]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/kern/mach_process.c
xnu-6153.81.5.tar.gz
[apple/xnu.git] / bsd / kern / mach_process.c
index caa043027c23e8eb8fac27a1b449dd6d67b1bc29..915a8cb45f3e1f6d47f3488ba91ee1f3d561c297 100644 (file)
@@ -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@
- * 
- * 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 Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * 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.
+ *
+ * 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.
- * 
- * @APPLE_LICENSE_HEADER_END@
+ * 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_OSREFERENCE_LICENSE_HEADER_END@
  */
 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
 /*-
 
 #include <sys/mount_internal.h>
 #include <sys/sysproto.h>
+#include <sys/kdebug.h>
+#include <sys/codesign.h>               /* cs_allow_invalid() */
 
-#include <bsm/audit_kernel.h>
+#include <security/audit/audit.h>
 
 #include <kern/task.h>
 #include <kern/thread.h>
-#include <mach/machine/thread_status.h>
 
+#include <mach/task.h>                  /* for task_resume() */
+#include <kern/sched_prim.h>            /* for thread_exception_return() */
+
+#include <pexpert/pexpert.h>
+
+#if CONFIG_MACF
+#include <security/mac_framework.h>
+#endif
+
+/* 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))
+#define SET(t, f)       (t) |= (f)
+#define CLR(t, f)       (t) &= ~(f)
+#define ISSET(t, f)     ((t) & (f))
 
-extern thread_t        port_name_to_thread(mach_port_name_t port_name);
-extern kern_return_t thread_getstatus(thread_t thread, int flavor, thread_state_t tstate, mach_msg_type_number_t *count);
 extern thread_t get_firstthread(task_t);
 
-#if defined (ppc)
-extern kern_return_t thread_setstatus(thread_t thread, int flavor, thread_state_t tstate, mach_msg_type_number_t count);
-#endif
 
 /*
  * sys-trace system call.
  */
 
 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 */
-       task_t          task;
-       thread_t        th_act;
-       struct uthread  *ut;
-       int             *locr0;
-#if defined(ppc)
-       struct ppc_thread_state64 statep;
-#elif  defined(i386)
-       struct i386_saved_state statep;
-#else
-#error architecture not supported
-#endif
-       unsigned long state_count;
+       struct proc *t = current_proc();        /* target process */
+       task_t          task;
+       thread_t        th_act;
+       struct uthread  *ut;
        int tr_sigexc = 0;
+       int error = 0;
+       int stopped = 0;
 
        AUDIT_ARG(cmd, uap->req);
        AUDIT_ARG(pid, uap->pid);
        AUDIT_ARG(addr, uap->addr);
-       AUDIT_ARG(value, uap->data);
+       AUDIT_ARG(value32, uap->data);
 
        if (uap->req == PT_DENY_ATTACH) {
-               if (ISSET(p->p_flag, P_TRACED)) {
+#if (DEVELOPMENT || DEBUG) && CONFIG_EMBEDDED
+               if (PE_i_can_has_debugger(NULL)) {
+                       return 0;
+               }
+#endif
+               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);
-                       /* drop funnel before we return */
-                       thread_funnel_set(kernel_flock, FALSE);
+
                        thread_exception_return();
                        /* NOTREACHED */
                }
-               SET(p->p_flag, P_NOATTACH);
+               SET(p->p_lflag, P_LNOATTACH);
+               proc_unlock(p);
 
-               return(0);
+               return 0;
        }
 
        if (uap->req == PT_FORCEQUOTA) {
-               if (is_suser()) {
-                       SET(t->p_flag, P_FORCEQUOTA);
-                       return (0);
-               } else
-                       return (EPERM);
+               if (kauth_cred_issuser(kauth_cred_get())) {
+                       OSBitOrAtomic(P_FORCEQUOTA, &t->p_flag);
+                       return 0;
+               } else {
+                       return EPERM;
+               }
        }
 
        /*
         *      Intercept and deal with "please trace me" request.
-        */      
+        */
        if (uap->req == PT_TRACE_ME) {
-               SET(p->p_flag, P_TRACED);
+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. */
-               t->p_oppid = t->p_pptr->p_pid;
-               return(0);
+               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);
-                       return(0);
-               } else
-                       return(EINVAL);
+               proc_lock(p);
+               if (ISSET(p->p_lflag, P_LTRACED)) {
+                       SET(p->p_lflag, P_LSIGEXC);
+                       proc_unlock(p);
+                       return 0;
+               } 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)
-                       return (ESRCH);
+       if ((t = proc_find(uap->pid)) == NULL) {
+               return ESRCH;
+       }
 
        AUDIT_ARG(process, t);
 
-       /* We do not want ptrace to do anything with kernel, init 
-        * and mach_init
-        */
-       if (uap->pid <=2 )
-               return (EPERM);
-
        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) {
-               int             err;
-               
-               if ( kauth_authorize_process(proc_ucred(p), KAUTH_PROCESS_CANTRACE, 
-                                                                        t, (uintptr_t)&err, 0, 0) == 0 ) {
+#pragma clang diagnostic pop
+               int             err;
+
+#if CONFIG_EMBEDDED
+               if (tr_sigexc == 0) {
+                       error = ENOTSUP;
+                       goto out;
+               }
+#endif
+
+               if (kauth_authorize_process(proc_ucred(p), KAUTH_PROCESS_CANTRACE,
+                   t, (uintptr_t)&err, 0, 0) == 0) {
                        /* it's OK to attach */
-                       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 ) {
-                               t->p_xstat = 0;
-                               psignal(t, SIGSTOP);
-                       } else {
-                               t->p_xstat = SIGSTOP; 
-                               task_resume(task);       
+                       proc_lock(t);
+                       SET(t->p_lflag, P_LTRACED);
+                       if (tr_sigexc) {
+                               SET(t->p_lflag, P_LSIGEXC);
                        }
-                       return(0);
-               }
-               else {
+
+                       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);
+                       /*
+                        * 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_flag, P_NOATTACH)) {
+                       if (ISSET(t->p_lflag, P_LNOATTACH)) {
                                psignal(p, SIGSEGV);
                        }
-                       return (err);
+
+                       error = err;
+                       goto out;
                }
        }
 
@@ -220,155 +296,188 @@ ptrace(p, uap, retval)
         * 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:
                /*
                 *      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 */
+       case PT_STEP:                   /* single step the child */
+       case PT_CONTINUE:               /* continue the child */
+               proc_unlock(t);
                th_act = (thread_t)get_firstthread(task);
-               if (th_act == THREAD_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_STATE64_COUNT;
-               if (thread_getstatus(th_act, PPC_THREAD_STATE64, (thread_state_t)&statep, (mach_msg_type_number_t *)&state_count)  != KERN_SUCCESS) {
-                       goto errorLabel;
-               }       
-#else
-#error architecture not supported
-#endif
+               if (th_act == THREAD_NULL) {
+                       error = EINVAL;
+                       goto out;
+               }
+
+               /* force use of Mach SPIs (and task_for_pid security checks) to adjust PC */
                if (uap->addr != (user_addr_t)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 = uap->addr;
-               state_count = PPC_THREAD_STATE64_COUNT;
-               if (thread_setstatus(th_act, PPC_THREAD_STATE64, (thread_state_t)&statep, state_count)  != KERN_SUCCESS) {
-                       goto errorLabel;
-               }       
-#undef         ALIGNED
-#else
-#error architecture not implemented!
-#endif
-               } /* uap->addr != (user_addr_t)1 */
+                       error = ENOTSUP;
+                       goto out;
+               }
 
-               if ((unsigned)uap->data >= NSIG)
-                       goto errorLabel;
+               if ((unsigned)uap->data >= NSIG) {
+                       error = EINVAL;
+                       goto out;
+               }
 
                if (uap->data != 0) {
-                       psignal_lock(t, uap->data, 0);
-                }
-#if defined(ppc)
-               state_count = PPC_THREAD_STATE64_COUNT;
-               if (thread_getstatus(th_act, PPC_THREAD_STATE64, (thread_state_t)&statep, (mach_msg_type_number_t *)&state_count)  != KERN_SUCCESS) {
-                       goto errorLabel;
-               }       
+#if CONFIG_MACF
+                       error = mac_proc_check_signal(p, t, uap->data);
+                       if (0 != error) {
+                               goto out;
+                       }
 #endif
-
-#define MSR_SE_BIT     21
+                       psignal(t, uap->data);
+               }
 
                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 (thread_setsinglestep(th_act, 0) != KERN_SUCCESS) {
+                               error = ENOTSUP;
+                               goto out;
+                       }
                }
-#if defined (ppc)
-               state_count = PPC_THREAD_STATE64_COUNT;
-               if (thread_setstatus(th_act, PPC_THREAD_STATE64, (thread_state_t)&statep, state_count)  != KERN_SUCCESS) {
-                       goto errorLabel;
-               }       
-#endif
-       resume:
+resume:
+               proc_lock(t);
                t->p_xstat = uap->data;
                t->p_stat = SRUN;
                if (t->sigwait) {
                        wakeup((caddr_t)&(t->sigwait));
-                       if ((t->p_flag & P_SIGEXC) == 0)
-                               task_release(task);
+                       proc_unlock(t);
+                       if ((t->p_lflag & P_LSIGEXC) == 0) {
+                               task_resume(task);
+                       }
+               } else {
+                       proc_unlock(t);
                }
+
                break;
-               
+
        case PT_THUPDATE:  {
-               if ((unsigned)uap->data >= NSIG)
-                       goto errorLabel;
-               th_act = port_name_to_thread(CAST_DOWN(mach_port_name_t, uap->addr));
-               if (th_act == THREAD_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),
+                   PORT_TO_THREAD_NONE);
+               if (th_act == THREAD_NULL) {
+                       error = ESRCH;
+                       goto out;
+               }
                ut = (uthread_t)get_bsdthread_info(th_act);
-               if (uap->data)
+               if (uap->data) {
                        ut->uu_siglist |= sigmask(uap->data);
+               }
+               proc_lock(t);
                t->p_xstat = uap->data;
                t->p_stat = SRUN;
+               proc_unlock(t);
                thread_deallocate(th_act);
-               return(0);
-               }
-               break;
-errorLabel:
+               error = 0;
+       }
+       break;
        default:
-               return(EINVAL);
+               proc_unlock(t);
+               error = EINVAL;
+               goto out;
        }
 
-       return(0);
+       error = 0;
+out:
+       proc_rele(t);
+       return error;
 }
 
 
@@ -379,43 +488,51 @@ errorLabel:
 int
 cantrace(proc_t cur_procp, kauth_cred_t creds, proc_t traced_procp, int *errp)
 {
-       int             my_err;
+       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);
+               return 0;
        }
 
        /*
         *      (2) it's already being traced, or
         */
-       if (ISSET(traced_procp->p_flag, P_TRACED)) {
+       if (ISSET(traced_procp->p_lflag, P_LTRACED)) {
                *errp = EBUSY;
-               return (0);
+               return 0;
        }
 
        /*
         *      (3) it's not owned by you, or is set-id on exec
         *          (unless you're root).
         */
-       if ((creds->cr_ruid != proc_ucred(traced_procp)->cr_ruid ||
-               ISSET(traced_procp->p_flag, P_SUGID)) &&
-               (my_err = suser(creds, &cur_procp->p_acflag)) != 0) {
+       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);
+               return 0;
        }
 
-       if ((cur_procp->p_flag & P_TRACED) && isinferior(cur_procp, traced_procp)) {
+       if ((cur_procp->p_lflag & P_LTRACED) && isinferior(cur_procp, traced_procp)) {
                *errp = EPERM;
-               return (0);
+               return 0;
        }
 
-       if (ISSET(traced_procp->p_flag, P_NOATTACH)) {
+       if (ISSET(traced_procp->p_lflag, P_LNOATTACH)) {
                *errp = EBUSY;
-               return (0);
+               return 0;
        }
-       return(1);
+
+#if CONFIG_MACF
+       if ((my_err = mac_proc_check_debug(cur_procp, traced_procp)) != 0) {
+               *errp = my_err;
+               return 0;
+       }
+#endif
+
+       return 1;
 }