xnu-2782.40.9.tar.gz

[apple/xnu.git] / bsd / kern / mach_process.c

diff --git a/bsd/kern/mach_process.c b/bsd/kern/mach_process.c
index 6ecd242b1efa803bc2d7b03efc4a3f95336edf6e..ef8ebffcd60e29d96e328c2174dea826a31a4f3f 100644 (file)
--- a/bsd/kern/mach_process.c
+++ b/bsd/kern/mach_process.c
@@ -1,5 +1,5 @@
 /*
 /*

- * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.

  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 


@@ -82,12 +82,21 @@
 
 #include <sys/mount_internal.h>
 #include <sys/sysproto.h>
 
 #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 <kern/task.h>
 #include <kern/thread.h>
 

+#include <mach/task.h>                 /* for task_resume() */
+#include <kern/sched_prim.h>           /* for thread_exception_return() */
+
+#include <pexpert/pexpert.h>
+
+/* 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)
 
 /* Macros to clear/set/test flags. */
 #define        SET(t, f)       (t) |= (f)


@@ -103,38 +112,41 @@ extern thread_t get_firstthread(task_t);
  */
 
 int
  */
 
 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 tr_sigexc = 0;
 {
        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(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 (uap->req == PT_DENY_ATTACH) {

-               if (ISSET(p->p_flag, P_TRACED)) {
+               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);
                        exit1(p, W_EXITCODE(ENOTSUP, 0), retval);

-                       /* drop funnel before we return */
-                       thread_funnel_set(kernel_flock, FALSE);
+

                        thread_exception_return();
                        /* NOTREACHED */
                }
                        thread_exception_return();
                        /* NOTREACHED */
                }

-               SET(p->p_flag, P_NOATTACH);
+               SET(p->p_lflag, P_LNOATTACH);
+               proc_unlock(p);

 
                return(0);
        }
 
        if (uap->req == PT_FORCEQUOTA) {
 
                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);
                        return (0);
                } else
                        return (EPERM);


@@ -144,33 +156,48 @@ ptrace(p, uap, retval)
         *      Intercept and deal with "please trace me" request.
         */      
        if (uap->req == PT_TRACE_ME) {
         *      Intercept and deal with "please trace me" request.
         */      
        if (uap->req == PT_TRACE_ME) {

-               SET(p->p_flag, P_TRACED);
+               proc_lock(p);
+               SET(p->p_lflag, P_LTRACED);

                /* Non-attached case, our tracer is our parent. */
                /* Non-attached case, our tracer is our parent. */

-               t->p_oppid = t->p_pptr->p_pid;
+               p->p_oppid = p->p_ppid;
+               /* Check whether child and parent are allowed to run modified
+                * code (they'll have to) */
+               struct proc *pproc=proc_find(p->p_oppid);
+               proc_unlock(p);
+               cs_allow_invalid(p);
+               if(pproc) {
+                       cs_allow_invalid(pproc);
+                       proc_rele(pproc);
+               }

                return(0);
        }
        if (uap->req == PT_SIGEXC) {
                return(0);
        }
        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);
                        return(0);

-               } else
+               } else {
+                       proc_unlock(p);

                        return(EINVAL);
                        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.
         */
        }
 
        /*
         *      Locate victim, and make sure it is traceable.
         */

-       if ((t = pfind(uap->pid)) == NULL)
+       if ((t = proc_find(uap->pid)) == NULL)

                        return (ESRCH);
 
        AUDIT_ARG(process, t);
 
                        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) {
                uap->req = PT_ATTACH;
        task = t->task;
        if (uap->req == PT_ATTACHEXC) {
                uap->req = PT_ATTACH;


@@ -182,29 +209,45 @@ ptrace(p, uap, retval)
                if ( kauth_authorize_process(proc_ucred(p), KAUTH_PROCESS_CANTRACE, 
                                                                         t, (uintptr_t)&err, 0, 0) == 0 ) {
                        /* it's OK to attach */
                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);
+                       proc_lock(t);
+                       SET(t->p_lflag, P_LTRACED);

                        if (tr_sigexc) 
                        if (tr_sigexc) 

-                               SET(t->p_flag, P_SIGEXC);
+                               SET(t->p_lflag, P_LSIGEXC);

        
        

-                       t->p_oppid = t->p_pptr->p_pid;
+                       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)
                        if (t->p_pptr != p)

-                               proc_reparent(t, p);
+                               proc_reparentlocked(t, p, 1, 0);

        
        

-                       if (get_task_userstop(task) == 0 ) {
-                               t->p_xstat = 0;
-                               psignal(t, SIGSTOP);
-                       } else {
-                               t->p_xstat = SIGSTOP; 
-                               task_resume(task);       
+                       proc_lock(t);
+                       if (get_task_userstop(task) > 0 ) {
+                               stopped = 1;

                        }
                        }

-                       return(0);
+                       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 */
                }
                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);
                        }
                                psignal(p, SIGSEGV);
                        }

-                       return (err);
+                       
+                       error = err;
+                       goto out;

                }
        }
 
                }
        }
 


@@ -212,38 +255,61 @@ ptrace(p, uap, retval)
         * You can't do what you want to the process if:
         *      (1) It's not being traced at all,
         */
         * 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
         */
 
        /*
         *      (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.
         */
 
        /*
         *      (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.
         */
 
        /*
         *      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:
        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;
 
                        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;
                }
 
                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:
                goto resume;
                
        case PT_KILL:


@@ -251,74 +317,115 @@ ptrace(p, uap, retval)
                 *      Tell child process to kill itself after it
                 *      is resumed by adding NSIG to p_cursig. [see issig]
                 */
                 *      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 */
                goto resume;
 
        case PT_STEP:                   /* single step the child */
        case PT_CONTINUE:               /* continue the child */

+               proc_unlock(t);

                th_act = (thread_t)get_firstthread(task);
                th_act = (thread_t)get_firstthread(task);

-               if (th_act == THREAD_NULL)
-                       goto errorLabel;
+               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 (uap->addr != (user_addr_t)1) {

-#if defined(ppc)
-#define ALIGNED(addr,size)     (((unsigned)(addr)&((size)-1))==0)
-                       if (!ALIGNED((int)uap->addr, sizeof(int)))
-                               return (ERESTART);
-#undef         ALIGNED
-#endif
-                       thread_setentrypoint(th_act, uap->addr);
+                       error = ENOTSUP;
+                       goto out;

                }
 
                }
 

-               if ((unsigned)uap->data >= NSIG)
-                       goto errorLabel;
+               if ((unsigned)uap->data >= NSIG) {
+                       error = EINVAL;
+                       goto out;
+               }

 
                if (uap->data != 0) {
 
                if (uap->data != 0) {

-                       psignal_lock(t, uap->data, 0);
+                       psignal(t, uap->data);

                 }
 
                if (uap->req == PT_STEP) {
                        /*
                 }
 
                if (uap->req == PT_STEP) {
                        /*

-                        * set trace bit
+                        * set trace bit 
+                        * we use sending SIGSTOP as a comparable security check.

                         */
                         */

-                       thread_setsinglestep(th_act, 1);
+#if CONFIG_MACF
+                       error = mac_proc_check_signal(p, t, SIGSTOP);
+                       if (0 != error) {
+                               goto out;
+                       }
+#endif
+                       if (thread_setsinglestep(th_act, 1) != KERN_SUCCESS) {
+                               error = ENOTSUP;
+                               goto out;
+                       }

                } else {
                        /*
                         * clear trace bit if on
                } else {
                        /*
                         * clear trace bit if on

+                        * we use sending SIGCONT as a comparable security check.

                         */
                         */

-                       thread_setsinglestep(th_act, 0);
-               }
+#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;
+                       }
+               }       

        resume:
        resume:

+               proc_lock(t);

                t->p_xstat = uap->data;
                t->p_stat = SRUN;
                if (t->sigwait) {
                        wakeup((caddr_t)&(t->sigwait));
                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:  {
                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));
+               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)
                        return (ESRCH);
                ut = (uthread_t)get_bsdthread_info(th_act);
                if (uap->data)
                        ut->uu_siglist |= sigmask(uap->data);
                if (th_act == THREAD_NULL)
                        return (ESRCH);
                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;
                t->p_xstat = uap->data;
                t->p_stat = SRUN;

+               proc_unlock(t);

                thread_deallocate(th_act);
                thread_deallocate(th_act);

-               return(0);
+               error = 0;

                }
                break;
                }
                break;

-errorLabel:

        default:
        default:

-               return(EINVAL);
+               proc_unlock(t);
+               error = EINVAL;
+               goto out;

        }
 
        }
 

-       return(0);
+       error = 0;
+out:
+       proc_rele(t);
+       return(error);

 }
 
 
 }
 
 


@@ -342,7 +449,7 @@ cantrace(proc_t cur_procp, kauth_cred_t creds, proc_t traced_procp, int *errp)
        /*
         *      (2) it's already being traced, or
         */
        /*
         *      (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);
        }
                *errp = EBUSY;
                return (0);
        }


@@ -351,21 +458,29 @@ cantrace(proc_t cur_procp, kauth_cred_t creds, proc_t traced_procp, int *errp)
         *      (3) it's not owned by you, or is set-id on exec
         *          (unless you're root).
         */
         *      (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 ||
+       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);
        }
 
                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_flag & P_TRACED) && isinferior(cur_procp, traced_procp)) {
+       if ((cur_procp->p_lflag & P_LTRACED) && isinferior(cur_procp, traced_procp)) {

                *errp = EPERM;
                return (0);
        }
 
                *errp = EPERM;
                return (0);
        }
 

-       if (ISSET(traced_procp->p_flag, P_NOATTACH)) {
+       if (ISSET(traced_procp->p_lflag, P_LNOATTACH)) {

                *errp = EBUSY;
                return (0);
        }
                *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);
 }
        return(1);
 }