int ptrace_machdep_dorequest(struct lwp *l, struct lwp *lt, int req, void *addr, int data) { struct uio uio; struct iovec iov; int write = 0; switch (req) { default: return EINVAL; #ifdef COMPAT_40 case PT___SETREGS40: write = 1; /* FALLTHROUGH*/ case PT___GETREGS40: if (!process_validregs(lt)) return EINVAL; iov.iov_base = addr; iov.iov_len = sizeof(struct __reg40); uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = 0; uio.uio_resid = sizeof(struct __reg40); uio.uio_rw = write ? UIO_WRITE : UIO_READ; uio.uio_vmspace = l->l_proc->p_vmspace; return process_machdep_doregs40(l, lt, &uio); #endif /* COMPAT_40 */ } }
/* * Process debugging system call. */ int sys_ptrace(struct lwp *l, const struct sys_ptrace_args *uap, register_t *retval) { /* { syscallarg(int) req; syscallarg(pid_t) pid; syscallarg(void *) addr; syscallarg(int) data; } */ struct proc *p = l->l_proc; struct lwp *lt; struct proc *t; /* target process */ struct uio uio; struct iovec iov; struct ptrace_io_desc piod; struct ptrace_lwpinfo pl; struct vmspace *vm; int error, write, tmp, req, pheld; int signo; ksiginfo_t ksi; #ifdef COREDUMP char *path; #endif error = 0; req = SCARG(uap, req); /* * If attaching or detaching, we need to get a write hold on the * proclist lock so that we can re-parent the target process. */ mutex_enter(proc_lock); /* "A foolish consistency..." XXX */ if (req == PT_TRACE_ME) { t = p; mutex_enter(t->p_lock); } else { /* Find the process we're supposed to be operating on. */ if ((t = p_find(SCARG(uap, pid), PFIND_LOCKED)) == NULL) { mutex_exit(proc_lock); return (ESRCH); } /* XXX-elad */ mutex_enter(t->p_lock); error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, t, KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL); if (error) { mutex_exit(proc_lock); mutex_exit(t->p_lock); return (ESRCH); } } /* * Grab a reference on the process to prevent it from execing or * exiting. */ if (!rw_tryenter(&t->p_reflock, RW_READER)) { mutex_exit(proc_lock); mutex_exit(t->p_lock); return EBUSY; } /* Make sure we can operate on it. */ switch (req) { case PT_TRACE_ME: /* Saying that you're being traced is always legal. */ break; case PT_ATTACH: /* * You can't attach to a process if: * (1) it's the process that's doing the attaching, */ if (t->p_pid == p->p_pid) { error = EINVAL; break; } /* * (2) it's a system process */ if (t->p_flag & PK_SYSTEM) { error = EPERM; break; } /* * (3) it's already being traced, or */ if (ISSET(t->p_slflag, PSL_TRACED)) { error = EBUSY; break; } /* * (4) the tracer is chrooted, and its root directory is * not at or above the root directory of the tracee */ mutex_exit(t->p_lock); /* XXXSMP */ tmp = proc_isunder(t, l); mutex_enter(t->p_lock); /* XXXSMP */ if (!tmp) { error = EPERM; break; } break; case PT_READ_I: case PT_READ_D: case PT_WRITE_I: case PT_WRITE_D: case PT_IO: #ifdef PT_GETREGS case PT_GETREGS: #endif #ifdef PT_SETREGS case PT_SETREGS: #endif #ifdef PT_GETFPREGS case PT_GETFPREGS: #endif #ifdef PT_SETFPREGS case PT_SETFPREGS: #endif #ifdef __HAVE_PTRACE_MACHDEP PTRACE_MACHDEP_REQUEST_CASES #endif /* * You can't read/write the memory or registers of a process * if the tracer is chrooted, and its root directory is not at * or above the root directory of the tracee. */ mutex_exit(t->p_lock); /* XXXSMP */ tmp = proc_isunder(t, l); mutex_enter(t->p_lock); /* XXXSMP */ if (!tmp) { error = EPERM; break; } /*FALLTHROUGH*/ case PT_CONTINUE: case PT_KILL: case PT_DETACH: case PT_LWPINFO: case PT_SYSCALL: #ifdef COREDUMP case PT_DUMPCORE: #endif #ifdef PT_STEP case PT_STEP: #endif /* * You can't do what you want to the process if: * (1) It's not being traced at all, */ if (!ISSET(t->p_slflag, PSL_TRACED)) { error = EPERM; break; } /* * (2) it's being traced by procfs (which has * different signal delivery semantics), */ if (ISSET(t->p_slflag, PSL_FSTRACE)) { uprintf("file system traced\n"); error = EBUSY; break; } /* * (3) it's not being traced by _you_, or */ if (t->p_pptr != p) { uprintf("parent %d != %d\n", t->p_pptr->p_pid, p->p_pid); error = EBUSY; break; } /* * (4) it's not currently stopped. */ if (t->p_stat != SSTOP || !t->p_waited /* XXXSMP */) { uprintf("stat %d flag %d\n", t->p_stat, !t->p_waited); error = EBUSY; break; } break; default: /* It was not a legal request. */ error = EINVAL; break; } if (error == 0) error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_PTRACE, t, KAUTH_ARG(req), NULL, NULL); if (error != 0) { mutex_exit(proc_lock); mutex_exit(t->p_lock); rw_exit(&t->p_reflock); return error; } /* Do single-step fixup if needed. */ FIX_SSTEP(t); /* * XXX NJWLWP * * The entire ptrace interface needs work to be useful to a * process with multiple LWPs. For the moment, we'll kluge * this; memory access will be fine, but register access will * be weird. */ lt = LIST_FIRST(&t->p_lwps); KASSERT(lt != NULL); lwp_addref(lt); /* * Which locks do we need held? XXX Ugly. */ switch (req) { #ifdef PT_STEP case PT_STEP: #endif case PT_CONTINUE: case PT_DETACH: case PT_KILL: case PT_SYSCALL: case PT_ATTACH: case PT_TRACE_ME: pheld = 1; break; default: mutex_exit(proc_lock); mutex_exit(t->p_lock); pheld = 0; break; } /* Now do the operation. */ write = 0; *retval = 0; tmp = 0; switch (req) { case PT_TRACE_ME: /* Just set the trace flag. */ SET(t->p_slflag, PSL_TRACED); t->p_opptr = t->p_pptr; break; case PT_WRITE_I: /* XXX no separate I and D spaces */ case PT_WRITE_D: #if defined(__HAVE_RAS) /* * Can't write to a RAS */ if (ras_lookup(t, SCARG(uap, addr)) != (void *)-1) { error = EACCES; break; } #endif write = 1; tmp = SCARG(uap, data); /* FALLTHROUGH */ case PT_READ_I: /* XXX no separate I and D spaces */ case PT_READ_D: /* write = 0 done above. */ iov.iov_base = (void *)&tmp; iov.iov_len = sizeof(tmp); uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = (off_t)(unsigned long)SCARG(uap, addr); uio.uio_resid = sizeof(tmp); uio.uio_rw = write ? UIO_WRITE : UIO_READ; UIO_SETUP_SYSSPACE(&uio); error = process_domem(l, lt, &uio); if (!write) *retval = tmp; break; case PT_IO: error = copyin(SCARG(uap, addr), &piod, sizeof(piod)); if (error) break; switch (piod.piod_op) { case PIOD_READ_D: case PIOD_READ_I: uio.uio_rw = UIO_READ; break; case PIOD_WRITE_D: case PIOD_WRITE_I: /* * Can't write to a RAS */ if (ras_lookup(t, SCARG(uap, addr)) != (void *)-1) { return (EACCES); } uio.uio_rw = UIO_WRITE; break; default: error = EINVAL; break; } if (error) break; error = proc_vmspace_getref(l->l_proc, &vm); if (error) break; iov.iov_base = piod.piod_addr; iov.iov_len = piod.piod_len; uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = (off_t)(unsigned long)piod.piod_offs; uio.uio_resid = piod.piod_len; uio.uio_vmspace = vm; error = process_domem(l, lt, &uio); piod.piod_len -= uio.uio_resid; (void) copyout(&piod, SCARG(uap, addr), sizeof(piod)); uvmspace_free(vm); break; #ifdef COREDUMP case PT_DUMPCORE: if ((path = SCARG(uap, addr)) != NULL) { char *dst; int len = SCARG(uap, data); if (len < 0 || len >= MAXPATHLEN) { error = EINVAL; break; } dst = malloc(len + 1, M_TEMP, M_WAITOK); if ((error = copyin(path, dst, len)) != 0) { free(dst, M_TEMP); break; } path = dst; path[len] = '\0'; } error = coredump(lt, path); if (path) free(path, M_TEMP); break; #endif #ifdef PT_STEP case PT_STEP: /* * From the 4.4BSD PRM: * "Execution continues as in request PT_CONTINUE; however * as soon as possible after execution of at least one * instruction, execution stops again. [ ... ]" */ #endif case PT_CONTINUE: case PT_SYSCALL: case PT_DETACH: if (req == PT_SYSCALL) { if (!ISSET(t->p_slflag, PSL_SYSCALL)) { SET(t->p_slflag, PSL_SYSCALL); #ifdef __HAVE_SYSCALL_INTERN (*t->p_emul->e_syscall_intern)(t); #endif } } else { if (ISSET(t->p_slflag, PSL_SYSCALL)) { CLR(t->p_slflag, PSL_SYSCALL); #ifdef __HAVE_SYSCALL_INTERN (*t->p_emul->e_syscall_intern)(t); #endif } } p->p_trace_enabled = trace_is_enabled(p); /* * From the 4.4BSD PRM: * "The data argument is taken as a signal number and the * child's execution continues at location addr as if it * incurred that signal. Normally the signal number will * be either 0 to indicate that the signal that caused the * stop should be ignored, or that value fetched out of * the process's image indicating which signal caused * the stop. If addr is (int *)1 then execution continues * from where it stopped." */ /* Check that the data is a valid signal number or zero. */ if (SCARG(uap, data) < 0 || SCARG(uap, data) >= NSIG) { error = EINVAL; break; } uvm_lwp_hold(lt); /* If the address parameter is not (int *)1, set the pc. */ if ((int *)SCARG(uap, addr) != (int *)1) if ((error = process_set_pc(lt, SCARG(uap, addr))) != 0) { uvm_lwp_rele(lt); break; } #ifdef PT_STEP /* * Arrange for a single-step, if that's requested and possible. */ error = process_sstep(lt, req == PT_STEP); if (error) { uvm_lwp_rele(lt); break; } #endif uvm_lwp_rele(lt); if (req == PT_DETACH) { CLR(t->p_slflag, PSL_TRACED|PSL_FSTRACE|PSL_SYSCALL); /* give process back to original parent or init */ if (t->p_opptr != t->p_pptr) { struct proc *pp = t->p_opptr; proc_reparent(t, pp ? pp : initproc); } /* not being traced any more */ t->p_opptr = NULL; } signo = SCARG(uap, data); sendsig: /* Finally, deliver the requested signal (or none). */ if (t->p_stat == SSTOP) { /* * Unstop the process. If it needs to take a * signal, make all efforts to ensure that at * an LWP runs to see it. */ t->p_xstat = signo; proc_unstop(t); } else if (signo != 0) { KSI_INIT_EMPTY(&ksi); ksi.ksi_signo = signo; kpsignal2(t, &ksi); } break; case PT_KILL: /* just send the process a KILL signal. */ signo = SIGKILL; goto sendsig; /* in PT_CONTINUE, above. */ case PT_ATTACH: /* * Go ahead and set the trace flag. * Save the old parent (it's reset in * _DETACH, and also in kern_exit.c:wait4() * Reparent the process so that the tracing * proc gets to see all the action. * Stop the target. */ t->p_opptr = t->p_pptr; if (t->p_pptr != p) { struct proc *parent = t->p_pptr; if (parent->p_lock < t->p_lock) { if (!mutex_tryenter(parent->p_lock)) { mutex_exit(t->p_lock); mutex_enter(parent->p_lock); } } else if (parent->p_lock > t->p_lock) { mutex_enter(parent->p_lock); } parent->p_slflag |= PSL_CHTRACED; proc_reparent(t, p); if (parent->p_lock != t->p_lock) mutex_exit(parent->p_lock); } SET(t->p_slflag, PSL_TRACED); signo = SIGSTOP; goto sendsig; case PT_LWPINFO: if (SCARG(uap, data) != sizeof(pl)) { error = EINVAL; break; } error = copyin(SCARG(uap, addr), &pl, sizeof(pl)); if (error) break; tmp = pl.pl_lwpid; lwp_delref(lt); mutex_enter(t->p_lock); if (tmp == 0) lt = LIST_FIRST(&t->p_lwps); else { lt = lwp_find(t, tmp); if (lt == NULL) { mutex_exit(t->p_lock); error = ESRCH; break; } lt = LIST_NEXT(lt, l_sibling); } while (lt != NULL && lt->l_stat == LSZOMB) lt = LIST_NEXT(lt, l_sibling); pl.pl_lwpid = 0; pl.pl_event = 0; if (lt) { lwp_addref(lt); pl.pl_lwpid = lt->l_lid; if (lt->l_lid == t->p_sigctx.ps_lwp) pl.pl_event = PL_EVENT_SIGNAL; } mutex_exit(t->p_lock); error = copyout(&pl, SCARG(uap, addr), sizeof(pl)); break; #ifdef PT_SETREGS case PT_SETREGS: write = 1; #endif #ifdef PT_GETREGS case PT_GETREGS: /* write = 0 done above. */ #endif #if defined(PT_SETREGS) || defined(PT_GETREGS) tmp = SCARG(uap, data); if (tmp != 0 && t->p_nlwps > 1) { lwp_delref(lt); mutex_enter(t->p_lock); lt = lwp_find(t, tmp); if (lt == NULL) { mutex_exit(t->p_lock); error = ESRCH; break; } lwp_addref(lt); mutex_exit(t->p_lock); } if (!process_validregs(lt)) error = EINVAL; else { error = proc_vmspace_getref(l->l_proc, &vm); if (error) break; iov.iov_base = SCARG(uap, addr); iov.iov_len = sizeof(struct reg); uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = 0; uio.uio_resid = sizeof(struct reg); uio.uio_rw = write ? UIO_WRITE : UIO_READ; uio.uio_vmspace = vm; error = process_doregs(l, lt, &uio); uvmspace_free(vm); } break; #endif #ifdef PT_SETFPREGS case PT_SETFPREGS: write = 1; #endif #ifdef PT_GETFPREGS case PT_GETFPREGS: /* write = 0 done above. */ #endif #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS) tmp = SCARG(uap, data); if (tmp != 0 && t->p_nlwps > 1) { lwp_delref(lt); mutex_enter(t->p_lock); lt = lwp_find(t, tmp); if (lt == NULL) { mutex_exit(t->p_lock); error = ESRCH; break; } lwp_addref(lt); mutex_exit(t->p_lock); } if (!process_validfpregs(lt)) error = EINVAL; else { error = proc_vmspace_getref(l->l_proc, &vm); if (error) break; iov.iov_base = SCARG(uap, addr); iov.iov_len = sizeof(struct fpreg); uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = 0; uio.uio_resid = sizeof(struct fpreg); uio.uio_rw = write ? UIO_WRITE : UIO_READ; uio.uio_vmspace = vm; error = process_dofpregs(l, lt, &uio); uvmspace_free(vm); } break; #endif #ifdef __HAVE_PTRACE_MACHDEP PTRACE_MACHDEP_REQUEST_CASES error = ptrace_machdep_dorequest(l, lt, req, SCARG(uap, addr), SCARG(uap, data)); break; #endif } if (pheld) { mutex_exit(t->p_lock); mutex_exit(proc_lock); } if (lt != NULL) lwp_delref(lt); rw_exit(&t->p_reflock); return error; }