/* * Copyright 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. */ /* * FreeBSD/arm-specific system call handling. This is probably the most * complex part of the entire truss program, although I've got lots of * it handled relatively cleanly now. The system call names are generated * automatically, thanks to /usr/src/sys/kern/syscalls.master. The * names used for the various structures are confusing, I sadly admit. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "truss.h" #include "syscall.h" #include "extern.h" #include "syscalls.h" static int nsyscalls = nitems(syscallnames); /* * 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. */ struct freebsd_syscall { struct syscall *sc; const char *name; int number; unsigned long *args; int nargs; /* number of arguments -- *not* number of words! */ char **s_args; /* the printable arguments */ }; static struct freebsd_syscall * alloc_fsc(void) { return (malloc(sizeof(struct freebsd_syscall))); } /* Clear up and free parts of the fsc structure. */ static void free_fsc(struct freebsd_syscall *fsc) { int i; free(fsc->args); if (fsc->s_args) { for (i = 0; i < fsc->nargs; i++) free(fsc->s_args[i]); free(fsc->s_args); } free(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 arm_syscall_entry(struct trussinfo *trussinfo, int nargs) { struct ptrace_io_desc iorequest; struct reg regs; struct freebsd_syscall *fsc; struct syscall *sc; lwpid_t tid; int i, syscall_num; register_t *ap; tid = trussinfo->curthread->tid; if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) { fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); return; } ap = ®s.r[0]; /* * FreeBSD has two special kinds of system call redirctions -- * SYS_syscall, and SYS___syscall. The former is the old syscall() * routine, basically; the latter is for quad-aligned arguments. */ #ifdef __ARM_EABI__ syscall_num = regs.r[7]; #else if ((syscall_num = ptrace(PT_READ_I, tid, (caddr_t)(regs.r[_REG_PC] - INSN_SIZE), 0)) == -1) { fprintf(trussinfo->outfile, "-- CANNOT READ PC --\n"); return; } syscall_num = syscall_num & 0x000fffff; #endif switch (syscall_num) { case SYS_syscall: syscall_num = *ap++; nargs--; break; case SYS___syscall: syscall_num = ap[_QUAD_LOWWORD]; ap += 2; nargs -= 2; break; } fsc = alloc_fsc(); if (fsc == NULL) return; fsc->number = syscall_num; fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ? NULL : syscallnames[syscall_num]; if (!fsc->name) { fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", syscall_num); } if (fsc->name && (trussinfo->flags & FOLLOWFORKS) && (strcmp(fsc->name, "fork") == 0 || strcmp(fsc->name, "pdfork") == 0 || strcmp(fsc->name, "rfork") == 0 || strcmp(fsc->name, "vfork") == 0)) trussinfo->curthread->in_fork = 1; if (nargs == 0) return; fsc->args = malloc((1 + nargs) * sizeof(unsigned long)); switch (nargs) { default: /* * The OS doesn't seem to allow more than 10 words of * parameters (yay!). So we shouldn't be here. */ warn("More than 10 words (%d) of arguments!\n", nargs); break; case 10: case 9: case 8: case 7: case 6: case 5: /* * If there are 7-10 words of arguments, they are placed * on the stack, as is normal for other processors. * The fall-through for all of these is deliberate!!! */ // XXX BAD constant used here iorequest.piod_op = PIOD_READ_D; iorequest.piod_offs = (void *)(regs.r_sp + 4 * sizeof(uint32_t)); iorequest.piod_addr = &fsc->args[4]; iorequest.piod_len = (nargs - 4) * sizeof(fsc->args[0]); ptrace(PT_IO, tid, (caddr_t)&iorequest, 0); if (iorequest.piod_len == 0) return; case 4: fsc->args[3] = ap[3]; case 3: fsc->args[2] = ap[2]; case 2: fsc->args[1] = ap[1]; case 1: fsc->args[0] = ap[0]; case 0: break; } sc = NULL; if (fsc->name) 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 = calloc(1, (1 + 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 trussinfo->curthread->fsc = fsc; } /* * And when the system call is done, we handle it here. * Currently, no attempt is made to ensure that the system calls * match -- this needs to be fixed (and is, in fact, why S_SCX includes * the system call number instead of, say, an error status). */ long arm_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused) { struct reg regs; struct freebsd_syscall *fsc; struct syscall *sc; lwpid_t tid; long retval; int errorp, i; if (trussinfo->curthread->fsc == NULL) return (-1); tid = trussinfo->curthread->tid; if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) { fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); return (-1); } retval = regs.r[0]; errorp = !!(regs.r_cpsr & PSR_C); /* * This code, while simpler than the initial versions I used, could * stand some significant cleaning. */ fsc = trussinfo->curthread->fsc; 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, then don't bother * 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; } } } if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 || strcmp(fsc->name, "exit") == 0)) trussinfo->curthread->in_syscall = 1; /* * It would probably be a good idea to merge the error handling, * but that complicates things considerably. */ print_syscall_ret(trussinfo, fsc->name, fsc->nargs, fsc->s_args, errorp, retval, fsc->sc); free_fsc(fsc); return (retval); }