/* * Copryight 1997 Sean Eric Fagan * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Sean Eric Fagan * 4. Neither the name of the author may be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint static const char rcsid[] = "$FreeBSD$"; #endif /* not lint */ /* * Linux/i386-specific system call handling. Given how much of this code * is taken from the freebsd equivalent, I can probably put even more of * it in support routines that can be used by any personality support. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "truss.h" #include "syscall.h" #include "extern.h" static int cpid = -1; #include "linux_syscalls.h" static int nsyscalls = sizeof(linux_syscallnames) / sizeof(linux_syscallnames[0]); /* * This is what this particular file uses to keep track of a system call. * It is probably not quite sufficient -- I can probably use the same * structure for the various syscall personalities, and I also probably * need to nest system calls (for signal handlers). * * 'struct syscall' describes the system call; it may be NULL, however, * if we don't know about this particular system call yet. */ static struct linux_syscall { struct syscall *sc; const char *name; int number; unsigned long args[5]; int nargs; /* number of arguments -- *not* number of words! */ char **s_args; /* the printable arguments */ } fsc; /* Clear up and free parts of the fsc structure. */ static __inline void clear_fsc(void) { if (fsc.s_args) { int i; for (i = 0; i < fsc.nargs; i++) if (fsc.s_args[i]) free(fsc.s_args[i]); free(fsc.s_args); } memset(&fsc, 0, sizeof(fsc)); } /* * Called when a process has entered a system call. nargs is the * number of words, not number of arguments (a necessary distinction * in some cases). Note that if the STOPEVENT() code in i386/i386/trap.c * is ever changed these functions need to keep up. */ void i386_linux_syscall_entry(struct trussinfo *trussinfo, int nargs) { struct reg regs; int syscall_num; int i; struct syscall *sc; cpid = trussinfo->curthread->tid; clear_fsc(); if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0) { fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); return; } syscall_num = regs.r_eax; fsc.number = syscall_num; fsc.name = (syscall_num < 0 || syscall_num > nsyscalls) ? NULL : linux_syscallnames[syscall_num]; if (!fsc.name) { fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", syscall_num); } if (fsc.name && (trussinfo->flags & FOLLOWFORKS) && ((!strcmp(fsc.name, "linux_fork") || !strcmp(fsc.name, "linux_vfork")))) { trussinfo->curthread->in_fork = 1; } if (nargs == 0) return; /* * Linux passes syscall arguments in registers, not * on the stack. Fortunately, we've got access to the * register set. Note that we don't bother checking the * number of arguments. And what does linux do for syscalls * that have more than five arguments? */ fsc.args[0] = regs.r_ebx; fsc.args[1] = regs.r_ecx; fsc.args[2] = regs.r_edx; fsc.args[3] = regs.r_esi; fsc.args[4] = regs.r_edi; sc = get_syscall(fsc.name); if (sc) { fsc.nargs = sc->nargs; } else { #if DEBUG fprintf(trussinfo->outfile, "unknown syscall %s -- setting args to %d\n", fsc.name, nargs); #endif fsc.nargs = nargs; } fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*)); memset(fsc.s_args, 0, fsc.nargs * sizeof(char*)); fsc.sc = sc; /* * At this point, we set up the system call arguments. * We ignore any OUT ones, however -- those are arguments that * are set by the system call, and so are probably meaningless * now. This doesn't currently support arguments that are * passed in *and* out, however. */ if (fsc.name) { #if DEBUG fprintf(stderr, "syscall %s(", fsc.name); #endif for (i = 0; i < fsc.nargs; i++) { #if DEBUG fprintf(stderr, "0x%x%s", sc ? fsc.args[sc->args[i].offset] : fsc.args[i], i < (fsc.nargs - 1) ? "," : ""); #endif if (sc && !(sc->args[i].type & OUT)) { fsc.s_args[i] = print_arg(&sc->args[i], fsc.args, 0, trussinfo); } } #if DEBUG fprintf(stderr, ")\n"); #endif } #if DEBUG fprintf(trussinfo->outfile, "\n"); #endif if (fsc.name != NULL && (!strcmp(fsc.name, "linux_execve") || !strcmp(fsc.name, "exit"))) { /* XXX * This could be done in a more general * manner but it still wouldn't be very pretty. */ if (!strcmp(fsc.name, "linux_execve")) { if ((trussinfo->flags & EXECVEARGS) == 0) if (fsc.s_args[1]) { free(fsc.s_args[1]); fsc.s_args[1] = NULL; } if ((trussinfo->flags & EXECVEENVS) == 0) if (fsc.s_args[2]) { free(fsc.s_args[2]); fsc.s_args[2] = NULL; } } } return; } /* * Linux syscalls return negative errno's, we do positive and map them */ const int bsd_to_linux_errno[] = { -0, -1, -2, -3, -4, -5, -6, -7, -8, -9, -10, -35, -12, -13, -14, -15, -16, -17, -18, -19, -20, -21, -22, -23, -24, -25, -26, -27, -28, -29, -30, -31, -32, -33, -34, -11,-115,-114, -88, -89, -90, -91, -92, -93, -94, -95, -96, -97, -98, -99, -100,-101,-102,-103,-104,-105,-106,-107,-108,-109, -110,-111, -40, -36,-112,-113, -39, -11, -87,-122, -116, -66, -6, -6, -6, -6, -6, -37, -38, -9, -6, }; long i386_linux_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused) { struct reg regs; long retval; int i; int errorp; struct syscall *sc; if (fsc.name == NULL) return (-1); cpid = trussinfo->curthread->tid; if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0) { fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); return (-1); } retval = regs.r_eax; errorp = !!(regs.r_eflags & PSL_C); /* * This code, while simpler than the initial versions I used, could * stand some significant cleaning. */ sc = fsc.sc; if (!sc) { for (i = 0; i < fsc.nargs; i++) asprintf(&fsc.s_args[i], "0x%lx", fsc.args[i]); } else { /* * Here, we only look for arguments that have OUT masked in -- * otherwise, they were handled in the syscall_entry function. */ for (i = 0; i < sc->nargs; i++) { char *temp; if (sc->args[i].type & OUT) { /* * If an error occurred, than don't bothe getting the data; * it may not be valid. */ if (errorp) asprintf(&temp, "0x%lx", fsc.args[sc->args[i].offset]); else temp = print_arg(&sc->args[i], fsc.args, retval, trussinfo); fsc.s_args[i] = temp; } } } /* * It would probably be a good idea to merge the error handling, * but that complicates things considerably. */ if (errorp) { for (i = 0; (size_t)i < sizeof(bsd_to_linux_errno) / sizeof(int); i++) if (retval == bsd_to_linux_errno[i]) break; } if (fsc.name != NULL && (!strcmp(fsc.name, "linux_execve") || !strcmp(fsc.name, "exit"))) { trussinfo->curthread->in_syscall = 1; } print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp, errorp ? i : retval, fsc.sc); clear_fsc(); return (retval); }