X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/4b17d6b6e417f714551ec129064745ea9919780e..bb59bff194111743b33cc36712410b5656329d3c:/bsd/kern/kern_fork.c?ds=sidebyside diff --git a/bsd/kern/kern_fork.c b/bsd/kern/kern_fork.c index 2f09ba8ee..9417b0911 100644 --- a/bsd/kern/kern_fork.c +++ b/bsd/kern/kern_fork.c @@ -97,14 +97,22 @@ /* Do not include dtrace.h, it redefines kmem_[alloc/free] */ extern void dtrace_fasttrap_fork(proc_t, proc_t); extern void (*dtrace_helpers_fork)(proc_t, proc_t); +extern void (*dtrace_proc_waitfor_exec_ptr)(proc_t); extern void dtrace_lazy_dofs_duplicate(proc_t, proc_t); +/* + * Since dtrace_proc_waitfor_exec_ptr can be added/removed in dtrace_subr.c, + * we will store its value before actually calling it. + */ +static void (*dtrace_proc_waitfor_hook)(proc_t) = NULL; + #include #endif #include #include +#include #include #include #include @@ -141,10 +149,10 @@ void thread_set_child(thread_t child, int pid); void *act_thread_csave(void); -thread_t cloneproc(task_t, proc_t, int); +thread_t cloneproc(task_t, coalition_t, proc_t, int, int); proc_t forkproc(proc_t); void forkproc_free(proc_t); -thread_t fork_create_child(task_t parent_task, proc_t child, int inherit_memory, int is64bit); +thread_t fork_create_child(task_t parent_task, coalition_t parent_coalition, proc_t child, int inherit_memory, int is64bit); void proc_vfork_begin(proc_t parent_proc); void proc_vfork_end(proc_t parent_proc); @@ -278,15 +286,11 @@ vfork(proc_t parent_proc, __unused struct vfork_args *uap, int32_t *retval) thread_t child_thread; int err; - if ((err = fork1(parent_proc, &child_thread, PROC_CREATE_VFORK)) != 0) { + if ((err = fork1(parent_proc, &child_thread, PROC_CREATE_VFORK, COALITION_NULL)) != 0) { retval[1] = 0; } else { - /* - * kludge: rely on uu_proc being set in the vfork case, - * rather than returning the actual thread. We can remove - * this when we remove the uu_proc/current_proc() kludge. - */ - proc_t child_proc = current_proc(); + uthread_t ut = get_bsdthread_info(current_thread()); + proc_t child_proc = ut->uu_proc; retval[0] = child_proc->p_pid; retval[1] = 1; /* flag child return for user space */ @@ -299,12 +303,12 @@ vfork(proc_t parent_proc, __unused struct vfork_args *uap, int32_t *retval) proc_signalend(child_proc, 0); proc_transend(child_proc, 0); - /* flag the fork has occurred */ proc_knote(parent_proc, NOTE_FORK | child_proc->p_pid); DTRACE_PROC1(create, proc_t, child_proc); + ut->uu_flag &= ~UT_VFORKING; } - return(err); + return (err); } @@ -319,6 +323,11 @@ vfork(proc_t parent_proc, __unused struct vfork_args *uap, int32_t *retval) * Mach thread_t of the child process * breated * kind kind of creation being requested + * coalition if spawn, coalition the child process + * should join, or COALITION_NULL to + * inherit the parent's. On non-spawns, + * this param is ignored and the child + * always inherits the parent's coalition. * * Notes: Permissable values for 'kind': * @@ -350,7 +359,7 @@ vfork(proc_t parent_proc, __unused struct vfork_args *uap, int32_t *retval) * back to the other information. */ int -fork1(proc_t parent_proc, thread_t *child_threadp, int kind) +fork1(proc_t parent_proc, thread_t *child_threadp, int kind, coalition_t coalition) { thread_t parent_thread = (thread_t)current_thread(); uthread_t parent_uthread = (uthread_t)get_bsdthread_info(parent_thread); @@ -484,7 +493,20 @@ fork1(proc_t parent_proc, thread_t *child_threadp, int kind) child_proc->p_vforkact = parent_thread; child_proc->p_stat = SRUN; - parent_uthread->uu_flag |= UT_VFORK; + /* + * Until UT_VFORKING is cleared at the end of the vfork + * syscall, the process identity of this thread is slightly + * murky. + * + * As long as UT_VFORK and it's associated field (uu_proc) + * is set, current_proc() will always return the child process. + * + * However dtrace_proc_selfpid() returns the parent pid to + * ensure that e.g. the proc:::create probe actions accrue + * to the parent. (Otherwise the child magically seems to + * have created itself!) + */ + parent_uthread->uu_flag |= UT_VFORK | UT_VFORKING; parent_uthread->uu_proc = child_proc; parent_uthread->uu_userstate = (void *)act_thread_csave(); parent_uthread->uu_vforkmask = parent_uthread->uu_sigmask; @@ -529,7 +551,11 @@ fork1(proc_t parent_proc, thread_t *child_threadp, int kind) * will, in effect, create a duplicate of it, with only minor * differences. Contrarily, spawned processes do not inherit. */ - if ((child_thread = cloneproc(parent_proc->task, parent_proc, spawn ? FALSE : TRUE)) == NULL) { + if ((child_thread = cloneproc(parent_proc->task, + spawn ? coalition : COALITION_NULL, + parent_proc, + spawn ? FALSE : TRUE, + FALSE)) == NULL) { /* Failed to create thread */ err = EAGAIN; goto bad; @@ -654,12 +680,6 @@ fork1(proc_t parent_proc, thread_t *child_threadp, int kind) /* return the thread pointer to the caller */ *child_threadp = child_thread; -#if CONFIG_MEMORYSTATUS - if (!err) { - memorystatus_list_add(child_proc->p_pid, DEFAULT_JETSAM_PRIORITY, -1); - } -#endif - bad: /* * In the error case, we return a 0 value for the returned pid (but @@ -738,6 +758,7 @@ vfork_return(proc_t child_proc, int32_t *retval, int rval) * process * * Parameters: parent_task parent task + * parent_coalition parent_coalition * child_proc child process * inherit_memory TRUE, if the parents address space is * to be inherited by the child @@ -751,17 +772,18 @@ vfork_return(proc_t child_proc, int32_t *retval, int rval) * vfork() equivalent call, and in the system bootstrap case. * * It creates a new task and thread (and as a side effect of the - * thread creation, a uthread), which is then associated with the - * process 'child'. If the parent process address space is to - * be inherited, then a flag indicates that the newly created - * task should inherit this from the child task. + * thread creation, a uthread) in the parent coalition, which is + * then associated with the process 'child'. If the parent + * process address space is to be inherited, then a flag + * indicates that the newly created task should inherit this from + * the child task. * * As a special concession to bootstrapping the initial process * in the system, it's possible for 'parent_task' to be TASK_NULL; * in this case, 'inherit_memory' MUST be FALSE. */ thread_t -fork_create_child(task_t parent_task, proc_t child_proc, int inherit_memory, int is64bit) +fork_create_child(task_t parent_task, coalition_t parent_coalition, proc_t child_proc, int inherit_memory, int is64bit) { thread_t child_thread = NULL; task_t child_task; @@ -769,11 +791,13 @@ fork_create_child(task_t parent_task, proc_t child_proc, int inherit_memory, int /* Create a new task for the child process */ result = task_create_internal(parent_task, + parent_coalition, inherit_memory, is64bit, &child_task); if (result != KERN_SUCCESS) { - printf("execve: task_create_internal failed. Code: %d\n", result); + printf("%s: task_create_internal failed. Code: %d\n", + __func__, result); goto bad; } @@ -793,12 +817,6 @@ fork_create_child(task_t parent_task, proc_t child_proc, int inherit_memory, int else vm_map_set_32bit(get_task_map(child_task)); -#if CONFIG_MACF - /* Update task for MAC framework */ - /* valid to use p_ucred as child is still not running ... */ - mac_task_label_update_cred(child_proc->p_ucred, child_task); -#endif - /* * Set child process BSD visible scheduler priority if nice value * inherited from parent @@ -809,14 +827,15 @@ fork_create_child(task_t parent_task, proc_t child_proc, int inherit_memory, int /* Create a new thread for the child process */ result = thread_create(child_task, &child_thread); if (result != KERN_SUCCESS) { - printf("execve: thread_create failed. Code: %d\n", result); + printf("%s: thread_create failed. Code: %d\n", + __func__, result); task_deallocate(child_task); child_task = NULL; } /* - * Tag thread as being the first thread in its task. - */ + * Tag thread as being the first thread in its task. + */ thread_set_tag(child_thread, THREAD_TAG_MAINTHREAD); bad: @@ -868,7 +887,7 @@ fork(proc_t parent_proc, __unused struct fork_args *uap, int32_t *retval) retval[1] = 0; /* flag parent return for user space */ - if ((err = fork1(parent_proc, &child_thread, PROC_CREATE_FORK)) == 0) { + if ((err = fork1(parent_proc, &child_thread, PROC_CREATE_FORK, COALITION_NULL)) == 0) { task_t child_task; proc_t child_proc; @@ -888,6 +907,11 @@ fork(proc_t parent_proc, __unused struct fork_args *uap, int32_t *retval) proc_knote(parent_proc, NOTE_FORK | child_proc->p_pid); DTRACE_PROC1(create, proc_t, child_proc); +#if CONFIG_DTRACE + if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) + (*dtrace_proc_waitfor_hook)(child_proc); +#endif + /* "Return" to the child */ (void)thread_resume(child_thread); @@ -918,6 +942,8 @@ fork(proc_t parent_proc, __unused struct fork_args *uap, int32_t *retval) * memory from the parent; if this is * non-NULL, then the parent_task must * also be non-NULL + * memstat_internal Whether to track the process in the + * jetsam priority list (if configured) * * Returns: !NULL pointer to new child thread * NULL Failure (unspecified) @@ -939,8 +965,11 @@ fork(proc_t parent_proc, __unused struct fork_args *uap, int32_t *retval) * live with this being somewhat awkward. */ thread_t -cloneproc(task_t parent_task, proc_t parent_proc, int inherit_memory) +cloneproc(task_t parent_task, coalition_t parent_coalition, proc_t parent_proc, int inherit_memory, int memstat_internal) { +#if !CONFIG_MEMORYSTATUS +#pragma unused(memstat_internal) +#endif task_t child_task; proc_t child_proc; thread_t child_thread = NULL; @@ -950,7 +979,7 @@ cloneproc(task_t parent_task, proc_t parent_proc, int inherit_memory) goto bad; } - child_thread = fork_create_child(parent_task, child_proc, inherit_memory, (parent_task == TASK_NULL) ? FALSE : (parent_proc->p_flag & P_LP64)); + child_thread = fork_create_child(parent_task, parent_coalition, child_proc, inherit_memory, (parent_task == TASK_NULL) ? FALSE : (parent_proc->p_flag & P_LP64)); if (child_thread == NULL) { /* @@ -970,6 +999,14 @@ cloneproc(task_t parent_task, proc_t parent_proc, int inherit_memory) OSBitAndAtomic(~((uint32_t)P_LP64), (UInt32 *)&child_proc->p_flag); } +#if CONFIG_MEMORYSTATUS + if (memstat_internal) { + proc_list_lock(); + child_proc->p_memstat_state |= P_MEMSTAT_INTERNAL; + proc_list_unlock(); + } +#endif + /* make child visible */ pinsertchild(parent_proc, child_proc); @@ -1027,12 +1064,6 @@ forkproc_free(proc_t p) /* Need to undo the effects of the fdcopy(), if any */ fdfree(p); -#if !CONFIG_EMBEDDED - if (p->p_legacy_behavior & PROC_LEGACY_BEHAVIOR_IOTHROTTLE) { - throttle_legacy_process_decr(); - } -#endif - /* * Drop the reference on a text vnode pointer, if any * XXX This code is broken in forkproc(); see ; @@ -1201,19 +1232,11 @@ retry: * Increase reference counts on shared objects. * The p_stats and p_sigacts substructs are set in vm_fork. */ -#if !CONFIG_EMBEDDED child_proc->p_flag = (parent_proc->p_flag & (P_LP64 | P_TRANSLATED | P_AFFINITY | P_DISABLE_ASLR | P_DELAYIDLESLEEP)); -#else /* !CONFIG_EMBEDDED */ - child_proc->p_flag = (parent_proc->p_flag & (P_LP64 | P_TRANSLATED | P_AFFINITY | P_DISABLE_ASLR)); -#endif /* !CONFIG_EMBEDDED */ if (parent_proc->p_flag & P_PROFIL) startprofclock(child_proc); -#if !CONFIG_EMBEDDED - if (child_proc->p_legacy_behavior & PROC_LEGACY_BEHAVIOR_IOTHROTTLE) { - throttle_legacy_process_incr(); - } -#endif + child_proc->p_vfs_iopolicy = (parent_proc->p_vfs_iopolicy & (P_VFS_IOPOLICY_FORCE_HFS_CASE_SENSITIVITY)); /* * Note that if the current thread has an assumed identity, this @@ -1281,12 +1304,8 @@ retry: /* Intialize new process stats, including start time */ /* non-zeroed portion contains garbage AFAICT */ - bzero(&child_proc->p_stats->pstat_startzero, - (unsigned) ((caddr_t)&child_proc->p_stats->pstat_endzero - - (caddr_t)&child_proc->p_stats->pstat_startzero)); - bzero(&child_proc->p_stats->user_p_prof, sizeof(struct user_uprof)); - microtime(&child_proc->p_start); - child_proc->p_stats->p_start = child_proc->p_start; /* for compat */ + bzero(child_proc->p_stats, sizeof(*child_proc->p_stats)); + microtime_with_abstime(&child_proc->p_start, &child_proc->p_stats->ps_start); if (parent_proc->p_sigacts != NULL) (void)memcpy(child_proc->p_sigacts, @@ -1305,9 +1324,10 @@ retry: * but indicate that the process is in (the creation) transition. */ proc_signalstart(child_proc, 0); - proc_transstart(child_proc, 0); + proc_transstart(child_proc, 0, 0); + + child_proc->p_pcaction = 0; - child_proc->p_pcaction = (parent_proc->p_pcaction) & P_PCMAX; TAILQ_INIT(&child_proc->p_uthlist); TAILQ_INIT(&child_proc->p_aio_activeq); TAILQ_INIT(&child_proc->p_aio_doneq); @@ -1340,6 +1360,7 @@ retry: child_proc->p_lflag |= P_LREGISTER; } child_proc->p_dispatchqueue_offset = parent_proc->p_dispatchqueue_offset; + child_proc->p_dispatchqueue_serialno_offset = parent_proc->p_dispatchqueue_serialno_offset; #if PSYNCH pth_proc_hashinit(child_proc); #endif /* PSYNCH */ @@ -1357,8 +1378,18 @@ retry: } #endif - /* Default to no tracking of dirty state */ - child_proc->p_dirty = 0; +#if CONFIG_MEMORYSTATUS + /* Memorystatus + jetsam init */ + child_proc->p_memstat_state = 0; + child_proc->p_memstat_effectivepriority = JETSAM_PRIORITY_DEFAULT; + child_proc->p_memstat_requestedpriority = JETSAM_PRIORITY_DEFAULT; + child_proc->p_memstat_userdata = 0; +#if CONFIG_FREEZE + child_proc->p_memstat_suspendedfootprint = 0; +#endif + child_proc->p_memstat_dirty = 0; + child_proc->p_memstat_idledeadline = 0; +#endif /* CONFIG_MEMORYSTATUS */ bad: return(child_proc); @@ -1433,7 +1464,6 @@ uthread_alloc(task_t task, thread_t thread, int noinherit) p = (proc_t) get_bsdtask_info(task); uth = (uthread_t)ut; - uth->uu_kwe.kwe_uth = uth; uth->uu_thread = thread; /* @@ -1507,7 +1537,7 @@ uthread_cleanup(task_t task, void *uthread, void * bsd_info) struct _select *sel; uthread_t uth = (uthread_t)uthread; proc_t p = (proc_t)bsd_info; - + void *pth_name; if (uth->uu_lowpri_window || uth->uu_throttle_info) { /* @@ -1520,7 +1550,7 @@ uthread_cleanup(task_t task, void *uthread, void * bsd_info) * Calling this routine will clean up any throttle info reference * still inuse by the thread. */ - throttle_lowpri_io(FALSE); + throttle_lowpri_io(0); } /* * Per-thread audit state should never last beyond system @@ -1545,17 +1575,25 @@ uthread_cleanup(task_t task, void *uthread, void * bsd_info) if (uth->uu_allocsize && uth->uu_wqset){ kfree(uth->uu_wqset, uth->uu_allocsize); - sel->count = 0; uth->uu_allocsize = 0; uth->uu_wqset = 0; - sel->wql = 0; } - - if(uth->pth_name != NULL) - { - kfree(uth->pth_name, MAXTHREADNAMESIZE); - uth->pth_name = 0; + + /* + * + * Set pth_name to NULL before calling free(). + * Previously there was a race condition in the + * case this code was executing during a stackshot + * where the stackshot could try and copy pth_name + * after it had been freed and before if was marked + * as null. + */ + if (uth->pth_name != NULL) { + pth_name = uth->pth_name; + uth->pth_name = NULL; + kfree(pth_name, MAXTHREADNAMESIZE); } + if ((task != kernel_task) && p) { if (((uth->uu_flag & UT_VFORK) == UT_VFORK) && (uth->uu_proc != PROC_NULL)) { @@ -1602,6 +1640,13 @@ uthread_cred_free(void *uthread) void uthread_zone_free(void *uthread) { + uthread_t uth = (uthread_t)uthread; + + if (uth->t_tombstone) { + kfree(uth->t_tombstone, sizeof(struct doc_tombstone)); + uth->t_tombstone = NULL; + } + /* and free the uthread itself */ zfree(uthread_zone, uthread); }