/*
- * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2007, 2015 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
*
* @(#)kern_fork.c 8.8 (Berkeley) 2/14/95
*/
+/*
+ * NOTICE: This file was modified by McAfee Research in 2004 to introduce
+ * support for mandatory and extensible security protections. This notice
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
+ */
+/*
+ * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
+ * support for mandatory and extensible security protections. This notice
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
+ */
#include <kern/assert.h>
#include <sys/param.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/user.h>
+#include <sys/reason.h>
#include <sys/resourcevar.h>
#include <sys/vnode_internal.h>
#include <sys/file_internal.h>
#include <sys/acct.h>
-#if KTRACE
-#include <sys/ktrace.h>
+#include <sys/codesign.h>
+#include <sys/sysproto.h>
+#if CONFIG_PERSONAS
+#include <sys/persona.h>
#endif
+#include <sys/doc_tombstone.h>
+#if CONFIG_DTRACE
+/* Do not include dtrace.h, it redefines kmem_[alloc/free] */
+extern void (*dtrace_proc_waitfor_exec_ptr)(proc_t);
+extern void dtrace_proc_fork(proc_t, proc_t, int);
-#include <bsm/audit_kernel.h>
+/*
+ * 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 <sys/dtrace_ptss.h>
+#endif
+
+#include <security/audit/audit.h>
#include <mach/mach_types.h>
+#include <kern/coalition.h>
#include <kern/kern_types.h>
#include <kern/kalloc.h>
#include <kern/mach_param.h>
#include <kern/task.h>
+#include <kern/thread.h>
+#include <kern/thread_call.h>
#include <kern/zalloc.h>
#include <machine/spl.h>
-#include <vm/vm_protos.h> // for vm_map_commpage64
+#if CONFIG_MACF
+#include <security/mac.h>
+#include <security/mac_mach_internal.h>
+#endif
+
+#include <vm/vm_map.h>
+#include <vm/vm_protos.h>
+#include <vm/vm_shared_region.h>
+
+#include <sys/shm_internal.h> /* for shmfork() */
+#include <mach/task.h> /* for thread_create() */
+#include <mach/thread_act.h> /* for thread_resume() */
-thread_t cloneproc(struct proc *, int);
-struct proc * forkproc(struct proc *, int);
-thread_t procdup(struct proc *child, struct proc *parent);
+#include <sys/sdt.h>
+
+#if CONFIG_MEMORYSTATUS
+#include <sys/kern_memorystatus.h>
+#endif
+
+/* XXX routines which should have Mach prototypes, but don't */
+void thread_set_parent(thread_t parent, int pid);
+extern void act_thread_catt(void *ctx);
+void thread_set_child(thread_t child, int pid);
+void *act_thread_csave(void);
+extern boolean_t task_is_exec_copy(task_t);
+
+
+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, coalition_t *parent_coalitions, proc_t child, int inherit_memory, int is64bit, int in_exec);
+void proc_vfork_begin(proc_t parent_proc);
+void proc_vfork_end(proc_t parent_proc);
#define DOFORK 0x1 /* fork() system call */
#define DOVFORK 0x2 /* vfork() system call */
-static int fork1(struct proc *, long, register_t *);
/*
- * fork system call.
+ * proc_vfork_begin
+ *
+ * Description: start a vfork on a process
+ *
+ * Parameters: parent_proc process (re)entering vfork state
+ *
+ * Returns: (void)
+ *
+ * Notes: Although this function increments a count, a count in
+ * excess of 1 is not currently supported. According to the
+ * POSIX standard, calling anything other than execve() or
+ * _exit() following a vfork(), including calling vfork()
+ * itself again, will result in undefined behaviour
+ */
+void
+proc_vfork_begin(proc_t parent_proc)
+{
+ proc_lock(parent_proc);
+ parent_proc->p_lflag |= P_LVFORK;
+ parent_proc->p_vforkcnt++;
+ proc_unlock(parent_proc);
+}
+
+/*
+ * proc_vfork_end
+ *
+ * Description: stop a vfork on a process
+ *
+ * Parameters: parent_proc process leaving vfork state
+ *
+ * Returns: (void)
+ *
+ * Notes: Decrements the count; currently, reentrancy of vfork()
+ * is unsupported on the current process
+ */
+void
+proc_vfork_end(proc_t parent_proc)
+{
+ proc_lock(parent_proc);
+ parent_proc->p_vforkcnt--;
+ if (parent_proc->p_vforkcnt < 0)
+ panic("vfork cnt is -ve");
+ if (parent_proc->p_vforkcnt == 0)
+ parent_proc->p_lflag &= ~P_LVFORK;
+ proc_unlock(parent_proc);
+}
+
+
+/*
+ * vfork
+ *
+ * Description: vfork system call
+ *
+ * Parameters: void [no arguments]
+ *
+ * Retval: 0 (to child process)
+ * !0 pid of child (to parent process)
+ * -1 error (see "Returns:")
+ *
+ * Returns: EAGAIN Administrative limit reached
+ * EINVAL vfork() called during vfork()
+ * ENOMEM Failed to allocate new process
+ *
+ * Note: After a successful call to this function, the parent process
+ * has its task, thread, and uthread lent to the child process,
+ * and control is returned to the caller; if this function is
+ * invoked as a system call, the return is to user space, and
+ * is effectively running on the child process.
+ *
+ * Subsequent calls that operate on process state are permitted,
+ * though discouraged, and will operate on the child process; any
+ * operations on the task, thread, or uthread will result in
+ * changes in the parent state, and, if inheritable, the child
+ * state, when a task, thread, and uthread are realized for the
+ * child process at execve() time, will also be effected. Given
+ * this, it's recemmended that people use the posix_spawn() call
+ * instead.
+ *
+ * BLOCK DIAGRAM OF VFORK
+ *
+ * Before:
+ *
+ * ,----------------. ,-------------.
+ * | | task | |
+ * | parent_thread | ------> | parent_task |
+ * | | <.list. | |
+ * `----------------' `-------------'
+ * uthread | ^ bsd_info | ^
+ * v | vc_thread v | task
+ * ,----------------. ,-------------.
+ * | | | |
+ * | parent_uthread | <.list. | parent_proc | <-- current_proc()
+ * | | | |
+ * `----------------' `-------------'
+ * uu_proc |
+ * v
+ * NULL
+ *
+ * After:
+ *
+ * ,----------------. ,-------------.
+ * | | task | |
+ * ,----> | parent_thread | ------> | parent_task |
+ * | | | <.list. | |
+ * | `----------------' `-------------'
+ * | uthread | ^ bsd_info | ^
+ * | v | vc_thread v | task
+ * | ,----------------. ,-------------.
+ * | | | | |
+ * | | parent_uthread | <.list. | parent_proc |
+ * | | | | |
+ * | `----------------' `-------------'
+ * | uu_proc | . list
+ * | v v
+ * | ,----------------.
+ * `----- | |
+ * p_vforkact | child_proc | <-- current_proc()
+ * | |
+ * `----------------'
*/
int
-fork(struct proc *p, __unused void *uap, register_t *retval)
+vfork(proc_t parent_proc, __unused struct vfork_args *uap, int32_t *retval)
{
- return (fork1(p, (long)DOFORK, retval));
+ thread_t child_thread;
+ int err;
+
+ if ((err = fork1(parent_proc, &child_thread, PROC_CREATE_VFORK, NULL)) != 0) {
+ retval[1] = 0;
+ } else {
+ 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 */
+
+ /*
+ * Drop the signal lock on the child which was taken on our
+ * behalf by forkproc()/cloneproc() to prevent signals being
+ * received by the child in a partially constructed state.
+ */
+ proc_signalend(child_proc, 0);
+ proc_transend(child_proc, 0);
+
+ proc_knote(parent_proc, NOTE_FORK | child_proc->p_pid);
+ DTRACE_PROC1(create, proc_t, child_proc);
+ ut->uu_flag &= ~UT_VFORKING;
+ }
+
+ return (err);
}
+
/*
- * vfork system call
+ * fork1
+ *
+ * Description: common code used by all new process creation other than the
+ * bootstrap of the initial process on the system
+ *
+ * Parameters: parent_proc parent process of the process being
+ * child_threadp pointer to location to receive the
+ * Mach thread_t of the child process
+ * created
+ * kind kind of creation being requested
+ * coalitions if spawn, the set of coalitions the
+ * child process should join, or NULL to
+ * inherit the parent's. On non-spawns,
+ * this param is ignored and the child
+ * always inherits the parent's
+ * coalitions.
+ *
+ * Notes: Permissable values for 'kind':
+ *
+ * PROC_CREATE_FORK Create a complete process which will
+ * return actively running in both the
+ * parent and the child; the child copies
+ * the parent address space.
+ * PROC_CREATE_SPAWN Create a complete process which will
+ * return actively running in the parent
+ * only after returning actively running
+ * in the child; the child address space
+ * is newly created by an image activator,
+ * after which the child is run.
+ * PROC_CREATE_VFORK Creates a partial process which will
+ * borrow the parent task, thread, and
+ * uthread to return running in the child;
+ * the child address space and other parts
+ * are lazily created at execve() time, or
+ * the child is terminated, and the parent
+ * does not actively run until that
+ * happens.
+ *
+ * At first it may seem strange that we return the child thread
+ * address rather than process structure, since the process is
+ * the only part guaranteed to be "new"; however, since we do
+ * not actualy adjust other references between Mach and BSD (see
+ * the block diagram above the implementation of vfork()), this
+ * is the only method which guarantees us the ability to get
+ * back to the other information.
*/
int
-vfork(struct proc *p, void *uap, register_t *retval)
+fork1(proc_t parent_proc, thread_t *child_threadp, int kind, coalition_t *coalitions)
{
- register struct proc * newproc;
- register uid_t uid;
- thread_t cur_act = (thread_t)current_thread();
+ thread_t parent_thread = (thread_t)current_thread();
+ uthread_t parent_uthread = (uthread_t)get_bsdthread_info(parent_thread);
+ proc_t child_proc = NULL; /* set in switch, but compiler... */
+ thread_t child_thread = NULL;
+ uid_t uid;
int count;
- task_t t;
- uthread_t ut;
+ int err = 0;
+ int spawn = 0;
/*
* Although process entries are dynamically created, we still keep
* exceed the limit. The variable nprocs is the current number of
* processes, maxproc is the limit.
*/
- uid = kauth_cred_get()->cr_ruid;
+ uid = kauth_getruid();
+ proc_list_lock();
if ((nprocs >= maxproc - 1 && uid != 0) || nprocs >= maxproc) {
+ proc_list_unlock();
tablefull("proc");
- retval[1] = 0;
return (EAGAIN);
}
+ proc_list_unlock();
/*
* Increment the count of procs running with this uid. Don't allow
- * a nonprivileged user to exceed their current limit.
+ * a nonprivileged user to exceed their current limit, which is
+ * always less than what an rlim_t can hold.
+ * (locking protection is provided by list lock held in chgproccnt)
*/
count = chgproccnt(uid, 1);
- if (uid != 0 && count > p->p_rlimit[RLIMIT_NPROC].rlim_cur) {
- (void)chgproccnt(uid, -1);
- return (EAGAIN);
+ if (uid != 0 &&
+ (rlim_t)count > parent_proc->p_rlimit[RLIMIT_NPROC].rlim_cur) {
+ err = EAGAIN;
+ goto bad;
}
- ut = (struct uthread *)get_bsdthread_info(cur_act);
- if (ut->uu_flag & UT_VFORK) {
- printf("vfork called recursively by %s\n", p->p_comm);
- (void)chgproccnt(uid, -1);
- return (EINVAL);
- }
- p->p_flag |= P_VFORK;
- p->p_vforkcnt++;
-
- /* The newly created process comes with signal lock held */
- newproc = (struct proc *)forkproc(p,1);
-
- AUDIT_ARG(pid, newproc->p_pid);
-
- LIST_INSERT_AFTER(p, newproc, p_pglist);
- newproc->p_pptr = p;
- newproc->task = p->task;
- LIST_INSERT_HEAD(&p->p_children, newproc, p_sibling);
- LIST_INIT(&newproc->p_children);
- LIST_INSERT_HEAD(&allproc, newproc, p_list);
- LIST_INSERT_HEAD(PIDHASH(newproc->p_pid), newproc, p_hash);
- TAILQ_INIT(& newproc->p_evlist);
- newproc->p_stat = SRUN;
- newproc->p_flag |= P_INVFORK;
- newproc->p_vforkact = cur_act;
-
- ut->uu_flag |= UT_VFORK;
- ut->uu_proc = newproc;
- ut->uu_userstate = (void *)act_thread_csave();
- ut->uu_vforkmask = ut->uu_sigmask;
-
- /* temporarily drop thread-set-id state */
- if (ut->uu_flag & UT_SETUID) {
- ut->uu_flag |= UT_WASSETUID;
- ut->uu_flag &= ~UT_SETUID;
+#if CONFIG_MACF
+ /*
+ * Determine if MAC policies applied to the process will allow
+ * it to fork. This is an advisory-only check.
+ */
+ err = mac_proc_check_fork(parent_proc);
+ if (err != 0) {
+ goto bad;
}
-
- thread_set_child(cur_act, newproc->p_pid);
+#endif
- microtime(&newproc->p_stats->p_start);
- newproc->p_acflag = AFORK;
+ switch(kind) {
+ case PROC_CREATE_VFORK:
+ /*
+ * Prevent a vfork while we are in vfork(); we should
+ * also likely preventing a fork here as well, and this
+ * check should then be outside the switch statement,
+ * since the proc struct contents will copy from the
+ * child and the tash/thread/uthread from the parent in
+ * that case. We do not support vfork() in vfork()
+ * because we don't have to; the same non-requirement
+ * is true of both fork() and posix_spawn() and any
+ * call other than execve() amd _exit(), but we've
+ * been historically lenient, so we continue to be so
+ * (for now).
+ *
+ * <rdar://6640521> Probably a source of random panics
+ */
+ if (parent_uthread->uu_flag & UT_VFORK) {
+ printf("fork1 called within vfork by %s\n", parent_proc->p_comm);
+ err = EINVAL;
+ goto bad;
+ }
- /*
- * Preserve synchronization semantics of vfork. If waiting for
- * child to exec or exit, set P_PPWAIT on child, and sleep on our
- * proc (in case of exit).
- */
- newproc->p_flag |= P_PPWAIT;
+ /*
+ * Flag us in progress; if we chose to support vfork() in
+ * vfork(), we would chain our parent at this point (in
+ * effect, a stack push). We don't, since we actually want
+ * to disallow everything not specified in the standard
+ */
+ proc_vfork_begin(parent_proc);
+
+ /* The newly created process comes with signal lock held */
+ if ((child_proc = forkproc(parent_proc)) == NULL) {
+ /* Failed to allocate new process */
+ proc_vfork_end(parent_proc);
+ err = ENOMEM;
+ goto bad;
+ }
+
+// XXX BEGIN: wants to move to be common code (and safe)
+#if CONFIG_MACF
+ /*
+ * allow policies to associate the credential/label that
+ * we referenced from the parent ... with the child
+ * JMM - this really isn't safe, as we can drop that
+ * association without informing the policy in other
+ * situations (keep long enough to get policies changed)
+ */
+ mac_cred_label_associate_fork(child_proc->p_ucred, child_proc);
+#endif
+
+ /*
+ * Propogate change of PID - may get new cred if auditing.
+ *
+ * NOTE: This has no effect in the vfork case, since
+ * child_proc->task != current_task(), but we duplicate it
+ * because this is probably, ultimately, wrong, since we
+ * will be running in the "child" which is the parent task
+ * with the wrong token until we get to the execve() or
+ * _exit() call; a lot of "undefined" can happen before
+ * that.
+ *
+ * <rdar://6640530> disallow everything but exeve()/_exit()?
+ */
+ set_security_token(child_proc);
+
+ AUDIT_ARG(pid, child_proc->p_pid);
+
+// XXX END: wants to move to be common code (and safe)
+
+ /*
+ * BORROW PARENT TASK, THREAD, UTHREAD FOR CHILD
+ *
+ * Note: this is where we would "push" state instead of setting
+ * it for nested vfork() support (see proc_vfork_end() for
+ * description if issues here).
+ */
+ child_proc->task = parent_proc->task;
+
+ child_proc->p_lflag |= P_LINVFORK;
+ child_proc->p_vforkact = parent_thread;
+ child_proc->p_stat = SRUN;
+
+ /*
+ * 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;
+
+ /* temporarily drop thread-set-id state */
+ if (parent_uthread->uu_flag & UT_SETUID) {
+ parent_uthread->uu_flag |= UT_WASSETUID;
+ parent_uthread->uu_flag &= ~UT_SETUID;
+ }
+
+ /* blow thread state information */
+ /* XXX is this actually necessary, given syscall return? */
+ thread_set_child(parent_thread, child_proc->p_pid);
+
+ child_proc->p_acflag = AFORK; /* forked but not exec'ed */
+
+ /*
+ * Preserve synchronization semantics of vfork. If
+ * waiting for child to exec or exit, set P_PPWAIT
+ * on child, and sleep on our proc (in case of exit).
+ */
+ child_proc->p_lflag |= P_LPPWAIT;
+ pinsertchild(parent_proc, child_proc); /* set visible */
+
+ break;
+
+ case PROC_CREATE_SPAWN:
+ /*
+ * A spawned process differs from a forked process in that
+ * the spawned process does not carry around the parents
+ * baggage with regard to address space copying, dtrace,
+ * and so on.
+ */
+ spawn = 1;
+
+ /* FALLSTHROUGH */
+
+ case PROC_CREATE_FORK:
+ /*
+ * When we clone the parent process, we are going to inherit
+ * its task attributes and memory, since when we fork, we
+ * 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,
+ spawn ? coalitions : NULL,
+ parent_proc,
+ spawn ? FALSE : TRUE,
+ FALSE)) == NULL) {
+ /* Failed to create thread */
+ err = EAGAIN;
+ goto bad;
+ }
+
+ /* copy current thread state into the child thread (only for fork) */
+ if (!spawn) {
+ thread_dup(child_thread);
+ }
+
+ /* child_proc = child_thread->task->proc; */
+ child_proc = (proc_t)(get_bsdtask_info(get_threadtask(child_thread)));
+
+// XXX BEGIN: wants to move to be common code (and safe)
+#if CONFIG_MACF
+ /*
+ * allow policies to associate the credential/label that
+ * we referenced from the parent ... with the child
+ * JMM - this really isn't safe, as we can drop that
+ * association without informing the policy in other
+ * situations (keep long enough to get policies changed)
+ */
+ mac_cred_label_associate_fork(child_proc->p_ucred, child_proc);
+#endif
+
+ /*
+ * Propogate change of PID - may get new cred if auditing.
+ *
+ * NOTE: This has no effect in the vfork case, since
+ * child_proc->task != current_task(), but we duplicate it
+ * because this is probably, ultimately, wrong, since we
+ * will be running in the "child" which is the parent task
+ * with the wrong token until we get to the execve() or
+ * _exit() call; a lot of "undefined" can happen before
+ * that.
+ *
+ * <rdar://6640530> disallow everything but exeve()/_exit()?
+ */
+ set_security_token(child_proc);
- /* drop the signal lock on the child */
- signal_unlock(newproc);
+ AUDIT_ARG(pid, child_proc->p_pid);
- retval[0] = newproc->p_pid;
- retval[1] = 1; /* mark child */
+// XXX END: wants to move to be common code (and safe)
- return (0);
+ /*
+ * Blow thread state information; this is what gives the child
+ * process its "return" value from a fork() call.
+ *
+ * Note: this should probably move to fork() proper, since it
+ * is not relevent to spawn, and the value won't matter
+ * until we resume the child there. If you are in here
+ * refactoring code, consider doing this at the same time.
+ */
+ thread_set_child(child_thread, child_proc->p_pid);
+
+ child_proc->p_acflag = AFORK; /* forked but not exec'ed */
+
+#if CONFIG_DTRACE
+ dtrace_proc_fork(parent_proc, child_proc, spawn);
+#endif /* CONFIG_DTRACE */
+ if (!spawn) {
+ /*
+ * Of note, we need to initialize the bank context behind
+ * the protection of the proc_trans lock to prevent a race with exit.
+ */
+ task_bank_init(get_threadtask(child_thread));
+ }
+
+ break;
+
+ default:
+ panic("fork1 called with unknown kind %d", kind);
+ break;
+ }
+
+
+ /* return the thread pointer to the caller */
+ *child_threadp = child_thread;
+
+bad:
+ /*
+ * In the error case, we return a 0 value for the returned pid (but
+ * it is ignored in the trampoline due to the error return); this
+ * is probably not necessary.
+ */
+ if (err) {
+ (void)chgproccnt(uid, -1);
+ }
+
+ return (err);
}
+
/*
- * Return to parent vfork ehread()
+ * vfork_return
+ *
+ * Description: "Return" to parent vfork thread() following execve/_exit;
+ * this is done by reassociating the parent process structure
+ * with the task, thread, and uthread.
+ *
+ * Refer to the ASCII art above vfork() to figure out the
+ * state we're undoing.
+ *
+ * Parameters: child_proc Child process
+ * retval System call return value array
+ * rval Return value to present to parent
+ *
+ * Returns: void
+ *
+ * Notes: The caller resumes or exits the parent, as appropriate, after
+ * calling this function.
*/
void
-vfork_return(__unused thread_t th_act, struct proc *p, struct proc *p2,
- register_t *retval)
+vfork_return(proc_t child_proc, int32_t *retval, int rval)
{
- thread_t cur_act = (thread_t)current_thread();
- uthread_t ut;
+ task_t parent_task = get_threadtask(child_proc->p_vforkact);
+ proc_t parent_proc = get_bsdtask_info(parent_task);
+ thread_t th = current_thread();
+ uthread_t uth = get_bsdthread_info(th);
- ut = (struct uthread *)get_bsdthread_info(cur_act);
+ act_thread_catt(uth->uu_userstate);
- act_thread_catt(ut->uu_userstate);
+ /* clear vfork state in parent proc structure */
+ proc_vfork_end(parent_proc);
- /* Make sure only one at this time */
- p->p_vforkcnt--;
- if (p->p_vforkcnt <0)
- panic("vfork cnt is -ve");
- if (p->p_vforkcnt <=0)
- p->p_flag &= ~P_VFORK;
- ut->uu_userstate = 0;
- ut->uu_flag &= ~UT_VFORK;
+ /* REPATRIATE PARENT TASK, THREAD, UTHREAD */
+ uth->uu_userstate = 0;
+ uth->uu_flag &= ~UT_VFORK;
/* restore thread-set-id state */
- if (ut->uu_flag & UT_WASSETUID) {
- ut->uu_flag |= UT_SETUID;
- ut->uu_flag &= UT_WASSETUID;
+ if (uth->uu_flag & UT_WASSETUID) {
+ uth->uu_flag |= UT_SETUID;
+ uth->uu_flag &= UT_WASSETUID;
}
- ut->uu_proc = 0;
- ut->uu_sigmask = ut->uu_vforkmask;
- p2->p_flag &= ~P_INVFORK;
- p2->p_vforkact = (void *)0;
+ uth->uu_proc = 0;
+ uth->uu_sigmask = uth->uu_vforkmask;
- thread_set_parent(cur_act, p2->p_pid);
+ proc_lock(child_proc);
+ child_proc->p_lflag &= ~P_LINVFORK;
+ child_proc->p_vforkact = 0;
+ proc_unlock(child_proc);
+
+ thread_set_parent(th, rval);
if (retval) {
- retval[0] = p2->p_pid;
+ retval[0] = rval;
retval[1] = 0; /* mark parent */
}
-
- return;
}
+
+/*
+ * fork_create_child
+ *
+ * Description: Common operations associated with the creation of a child
+ * process
+ *
+ * Parameters: parent_task parent task
+ * parent_coalitions parent's set of coalitions
+ * child_proc child process
+ * inherit_memory TRUE, if the parents address space is
+ * to be inherited by the child
+ * is64bit TRUE, if the child being created will
+ * be associated with a 64 bit process
+ * rather than a 32 bit process
+ * in_exec TRUE, if called from execve or posix spawn set exec
+ * FALSE, if called from fork or vfexec
+ *
+ * Note: This code is called in the fork() case, from the execve() call
+ * graph, if implementing an execve() following a vfork(), from
+ * the posix_spawn() call graph (which implicitly includes a
+ * 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) in the parent coalition set, 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
-procdup(struct proc *child, struct proc *parent)
+fork_create_child(task_t parent_task, coalition_t *parent_coalitions, proc_t child_proc, int inherit_memory, int is64bit, int in_exec)
{
- thread_t thread;
- task_t task;
- kern_return_t result;
+ thread_t child_thread = NULL;
+ task_t child_task;
+ kern_return_t result;
+
+ /* Create a new task for the child process */
+ result = task_create_internal(parent_task,
+ parent_coalitions,
+ inherit_memory,
+ is64bit,
+ TF_LRETURNWAIT | TF_LRETURNWAITER, /* All created threads will wait in task_wait_to_return */
+ in_exec ? TPF_EXEC_COPY : TPF_NONE, /* Mark the task exec copy if in execve */
+ &child_task);
+ if (result != KERN_SUCCESS) {
+ printf("%s: task_create_internal failed. Code: %d\n",
+ __func__, result);
+ goto bad;
+ }
- if (parent->task == kernel_task)
- result = task_create_internal(TASK_NULL, FALSE, &task);
- else
- result = task_create_internal(parent->task, TRUE, &task);
- if (result != KERN_SUCCESS)
- printf("fork/procdup: task_create failed. Code: 0x%x\n", result);
- child->task = task;
- /* task->proc = child; */
- set_bsdtask_info(task, child);
- if (parent->p_flag & P_LP64) {
- task_set_64bit(task, TRUE);
- child->p_flag |= P_LP64;
-#ifdef __PPC__
- /* LP64todo - clean up this hacked mapping of commpage */
- pmap_map_sharedpage(task, get_map_pmap(get_task_map(task)));
- vm_map_commpage64(get_task_map(task));
-#endif /* __PPC__ */
- } else {
- task_set_64bit(task, FALSE);
- child->p_flag &= ~P_LP64;
+ if (!in_exec) {
+ /*
+ * Set the child process task to the new task if not in exec,
+ * will set the task for exec case in proc_exec_switch_task after image activation.
+ */
+ child_proc->task = child_task;
}
- if (child->p_nice != 0)
- resetpriority(child);
-
- result = thread_create(task, &thread);
- if (result != KERN_SUCCESS)
- printf("fork/procdup: thread_create failed. Code: 0x%x\n", result);
- return(thread);
-}
+ /* Set child task process to child proc */
+ set_bsdtask_info(child_task, child_proc);
+ /* Propagate CPU limit timer from parent */
+ if (timerisset(&child_proc->p_rlim_cpu))
+ task_vtimer_set(child_task, TASK_VTIMER_RLIM);
-static int
-fork1(p1, flags, retval)
- struct proc *p1;
- long flags;
- register_t *retval;
-{
- register struct proc *p2;
- register uid_t uid;
- thread_t newth;
- int count;
- task_t t;
+ /* Set/clear 64 bit vm_map flag */
+ if (is64bit)
+ vm_map_set_64bit(get_task_map(child_task));
+ else
+ vm_map_set_32bit(get_task_map(child_task));
/*
- * Although process entries are dynamically created, we still keep
- * a global limit on the maximum number we will create. Don't allow
- * a nonprivileged user to use the last process; don't let root
- * exceed the limit. The variable nprocs is the current number of
- * processes, maxproc is the limit.
+ * Set child process BSD visible scheduler priority if nice value
+ * inherited from parent
*/
- uid = kauth_cred_get()->cr_ruid;
- if ((nprocs >= maxproc - 1 && uid != 0) || nprocs >= maxproc) {
- tablefull("proc");
- retval[1] = 0;
- return (EAGAIN);
- }
+ if (child_proc->p_nice != 0)
+ resetpriority(child_proc);
/*
- * Increment the count of procs running with this uid. Don't allow
- * a nonprivileged user to exceed their current limit.
+ * Create a new thread for the child process
+ * The new thread is waiting on the event triggered by 'task_clear_return_wait'
*/
- count = chgproccnt(uid, 1);
- if (uid != 0 && count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur) {
- (void)chgproccnt(uid, -1);
- return (EAGAIN);
+ result = thread_create_waiting(child_task,
+ (thread_continue_t)task_wait_to_return,
+ task_get_return_wait_event(child_task),
+ &child_thread);
+
+ if (result != KERN_SUCCESS) {
+ printf("%s: thread_create failed. Code: %d\n",
+ __func__, result);
+ task_deallocate(child_task);
+ child_task = NULL;
}
- /* The newly created process comes with signal lock held */
- newth = cloneproc(p1, 1);
- thread_dup(newth);
- /* p2 = newth->task->proc; */
- p2 = (struct proc *)(get_bsdtask_info(get_threadtask(newth)));
- set_security_token(p2); /* propagate change of PID */
+ /*
+ * Tag thread as being the first thread in its task.
+ */
+ thread_set_tag(child_thread, THREAD_TAG_MAINTHREAD);
- AUDIT_ARG(pid, p2->p_pid);
+bad:
+ thread_yield_internal(1);
- thread_set_child(newth, p2->p_pid);
+ return(child_thread);
+}
- microtime(&p2->p_stats->p_start);
- p2->p_acflag = AFORK;
- /*
- * Preserve synchronization semantics of vfork. If waiting for
- * child to exec or exit, set P_PPWAIT on child, and sleep on our
- * proc (in case of exit).
- */
- if (flags == DOVFORK)
- p2->p_flag |= P_PPWAIT;
- /* drop the signal lock on the child */
- signal_unlock(p2);
+/*
+ * fork
+ *
+ * Description: fork system call.
+ *
+ * Parameters: parent Parent process to fork
+ * uap (void) [unused]
+ * retval Return value
+ *
+ * Returns: 0 Success
+ * EAGAIN Resource unavailable, try again
+ *
+ * Notes: Attempts to create a new child process which inherits state
+ * from the parent process. If successful, the call returns
+ * having created an initially suspended child process with an
+ * extra Mach task and thread reference, for which the thread
+ * is initially suspended. Until we resume the child process,
+ * it is not yet running.
+ *
+ * The return information to the child is contained in the
+ * thread state structure of the new child, and does not
+ * become visible to the child through a normal return process,
+ * since it never made the call into the kernel itself in the
+ * first place.
+ *
+ * After resuming the thread, this function returns directly to
+ * the parent process which invoked the fork() system call.
+ *
+ * Important: The child thread_resume occurs before the parent returns;
+ * depending on scheduling latency, this means that it is not
+ * deterministic as to whether the parent or child is scheduled
+ * to run first. It is entirely possible that the child could
+ * run to completion prior to the parent running.
+ */
+int
+fork(proc_t parent_proc, __unused struct fork_args *uap, int32_t *retval)
+{
+ thread_t child_thread;
+ int err;
- (void) thread_resume(newth);
+ retval[1] = 0; /* flag parent return for user space */
- /* drop the extra references we got during the creation */
- if ((t = (task_t)get_threadtask(newth)) != NULL) {
- task_deallocate(t);
- }
- thread_deallocate(newth);
+ if ((err = fork1(parent_proc, &child_thread, PROC_CREATE_FORK, NULL)) == 0) {
+ task_t child_task;
+ proc_t child_proc;
- KNOTE(&p1->p_klist, NOTE_FORK | p2->p_pid);
+ /* Return to the parent */
+ child_proc = (proc_t)get_bsdthreadtask_info(child_thread);
+ retval[0] = child_proc->p_pid;
- while (p2->p_flag & P_PPWAIT)
- tsleep(p1, PWAIT, "ppwait", 0);
+ /*
+ * Drop the signal lock on the child which was taken on our
+ * behalf by forkproc()/cloneproc() to prevent signals being
+ * received by the child in a partially constructed state.
+ */
+ proc_signalend(child_proc, 0);
+ proc_transend(child_proc, 0);
- retval[0] = p2->p_pid;
- retval[1] = 0; /* mark parent */
+ /* flag the fork has occurred */
+ proc_knote(parent_proc, NOTE_FORK | child_proc->p_pid);
+ DTRACE_PROC1(create, proc_t, child_proc);
- return (0);
+#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 */
+ task_clear_return_wait(get_threadtask(child_thread));
+
+ /* drop the extra references we got during the creation */
+ if ((child_task = (task_t)get_threadtask(child_thread)) != NULL) {
+ task_deallocate(child_task);
+ }
+ thread_deallocate(child_thread);
+ }
+
+ return(err);
}
+
/*
- * cloneproc()
+ * cloneproc
*
- * Create a new process from a specified process.
- * On return newly created child process has signal
- * lock held to block delivery of signal to it if called with
- * lock set. fork() code needs to explicity remove this lock
- * before signals can be delivered
+ * Description: Create a new process from a specified process.
+ *
+ * Parameters: parent_task The parent task to be cloned, or
+ * TASK_NULL is task characteristics
+ * are not to be inherited
+ * be cloned, or TASK_NULL if the new
+ * task is not to inherit the VM
+ * characteristics of the parent
+ * parent_proc The parent process to be cloned
+ * inherit_memory True if the child is to inherit
+ * 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)
+ *
+ * Note: On return newly created child process has signal lock held
+ * to block delivery of signal to it if called with lock set.
+ * fork() code needs to explicity remove this lock before
+ * signals can be delivered
+ *
+ * In the case of bootstrap, this function can be called from
+ * bsd_utaskbootstrap() in order to bootstrap the first process;
+ * the net effect is to provide a uthread structure for the
+ * kernel process associated with the kernel task.
+ *
+ * XXX: Tristating using the value parent_task as the major key
+ * and inherit_memory as the minor key is something we should
+ * refactor later; we owe the current semantics, ultimately,
+ * to the semantics of task_create_internal. For now, we will
+ * live with this being somewhat awkward.
*/
thread_t
-cloneproc(p1, lock)
- register struct proc *p1;
- register int lock;
+cloneproc(task_t parent_task, coalition_t *parent_coalitions, proc_t parent_proc, int inherit_memory, int memstat_internal)
{
- register struct proc *p2;
- thread_t th;
+#if !CONFIG_MEMORYSTATUS
+#pragma unused(memstat_internal)
+#endif
+ task_t child_task;
+ proc_t child_proc;
+ thread_t child_thread = NULL;
- p2 = (struct proc *)forkproc(p1,lock);
+ if ((child_proc = forkproc(parent_proc)) == NULL) {
+ /* Failed to allocate new process */
+ goto bad;
+ }
+
+ child_thread = fork_create_child(parent_task, parent_coalitions, child_proc, inherit_memory, parent_proc->p_flag & P_LP64, FALSE);
+
+ if (child_thread == NULL) {
+ /*
+ * Failed to create thread; now we must deconstruct the new
+ * process previously obtained from forkproc().
+ */
+ forkproc_free(child_proc);
+ goto bad;
+ }
+ child_task = get_threadtask(child_thread);
+ if (parent_proc->p_flag & P_LP64) {
+ task_set_64bit(child_task, TRUE);
+ OSBitOrAtomic(P_LP64, (UInt32 *)&child_proc->p_flag);
+ } else {
+ task_set_64bit(child_task, FALSE);
+ 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
- th = procdup(p2, p1); /* child, parent */
+ /* make child visible */
+ pinsertchild(parent_proc, child_proc);
- LIST_INSERT_AFTER(p1, p2, p_pglist);
- p2->p_pptr = p1;
- LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling);
- LIST_INIT(&p2->p_children);
- LIST_INSERT_HEAD(&allproc, p2, p_list);
- LIST_INSERT_HEAD(PIDHASH(p2->p_pid), p2, p_hash);
- TAILQ_INIT(&p2->p_evlist);
/*
* Make child runnable, set start time.
*/
- p2->p_stat = SRUN;
+ child_proc->p_stat = SRUN;
+bad:
+ return(child_thread);
+}
+
+
+/*
+ * Destroy a process structure that resulted from a call to forkproc(), but
+ * which must be returned to the system because of a subsequent failure
+ * preventing it from becoming active.
+ *
+ * Parameters: p The incomplete process from forkproc()
+ *
+ * Returns: (void)
+ *
+ * Note: This function should only be used in an error handler following
+ * a call to forkproc().
+ *
+ * Operations occur in reverse order of those in forkproc().
+ */
+void
+forkproc_free(proc_t p)
+{
+#if CONFIG_PERSONAS
+ persona_proc_drop(p);
+#endif /* CONFIG_PERSONAS */
+
+#if PSYNCH
+ pth_proc_hashdelete(p);
+#endif /* PSYNCH */
+
+ /* We held signal and a transition locks; drop them */
+ proc_signalend(p, 0);
+ proc_transend(p, 0);
+
+ /*
+ * If we have our own copy of the resource limits structure, we
+ * need to free it. If it's a shared copy, we need to drop our
+ * reference on it.
+ */
+ proc_limitdrop(p, 0);
+ p->p_limit = NULL;
+
+#if SYSV_SHM
+ /* Need to drop references to the shared memory segment(s), if any */
+ if (p->vm_shm) {
+ /*
+ * Use shmexec(): we have no address space, so no mappings
+ *
+ * XXX Yes, the routine is badly named.
+ */
+ shmexec(p);
+ }
+#endif
+
+ /* Need to undo the effects of the fdcopy(), if any */
+ fdfree(p);
+
+ /*
+ * Drop the reference on a text vnode pointer, if any
+ * XXX This code is broken in forkproc(); see <rdar://4256419>;
+ * XXX if anyone ever uses this field, we will be extremely unhappy.
+ */
+ if (p->p_textvp) {
+ vnode_rele(p->p_textvp);
+ p->p_textvp = NULL;
+ }
+
+ /* Stop the profiling clock */
+ stopprofclock(p);
+
+ /* Update the audit session proc count */
+ AUDIT_SESSION_PROCEXIT(p);
+
+#if CONFIG_FINE_LOCK_GROUPS
+ lck_mtx_destroy(&p->p_mlock, proc_mlock_grp);
+ lck_mtx_destroy(&p->p_fdmlock, proc_fdmlock_grp);
+ lck_mtx_destroy(&p->p_ucred_mlock, proc_ucred_mlock_grp);
+#if CONFIG_DTRACE
+ lck_mtx_destroy(&p->p_dtrace_sprlock, proc_lck_grp);
+#endif
+ lck_spin_destroy(&p->p_slock, proc_slock_grp);
+#else /* CONFIG_FINE_LOCK_GROUPS */
+ lck_mtx_destroy(&p->p_mlock, proc_lck_grp);
+ lck_mtx_destroy(&p->p_fdmlock, proc_lck_grp);
+ lck_mtx_destroy(&p->p_ucred_mlock, proc_lck_grp);
+#if CONFIG_DTRACE
+ lck_mtx_destroy(&p->p_dtrace_sprlock, proc_lck_grp);
+#endif
+ lck_spin_destroy(&p->p_slock, proc_lck_grp);
+#endif /* CONFIG_FINE_LOCK_GROUPS */
+
+ /* Release the credential reference */
+ kauth_cred_unref(&p->p_ucred);
- return(th);
+ proc_list_lock();
+ /* Decrement the count of processes in the system */
+ nprocs--;
+
+ /* Take it out of process hash */
+ LIST_REMOVE(p, p_hash);
+
+ proc_list_unlock();
+
+ thread_call_free(p->p_rcall);
+
+ /* Free allocated memory */
+ FREE_ZONE(p->p_sigacts, sizeof *p->p_sigacts, M_SIGACTS);
+ FREE_ZONE(p->p_stats, sizeof *p->p_stats, M_PSTATS);
+ proc_checkdeadrefs(p);
+ FREE_ZONE(p, sizeof *p, M_PROC);
}
-struct proc *
-forkproc(p1, lock)
- register struct proc *p1;
- register int lock;
+
+/*
+ * forkproc
+ *
+ * Description: Create a new process structure, given a parent process
+ * structure.
+ *
+ * Parameters: parent_proc The parent process
+ *
+ * Returns: !NULL The new process structure
+ * NULL Error (insufficient free memory)
+ *
+ * Note: When successful, the newly created process structure is
+ * partially initialized; if a caller needs to deconstruct the
+ * returned structure, they must call forkproc_free() to do so.
+ */
+proc_t
+forkproc(proc_t parent_proc)
{
- register struct proc *p2, *newproc;
- static int nextpid = 0, pidchecked = 0;
-
- /* Allocate new proc. */
- MALLOC_ZONE(newproc, struct proc *,
- sizeof *newproc, M_PROC, M_WAITOK);
- if (newproc == NULL)
- panic("forkproc: M_PROC zone exhausted");
- MALLOC_ZONE(newproc->p_stats, struct pstats *,
- sizeof *newproc->p_stats, M_SUBPROC, M_WAITOK);
- if (newproc->p_stats == NULL)
- panic("forkproc: M_SUBPROC zone exhausted (p_stats)");
- MALLOC_ZONE(newproc->p_sigacts, struct sigacts *,
- sizeof *newproc->p_sigacts, M_SUBPROC, M_WAITOK);
- if (newproc->p_sigacts == NULL)
- panic("forkproc: M_SUBPROC zone exhausted (p_sigacts)");
+ proc_t child_proc; /* Our new process */
+ static int nextpid = 0, pidwrap = 0, nextpidversion = 0;
+ static uint64_t nextuniqueid = 0;
+ int error = 0;
+ struct session *sessp;
+ uthread_t parent_uthread = (uthread_t)get_bsdthread_info(current_thread());
+
+ MALLOC_ZONE(child_proc, proc_t , sizeof *child_proc, M_PROC, M_WAITOK);
+ if (child_proc == NULL) {
+ printf("forkproc: M_PROC zone exhausted\n");
+ goto bad;
+ }
+ /* zero it out as we need to insert in hash */
+ bzero(child_proc, sizeof *child_proc);
+
+ MALLOC_ZONE(child_proc->p_stats, struct pstats *,
+ sizeof *child_proc->p_stats, M_PSTATS, M_WAITOK);
+ if (child_proc->p_stats == NULL) {
+ printf("forkproc: M_SUBPROC zone exhausted (p_stats)\n");
+ FREE_ZONE(child_proc, sizeof *child_proc, M_PROC);
+ child_proc = NULL;
+ goto bad;
+ }
+ MALLOC_ZONE(child_proc->p_sigacts, struct sigacts *,
+ sizeof *child_proc->p_sigacts, M_SIGACTS, M_WAITOK);
+ if (child_proc->p_sigacts == NULL) {
+ printf("forkproc: M_SUBPROC zone exhausted (p_sigacts)\n");
+ FREE_ZONE(child_proc->p_stats, sizeof *child_proc->p_stats, M_PSTATS);
+ FREE_ZONE(child_proc, sizeof *child_proc, M_PROC);
+ child_proc = NULL;
+ goto bad;
+ }
+
+ /* allocate a callout for use by interval timers */
+ child_proc->p_rcall = thread_call_allocate((thread_call_func_t)realitexpire, child_proc);
+ if (child_proc->p_rcall == NULL) {
+ FREE_ZONE(child_proc->p_sigacts, sizeof *child_proc->p_sigacts, M_SIGACTS);
+ FREE_ZONE(child_proc->p_stats, sizeof *child_proc->p_stats, M_PSTATS);
+ FREE_ZONE(child_proc, sizeof *child_proc, M_PROC);
+ child_proc = NULL;
+ goto bad;
+ }
+
/*
- * Find an unused process ID. We remember a range of unused IDs
- * ready to use (from nextpid+1 through pidchecked-1).
+ * Find an unused PID.
*/
+
+ proc_list_lock();
+
nextpid++;
retry:
/*
*/
if (nextpid >= PID_MAX) {
nextpid = 100;
- pidchecked = 0;
+ pidwrap = 1;
}
- if (nextpid >= pidchecked) {
- int doingzomb = 0;
+ if (pidwrap != 0) {
- pidchecked = PID_MAX;
- /*
- * Scan the active and zombie procs to check whether this pid
- * is in use. Remember the lowest pid that's greater
- * than nextpid, so we can avoid checking for a while.
- */
- p2 = allproc.lh_first;
-again:
- for (; p2 != 0; p2 = p2->p_list.le_next) {
- while (p2->p_pid == nextpid ||
- p2->p_pgrp->pg_id == nextpid ||
- p2->p_session->s_sid == nextpid) {
- nextpid++;
- if (nextpid >= pidchecked)
- goto retry;
- }
- if (p2->p_pid > nextpid && pidchecked > p2->p_pid)
- pidchecked = p2->p_pid;
- if (p2->p_pgrp && p2->p_pgrp->pg_id > nextpid &&
- pidchecked > p2->p_pgrp->pg_id)
- pidchecked = p2->p_pgrp->pg_id;
- if (p2->p_session->s_sid > nextpid &&
- pidchecked > p2->p_session->s_sid)
- pidchecked = p2->p_session->s_sid;
+ /* if the pid stays in hash both for zombie and runniing state */
+ if (pfind_locked(nextpid) != PROC_NULL) {
+ nextpid++;
+ goto retry;
}
- if (!doingzomb) {
- doingzomb = 1;
- p2 = zombproc.lh_first;
- goto again;
- }
- }
+ if (pgfind_internal(nextpid) != PGRP_NULL) {
+ nextpid++;
+ goto retry;
+ }
+ if (session_find_internal(nextpid) != SESSION_NULL) {
+ nextpid++;
+ goto retry;
+ }
+ }
nprocs++;
- p2 = newproc;
- p2->p_stat = SIDL;
- p2->p_shutdownstate = 0;
- p2->p_pid = nextpid;
+ child_proc->p_pid = nextpid;
+ child_proc->p_responsible_pid = nextpid; /* initially responsible for self */
+ child_proc->p_idversion = nextpidversion++;
+ /* kernel process is handcrafted and not from fork, so start from 1 */
+ child_proc->p_uniqueid = ++nextuniqueid;
+#if 1
+ if (child_proc->p_pid != 0) {
+ if (pfind_locked(child_proc->p_pid) != PROC_NULL)
+ panic("proc in the list already\n");
+ }
+#endif
+ /* Insert in the hash */
+ child_proc->p_listflag |= (P_LIST_INHASH | P_LIST_INCREATE);
+ LIST_INSERT_HEAD(PIDHASH(child_proc->p_pid), child_proc, p_hash);
+ proc_list_unlock();
+
+
+ /*
+ * We've identified the PID we are going to use; initialize the new
+ * process structure.
+ */
+ child_proc->p_stat = SIDL;
+ child_proc->p_pgrpid = PGRPID_DEAD;
/*
- * Make a proc table entry for the new process.
- * Start by zeroing the section of proc that is zero-initialized,
- * then copy the section that is copied directly from the parent.
+ * The zero'ing of the proc was at the allocation time due to need
+ * for insertion to hash. Copy the section that is to be copied
+ * directly from the parent.
*/
- bzero(&p2->p_startzero,
- (unsigned) ((caddr_t)&p2->p_endzero - (caddr_t)&p2->p_startzero));
- bcopy(&p1->p_startcopy, &p2->p_startcopy,
- (unsigned) ((caddr_t)&p2->p_endcopy - (caddr_t)&p2->p_startcopy));
- p2->vm_shm = (void *)NULL; /* Make sure it is zero */
+ bcopy(&parent_proc->p_startcopy, &child_proc->p_startcopy,
+ (unsigned) ((caddr_t)&child_proc->p_endcopy - (caddr_t)&child_proc->p_startcopy));
/*
* Some flags are inherited from the parent.
* Increase reference counts on shared objects.
* The p_stats and p_sigacts substructs are set in vm_fork.
*/
- p2->p_flag = (p1->p_flag & (P_LP64 | P_CLASSIC | P_AFFINITY));
- if (p1->p_flag & P_PROFIL)
- startprofclock(p2);
+ child_proc->p_flag = (parent_proc->p_flag & (P_LP64 | P_DISABLE_ASLR | P_DELAYIDLESLEEP | P_SUGID));
+ if (parent_proc->p_flag & P_PROFIL)
+ startprofclock(child_proc);
+
+ 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
* credential will be granted to the new process.
*/
- p2->p_ucred = kauth_cred_get_with_ref();
-
- lck_mtx_init(&p2->p_mlock, proc_lck_grp, proc_lck_attr);
- lck_mtx_init(&p2->p_fdmlock, proc_lck_grp, proc_lck_attr);
- klist_init(&p2->p_klist);
-
- /* bump references to the text vnode */
- p2->p_textvp = p1->p_textvp;
- if (p2->p_textvp) {
- vnode_rele(p2->p_textvp);
+ child_proc->p_ucred = kauth_cred_get_with_ref();
+ /* update cred on proc */
+ PROC_UPDATE_CREDS_ONPROC(child_proc);
+ /* update audit session proc count */
+ AUDIT_SESSION_PROCNEW(child_proc);
+
+#if CONFIG_FINE_LOCK_GROUPS
+ lck_mtx_init(&child_proc->p_mlock, proc_mlock_grp, proc_lck_attr);
+ lck_mtx_init(&child_proc->p_fdmlock, proc_fdmlock_grp, proc_lck_attr);
+ lck_mtx_init(&child_proc->p_ucred_mlock, proc_ucred_mlock_grp, proc_lck_attr);
+#if CONFIG_DTRACE
+ lck_mtx_init(&child_proc->p_dtrace_sprlock, proc_lck_grp, proc_lck_attr);
+#endif
+ lck_spin_init(&child_proc->p_slock, proc_slock_grp, proc_lck_attr);
+#else /* !CONFIG_FINE_LOCK_GROUPS */
+ lck_mtx_init(&child_proc->p_mlock, proc_lck_grp, proc_lck_attr);
+ lck_mtx_init(&child_proc->p_fdmlock, proc_lck_grp, proc_lck_attr);
+ lck_mtx_init(&child_proc->p_ucred_mlock, proc_lck_grp, proc_lck_attr);
+#if CONFIG_DTRACE
+ lck_mtx_init(&child_proc->p_dtrace_sprlock, proc_lck_grp, proc_lck_attr);
+#endif
+ lck_spin_init(&child_proc->p_slock, proc_lck_grp, proc_lck_attr);
+#endif /* !CONFIG_FINE_LOCK_GROUPS */
+ klist_init(&child_proc->p_klist);
+
+ if (child_proc->p_textvp != NULLVP) {
+ /* bump references to the text vnode */
+ /* Need to hold iocount across the ref call */
+ if (vnode_getwithref(child_proc->p_textvp) == 0) {
+ error = vnode_ref(child_proc->p_textvp);
+ vnode_put(child_proc->p_textvp);
+ if (error != 0)
+ child_proc->p_textvp = NULLVP;
+ }
}
- /* XXX may fail to copy descriptors to child */
- p2->p_fd = fdcopy(p1);
- if (p1->vm_shm) {
+ /*
+ * Copy the parents per process open file table to the child; if
+ * there is a per-thread current working directory, set the childs
+ * per-process current working directory to that instead of the
+ * parents.
+ *
+ * XXX may fail to copy descriptors to child
+ */
+ child_proc->p_fd = fdcopy(parent_proc, parent_uthread->uu_cdir);
+
+#if SYSV_SHM
+ if (parent_proc->vm_shm) {
/* XXX may fail to attach shm to child */
- (void)shmfork(p1,p2);
+ (void)shmfork(parent_proc, child_proc);
}
+#endif
/*
- * If p_limit is still copy-on-write, bump refcnt,
- * otherwise get a copy that won't be modified.
- * (If PL_SHAREMOD is clear, the structure is shared
- * copy-on-write.)
+ * inherit the limit structure to child
*/
- if (p1->p_limit->p_lflags & PL_SHAREMOD)
- p2->p_limit = limcopy(p1->p_limit);
- else {
- p2->p_limit = p1->p_limit;
- p2->p_limit->p_refcnt++;
- }
+ proc_limitfork(parent_proc, child_proc);
- bzero(&p2->p_stats->pstat_startzero,
- (unsigned) ((caddr_t)&p2->p_stats->pstat_endzero -
- (caddr_t)&p2->p_stats->pstat_startzero));
- bcopy(&p1->p_stats->pstat_startcopy, &p2->p_stats->pstat_startcopy,
- ((caddr_t)&p2->p_stats->pstat_endcopy -
- (caddr_t)&p2->p_stats->pstat_startcopy));
+ if (child_proc->p_limit->pl_rlimit[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
+ uint64_t rlim_cur = child_proc->p_limit->pl_rlimit[RLIMIT_CPU].rlim_cur;
+ child_proc->p_rlim_cpu.tv_sec = (rlim_cur > __INT_MAX__) ? __INT_MAX__ : rlim_cur;
+ }
- bzero(&p2->p_stats->user_p_prof, sizeof(struct user_uprof));
+ /* Intialize new process stats, including start time */
+ /* <rdar://6640543> non-zeroed portion contains garbage AFAICT */
+ bzero(child_proc->p_stats, sizeof(*child_proc->p_stats));
+ microtime_with_abstime(&child_proc->p_start, &child_proc->p_stats->ps_start);
- if (p1->p_sigacts != NULL)
- (void)memcpy(p2->p_sigacts,
- p1->p_sigacts, sizeof *p2->p_sigacts);
+ if (parent_proc->p_sigacts != NULL)
+ (void)memcpy(child_proc->p_sigacts,
+ parent_proc->p_sigacts, sizeof *child_proc->p_sigacts);
else
- (void)memset(p2->p_sigacts, 0, sizeof *p2->p_sigacts);
-
- if (p1->p_session->s_ttyvp != NULL && p1->p_flag & P_CONTROLT)
- p2->p_flag |= P_CONTROLT;
-
- p2->p_argslen = p1->p_argslen;
- p2->p_argc = p1->p_argc;
- p2->p_xstat = 0;
- p2->p_ru = NULL;
-
- p2->p_debugger = 0; /* don't inherit */
- lockinit(&p2->signal_lock, PVM, "signal", 0, 0);
- /* block all signals to reach the process */
- if (lock)
- signal_lock(p2);
- p2->sigwait = FALSE;
- p2->sigwait_thread = NULL;
- p2->exit_thread = NULL;
- p2->user_stack = p1->user_stack;
- p2->p_vforkcnt = 0;
- p2->p_vforkact = 0;
- p2->p_lflag = 0;
- p2->p_ladvflag = 0;
- p2->p_internalref = 0;
- TAILQ_INIT(&p2->p_uthlist);
- TAILQ_INIT(&p2->aio_activeq);
- TAILQ_INIT(&p2->aio_doneq);
- p2->aio_active_count = 0;
- p2->aio_done_count = 0;
-
-#if KTRACE
+ (void)memset(child_proc->p_sigacts, 0, sizeof *child_proc->p_sigacts);
+
+ sessp = proc_session(parent_proc);
+ if (sessp->s_ttyvp != NULL && parent_proc->p_flag & P_CONTROLT)
+ OSBitOrAtomic(P_CONTROLT, &child_proc->p_flag);
+ session_rele(sessp);
+
/*
- * Copy traceflag and tracefile if enabled.
- * If not inherited, these were zeroed above.
+ * block all signals to reach the process.
+ * no transition race should be occuring with the child yet,
+ * but indicate that the process is in (the creation) transition.
*/
- if (p1->p_traceflag&KTRFAC_INHERIT) {
- p2->p_traceflag = p1->p_traceflag;
- if ((p2->p_tracep = p1->p_tracep) != NULL) {
- vnode_ref(p2->p_tracep);
- }
+ proc_signalstart(child_proc, 0);
+ proc_transstart(child_proc, 0, 0);
+
+ child_proc->p_pcaction = 0;
+
+ TAILQ_INIT(&child_proc->p_uthlist);
+ TAILQ_INIT(&child_proc->p_aio_activeq);
+ TAILQ_INIT(&child_proc->p_aio_doneq);
+
+ /* Inherit the parent flags for code sign */
+ child_proc->p_csflags = (parent_proc->p_csflags & ~CS_KILLED);
+
+ /*
+ * Copy work queue information
+ *
+ * Note: This should probably only happen in the case where we are
+ * creating a child that is a copy of the parent; since this
+ * routine is called in the non-duplication case of vfork()
+ * or posix_spawn(), then this information should likely not
+ * be duplicated.
+ *
+ * <rdar://6640553> Work queue pointers that no longer point to code
+ */
+ child_proc->p_wqthread = parent_proc->p_wqthread;
+ child_proc->p_threadstart = parent_proc->p_threadstart;
+ child_proc->p_pthsize = parent_proc->p_pthsize;
+ if ((parent_proc->p_lflag & P_LREGISTER) != 0) {
+ child_proc->p_lflag |= P_LREGISTER;
}
+ child_proc->p_wqkqueue = NULL;
+ 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 */
+
+#if CONFIG_PERSONAS
+ child_proc->p_persona = NULL;
+ error = persona_proc_inherit(child_proc, parent_proc);
+ if (error != 0) {
+ printf("forkproc: persona_proc_inherit failed (persona %d being destroyed?)\n", persona_get_uid(parent_proc->p_persona));
+ forkproc_free(child_proc);
+ child_proc = NULL;
+ goto bad;
+ }
+#endif
+
+#if CONFIG_MEMORYSTATUS
+ /* Memorystatus 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;
+ child_proc->p_memstat_idle_start = 0;
+ child_proc->p_memstat_idle_delta = 0;
+ child_proc->p_memstat_memlimit = 0;
+ child_proc->p_memstat_memlimit_active = 0;
+ child_proc->p_memstat_memlimit_inactive = 0;
+#if CONFIG_FREEZE
+ child_proc->p_memstat_suspendedfootprint = 0;
#endif
- return(p2);
+ child_proc->p_memstat_dirty = 0;
+ child_proc->p_memstat_idledeadline = 0;
+#endif /* CONFIG_MEMORYSTATUS */
+bad:
+ return(child_proc);
}
void
proc_lock(proc_t p)
{
+ lck_mtx_assert(proc_list_mlock, LCK_MTX_ASSERT_NOTOWNED);
lck_mtx_lock(&p->p_mlock);
}
lck_mtx_unlock(&p->p_mlock);
}
+void
+proc_spinlock(proc_t p)
+{
+ lck_spin_lock(&p->p_slock);
+}
+
+void
+proc_spinunlock(proc_t p)
+{
+ lck_spin_unlock(&p->p_slock);
+}
+
+void
+proc_list_lock(void)
+{
+ lck_mtx_lock(proc_list_mlock);
+}
+
+void
+proc_list_unlock(void)
+{
+ lck_mtx_unlock(proc_list_mlock);
+}
+
+void
+proc_ucred_lock(proc_t p)
+{
+ lck_mtx_lock(&p->p_ucred_mlock);
+}
+
+void
+proc_ucred_unlock(proc_t p)
+{
+ lck_mtx_unlock(&p->p_ucred_mlock);
+}
+
#include <kern/zalloc.h>
-struct zone *uthread_zone;
-int uthread_zone_inited = 0;
+struct zone *uthread_zone = NULL;
-void
+static lck_grp_t *rethrottle_lock_grp;
+static lck_attr_t *rethrottle_lock_attr;
+static lck_grp_attr_t *rethrottle_lock_grp_attr;
+
+static void
uthread_zone_init(void)
{
- if (!uthread_zone_inited) {
- uthread_zone = zinit(sizeof(struct uthread),
- THREAD_MAX * sizeof(struct uthread),
- THREAD_CHUNK * sizeof(struct uthread),
- "uthreads");
- uthread_zone_inited = 1;
- }
+ assert(uthread_zone == NULL);
+
+ rethrottle_lock_grp_attr = lck_grp_attr_alloc_init();
+ rethrottle_lock_grp = lck_grp_alloc_init("rethrottle", rethrottle_lock_grp_attr);
+ rethrottle_lock_attr = lck_attr_alloc_init();
+
+ uthread_zone = zinit(sizeof(struct uthread),
+ thread_max * sizeof(struct uthread),
+ THREAD_CHUNK * sizeof(struct uthread),
+ "uthreads");
}
void *
-uthread_alloc(task_t task, thread_t thr_act )
+uthread_alloc(task_t task, thread_t thread, int noinherit)
{
- struct proc *p;
- struct uthread *uth, *uth_parent;
+ proc_t p;
+ uthread_t uth;
+ uthread_t uth_parent;
void *ut;
- boolean_t funnel_state;
- if (!uthread_zone_inited)
+ if (uthread_zone == NULL)
uthread_zone_init();
ut = (void *)zalloc(uthread_zone);
bzero(ut, sizeof(struct uthread));
- p = (struct proc *) get_bsdtask_info(task);
- uth = (struct uthread *)ut;
+ p = (proc_t) get_bsdtask_info(task);
+ uth = (uthread_t)ut;
+ uth->uu_thread = thread;
+
+ lck_spin_init(&uth->uu_rethrottle_lock, rethrottle_lock_grp,
+ rethrottle_lock_attr);
/*
* Thread inherits credential from the creating thread, if both
* task we can leave the new thread credential NULL. If it needs
* one later, it will be lazily assigned from the task's process.
*/
- uth_parent = (struct uthread *)get_bsdthread_info(current_thread());
- if ((task == current_task()) &&
- (uth_parent != NULL) &&
- (uth_parent->uu_ucred != NOCRED)) {
+ uth_parent = (uthread_t)get_bsdthread_info(current_thread());
+ if ((noinherit == 0) && task == current_task() &&
+ uth_parent != NULL &&
+ IS_VALID_CRED(uth_parent->uu_ucred)) {
+ /*
+ * XXX The new thread is, in theory, being created in context
+ * XXX of parent thread, so a direct reference to the parent
+ * XXX is OK.
+ */
+ kauth_cred_ref(uth_parent->uu_ucred);
uth->uu_ucred = uth_parent->uu_ucred;
- kauth_cred_ref(uth->uu_ucred);
/* the credential we just inherited is an assumed credential */
if (uth_parent->uu_flag & UT_SETUID)
uth->uu_flag |= UT_SETUID;
} else {
- uth->uu_ucred = NOCRED;
+ /* sometimes workqueue threads are created out task context */
+ if ((task != kernel_task) && (p != PROC_NULL))
+ uth->uu_ucred = kauth_cred_proc_ref(p);
+ else
+ uth->uu_ucred = NOCRED;
}
+
- if (task != kernel_task) {
+ if ((task != kernel_task) && p) {
- funnel_state = thread_funnel_set(kernel_flock, TRUE);
- if (uth_parent) {
+ proc_lock(p);
+ if (noinherit != 0) {
+ /* workq threads will not inherit masks */
+ uth->uu_sigmask = ~workq_threadmask;
+ } else if (uth_parent) {
if (uth_parent->uu_flag & UT_SAS_OLDMASK)
uth->uu_sigmask = uth_parent->uu_oldmask;
else
uth->uu_sigmask = uth_parent->uu_sigmask;
}
- uth->uu_act = thr_act;
- //signal_lock(p);
- if (p) {
+ uth->uu_context.vc_thread = thread;
+ /*
+ * Do not add the uthread to proc uthlist for exec copy task,
+ * since they do not hold a ref on proc.
+ */
+ if (!task_is_exec_copy(task)) {
TAILQ_INSERT_TAIL(&p->p_uthlist, uth, uu_list);
}
- //signal_unlock(p);
- (void)thread_funnel_set(kernel_flock, funnel_state);
+ proc_unlock(p);
+
+#if CONFIG_DTRACE
+ if (p->p_dtrace_ptss_pages != NULL && !task_is_exec_copy(task)) {
+ uth->t_dtrace_scratch = dtrace_ptss_claim_entry(p);
+ }
+#endif
}
return (ut);
}
+/*
+ * This routine frees the thread name field of the uthread_t structure. Split out of
+ * uthread_cleanup() so thread name does not get deallocated while generating a corpse fork.
+ */
+void
+uthread_cleanup_name(void *uthread)
+{
+ uthread_t uth = (uthread_t)uthread;
+
+ /*
+ * <rdar://17834538>
+ * 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) {
+ void *pth_name = uth->pth_name;
+ uth->pth_name = NULL;
+ kfree(pth_name, MAXTHREADNAMESIZE);
+ }
+ return;
+}
+/*
+ * This routine frees all the BSD context in uthread except the credential.
+ * It does not free the uthread structure as well
+ */
void
-uthread_free(task_t task, void *uthread, void * bsd_info)
+uthread_cleanup(task_t task, void *uthread, void * bsd_info)
{
struct _select *sel;
- struct uthread *uth = (struct uthread *)uthread;
- struct proc * p = (struct proc *)bsd_info;
- boolean_t funnel_state;
+ uthread_t uth = (uthread_t)uthread;
+ proc_t p = (proc_t)bsd_info;
+
+#if PROC_REF_DEBUG
+ if (__improbable(uthread_get_proc_refcount(uthread) != 0)) {
+ panic("uthread_cleanup called for uthread %p with uu_proc_refcount != 0", uthread);
+ }
+#endif
+ if (uth->uu_lowpri_window || uth->uu_throttle_info) {
+ /*
+ * task is marked as a low priority I/O type
+ * and we've somehow managed to not dismiss the throttle
+ * through the normal exit paths back to user space...
+ * no need to throttle this thread since its going away
+ * but we do need to update our bookeeping w/r to throttled threads
+ *
+ * Calling this routine will clean up any throttle info reference
+ * still inuse by the thread.
+ */
+ throttle_lowpri_io(0);
+ }
/*
* Per-thread audit state should never last beyond system
* call return. Since we don't audit the thread creation/
*/
assert(uth->uu_ar == NULL);
+ if (uth->uu_kqueue_bound) {
+ kevent_qos_internal_unbind(p,
+ uth->uu_kqueue_bound,
+ uth->uu_thread,
+ uth->uu_kqueue_flags);
+ uth->uu_kqueue_flags = 0;
+ uth->uu_kqueue_bound = 0;
+ }
+
sel = &uth->uu_select;
/* cleanup the select bit space */
if (sel->nbytes) {
FREE(sel->ibits, M_TEMP);
FREE(sel->obits, M_TEMP);
+ sel->nbytes = 0;
+ }
+
+ if (uth->uu_cdir) {
+ vnode_rele(uth->uu_cdir);
+ uth->uu_cdir = NULLVP;
}
- if (sel->allocsize && sel->wqset){
- kfree(sel->wqset, sel->allocsize);
- sel->count = 0;
- sel->allocsize = 0;
- sel->wqset = 0;
- sel->wql = 0;
+ if (uth->uu_wqset) {
+ if (waitq_set_is_valid(uth->uu_wqset))
+ waitq_set_deinit(uth->uu_wqset);
+ FREE(uth->uu_wqset, M_SELECT);
+ uth->uu_wqset = NULL;
+ uth->uu_wqstate_sz = 0;
}
- if (uth->uu_ucred != NOCRED)
- kauth_cred_rele(uth->uu_ucred);
+ os_reason_free(uth->uu_exit_reason);
if ((task != kernel_task) && p) {
- funnel_state = thread_funnel_set(kernel_flock, TRUE);
- //signal_lock(p);
- TAILQ_REMOVE(&p->p_uthlist, uth, uu_list);
- //signal_unlock(p);
- (void)thread_funnel_set(kernel_flock, funnel_state);
+
+ if (((uth->uu_flag & UT_VFORK) == UT_VFORK) && (uth->uu_proc != PROC_NULL)) {
+ vfork_exit_internal(uth->uu_proc, 0, 1);
+ }
+ /*
+ * Remove the thread from the process list and
+ * transfer [appropriate] pending signals to the process.
+ * Do not remove the uthread from proc uthlist for exec
+ * copy task, since they does not have a ref on proc and
+ * would not have been added to the list.
+ */
+ if (get_bsdtask_info(task) == p && !task_is_exec_copy(task)) {
+ proc_lock(p);
+
+ TAILQ_REMOVE(&p->p_uthlist, uth, uu_list);
+ p->p_siglist |= (uth->uu_siglist & execmask & (~p->p_sigignore | sigcantmask));
+ proc_unlock(p);
+ }
+#if CONFIG_DTRACE
+ struct dtrace_ptss_page_entry *tmpptr = uth->t_dtrace_scratch;
+ uth->t_dtrace_scratch = NULL;
+ if (tmpptr != NULL && !task_is_exec_copy(task)) {
+ dtrace_ptss_release_entry(p, tmpptr);
+ }
+#endif
+ }
+}
+
+/* This routine releases the credential stored in uthread */
+void
+uthread_cred_free(void *uthread)
+{
+ uthread_t uth = (uthread_t)uthread;
+
+ /* and free the uthread itself */
+ if (IS_VALID_CRED(uth->uu_ucred)) {
+ kauth_cred_t oldcred = uth->uu_ucred;
+ uth->uu_ucred = NOCRED;
+ kauth_cred_unref(&oldcred);
+ }
+}
+
+/* This routine frees the uthread structure held in thread structure */
+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;
}
+
+ lck_spin_destroy(&uth->uu_rethrottle_lock, rethrottle_lock_grp);
+
+ uthread_cleanup_name(uthread);
/* and free the uthread itself */
zfree(uthread_zone, uthread);
}
projects / apple / xnu.git / blobdiff