X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/de355530ae67247cbd0da700edb3a2a1dae884c2..3903760236c30e3b5ace7a4eefac3a269d68957c:/bsd/kern/mach_process.c diff --git a/bsd/kern/mach_process.c b/bsd/kern/mach_process.c index e7df848de..d8bc4f07a 100644 --- a/bsd/kern/mach_process.c +++ b/bsd/kern/mach_process.c @@ -1,23 +1,29 @@ /* - * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * - * The contents of this file constitute Original Code as defined in and - * are subject to the Apple Public Source License Version 1.1 (the - * "License"). You may not use this file except in compliance with the - * License. Please obtain a copy of the License at - * http://www.apple.com/publicsource and read it before using this file. + * This file contains Original Code and/or Modifications of Original Code + * as defined in and that are subject to the Apple Public Source License + * Version 2.0 (the 'License'). You may not use this file except in + * compliance with the License. The rights granted to you under the License + * may not be used to create, or enable the creation or redistribution of, + * unlawful or unlicensed copies of an Apple operating system, or to + * circumvent, violate, or enable the circumvention or violation of, any + * terms of an Apple operating system software license agreement. * - * This Original Code and all software distributed under the License are - * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * Please obtain a copy of the License at + * http://www.opensource.apple.com/apsl/ and read it before using this file. + * + * The Original Code and all software distributed under the License are + * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the - * License for the specific language governing rights and limitations - * under the License. + * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. + * Please see the License for the specific language governing rights and + * limitations under the License. * - * @APPLE_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */ /*- @@ -65,7 +71,8 @@ #include #include -#include +#include +#include #include #include #include @@ -73,73 +80,73 @@ #include #include -#include +#include +#include +#include +#include /* cs_allow_invalid() */ + +#include #include #include -#include + +#include /* for task_resume() */ +#include /* for thread_exception_return() */ + +#include + +/* XXX ken/bsd_kern.c - prototype should be in common header */ +int get_task_userstop(task_t); /* Macros to clear/set/test flags. */ #define SET(t, f) (t) |= (f) #define CLR(t, f) (t) &= ~(f) #define ISSET(t, f) ((t) & (f)) -void psignal_lock __P((struct proc *, int, int)); -int isinferior __P((struct proc *, struct proc *)); +extern thread_t port_name_to_thread(mach_port_name_t port_name); +extern thread_t get_firstthread(task_t); + /* * sys-trace system call. */ -struct ptrace_args { - int req; - pid_t pid; - caddr_t addr; - int data; -}; int -ptrace(p, uap, retval) - struct proc *p; - struct ptrace_args *uap; - register_t *retval; +ptrace(struct proc *p, struct ptrace_args *uap, int32_t *retval) { struct proc *t = current_proc(); /* target process */ - vm_offset_t start_addr, end_addr, - kern_addr, offset; - vm_size_t size; task_t task; - thread_t thread; - thread_act_t th_act; + thread_t th_act; struct uthread *ut; - int *locr0; - int error = 0; -#if defined(ppc) - struct ppc_thread_state statep; -#elif defined(i386) - struct i386_saved_state statep; -#else -#error architecture not supported -#endif - unsigned long state_count; int tr_sigexc = 0; - - - if (uap->req == PT_DENY_ATTACH) { - if (ISSET(p->p_flag, P_TRACED)) { - exit1(p, W_EXITCODE(ENOTSUP, 0), retval); - /* drop funnel before we return */ - thread_funnel_set(kernel_flock, FALSE); - thread_exception_return(); - /* NOTREACHED */ - } - SET(p->p_flag, P_NOATTACH); + int error = 0; + int stopped = 0; + + AUDIT_ARG(cmd, uap->req); + AUDIT_ARG(pid, uap->pid); + AUDIT_ARG(addr, uap->addr); + AUDIT_ARG(value32, uap->data); + + if (uap->req == PT_DENY_ATTACH) { + proc_lock(p); + if (ISSET(p->p_lflag, P_LTRACED)) { + proc_unlock(p); + KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_FRCEXIT) | DBG_FUNC_NONE, + p->p_pid, W_EXITCODE(ENOTSUP, 0), 4, 0, 0); + exit1(p, W_EXITCODE(ENOTSUP, 0), retval); + + thread_exception_return(); + /* NOTREACHED */ + } + SET(p->p_lflag, P_LNOATTACH); + proc_unlock(p); return(0); } if (uap->req == PT_FORCEQUOTA) { - if (is_suser()) { - SET(t->p_flag, P_FORCEQUOTA); + if (kauth_cred_issuser(kauth_cred_get())) { + OSBitOrAtomic(P_FORCEQUOTA, &t->p_flag); return (0); } else return (EPERM); @@ -149,122 +156,182 @@ ptrace(p, uap, retval) * Intercept and deal with "please trace me" request. */ if (uap->req == PT_TRACE_ME) { - SET(p->p_flag, P_TRACED); - /* Non-attached case, our tracer is our parent. */ - t->p_oppid = t->p_pptr->p_pid; - return(0); +retry_trace_me:; + proc_t pproc = proc_parent(p); + if (pproc == NULL) + return (EINVAL); +#if CONFIG_MACF + /* + * NB: Cannot call kauth_authorize_process(..., KAUTH_PROCESS_CANTRACE, ...) + * since that assumes the process being checked is the current process + * when, in this case, it is the current process's parent. + * Most of the other checks in cantrace() don't apply either. + */ + if ((error = mac_proc_check_debug(pproc, p)) == 0) { +#endif + proc_lock(p); + /* Make sure the process wasn't re-parented. */ + if (p->p_ppid != pproc->p_pid) { + proc_unlock(p); + proc_rele(pproc); + goto retry_trace_me; + } + SET(p->p_lflag, P_LTRACED); + /* Non-attached case, our tracer is our parent. */ + p->p_oppid = p->p_ppid; + proc_unlock(p); + /* Child and parent will have to be able to run modified code. */ + cs_allow_invalid(p); + cs_allow_invalid(pproc); +#if CONFIG_MACF + } +#endif + proc_rele(pproc); + return (error); } if (uap->req == PT_SIGEXC) { - if (ISSET(p->p_flag, P_TRACED)) { - SET(p->p_flag, P_SIGEXC); + proc_lock(p); + if (ISSET(p->p_lflag, P_LTRACED)) { + SET(p->p_lflag, P_LSIGEXC); + proc_unlock(p); return(0); - } else + } else { + proc_unlock(p); return(EINVAL); + } + } + + /* + * We do not want ptrace to do anything with kernel or launchd + */ + if (uap->pid < 2) { + return(EPERM); } /* * Locate victim, and make sure it is traceable. */ - if ((t = pfind(uap->pid)) == NULL) + if ((t = proc_find(uap->pid)) == NULL) return (ESRCH); - - /* We do not want ptrace to do anything with kernel, init - * and mach_init - */ - if (uap->pid <=2 ) - return (EPERM); + AUDIT_ARG(process, t); task = t->task; if (uap->req == PT_ATTACHEXC) { +#pragma clang diagnostic push +#pragma clang diagnostic ignored "-Wdeprecated-declarations" uap->req = PT_ATTACH; tr_sigexc = 1; } if (uap->req == 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) - return (EINVAL); - - /* - * (2) it's already being traced, or - */ - if (ISSET(t->p_flag, P_TRACED)) - return (EBUSY); - - /* - * (3) it's not owned by you, or is set-id on exec - * (unless you're root). - */ - if ((t->p_cred->p_ruid != p->p_cred->p_ruid || - ISSET(t->p_flag, P_SUGID)) && - (error = suser(p->p_ucred, &p->p_acflag)) != 0) - return (error); - - if ((p->p_flag & P_TRACED) && isinferior(p, t)) - return(EPERM); - - if (ISSET(t->p_flag, P_NOATTACH)) { - psignal(p, SIGSEGV); - return (EBUSY); - } - SET(t->p_flag, P_TRACED); - if (tr_sigexc) - SET(t->p_flag, P_SIGEXC); - - t->p_oppid = t->p_pptr->p_pid; - if (t->p_pptr != p) - proc_reparent(t, p); - - if (get_task_userstop(task) == 0 ) { +#pragma clang diagnostic pop + int err; + + + if ( kauth_authorize_process(proc_ucred(p), KAUTH_PROCESS_CANTRACE, + t, (uintptr_t)&err, 0, 0) == 0 ) { + /* it's OK to attach */ + proc_lock(t); + SET(t->p_lflag, P_LTRACED); + if (tr_sigexc) + SET(t->p_lflag, P_LSIGEXC); + + t->p_oppid = t->p_ppid; + /* Check whether child and parent are allowed to run modified + * code (they'll have to) */ + proc_unlock(t); + cs_allow_invalid(t); + cs_allow_invalid(p); + if (t->p_pptr != p) + proc_reparentlocked(t, p, 1, 0); + + proc_lock(t); + if (get_task_userstop(task) > 0 ) { + stopped = 1; + } t->p_xstat = 0; + proc_unlock(t); psignal(t, SIGSTOP); - } else { - t->p_xstat = SIGSTOP; - task_resume(task); + /* + * If the process was stopped, wake up and run through + * issignal() again to properly connect to the tracing + * process. + */ + if (stopped) + task_resume(task); + error = 0; + goto out; + } + else { + /* not allowed to attach, proper error code returned by kauth_authorize_process */ + if (ISSET(t->p_lflag, P_LNOATTACH)) { + psignal(p, SIGSEGV); + } + + error = err; + goto out; } - return(0); } /* * You can't do what you want to the process if: * (1) It's not being traced at all, */ - if (!ISSET(t->p_flag, P_TRACED)) - return (EPERM); + proc_lock(t); + if (!ISSET(t->p_lflag, P_LTRACED)) { + proc_unlock(t); + error = EPERM; + goto out; + } /* * (2) it's not being traced by _you_, or */ - if (t->p_pptr != p) - return (EBUSY); + if (t->p_pptr != p) { + proc_unlock(t); + error = EBUSY; + goto out; + } /* * (3) it's not currently stopped. */ - if (t->p_stat != SSTOP) - return (EBUSY); + if (t->p_stat != SSTOP) { + proc_unlock(t); + error = EBUSY; + goto out; + } /* * Mach version of ptrace executes request directly here, * thus simplifying the interaction of ptrace and signals. */ + /* proc lock is held here */ switch (uap->req) { case PT_DETACH: - if (t->p_oppid != t->p_pptr->p_pid) { + if (t->p_oppid != t->p_ppid) { struct proc *pp; - pp = pfind(t->p_oppid); - proc_reparent(t, pp ? pp : initproc); + proc_unlock(t); + pp = proc_find(t->p_oppid); + if (pp != PROC_NULL) { + proc_reparentlocked(t, pp, 1, 0); + proc_rele(pp); + } else { + /* original parent exited while traced */ + proc_list_lock(); + t->p_listflag |= P_LIST_DEADPARENT; + proc_list_unlock(); + proc_reparentlocked(t, initproc, 1, 0); + } + proc_lock(t); } t->p_oppid = 0; - CLR(t->p_flag, P_TRACED); - CLR(t->p_flag, P_SIGEXC); + CLR(t->p_lflag, P_LTRACED); + CLR(t->p_lflag, P_LSIGEXC); + proc_unlock(t); goto resume; case PT_KILL: @@ -272,116 +339,172 @@ ptrace(p, uap, retval) * Tell child process to kill itself after it * is resumed by adding NSIG to p_cursig. [see issig] */ - psignal_lock(t, SIGKILL, 0); + proc_unlock(t); +#if CONFIG_MACF + error = mac_proc_check_signal(p, t, SIGKILL); + if (0 != error) + goto resume; +#endif + psignal(t, SIGKILL); goto resume; case PT_STEP: /* single step the child */ case PT_CONTINUE: /* continue the child */ - th_act = (thread_act_t)get_firstthread(task); - if (th_act == THR_ACT_NULL) - goto errorLabel; - ut = (uthread_t)get_bsdthread_info(th_act); - locr0 = ut->uu_ar0; -#if defined(i386) - state_count = i386_NEW_THREAD_STATE_COUNT; - if (thread_getstatus(th_act, i386_NEW_THREAD_STATE, &statep, &state_count) != KERN_SUCCESS) { - goto errorLabel; - } -#elif defined(ppc) - state_count = PPC_THREAD_STATE_COUNT; - if (thread_getstatus(th_act, PPC_THREAD_STATE, &statep, &state_count) != KERN_SUCCESS) { - goto errorLabel; - } -#else -#error architecture not supported -#endif - if ((int)uap->addr != 1) { -#if defined(i386) - locr0[PC] = (int)uap->addr; -#elif defined(ppc) -#define ALIGNED(addr,size) (((unsigned)(addr)&((size)-1))==0) - if (!ALIGNED((int)uap->addr, sizeof(int))) - return (ERESTART); - - statep.srr0 = (int)uap->addr; - state_count = PPC_THREAD_STATE_COUNT; - if (thread_setstatus(th_act, PPC_THREAD_STATE, &statep, &state_count) != KERN_SUCCESS) { - goto errorLabel; - } -#undef ALIGNED -#else -#error architecture not implemented! -#endif - } /* (int)uap->addr != 1 */ + proc_unlock(t); + th_act = (thread_t)get_firstthread(task); + if (th_act == THREAD_NULL) { + error = EINVAL; + goto out; + } - if ((unsigned)uap->data < 0 || (unsigned)uap->data >= NSIG) - goto errorLabel; + /* force use of Mach SPIs (and task_for_pid security checks) to adjust PC */ + if (uap->addr != (user_addr_t)1) { + error = ENOTSUP; + goto out; + } + + if ((unsigned)uap->data >= NSIG) { + error = EINVAL; + goto out; + } if (uap->data != 0) { - psignal_lock(t, uap->data, 0); + psignal(t, uap->data); } -#if defined(ppc) - state_count = PPC_THREAD_STATE_COUNT; - if (thread_getstatus(th_act, PPC_THREAD_STATE, &statep, &state_count) != KERN_SUCCESS) { - goto errorLabel; - } -#endif - -#define MSR_SE_BIT 21 if (uap->req == PT_STEP) { -#if defined(i386) - locr0[PS] |= PSL_T; -#elif defined(ppc) - statep.srr1 |= MASK(MSR_SE); -#else -#error architecture not implemented! + /* + * set trace bit + * we use sending SIGSTOP as a comparable security check. + */ +#if CONFIG_MACF + error = mac_proc_check_signal(p, t, SIGSTOP); + if (0 != error) { + goto out; + } #endif - } /* uap->req == PT_STEP */ - else { /* PT_CONTINUE - clear trace bit if set */ -#if defined(i386) - locr0[PS] &= ~PSL_T; -#elif defined(ppc) - statep.srr1 &= ~MASK(MSR_SE); + if (thread_setsinglestep(th_act, 1) != KERN_SUCCESS) { + error = ENOTSUP; + goto out; + } + } else { + /* + * clear trace bit if on + * we use sending SIGCONT as a comparable security check. + */ +#if CONFIG_MACF + error = mac_proc_check_signal(p, t, SIGCONT); + if (0 != error) { + goto out; + } #endif - } -#if defined (ppc) - state_count = PPC_THREAD_STATE_COUNT; - if (thread_setstatus(th_act, PPC_THREAD_STATE, &statep, &state_count) != KERN_SUCCESS) { - goto errorLabel; + if (thread_setsinglestep(th_act, 0) != KERN_SUCCESS) { + error = ENOTSUP; + goto out; + } } -#endif resume: + proc_lock(t); t->p_xstat = uap->data; t->p_stat = SRUN; if (t->sigwait) { wakeup((caddr_t)&(t->sigwait)); - task_release(task); - } + proc_unlock(t); + if ((t->p_lflag & P_LSIGEXC) == 0) { + task_resume(task); + } + } else + proc_unlock(t); + break; case PT_THUPDATE: { - thread_act_t target_act; - - if ((unsigned)uap->data >= NSIG) - goto errorLabel; - th_act = (thread_act_t)port_name_to_act((void *)uap->addr); - if (th_act == THR_ACT_NULL) - return (ESRCH); + proc_unlock(t); + if ((unsigned)uap->data >= NSIG) { + error = EINVAL; + goto out; + } + th_act = port_name_to_thread(CAST_MACH_PORT_TO_NAME(uap->addr)); + if (th_act == THREAD_NULL) { + error = ESRCH; + goto out; + } ut = (uthread_t)get_bsdthread_info(th_act); if (uap->data) ut->uu_siglist |= sigmask(uap->data); + proc_lock(t); t->p_xstat = uap->data; t->p_stat = SRUN; - act_deallocate(th_act); - return(0); + proc_unlock(t); + thread_deallocate(th_act); + error = 0; } break; -errorLabel: default: - return(EINVAL); + proc_unlock(t); + error = EINVAL; + goto out; } - return(0); + error = 0; +out: + proc_rele(t); + return(error); } + +/* + * determine if one process (cur_procp) can trace another process (traced_procp). + */ + +int +cantrace(proc_t cur_procp, kauth_cred_t creds, proc_t traced_procp, int *errp) +{ + int my_err; + /* + * You can't trace a process if: + * (1) it's the process that's doing the tracing, + */ + if (traced_procp->p_pid == cur_procp->p_pid) { + *errp = EINVAL; + return (0); + } + + /* + * (2) it's already being traced, or + */ + if (ISSET(traced_procp->p_lflag, P_LTRACED)) { + *errp = EBUSY; + return (0); + } + + /* + * (3) it's not owned by you, or is set-id on exec + * (unless you're root). + */ + if ((kauth_cred_getruid(creds) != kauth_cred_getruid(proc_ucred(traced_procp)) || + ISSET(traced_procp->p_flag, P_SUGID)) && + (my_err = suser(creds, &cur_procp->p_acflag)) != 0) { + *errp = my_err; + return (0); + } + + if ((cur_procp->p_lflag & P_LTRACED) && isinferior(cur_procp, traced_procp)) { + *errp = EPERM; + return (0); + } + + if (ISSET(traced_procp->p_lflag, P_LNOATTACH)) { + *errp = EBUSY; + return (0); + } + +#if CONFIG_MACF + if ((my_err = mac_proc_check_debug(cur_procp, traced_procp)) != 0) { + *errp = my_err; + return (0); + } +#endif + + return(1); +}