) {
 237       char *temp;
 238       if (sc->args[i].type & OUT) {
 239         if (errorp) {
 240           temp = malloc(12);
 241           sprintf(temp, "0x%lx", lsc.args[sc->args[i].offset]);
 242         } else {
 243           temp = print_arg(Procfd, &sc->args[i], lsc.args);
 244         }
 245         lsc.s_args[i] = temp;
 246       }
 247     }
 248   }
 249   if (errorp) {
 250     for (i = 0; i < sizeof(bsd_to_linux_errno) / sizeof(int); i++)
 251       if (retval == bsd_to_linux_errno[i])
 252       break;
 253   }
 254   print_syscall_ret(outfile, lsc.name, lsc.nargs, lsc.s_args, errorp,
 255     errorp ? i : retval);
 256   clear_lsc();
 257   return;
 258 }