]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/kern/sys_generic.c
xnu-7195.101.1.tar.gz
[apple/xnu.git] / bsd / kern / sys_generic.c
index f41cd0018ef8e9f457f6cb4915f46a6f671a459b..1d88f75a81ce811fde65f7977e631e6c93065793 100644 (file)
@@ -1,8 +1,8 @@
 /*
- * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2015 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- * 
+ *
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * unlawful or unlicensed copies of an Apple operating system, or to
  * circumvent, violate, or enable the circumvention or violation of, any
  * terms of an Apple operating system software license agreement.
- * 
+ *
  * Please obtain a copy of the License at
  * http://www.opensource.apple.com/apsl/ and read it before using this file.
- * 
+ *
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
@@ -22,7 +22,7 @@
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.
- * 
+ *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
@@ -81,6 +81,7 @@
 #include <sys/socketvar.h>
 #include <sys/uio_internal.h>
 #include <sys/kernel.h>
+#include <sys/guarded.h>
 #include <sys/stat.h>
 #include <sys/malloc.h>
 #include <sys/sysproto.h>
@@ -96,6 +97,7 @@
 #include <sys/proc.h>
 #include <sys/kauth.h>
 
+#include <machine/smp.h>
 #include <mach/mach_types.h>
 #include <kern/kern_types.h>
 #include <kern/assert.h>
 #include <kern/clock.h>
 #include <kern/ledger.h>
 #include <kern/task.h>
-#if CONFIG_TELEMETRY
 #include <kern/telemetry.h>
-#endif
+#include <kern/waitq.h>
+#include <kern/sched_prim.h>
+#include <kern/mpsc_queue.h>
+#include <kern/debug.h>
 
 #include <sys/mbuf.h>
 #include <sys/domain.h>
 #include <netinet/tcpip.h>
 #include <netinet/tcp_debug.h>
 /* for wait queue based select */
-#include <kern/wait_queue.h>
-#include <kern/kalloc.h>
+#include <kern/waitq.h>
 #include <sys/vnode_internal.h>
+/* for remote time api*/
+#include <kern/remote_time.h>
+#include <os/log.h>
+#include <sys/log_data.h>
 
-#include <pexpert/pexpert.h>
+#if CONFIG_MACF
+#include <security/mac_framework.h>
+#endif
+
+/* for entitlement check */
+#include <IOKit/IOBSD.h>
+/*
+ * If you need accounting for KM_SELECT consider using
+ * KALLOC_HEAP_DEFINE to define a view.
+ */
+#define KM_SELECT       KHEAP_DEFAULT
 
 /* XXX should be in a header file somewhere */
-void evsofree(struct socket *);
-void evpipefree(struct pipe *);
-void postpipeevent(struct pipe *, int);
-void postevent(struct socket *, struct sockbuf *, int);
 extern kern_return_t IOBSDGetPlatformUUID(__darwin_uuid_t uuid, mach_timespec_t timeoutp);
 
-int rd_uio(struct proc *p, int fdes, uio_t uio, user_ssize_t *retval);
-int wr_uio(struct proc *p, int fdes, uio_t uio, user_ssize_t *retval);
-extern void    *get_bsduthreadarg(thread_t);
-extern int     *get_bsduthreadrval(thread_t);
-
-__private_extern__ int dofileread(vfs_context_t ctx, struct fileproc *fp,
-                                                                  user_addr_t bufp, user_size_t nbyte, 
-                                                                  off_t offset, int flags, user_ssize_t *retval);
-__private_extern__ int dofilewrite(vfs_context_t ctx, struct fileproc *fp,
-                                                                       user_addr_t bufp, user_size_t nbyte, 
-                                                                       off_t offset, int flags, user_ssize_t *retval);
-__private_extern__ int preparefileread(struct proc *p, struct fileproc **fp_ret, int fd, int check_for_vnode);
-__private_extern__ void        donefileread(struct proc *p, struct fileproc *fp_ret, int fd);
+int rd_uio(struct proc *p, int fdes, uio_t uio, int is_preadv, user_ssize_t *retval);
+int wr_uio(struct proc *p, int fdes, uio_t uio, int is_pwritev, user_ssize_t *retval);
+int do_uiowrite(struct proc *p, struct fileproc *fp, uio_t uio, int flags, user_ssize_t *retval);
 
+__private_extern__ int  dofileread(vfs_context_t ctx, struct fileproc *fp,
+    user_addr_t bufp, user_size_t nbyte,
+    off_t offset, int flags, user_ssize_t *retval);
+__private_extern__ int  dofilewrite(vfs_context_t ctx, struct fileproc *fp,
+    user_addr_t bufp, user_size_t nbyte,
+    off_t offset, int flags, user_ssize_t *retval);
+static int preparefileread(struct proc *p, struct fileproc **fp_ret, int fd, int check_for_vnode);
 
 /* Conflict wait queue for when selects collide (opaque type) */
-struct wait_queue select_conflict_queue;
-
-#if 13841988
-int temp_debug_13841988 = 0;
-#endif
+struct waitq select_conflict_queue;
 
 /*
  * Init routine called from bsd_init.c
  */
-void select_wait_queue_init(void);
+void select_waitq_init(void);
 void
-select_wait_queue_init(void)
+select_waitq_init(void)
 {
-       wait_queue_init(&select_conflict_queue, SYNC_POLICY_FIFO);
-#if 13841988
-       if (PE_parse_boot_argn("temp_debug_13841988", &temp_debug_13841988, sizeof(temp_debug_13841988))) {
-               kprintf("Temporary debugging for 13841988 enabled\n");
-       }
-#endif
+       waitq_init(&select_conflict_queue, SYNC_POLICY_FIFO);
 }
 
-#define f_flag f_fglob->fg_flag
-#define f_type f_fglob->fg_ops->fo_type
-#define f_msgcount f_fglob->fg_msgcount
-#define f_cred f_fglob->fg_cred
-#define f_ops f_fglob->fg_ops
-#define f_offset f_fglob->fg_offset
-#define f_data f_fglob->fg_data
+#define f_flag fp_glob->fg_flag
+#define f_type fp_glob->fg_ops->fo_type
+#define f_cred fp_glob->fg_cred
+#define f_ops fp_glob->fg_ops
+#define f_data fp_glob->fg_data
 
 /*
  * Read system call.
@@ -207,7 +206,7 @@ int
 read(struct proc *p, struct read_args *uap, user_ssize_t *retval)
 {
        __pthread_testcancel(1);
-       return(read_nocancel(p, (struct read_nocancel_args *)uap, retval));
+       return read_nocancel(p, (struct read_nocancel_args *)uap, retval);
 }
 
 int
@@ -218,21 +217,22 @@ read_nocancel(struct proc *p, struct read_nocancel_args *uap, user_ssize_t *retv
        int fd = uap->fd;
        struct vfs_context context;
 
-       if ( (error = preparefileread(p, &fp, fd, 0)) )
-               return (error);
+       if ((error = preparefileread(p, &fp, fd, 0))) {
+               return error;
+       }
 
        context = *(vfs_context_current());
-       context.vc_ucred = fp->f_fglob->fg_cred;
+       context.vc_ucred = fp->fp_glob->fg_cred;
 
        error = dofileread(&context, fp, uap->cbuf, uap->nbyte,
-                          (off_t)-1, 0, retval);
+           (off_t)-1, 0, retval);
 
-       donefileread(p, fp, fd);
+       fp_drop(p, fd, fp, 0);
 
-       return (error);
+       return error;
 }
 
-/* 
+/*
  * Pread system call
  *
  * Returns:    0                       Success
@@ -246,60 +246,52 @@ int
 pread(struct proc *p, struct pread_args *uap, user_ssize_t *retval)
 {
        __pthread_testcancel(1);
-       return(pread_nocancel(p, (struct pread_nocancel_args *)uap, retval));
+       return pread_nocancel(p, (struct pread_nocancel_args *)uap, retval);
 }
 
 int
 pread_nocancel(struct proc *p, struct pread_nocancel_args *uap, user_ssize_t *retval)
 {
-       struct fileproc *fp = NULL;     /* fp set by preparefileread() */
+       struct fileproc *fp = NULL;     /* fp set by preparefileread() */
        int fd = uap->fd;
        int error;
        struct vfs_context context;
 
-       if ( (error = preparefileread(p, &fp, fd, 1)) )
+       if ((error = preparefileread(p, &fp, fd, 1))) {
                goto out;
+       }
 
        context = *(vfs_context_current());
-       context.vc_ucred = fp->f_fglob->fg_cred;
+       context.vc_ucred = fp->fp_glob->fg_cred;
 
        error = dofileread(&context, fp, uap->buf, uap->nbyte,
-                       uap->offset, FOF_OFFSET, retval);
-       
-       donefileread(p, fp, fd);
+           uap->offset, FOF_OFFSET, retval);
+
+       fp_drop(p, fd, fp, 0);
 
        KERNEL_DEBUG_CONSTANT((BSDDBG_CODE(DBG_BSD_SC_EXTENDED_INFO, SYS_pread) | DBG_FUNC_NONE),
-             uap->fd, uap->nbyte, (unsigned int)((uap->offset >> 32)), (unsigned int)(uap->offset), 0);
+           uap->fd, uap->nbyte, (unsigned int)((uap->offset >> 32)), (unsigned int)(uap->offset), 0);
 
 out:
-       return (error);
+       return error;
 }
 
 /*
  * Code common for read and pread
  */
 
-void
-donefileread(struct proc *p, struct fileproc *fp, int fd)
-{
-       proc_fdlock_spin(p);
-       fp_drop(p, fd, fp, 1);
-        proc_fdunlock(p);
-}
-
 /*
  * Returns:    0                       Success
  *             EBADF
  *             ESPIPE
  *             ENXIO
  *     fp_lookup:EBADF
- *     fo_read:???
  */
-int
+static int
 preparefileread(struct proc *p, struct fileproc **fp_ret, int fd, int check_for_pread)
 {
        vnode_t vp;
-       int     error;
+       int     error;
        struct fileproc *fp;
 
        AUDIT_ARG(fd, fd);
@@ -309,24 +301,24 @@ preparefileread(struct proc *p, struct fileproc **fp_ret, int fd, int check_for_
        error = fp_lookup(p, fd, &fp, 1);
 
        if (error) {
-               proc_fdunlock(p);
-               return (error);
+               proc_fdunlock(p);
+               return error;
        }
        if ((fp->f_flag & FREAD) == 0) {
-               error = EBADF;
+               error = EBADF;
                goto out;
        }
        if (check_for_pread && (fp->f_type != DTYPE_VNODE)) {
-               error = ESPIPE;
+               error = ESPIPE;
                goto out;
        }
        if (fp->f_type == DTYPE_VNODE) {
-               vp = (struct vnode *)fp->f_fglob->fg_data;
+               vp = (struct vnode *)fp->fp_glob->fg_data;
 
                if (check_for_pread && (vnode_isfifo(vp))) {
                        error = ESPIPE;
                        goto out;
-               } 
+               }
                if (check_for_pread && (vp->v_flag & VISTTY)) {
                        error = ENXIO;
                        goto out;
@@ -335,13 +327,13 @@ preparefileread(struct proc *p, struct fileproc **fp_ret, int fd, int check_for_
 
        *fp_ret = fp;
 
-        proc_fdunlock(p);
-       return (0);
+       proc_fdunlock(p);
+       return 0;
 
 out:
        fp_drop(p, fd, fp, 1);
        proc_fdunlock(p);
-       return (error);
+       return error;
 }
 
 
@@ -352,72 +344,77 @@ out:
  */
 __private_extern__ int
 dofileread(vfs_context_t ctx, struct fileproc *fp,
-          user_addr_t bufp, user_size_t nbyte, off_t offset, int flags,
-          user_ssize_t *retval)
+    user_addr_t bufp, user_size_t nbyte, off_t offset, int flags,
+    user_ssize_t *retval)
 {
        uio_t auio;
        user_ssize_t bytecnt;
-       long error = 0;
-       char uio_buf[ UIO_SIZEOF(1) ];
+       int error = 0;
+       char uio_buf[UIO_SIZEOF(1)];
 
-       if (nbyte > INT_MAX)
-               return (EINVAL);
+       if (nbyte > INT_MAX) {
+               return EINVAL;
+       }
 
        if (IS_64BIT_PROCESS(vfs_context_proc(ctx))) {
-               auio = uio_createwithbuffer(1, offset, UIO_USERSPACE64, UIO_READ, 
-                                                                         &uio_buf[0], sizeof(uio_buf));
+               auio = uio_createwithbuffer(1, offset, UIO_USERSPACE64, UIO_READ,
+                   &uio_buf[0], sizeof(uio_buf));
        } else {
-               auio = uio_createwithbuffer(1, offset, UIO_USERSPACE32, UIO_READ, 
-                                                                         &uio_buf[0], sizeof(uio_buf));
+               auio = uio_createwithbuffer(1, offset, UIO_USERSPACE32, UIO_READ,
+                   &uio_buf[0], sizeof(uio_buf));
+       }
+       if (uio_addiov(auio, bufp, nbyte) != 0) {
+               *retval = 0;
+               return EINVAL;
        }
-       uio_addiov(auio, bufp, nbyte);
 
        bytecnt = nbyte;
 
        if ((error = fo_read(fp, auio, flags, ctx))) {
                if (uio_resid(auio) != bytecnt && (error == ERESTART ||
-                       error == EINTR || error == EWOULDBLOCK))
+                   error == EINTR || error == EWOULDBLOCK)) {
                        error = 0;
+               }
        }
        bytecnt -= uio_resid(auio);
 
        *retval = bytecnt;
 
-       return (error);
+       return error;
 }
 
-/*      
- * Scatter read system call.
+/*
+ * Vector read.
  *
- * Returns:    0                       Success
- *             EINVAL
- *             ENOMEM
- *     copyin:EFAULT
- *     rd_uio:???
+ * Returns:    0                       Success
+ *             EINVAL
+ *             ENOMEM
+ *     preparefileread:EBADF
+ *     preparefileread:ESPIPE
+ *     preparefileread:ENXIO
+ *     preparefileread:EBADF
+ *     copyin:EFAULT
+ *     rd_uio:???
  */
-int
-readv(struct proc *p, struct readv_args *uap, user_ssize_t *retval)
-{
-       __pthread_testcancel(1);
-       return(readv_nocancel(p, (struct readv_nocancel_args *)uap, retval));
-}
-
-int
-readv_nocancel(struct proc *p, struct readv_nocancel_args *uap, user_ssize_t *retval)
+static int
+readv_preadv_uio(struct proc *p, int fdes,
+    user_addr_t user_iovp, int iovcnt, off_t offset, int is_preadv,
+    user_ssize_t *retval)
 {
        uio_t auio = NULL;
        int error;
        struct user_iovec *iovp;
 
-       /* Verify range bedfore calling uio_create() */
-       if (uap->iovcnt <= 0 || uap->iovcnt > UIO_MAXIOV)
-               return (EINVAL);
+       /* Verify range before calling uio_create() */
+       if (iovcnt <= 0 || iovcnt > UIO_MAXIOV) {
+               return EINVAL;
+       }
 
        /* allocate a uio large enough to hold the number of iovecs passed */
-       auio = uio_create(uap->iovcnt, 0,
-                                 (IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32),
-                                 UIO_READ);
-                                 
+       auio = uio_create(iovcnt, offset,
+           (IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32),
+           UIO_READ);
+
        /* get location of iovecs within the uio.  then copyin the iovecs from
         * user space.
         */
@@ -426,26 +423,58 @@ readv_nocancel(struct proc *p, struct readv_nocancel_args *uap, user_ssize_t *re
                error = ENOMEM;
                goto ExitThisRoutine;
        }
-       error = copyin_user_iovec_array(uap->iovp,
-               IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32,
-               uap->iovcnt, iovp);
+       error = copyin_user_iovec_array(user_iovp,
+           IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32,
+           iovcnt, iovp);
        if (error) {
                goto ExitThisRoutine;
        }
-       
-       /* finalize uio_t for use and do the IO 
+
+       /* finalize uio_t for use and do the IO
         */
        error = uio_calculateresid(auio);
        if (error) {
                goto ExitThisRoutine;
        }
-       error = rd_uio(p, uap->fd, auio, retval);
+       error = rd_uio(p, fdes, auio, is_preadv, retval);
 
 ExitThisRoutine:
        if (auio != NULL) {
                uio_free(auio);
        }
-       return (error);
+       return error;
+}
+
+/*
+ * Scatter read system call.
+ */
+int
+readv(struct proc *p, struct readv_args *uap, user_ssize_t *retval)
+{
+       __pthread_testcancel(1);
+       return readv_nocancel(p, (struct readv_nocancel_args *)uap, retval);
+}
+
+int
+readv_nocancel(struct proc *p, struct readv_nocancel_args *uap, user_ssize_t *retval)
+{
+       return readv_preadv_uio(p, uap->fd, uap->iovp, uap->iovcnt, 0, 0, retval);
+}
+
+/*
+ * Preadv system call
+ */
+int
+sys_preadv(struct proc *p, struct preadv_args *uap, user_ssize_t *retval)
+{
+       __pthread_testcancel(1);
+       return sys_preadv_nocancel(p, (struct preadv_nocancel_args *)uap, retval);
+}
+
+int
+sys_preadv_nocancel(struct proc *p, struct preadv_nocancel_args *uap, user_ssize_t *retval)
+{
+       return readv_preadv_uio(p, uap->fd, uap->iovp, uap->iovcnt, uap->offset, 1, retval);
 }
 
 /*
@@ -460,39 +489,40 @@ int
 write(struct proc *p, struct write_args *uap, user_ssize_t *retval)
 {
        __pthread_testcancel(1);
-       return(write_nocancel(p, (struct write_nocancel_args *)uap, retval));
-
+       return write_nocancel(p, (struct write_nocancel_args *)uap, retval);
 }
 
 int
 write_nocancel(struct proc *p, struct write_nocancel_args *uap, user_ssize_t *retval)
 {
        struct fileproc *fp;
-       int error;      
+       int error;
        int fd = uap->fd;
 
        AUDIT_ARG(fd, fd);
 
-       error = fp_lookup(p,fd,&fp,0);
-       if (error)
-               return(error);
+       error = fp_lookup(p, fd, &fp, 0);
+       if (error) {
+               return error;
+       }
        if ((fp->f_flag & FWRITE) == 0) {
                error = EBADF;
+       } else if (fp_isguarded(fp, GUARD_WRITE)) {
+               proc_fdlock(p);
+               error = fp_guard_exception(p, fd, fp, kGUARD_EXC_WRITE);
+               proc_fdunlock(p);
        } else {
                struct vfs_context context = *(vfs_context_current());
-               context.vc_ucred = fp->f_fglob->fg_cred;
+               context.vc_ucred = fp->fp_glob->fg_cred;
 
                error = dofilewrite(&context, fp, uap->cbuf, uap->nbyte,
-                       (off_t)-1, 0, retval);
+                   (off_t)-1, 0, retval);
        }
-       if (error == 0)
-               fp_drop_written(p, fd, fp);
-       else
-               fp_drop(p, fd, fp, 0);
-       return(error);  
+       fp_drop(p, fd, fp, 0);
+       return error;
 }
 
-/*                          
+/*
  * pwrite system call
  *
  * Returns:    0                       Success
@@ -507,38 +537,39 @@ int
 pwrite(struct proc *p, struct pwrite_args *uap, user_ssize_t *retval)
 {
        __pthread_testcancel(1);
-       return(pwrite_nocancel(p, (struct pwrite_nocancel_args *)uap, retval));
+       return pwrite_nocancel(p, (struct pwrite_nocancel_args *)uap, retval);
 }
 
 int
 pwrite_nocancel(struct proc *p, struct pwrite_nocancel_args *uap, user_ssize_t *retval)
 {
-        struct fileproc *fp;
-        int error; 
+       struct fileproc *fp;
+       int error;
        int fd = uap->fd;
        vnode_t vp  = (vnode_t)0;
 
        AUDIT_ARG(fd, fd);
 
-       error = fp_lookup(p,fd,&fp,0);
-       if (error)
-               return(error);
+       error = fp_get_ftype(p, fd, DTYPE_VNODE, ESPIPE, &fp);
+       if (error) {
+               return error;
+       }
 
        if ((fp->f_flag & FWRITE) == 0) {
                error = EBADF;
+       } else if (fp_isguarded(fp, GUARD_WRITE)) {
+               proc_fdlock(p);
+               error = fp_guard_exception(p, fd, fp, kGUARD_EXC_WRITE);
+               proc_fdunlock(p);
        } else {
                struct vfs_context context = *vfs_context_current();
-               context.vc_ucred = fp->f_fglob->fg_cred;
+               context.vc_ucred = fp->fp_glob->fg_cred;
 
-               if (fp->f_type != DTYPE_VNODE) {
-                       error = ESPIPE;
-                       goto errout;
-               }
-               vp = (vnode_t)fp->f_fglob->fg_data;
+               vp = (vnode_t)fp->fp_glob->fg_data;
                if (vnode_isfifo(vp)) {
                        error = ESPIPE;
                        goto errout;
-               } 
+               }
                if ((vp->v_flag & VISTTY)) {
                        error = ENXIO;
                        goto errout;
@@ -548,19 +579,16 @@ pwrite_nocancel(struct proc *p, struct pwrite_nocancel_args *uap, user_ssize_t *
                        goto errout;
                }
 
-                   error = dofilewrite(&context, fp, uap->buf, uap->nbyte,
-                       uap->offset, FOF_OFFSET, retval);
-        }
+               error = dofilewrite(&context, fp, uap->buf, uap->nbyte,
+                   uap->offset, FOF_OFFSET, retval);
+       }
 errout:
-       if (error == 0)
-               fp_drop_written(p, fd, fp);
-       else
-               fp_drop(p, fd, fp, 0);
+       fp_drop(p, fd, fp, 0);
 
        KERNEL_DEBUG_CONSTANT((BSDDBG_CODE(DBG_BSD_SC_EXTENDED_INFO, SYS_pwrite) | DBG_FUNC_NONE),
-             uap->fd, uap->nbyte, (unsigned int)((uap->offset >> 32)), (unsigned int)(uap->offset), 0);
-       
-        return(error);
+           uap->fd, uap->nbyte, (unsigned int)((uap->offset >> 32)), (unsigned int)(uap->offset), 0);
+
+       return error;
 }
 
 /*
@@ -569,74 +597,135 @@ errout:
  *     <fo_write>:EPIPE
  *     <fo_write>:???                  [indirect through struct fileops]
  */
-__private_extern__ int                  
+__private_extern__ int
 dofilewrite(vfs_context_t ctx, struct fileproc *fp,
-           user_addr_t bufp, user_size_t nbyte, off_t offset, int flags,
-           user_ssize_t *retval)
-{       
+    user_addr_t bufp, user_size_t nbyte, off_t offset, int flags,
+    user_ssize_t *retval)
+{
        uio_t auio;
-       long error = 0;
+       int error = 0;
        user_ssize_t bytecnt;
-       char uio_buf[ UIO_SIZEOF(1) ];
+       char uio_buf[UIO_SIZEOF(1)];
 
-       if (nbyte > INT_MAX)   
-               return (EINVAL);
+       if (nbyte > INT_MAX) {
+               *retval = 0;
+               return EINVAL;
+       }
 
        if (IS_64BIT_PROCESS(vfs_context_proc(ctx))) {
-               auio = uio_createwithbuffer(1, offset, UIO_USERSPACE64, UIO_WRITE, 
-                                                                         &uio_buf[0], sizeof(uio_buf));
+               auio = uio_createwithbuffer(1, offset, UIO_USERSPACE64, UIO_WRITE,
+                   &uio_buf[0], sizeof(uio_buf));
        } else {
-               auio = uio_createwithbuffer(1, offset, UIO_USERSPACE32, UIO_WRITE, 
-                                                                         &uio_buf[0], sizeof(uio_buf));
+               auio = uio_createwithbuffer(1, offset, UIO_USERSPACE32, UIO_WRITE,
+                   &uio_buf[0], sizeof(uio_buf));
+       }
+       if (uio_addiov(auio, bufp, nbyte) != 0) {
+               *retval = 0;
+               return EINVAL;
        }
-       uio_addiov(auio, bufp, nbyte);
 
-       bytecnt = nbyte; 
+       bytecnt = nbyte;
        if ((error = fo_write(fp, auio, flags, ctx))) {
                if (uio_resid(auio) != bytecnt && (error == ERESTART ||
-                       error == EINTR || error == EWOULDBLOCK))
+                   error == EINTR || error == EWOULDBLOCK)) {
                        error = 0;
+               }
                /* The socket layer handles SIGPIPE */
                if (error == EPIPE && fp->f_type != DTYPE_SOCKET &&
-                   (fp->f_fglob->fg_lflags & FG_NOSIGPIPE) == 0) {
+                   (fp->fp_glob->fg_lflags & FG_NOSIGPIPE) == 0) {
                        /* XXX Raise the signal on the thread? */
                        psignal(vfs_context_proc(ctx), SIGPIPE);
                }
        }
        bytecnt -= uio_resid(auio);
+       if (bytecnt) {
+               os_atomic_or(&fp->fp_glob->fg_flag, FWASWRITTEN, relaxed);
+       }
        *retval = bytecnt;
 
-       return (error); 
+       return error;
 }
-        
-/*      
- * Gather write system call  
- */     
-int
-writev(struct proc *p, struct writev_args *uap, user_ssize_t *retval)
+
+/*
+ * Returns:    0                       Success
+ *             EBADF
+ *             ESPIPE
+ *             ENXIO
+ *     fp_lookup:EBADF
+ *     fp_guard_exception:???
+ */
+static int
+preparefilewrite(struct proc *p, struct fileproc **fp_ret, int fd, int check_for_pwrite)
 {
-       __pthread_testcancel(1);
-       return(writev_nocancel(p, (struct writev_nocancel_args *)uap, retval));
+       vnode_t vp;
+       int error;
+       struct fileproc *fp;
+
+       AUDIT_ARG(fd, fd);
+
+       proc_fdlock_spin(p);
+
+       error = fp_lookup(p, fd, &fp, 1);
+
+       if (error) {
+               proc_fdunlock(p);
+               return error;
+       }
+       if ((fp->f_flag & FWRITE) == 0) {
+               error = EBADF;
+               goto ExitThisRoutine;
+       }
+       if (fp_isguarded(fp, GUARD_WRITE)) {
+               error = fp_guard_exception(p, fd, fp, kGUARD_EXC_WRITE);
+               goto ExitThisRoutine;
+       }
+       if (check_for_pwrite) {
+               if (fp->f_type != DTYPE_VNODE) {
+                       error = ESPIPE;
+                       goto ExitThisRoutine;
+               }
+
+               vp = (vnode_t)fp->fp_glob->fg_data;
+               if (vnode_isfifo(vp)) {
+                       error = ESPIPE;
+                       goto ExitThisRoutine;
+               }
+               if ((vp->v_flag & VISTTY)) {
+                       error = ENXIO;
+                       goto ExitThisRoutine;
+               }
+       }
+
+       *fp_ret = fp;
+
+       proc_fdunlock(p);
+       return 0;
+
+ExitThisRoutine:
+       fp_drop(p, fd, fp, 1);
+       proc_fdunlock(p);
+       return error;
 }
 
-int
-writev_nocancel(struct proc *p, struct writev_nocancel_args *uap, user_ssize_t *retval)
+static int
+writev_prwritev_uio(struct proc *p, int fd,
+    user_addr_t user_iovp, int iovcnt, off_t offset, int is_pwritev,
+    user_ssize_t *retval)
 {
        uio_t auio = NULL;
        int error;
        struct user_iovec *iovp;
 
-       AUDIT_ARG(fd, uap->fd);
-
-       /* Verify range bedfore calling uio_create() */
-       if (uap->iovcnt <= 0 || uap->iovcnt > UIO_MAXIOV)
-               return (EINVAL);
+       /* Verify range before calling uio_create() */
+       if (iovcnt <= 0 || iovcnt > UIO_MAXIOV || offset < 0) {
+               return EINVAL;
+       }
 
        /* allocate a uio large enough to hold the number of iovecs passed */
-       auio = uio_create(uap->iovcnt, 0,
-                                 (IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32),
-                                 UIO_WRITE);
-                                 
+       auio = uio_create(iovcnt, offset,
+           (IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32),
+           UIO_WRITE);
+
        /* get location of iovecs within the uio.  then copyin the iovecs from
         * user space.
         */
@@ -645,96 +734,156 @@ writev_nocancel(struct proc *p, struct writev_nocancel_args *uap, user_ssize_t *
                error = ENOMEM;
                goto ExitThisRoutine;
        }
-       error = copyin_user_iovec_array(uap->iovp,
-               IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32,
-               uap->iovcnt, iovp);
+       error = copyin_user_iovec_array(user_iovp,
+           IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32,
+           iovcnt, iovp);
        if (error) {
                goto ExitThisRoutine;
        }
-       
-       /* finalize uio_t for use and do the IO 
+
+       /* finalize uio_t for use and do the IO
         */
        error = uio_calculateresid(auio);
        if (error) {
                goto ExitThisRoutine;
        }
-       error = wr_uio(p, uap->fd, auio, retval);
+
+       error = wr_uio(p, fd, auio, is_pwritev, retval);
 
 ExitThisRoutine:
        if (auio != NULL) {
                uio_free(auio);
        }
-       return (error);
+       return error;
+}
+
+/*
+ * Gather write system call
+ */
+int
+writev(struct proc *p, struct writev_args *uap, user_ssize_t *retval)
+{
+       __pthread_testcancel(1);
+       return writev_nocancel(p, (struct writev_nocancel_args *)uap, retval);
+}
+
+int
+writev_nocancel(struct proc *p, struct writev_nocancel_args *uap, user_ssize_t *retval)
+{
+       return writev_prwritev_uio(p, uap->fd, uap->iovp, uap->iovcnt, 0, 0, retval);
 }
 
+/*
+ * Pwritev system call
+ */
+int
+sys_pwritev(struct proc *p, struct pwritev_args *uap, user_ssize_t *retval)
+{
+       __pthread_testcancel(1);
+       return sys_pwritev_nocancel(p, (struct pwritev_nocancel_args *)uap, retval);
+}
+
+int
+sys_pwritev_nocancel(struct proc *p, struct pwritev_nocancel_args *uap, user_ssize_t *retval)
+{
+       return writev_prwritev_uio(p, uap->fd, uap->iovp, uap->iovcnt, uap->offset, 1, retval);
+}
 
+/*
+ * Returns:    0                       Success
+ *     preparefileread:EBADF
+ *     preparefileread:ESPIPE
+ *     preparefileread:ENXIO
+ *     preparefileread:???
+ *     fo_write:???
+ */
 int
-wr_uio(struct proc *p, int fdes, uio_t uio, user_ssize_t *retval)
+wr_uio(struct proc *p, int fd, uio_t uio, int is_pwritev, user_ssize_t *retval)
 {
        struct fileproc *fp;
+       int error;
+       int flags;
+
+       if ((error = preparefilewrite(p, &fp, fd, is_pwritev))) {
+               return error;
+       }
+
+       flags = is_pwritev ? FOF_OFFSET : 0;
+       error = do_uiowrite(p, fp, uio, flags, retval);
+
+       fp_drop(p, fd, fp, 0);
+
+       return error;
+}
+
+int
+do_uiowrite(struct proc *p, struct fileproc *fp, uio_t uio, int flags, user_ssize_t *retval)
+{
        int error;
        user_ssize_t count;
        struct vfs_context context = *vfs_context_current();
 
-       error = fp_lookup(p,fdes,&fp,0);
-       if (error)
-               return(error);
-
-       if ((fp->f_flag & FWRITE) == 0) {
-               error = EBADF;
-               goto out;
-       }
        count = uio_resid(uio);
 
        context.vc_ucred = fp->f_cred;
-       error = fo_write(fp, uio, 0, &context);
+       error = fo_write(fp, uio, flags, &context);
        if (error) {
                if (uio_resid(uio) != count && (error == ERESTART ||
-                                               error == EINTR || error == EWOULDBLOCK))
-                       error = 0;
+                   error == EINTR || error == EWOULDBLOCK)) {
+                       error = 0;
+               }
                /* The socket layer handles SIGPIPE */
                if (error == EPIPE && fp->f_type != DTYPE_SOCKET &&
-                   (fp->f_fglob->fg_lflags & FG_NOSIGPIPE) == 0)
-                       psignal(p, SIGPIPE);
+                   (fp->fp_glob->fg_lflags & FG_NOSIGPIPE) == 0) {
+                       psignal(p, SIGPIPE);
+               }
        }
-       *retval = count - uio_resid(uio);
+       count -= uio_resid(uio);
+       if (count) {
+               os_atomic_or(&fp->fp_glob->fg_flag, FWASWRITTEN, relaxed);
+       }
+       *retval = count;
 
-out:
-       if (error == 0)
-               fp_drop_written(p, fdes, fp);
-       else
-               fp_drop(p, fdes, fp, 0);
-       return(error);
+       return error;
 }
 
-
+/*
+ * Returns:    0                       Success
+ *     preparefileread:EBADF
+ *     preparefileread:ESPIPE
+ *     preparefileread:ENXIO
+ *     fo_read:???
+ */
 int
-rd_uio(struct proc *p, int fdes, uio_t uio, user_ssize_t *retval)
+rd_uio(struct proc *p, int fdes, uio_t uio, int is_preadv, user_ssize_t *retval)
 {
        struct fileproc *fp;
        int error;
        user_ssize_t count;
        struct vfs_context context = *vfs_context_current();
 
-       if ( (error = preparefileread(p, &fp, fdes, 0)) )
-               return (error);
+       if ((error = preparefileread(p, &fp, fdes, is_preadv))) {
+               return error;
+       }
 
        count = uio_resid(uio);
 
        context.vc_ucred = fp->f_cred;
 
-       error = fo_read(fp, uio, 0, &context);
+       int flags = is_preadv ? FOF_OFFSET : 0;
+       error = fo_read(fp, uio, flags, &context);
 
        if (error) {
-               if (uio_resid(uio) != count && (error == ERESTART ||
-                                               error == EINTR || error == EWOULDBLOCK))
-                       error = 0;
+               if (uio_resid(uio) != count && (error == ERESTART ||
+                   error == EINTR || error == EWOULDBLOCK)) {
+                       error = 0;
+               }
        }
        *retval = count - uio_resid(uio);
 
-       donefileread(p, fp, fdes);
+       fp_drop(p, fdes, fp, 0);
 
-       return (error);
+       return error;
 }
 
 /*
@@ -759,8 +908,8 @@ ioctl(struct proc *p, struct ioctl_args *uap, __unused int32_t *retval)
        caddr_t datap = NULL, memp = NULL;
        boolean_t is64bit = FALSE;
        int tmp = 0;
-#define STK_PARAMS     128
-       char stkbuf[STK_PARAMS];
+#define STK_PARAMS      128
+       char stkbuf[STK_PARAMS] = {};
        int fd = uap->fd;
        u_long com = uap->com;
        struct vfs_context context = *vfs_context_current();
@@ -770,10 +919,11 @@ ioctl(struct proc *p, struct ioctl_args *uap, __unused int32_t *retval)
 
        is64bit = proc_is64bit(p);
 #if CONFIG_AUDIT
-       if (is64bit)
+       if (is64bit) {
                AUDIT_ARG(value64, com);
-       else
+       } else {
                AUDIT_ARG(cmd, CAST_DOWN_EXPLICIT(int, com));
+       }
 #endif /* CONFIG_AUDIT */
 
        /*
@@ -781,47 +931,50 @@ ioctl(struct proc *p, struct ioctl_args *uap, __unused int32_t *retval)
         * copied to/from the user's address space.
         */
        size = IOCPARM_LEN(com);
-       if (size > IOCPARM_MAX)
-                       return ENOTTY;
-       if (size > sizeof (stkbuf)) {
-               if ((memp = (caddr_t)kalloc(size)) == 0)
+       if (size > IOCPARM_MAX) {
+               return ENOTTY;
+       }
+       if (size > sizeof(stkbuf)) {
+               memp = (caddr_t)kheap_alloc(KHEAP_TEMP, size, Z_WAITOK);
+               if (memp == 0) {
                        return ENOMEM;
+               }
                datap = memp;
-       } else
+       } else {
                datap = &stkbuf[0];
+       }
        if (com & IOC_IN) {
                if (size) {
                        error = copyin(uap->data, datap, size);
-                       if (error)
+                       if (error) {
                                goto out_nofp;
+                       }
                } else {
                        /* XXX - IOC_IN and no size?  we should proably return an error here!! */
                        if (is64bit) {
                                *(user_addr_t *)datap = uap->data;
-                       }
-                       else {
+                       } else {
                                *(uint32_t *)datap = (uint32_t)uap->data;
                        }
                }
-       } else if ((com & IOC_OUT) && size)
+       } else if ((com & IOC_OUT) && size) {
                /*
                 * Zero the buffer so the user always
                 * gets back something deterministic.
                 */
                bzero(datap, size);
-       else if (com & IOC_VOID) {
+       else if (com & IOC_VOID) {
                /* XXX - this is odd since IOC_VOID means no parameters */
                if (is64bit) {
                        *(user_addr_t *)datap = uap->data;
-               }
-               else {
+               } else {
                        *(uint32_t *)datap = (uint32_t)uap->data;
                }
        }
 
        proc_fdlock(p);
-       error = fp_lookup(p,fd,&fp,1);
-       if (error)  {
+       error = fp_lookup(p, fd, &fp, 1);
+       if (error) {
                proc_fdunlock(p);
                goto out_nofp;
        }
@@ -829,16 +982,17 @@ ioctl(struct proc *p, struct ioctl_args *uap, __unused int32_t *retval)
        AUDIT_ARG(file, p, fp);
 
        if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
-                       error = EBADF;
-                       goto out;
+               error = EBADF;
+               goto out;
        }
 
-       context.vc_ucred = fp->f_fglob->fg_cred;
+       context.vc_ucred = fp->fp_glob->fg_cred;
 
 #if CONFIG_MACF
-       error = mac_file_check_ioctl(context.vc_ucred, fp->f_fglob, com);
-       if (error)
+       error = mac_file_check_ioctl(context.vc_ucred, fp->fp_glob, com);
+       if (error) {
                goto out;
+       }
 #endif
 
        switch (com) {
@@ -851,18 +1005,28 @@ ioctl(struct proc *p, struct ioctl_args *uap, __unused int32_t *retval)
                break;
 
        case FIONBIO:
-               if ( (tmp = *(int *)datap) )
-                       fp->f_flag |= FNONBLOCK;
-               else
-                       fp->f_flag &= ~FNONBLOCK;
+               // FIXME (rdar://54898652)
+               //
+               // this code is broken if fnctl(F_SETFL), ioctl() are
+               // called concurrently for the same fileglob.
+               if ((tmp = *(int *)datap)) {
+                       os_atomic_or(&fp->f_flag, FNONBLOCK, relaxed);
+               } else {
+                       os_atomic_andnot(&fp->f_flag, FNONBLOCK, relaxed);
+               }
                error = fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, &context);
                break;
 
        case FIOASYNC:
-               if ( (tmp = *(int *)datap) )
-                       fp->f_flag |= FASYNC;
-               else
-                       fp->f_flag &= ~FASYNC;
+               // FIXME (rdar://54898652)
+               //
+               // this code is broken if fnctl(F_SETFL), ioctl() are
+               // called concurrently for the same fileglob.
+               if ((tmp = *(int *)datap)) {
+                       os_atomic_or(&fp->f_flag, FASYNC, relaxed);
+               } else {
+                       os_atomic_andnot(&fp->f_flag, FASYNC, relaxed);
+               }
                error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, &context);
                break;
 
@@ -873,7 +1037,7 @@ ioctl(struct proc *p, struct ioctl_args *uap, __unused int32_t *retval)
                        break;
                }
                if (fp->f_type == DTYPE_PIPE) {
-                       error = fo_ioctl(fp, (int)TIOCSPGRP, (caddr_t)&tmp, &context);
+                       error = fo_ioctl(fp, TIOCSPGRP, (caddr_t)&tmp, &context);
                        break;
                }
                if (tmp <= 0) {
@@ -887,7 +1051,7 @@ ioctl(struct proc *p, struct ioctl_args *uap, __unused int32_t *retval)
                        tmp = p1->p_pgrpid;
                        proc_rele(p1);
                }
-               error = fo_ioctl(fp, (int)TIOCSPGRP, (caddr_t)&tmp, &context);
+               error = fo_ioctl(fp, TIOCSPGRP, (caddr_t)&tmp, &context);
                break;
 
        case FIOGETOWN:
@@ -905,8 +1069,9 @@ ioctl(struct proc *p, struct ioctl_args *uap, __unused int32_t *retval)
                 * Copy any data to user, size was
                 * already set and checked above.
                 */
-               if (error == 0 && (com & IOC_OUT) && size)
+               if (error == 0 && (com & IOC_OUT) && size) {
                        error = copyout(datap, uap->data, (u_int)size);
+               }
                break;
        }
 out:
@@ -914,21 +1079,23 @@ out:
        proc_fdunlock(p);
 
 out_nofp:
-       if (memp)
-               kfree(memp, size);
-       return(error);
+       if (memp) {
+               kheap_free(KHEAP_TEMP, memp, size);
+       }
+       return error;
 }
 
-int    selwait, nselcoll;
+int     selwait, nselcoll;
 #define SEL_FIRSTPASS 1
 #define SEL_SECONDPASS 2
 extern int selcontinue(int error);
 extern int selprocess(int error, int sel_pass);
-static int selscan(struct proc *p, struct _select * sel,
-                       int nfd, int32_t *retval, int sel_pass, wait_queue_sub_t wqsub);
+static int selscan(struct proc *p, struct _select * sel, struct _select_data * seldata,
+    int nfd, int32_t *retval, int sel_pass, struct waitq_set *wqset);
 static int selcount(struct proc *p, u_int32_t *ibits, int nfd, int *count);
-static int seldrop_locked(struct proc *p, u_int32_t *ibits, int nfd, int lim, int *need_wakeup, int fromselcount);
-static int seldrop(struct proc *p, u_int32_t *ibits, int nfd);
+static int seldrop_locked(struct proc *p, u_int32_t *ibits, int nfd, int lim, int *need_wakeup);
+static int seldrop(struct proc *p, u_int32_t *ibits, int nfd, int lim);
+static int select_internal(struct proc *p, struct select_nocancel_args *uap, uint64_t timeout, int32_t *retval);
 
 /*
  * Select system call.
@@ -936,45 +1103,190 @@ static int seldrop(struct proc *p, u_int32_t *ibits, int nfd);
  * Returns:    0                       Success
  *             EINVAL                  Invalid argument
  *             EAGAIN                  Nonconformant error if allocation fails
- *     selprocess:???
  */
 int
 select(struct proc *p, struct select_args *uap, int32_t *retval)
 {
        __pthread_testcancel(1);
-       return(select_nocancel(p, (struct select_nocancel_args *)uap, retval));
+       return select_nocancel(p, (struct select_nocancel_args *)uap, retval);
 }
 
 int
 select_nocancel(struct proc *p, struct select_nocancel_args *uap, int32_t *retval)
+{
+       uint64_t timeout = 0;
+
+       if (uap->tv) {
+               int err;
+               struct timeval atv;
+               if (IS_64BIT_PROCESS(p)) {
+                       struct user64_timeval atv64;
+                       err = copyin(uap->tv, (caddr_t)&atv64, sizeof(atv64));
+                       /* Loses resolution - assume timeout < 68 years */
+                       atv.tv_sec = (__darwin_time_t)atv64.tv_sec;
+                       atv.tv_usec = atv64.tv_usec;
+               } else {
+                       struct user32_timeval atv32;
+                       err = copyin(uap->tv, (caddr_t)&atv32, sizeof(atv32));
+                       atv.tv_sec = atv32.tv_sec;
+                       atv.tv_usec = atv32.tv_usec;
+               }
+               if (err) {
+                       return err;
+               }
+
+               if (itimerfix(&atv)) {
+                       err = EINVAL;
+                       return err;
+               }
+
+               clock_absolutetime_interval_to_deadline(tvtoabstime(&atv), &timeout);
+       }
+
+       return select_internal(p, uap, timeout, retval);
+}
+
+int
+pselect(struct proc *p, struct pselect_args *uap, int32_t *retval)
+{
+       __pthread_testcancel(1);
+       return pselect_nocancel(p, (struct pselect_nocancel_args *)uap, retval);
+}
+
+int
+pselect_nocancel(struct proc *p, struct pselect_nocancel_args *uap, int32_t *retval)
+{
+       int err;
+       struct uthread *ut;
+       uint64_t timeout = 0;
+
+       if (uap->ts) {
+               struct timespec ts;
+
+               if (IS_64BIT_PROCESS(p)) {
+                       struct user64_timespec ts64;
+                       err = copyin(uap->ts, (caddr_t)&ts64, sizeof(ts64));
+                       ts.tv_sec = (__darwin_time_t)ts64.tv_sec;
+                       ts.tv_nsec = (long)ts64.tv_nsec;
+               } else {
+                       struct user32_timespec ts32;
+                       err = copyin(uap->ts, (caddr_t)&ts32, sizeof(ts32));
+                       ts.tv_sec = ts32.tv_sec;
+                       ts.tv_nsec = ts32.tv_nsec;
+               }
+               if (err) {
+                       return err;
+               }
+
+               if (!timespec_is_valid(&ts)) {
+                       return EINVAL;
+               }
+               clock_absolutetime_interval_to_deadline(tstoabstime(&ts), &timeout);
+       }
+
+       ut = get_bsdthread_info(current_thread());
+
+       if (uap->mask != USER_ADDR_NULL) {
+               /* save current mask, then copyin and set new mask */
+               sigset_t newset;
+               err = copyin(uap->mask, &newset, sizeof(sigset_t));
+               if (err) {
+                       return err;
+               }
+               ut->uu_oldmask = ut->uu_sigmask;
+               ut->uu_flag |= UT_SAS_OLDMASK;
+               ut->uu_sigmask = (newset & ~sigcantmask);
+       }
+
+       err = select_internal(p, (struct select_nocancel_args *)uap, timeout, retval);
+
+       if (err != EINTR && ut->uu_flag & UT_SAS_OLDMASK) {
+               /*
+                * Restore old mask (direct return case). NOTE: EINTR can also be returned
+                * if the thread is cancelled. In that case, we don't reset the signal
+                * mask to its original value (which usually happens in the signal
+                * delivery path). This behavior is permitted by POSIX.
+                */
+               ut->uu_sigmask = ut->uu_oldmask;
+               ut->uu_oldmask = 0;
+               ut->uu_flag &= ~UT_SAS_OLDMASK;
+       }
+
+       return err;
+}
+
+void
+select_cleanup_uthread(struct _select *sel)
+{
+       kheap_free(KHEAP_DATA_BUFFERS, sel->ibits, 2 * sel->nbytes);
+       sel->ibits = sel->obits = NULL;
+       sel->nbytes = 0;
+}
+
+static int
+select_grow_uthread_cache(struct _select *sel, uint32_t nbytes)
+{
+       uint32_t *buf;
+
+       buf = kheap_alloc(KHEAP_DATA_BUFFERS, 2 * nbytes, Z_WAITOK | Z_ZERO);
+       if (buf) {
+               select_cleanup_uthread(sel);
+               sel->ibits = buf;
+               sel->obits = buf + nbytes / sizeof(uint32_t);
+               sel->nbytes = nbytes;
+               return true;
+       }
+       return false;
+}
+
+static void
+select_bzero_uthread_cache(struct _select *sel)
+{
+       bzero(sel->ibits, sel->nbytes * 2);
+}
+
+/*
+ * Generic implementation of {,p}select. Care: we type-pun uap across the two
+ * syscalls, which differ slightly. The first 4 arguments (nfds and the fd sets)
+ * are identical. The 5th (timeout) argument points to different types, so we
+ * unpack in the syscall-specific code, but the generic code still does a null
+ * check on this argument to determine if a timeout was specified.
+ */
+static int
+select_internal(struct proc *p, struct select_nocancel_args *uap, uint64_t timeout, int32_t *retval)
 {
        int error = 0;
-       u_int ni, nw, size;
+       u_int ni, nw;
        thread_t th_act;
-       struct uthread  *uth;
+       struct uthread  *uth;
        struct _select *sel;
-       int needzerofill = 1;
+       struct _select_data *seldata;
        int count = 0;
+       size_t sz = 0;
 
        th_act = current_thread();
        uth = get_bsdthread_info(th_act);
        sel = &uth->uu_select;
-       sel->data = &uth->uu_kevent.ss_select_data;
-       retval = (int *)get_bsduthreadrval(th_act);
+       seldata = &uth->uu_save.uus_select_data;
        *retval = 0;
 
+       seldata->args = uap;
+       seldata->retval = retval;
+       seldata->wqp = NULL;
+       seldata->count = 0;
+
        if (uap->nd < 0) {
-               return (EINVAL);
+               return EINVAL;
        }
 
        /* select on thread of process that already called proc_exit() */
        if (p->p_fd == NULL) {
-               return (EBADF);
+               return EBADF;
        }
 
-       if (uap->nd > p->p_fd->fd_nfiles)
+       if (uap->nd > p->p_fd->fd_nfiles) {
                uap->nd = p->p_fd->fd_nfiles; /* forgiving; slightly wrong */
-
+       }
        nw = howmany(uap->nd, NFDBITS);
        ni = nw * sizeof(fd_mask);
 
@@ -988,103 +1300,89 @@ select_nocancel(struct proc *p, struct select_nocancel_args *uap, int32_t *retva
         * it is not a POSIX compliant error code for select().
         */
        if (sel->nbytes < (3 * ni)) {
-               int nbytes = 3 * ni;
-
-               /* Free previous allocation, if any */
-               if (sel->ibits != NULL)
-                       FREE(sel->ibits, M_TEMP);
-               if (sel->obits != NULL) {
-                       FREE(sel->obits, M_TEMP);
-                       /* NULL out; subsequent ibits allocation may fail */
-                       sel->obits = NULL;
-               }
-
-               MALLOC(sel->ibits, u_int32_t *, nbytes, M_TEMP, M_WAITOK | M_ZERO);
-               if (sel->ibits == NULL)
-                       return (EAGAIN);
-               MALLOC(sel->obits, u_int32_t *, nbytes, M_TEMP, M_WAITOK | M_ZERO);
-               if (sel->obits == NULL) {
-                       FREE(sel->ibits, M_TEMP);
-                       sel->ibits = NULL;
-                       return (EAGAIN);
+               if (!select_grow_uthread_cache(sel, 3 * ni)) {
+                       return EAGAIN;
                }
-               sel->nbytes = nbytes;
-               needzerofill = 0;
-       }
-
-       if (needzerofill) {
-               bzero((caddr_t)sel->ibits, sel->nbytes);
-               bzero((caddr_t)sel->obits, sel->nbytes);
+       } else {
+               select_bzero_uthread_cache(sel);
        }
 
        /*
         * get the bits from the user address space
         */
-#define        getbits(name, x) \
+#define getbits(name, x) \
        do { \
-               if (uap->name && (error = copyin(uap->name, \
-                       (caddr_t)&sel->ibits[(x) * nw], ni))) \
-                       goto continuation; \
+               if (uap->name && (error = copyin(uap->name, \
+                       (caddr_t)&sel->ibits[(x) * nw], ni))) \
+                       goto continuation; \
        } while (0)
 
        getbits(in, 0);
        getbits(ou, 1);
        getbits(ex, 2);
-#undef getbits
+#undef  getbits
 
-       if (uap->tv) {
-               struct timeval atv;
-               if (IS_64BIT_PROCESS(p)) {
-                       struct user64_timeval atv64;
-                       error = copyin(uap->tv, (caddr_t)&atv64, sizeof(atv64));
-                       /* Loses resolution - assume timeout < 68 years */
-                       atv.tv_sec = atv64.tv_sec;
-                       atv.tv_usec = atv64.tv_usec;
-               } else {
-                       struct user32_timeval atv32;
-                       error = copyin(uap->tv, (caddr_t)&atv32, sizeof(atv32));
-                       atv.tv_sec = atv32.tv_sec;
-                       atv.tv_usec = atv32.tv_usec;
-               }
-               if (error)
-                       goto continuation;
-               if (itimerfix(&atv)) {
-                       error = EINVAL;
-                       goto continuation;
-               }
+       seldata->abstime = timeout;
 
-               clock_absolutetime_interval_to_deadline(
-                                                                               tvtoabstime(&atv), &sel->data->abstime);
+       if ((error = selcount(p, sel->ibits, uap->nd, &count))) {
+               goto continuation;
        }
-       else
-               sel->data->abstime = 0;
 
-       if ( (error = selcount(p, sel->ibits, uap->nd, &count)) ) {
-                       goto continuation;
+       /*
+        * We need an array of waitq pointers. This is due to the new way
+        * in which waitqs are linked to sets. When a thread selects on a
+        * file descriptor, a waitq (embedded in a selinfo structure) is
+        * added to the thread's local waitq set. There is no longer any
+        * way to directly iterate over all members of a given waitq set.
+        * The process of linking a waitq into a set may allocate a link
+        * table object. Because we can't iterate over all the waitqs to
+        * which our thread waitq set belongs, we need a way of removing
+        * this link object!
+        *
+        * Thus we need a buffer which will hold one waitq pointer
+        * per FD being selected. During the tear-down phase we can use
+        * these pointers to dis-associate the underlying selinfo's waitq
+        * from our thread's waitq set.
+        *
+        * Because we also need to allocate a waitq set for this thread,
+        * we use a bare buffer pointer to hold all the memory. Note that
+        * this memory is cached in the thread pointer and not reaped until
+        * the thread exists. This is generally OK because threads that
+        * call select tend to keep calling select repeatedly.
+        */
+       sz = ALIGN(sizeof(struct waitq_set)) + (count * sizeof(uint64_t));
+       if (sz > uth->uu_wqstate_sz) {
+               /* (re)allocate a buffer to hold waitq pointers */
+               if (uth->uu_wqset) {
+                       if (waitq_set_is_valid(uth->uu_wqset)) {
+                               waitq_set_deinit(uth->uu_wqset);
+                       }
+                       kheap_free(KM_SELECT, uth->uu_wqset, uth->uu_wqstate_sz);
+               } else if (uth->uu_wqstate_sz && !uth->uu_wqset) {
+                       panic("select: thread structure corrupt! "
+                           "uu_wqstate_sz:%ld, wqstate_buf == NULL",
+                           uth->uu_wqstate_sz);
+               }
+               uth->uu_wqstate_sz = sz;
+               uth->uu_wqset = kheap_alloc(KM_SELECT, sz, Z_WAITOK);
+               if (!uth->uu_wqset) {
+                       panic("can't allocate %ld bytes for wqstate buffer",
+                           uth->uu_wqstate_sz);
+               }
+               waitq_set_init(uth->uu_wqset,
+                   SYNC_POLICY_FIFO | SYNC_POLICY_PREPOST, NULL, NULL);
        }
 
-       sel->data->count = count;
-       size = SIZEOF_WAITQUEUE_SET + (count * SIZEOF_WAITQUEUE_LINK);
-       if (uth->uu_allocsize) {
-               if (uth->uu_wqset == 0)
-                       panic("select: wql memory smashed");
-               /* needed for the select now */
-               if (size > uth->uu_allocsize) {
-                       kfree(uth->uu_wqset,  uth->uu_allocsize);
-                       uth->uu_allocsize = size;
-                       uth->uu_wqset = (wait_queue_set_t)kalloc(size);
-                       if (uth->uu_wqset == (wait_queue_set_t)NULL)
-                               panic("failed to allocate memory for waitqueue\n");
-               }
-       } else {
-               uth->uu_allocsize = size;
-               uth->uu_wqset = (wait_queue_set_t)kalloc(uth->uu_allocsize);
-               if (uth->uu_wqset == (wait_queue_set_t)NULL)
-                       panic("failed to allocate memory for waitqueue\n");
+       if (!waitq_set_is_valid(uth->uu_wqset)) {
+               waitq_set_init(uth->uu_wqset,
+                   SYNC_POLICY_FIFO | SYNC_POLICY_PREPOST, NULL, NULL);
        }
-       bzero(uth->uu_wqset, size);
-       sel->data->wql = (char *)uth->uu_wqset + SIZEOF_WAITQUEUE_SET;
-       wait_queue_set_init(uth->uu_wqset, (SYNC_POLICY_FIFO | SYNC_POLICY_PREPOST));
+
+       /* the last chunk of our buffer is an array of waitq pointers */
+       seldata->wqp = (uint64_t *)((char *)(uth->uu_wqset) + ALIGN(sizeof(struct waitq_set)));
+       bzero(seldata->wqp, sz - ALIGN(sizeof(struct waitq_set)));
+
+       seldata->count = count;
 
 continuation:
 
@@ -1095,7 +1393,7 @@ continuation:
                 * need to wait_subqueue_unlink_all(), since we haven't set
                 * anything at this point.
                 */
-               return (error);
+               return error;
        }
 
        return selprocess(0, SEL_FIRSTPASS);
@@ -1120,11 +1418,12 @@ selprocess(int error, int sel_pass)
        int ncoll;
        u_int ni, nw;
        thread_t th_act;
-       struct uthread  *uth;
+       struct uthread  *uth;
        struct proc *p;
-       struct select_args *uap;
+       struct select_nocancel_args *uap;
        int *retval;
        struct _select *sel;
+       struct _select_data *seldata;
        int unwind = 1;
        int prepost = 0;
        int somewakeup = 0;
@@ -1133,55 +1432,51 @@ selprocess(int error, int sel_pass)
 
        p = current_proc();
        th_act = current_thread();
-       uap = (struct select_args *)get_bsduthreadarg(th_act);
-       retval = (int *)get_bsduthreadrval(th_act);
        uth = get_bsdthread_info(th_act);
        sel = &uth->uu_select;
+       seldata = &uth->uu_save.uus_select_data;
+       uap = seldata->args;
+       retval = seldata->retval;
 
-       if ((error != 0) && (sel_pass == SEL_FIRSTPASS))
-                       unwind = 0;
-       if (sel->data->count == 0)
-                       unwind = 0;
+       if ((error != 0) && (sel_pass == SEL_FIRSTPASS)) {
+               unwind = 0;
+       }
+       if (seldata->count == 0) {
+               unwind = 0;
+       }
 retry:
        if (error != 0) {
-               sel_pass = SEL_FIRSTPASS;       /* Reset for seldrop */
                goto done;
        }
 
        ncoll = nselcoll;
        OSBitOrAtomic(P_SELECT, &p->p_flag);
-       /* skip scans if the select is just for timeouts */
-       if (sel->data->count) {
-               /*
-                * Clear out any dangling refs from prior calls; technically
-                * there should not be any.
-                */
-               if (sel_pass == SEL_FIRSTPASS)
-                       wait_queue_sub_clearrefs(uth->uu_wqset);
 
-               error = selscan(p, sel, uap->nd, retval, sel_pass, (wait_queue_sub_t)uth->uu_wqset);
+       /* skip scans if the select is just for timeouts */
+       if (seldata->count) {
+               error = selscan(p, sel, seldata, uap->nd, retval, sel_pass, uth->uu_wqset);
                if (error || *retval) {
                        goto done;
                }
-               if (prepost) {
-                       /* if the select of log, then we canwakeup and discover some one
-                       * else already read the data; go toselct again if time permits
-                       */
-                       prepost = 0;
-                       doretry = 1;
-               }
-               if (somewakeup) {
-                       somewakeup = 0;
-                       doretry = 1;
+               if (prepost || somewakeup) {
+                       /*
+                        * if the select of log, then we can wakeup and
+                        * discover some one else already read the data;
+                        * go to select again if time permits
+                        */
+                       prepost = 0;
+                       somewakeup = 0;
+                       doretry = 1;
                }
        }
 
        if (uap->tv) {
-               uint64_t        now;
+               uint64_t        now;
 
                clock_get_uptime(&now);
-               if (now >= sel->data->abstime)
+               if (now >= seldata->abstime) {
                        goto done;
+               }
        }
 
        if (doretry) {
@@ -1195,12 +1490,12 @@ retry:
         * To effect a poll, the timeout argument should be
         * non-nil, pointing to a zero-valued timeval structure.
         */
-       if (uap->tv && sel->data->abstime == 0) {
+       if (uap->tv && seldata->abstime == 0) {
                goto done;
        }
 
        /* No spurious wakeups due to colls,no need to check for them */
-        if ((sel_pass == SEL_SECONDPASS) || ((p->p_flag & P_SELECT) == 0)) {
+       if ((sel_pass == SEL_SECONDPASS) || ((p->p_flag & P_SELECT) == 0)) {
                sel_pass = SEL_FIRSTPASS;
                goto retry;
        }
@@ -1208,47 +1503,59 @@ retry:
        OSBitAndAtomic(~((uint32_t)P_SELECT), &p->p_flag);
 
        /* if the select is just for timeout skip check */
-       if (sel->data->count &&(sel_pass == SEL_SECONDPASS))
+       if (seldata->count && (sel_pass == SEL_SECONDPASS)) {
                panic("selprocess: 2nd pass assertwaiting");
+       }
 
-       /* Wait Queue Subordinate has waitqueue as first element */
-       wait_result = wait_queue_assert_wait_with_leeway((wait_queue_t)uth->uu_wqset,
-                                            NULL, THREAD_ABORTSAFE,
-                                            TIMEOUT_URGENCY_USER_NORMAL, sel->data->abstime, 0);
+       /* waitq_set has waitqueue as first element */
+       wait_result = waitq_assert_wait64_leeway((struct waitq *)uth->uu_wqset,
+           NO_EVENT64, THREAD_ABORTSAFE,
+           TIMEOUT_URGENCY_USER_NORMAL,
+           seldata->abstime,
+           TIMEOUT_NO_LEEWAY);
        if (wait_result != THREAD_AWAKENED) {
                /* there are no preposted events */
                error = tsleep1(NULL, PSOCK | PCATCH,
-                               "select", 0, selcontinue);
-       } else  {
+                   "select", 0, selcontinue);
+       } else {
                prepost = 1;
                error = 0;
        }
 
        if (error == 0) {
                sel_pass = SEL_SECONDPASS;
-               if (!prepost)
+               if (!prepost) {
                        somewakeup = 1;
+               }
                goto retry;
        }
 done:
        if (unwind) {
-               wait_subqueue_unlink_all(uth->uu_wqset);
-               seldrop(p, sel->ibits, uap->nd);
+               seldrop(p, sel->ibits, uap->nd, seldata->count);
+               waitq_set_deinit(uth->uu_wqset);
+               /*
+                * zero out the waitq pointer array to avoid use-after free
+                * errors in the selcount error path (seldrop_locked) if/when
+                * the thread re-calls select().
+                */
+               bzero((void *)uth->uu_wqset, uth->uu_wqstate_sz);
        }
        OSBitAndAtomic(~((uint32_t)P_SELECT), &p->p_flag);
        /* select is not restarted after signals... */
-       if (error == ERESTART)
+       if (error == ERESTART) {
                error = EINTR;
-       if (error == EWOULDBLOCK)
+       }
+       if (error == EWOULDBLOCK) {
                error = 0;
+       }
        nw = howmany(uap->nd, NFDBITS);
        ni = nw * sizeof(fd_mask);
 
-#define        putbits(name, x) \
+#define putbits(name, x) \
        do { \
-               if (uap->name && (error2 = \
-                       copyout((caddr_t)&sel->obits[(x) * nw], uap->name, ni))) \
-                       error = error2; \
+               if (uap->name && (error2 = \
+                       copyout((caddr_t)&sel->obits[(x) * nw], uap->name, ni))) \
+                       error = error2; \
        } while (0)
 
        if (error == 0) {
@@ -1259,7 +1566,127 @@ done:
                putbits(ex, 2);
 #undef putbits
        }
-       return(error);
+
+       if (error != EINTR && sel_pass == SEL_SECONDPASS && uth->uu_flag & UT_SAS_OLDMASK) {
+               /* restore signal mask - continuation case */
+               uth->uu_sigmask = uth->uu_oldmask;
+               uth->uu_oldmask = 0;
+               uth->uu_flag &= ~UT_SAS_OLDMASK;
+       }
+
+       return error;
+}
+
+
+/**
+ * remove the fileproc's underlying waitq from the supplied waitq set;
+ * clear FP_INSELECT when appropriate
+ *
+ * Parameters:
+ *             fp      File proc that is potentially currently in select
+ *             wqset   Waitq set to which the fileproc may belong
+ *                     (usually this is the thread's private waitq set)
+ * Conditions:
+ *             proc_fdlock is held
+ */
+static void
+selunlinkfp(struct fileproc *fp, uint64_t wqp_id, struct waitq_set *wqset)
+{
+       int valid_set = waitq_set_is_valid(wqset);
+       int valid_q = !!wqp_id;
+
+       /*
+        * This could be called (from selcount error path) before we setup
+        * the thread's wqset. Check the wqset passed in, and only unlink if
+        * the set is valid.
+        */
+
+       /* unlink the underlying waitq from the input set (thread waitq set) */
+       if (valid_q && valid_set) {
+               waitq_unlink_by_prepost_id(wqp_id, wqset);
+       }
+
+       /* allow passing a invalid fp for seldrop unwind */
+       if (!(fp->fp_flags & (FP_INSELECT | FP_SELCONFLICT))) {
+               return;
+       }
+
+       /*
+        * We can always remove the conflict queue from our thread's set: this
+        * will not affect other threads that potentially need to be awoken on
+        * the conflict queue during a fileproc_drain - those sets will still
+        * be linked with the global conflict queue, and the last waiter
+        * on the fp clears the CONFLICT marker.
+        */
+       if (valid_set && (fp->fp_flags & FP_SELCONFLICT)) {
+               waitq_unlink(&select_conflict_queue, wqset);
+       }
+
+       /* jca: TODO:
+        * This isn't quite right - we don't actually know if this
+        * fileproc is in another select or not! Here we just assume
+        * that if we were the first thread to select on the FD, then
+        * we'll be the one to clear this flag...
+        */
+       if (valid_set && fp->fp_wset == (void *)wqset) {
+               fp->fp_flags &= ~FP_INSELECT;
+               fp->fp_wset = NULL;
+       }
+}
+
+/**
+ * connect a fileproc to the given wqset, potentially bridging to a waitq
+ * pointed to indirectly by wq_data
+ *
+ * Parameters:
+ *             fp      File proc potentially currently in select
+ *             wq_data Pointer to a pointer to a waitq (could be NULL)
+ *             wqset   Waitq set to which the fileproc should now belong
+ *                     (usually this is the thread's private waitq set)
+ *
+ * Conditions:
+ *             proc_fdlock is held
+ */
+static uint64_t
+sellinkfp(struct fileproc *fp, void **wq_data, struct waitq_set *wqset)
+{
+       struct waitq *f_wq = NULL;
+
+       if ((fp->fp_flags & FP_INSELECT) != FP_INSELECT) {
+               if (wq_data) {
+                       panic("non-null data:%p on fp:%p not in select?!"
+                           "(wqset:%p)", wq_data, fp, wqset);
+               }
+               return 0;
+       }
+
+       if ((fp->fp_flags & FP_SELCONFLICT) == FP_SELCONFLICT) {
+               waitq_link(&select_conflict_queue, wqset, WAITQ_SHOULD_LOCK, NULL);
+       }
+
+       /*
+        * The wq_data parameter has potentially been set by selrecord called
+        * from a subsystems fo_select() function. If the subsystem does not
+        * call selrecord, then wq_data will be NULL
+        *
+        * Use memcpy to get the value into a proper pointer because
+        * wq_data most likely points to a stack variable that could be
+        * unaligned on 32-bit systems.
+        */
+       if (wq_data) {
+               memcpy(&f_wq, wq_data, sizeof(f_wq));
+               if (!waitq_is_valid(f_wq)) {
+                       f_wq = NULL;
+               }
+       }
+
+       /* record the first thread's wqset in the fileproc structure */
+       if (!fp->fp_wset) {
+               fp->fp_wset = (void *)wqset;
+       }
+
+       /* handles NULL f_wq */
+       return waitq_get_prepost_id(f_wq);
 }
 
 
@@ -1272,7 +1699,7 @@ done:
  *             retval                  The per thread system call return area
  *             sel_pass                Which pass this is; allowed values are
  *                                             SEL_FIRSTPASS and SEL_SECONDPASS
- *             wqsub                   The per thread wait queue set
+ *             wqset                   The per thread wait queue set
  *
  * Returns:    0                       Success
  *             EIO                     Invalid p->p_fd field XXX Obsolete?
@@ -1280,21 +1707,20 @@ done:
  *                                             invalid.
  */
 static int
-selscan(struct proc *p, struct _select *sel, int nfd, int32_t *retval,
-       int sel_pass, wait_queue_sub_t wqsub)
+selscan(struct proc *p, struct _select *sel, struct _select_data * seldata,
+    int nfd, int32_t *retval, int sel_pass, struct waitq_set *wqset)
 {
        struct filedesc *fdp = p->p_fd;
        int msk, i, j, fd;
        u_int32_t bits;
        struct fileproc *fp;
-       int n = 0;              /* count of bits */
-       int nc = 0;             /* bit vector offset (nc'th bit) */
+       int n = 0;              /* count of bits */
+       int nc = 0;             /* bit vector offset (nc'th bit) */
        static int flag[3] = { FREAD, FWRITE, 0 };
        u_int32_t *iptr, *optr;
        u_int nw;
        u_int32_t *ibits, *obits;
-       char * wql;
-       char * wql_ptr;
+       uint64_t reserved_link, *rl_ptr = NULL;
        int count;
        struct vfs_context context = *vfs_context_current();
 
@@ -1303,103 +1729,122 @@ selscan(struct proc *p, struct _select *sel, int nfd, int32_t *retval,
         * in Beaker1C ; verify that the p->p_fd is valid
         */
        if (fdp == NULL) {
-               *retval=0;
-               return(EIO);
+               *retval = 0;
+               return EIO;
        }
        ibits = sel->ibits;
        obits = sel->obits;
-       wql = sel->data->wql;
 
        nw = howmany(nfd, NFDBITS);
 
-       count = sel->data->count;
+       count = seldata->count;
 
        nc = 0;
-       if (count) {
-               proc_fdlock(p);
-               for (msk = 0; msk < 3; msk++) {
-                       iptr = (u_int32_t *)&ibits[msk * nw];
-                       optr = (u_int32_t *)&obits[msk * nw];
-
-                       for (i = 0; i < nfd; i += NFDBITS) {
-                               bits = iptr[i/NFDBITS];
-
-                               while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
-                                       bits &= ~(1 << j);
-                                       fp = fdp->fd_ofiles[fd];
-
-                                       if (fp == NULL || (fdp->fd_ofileflags[fd] & UF_RESERVED)) {
-                                               /*
-                                                * If we abort because of a bad
-                                                * fd, let the caller unwind...
-                                                */
-                                               proc_fdunlock(p);
-                                               return(EBADF);
-                                       }
-                                       if (sel_pass == SEL_SECONDPASS) {
-                                               wql_ptr = (char *)0;
-                                               if ((fp->f_flags & FP_INSELECT) && (fp->f_waddr == (void *)wqsub)) {
-                                                       fp->f_flags &= ~FP_INSELECT;
-                                                       fp->f_waddr = (void *)0;
-                                               }
+       if (!count) {
+               *retval = 0;
+               return 0;
+       }
+
+       proc_fdlock(p);
+       for (msk = 0; msk < 3; msk++) {
+               iptr = (u_int32_t *)&ibits[msk * nw];
+               optr = (u_int32_t *)&obits[msk * nw];
+
+               for (i = 0; i < nfd; i += NFDBITS) {
+                       bits = iptr[i / NFDBITS];
+
+                       while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
+                               bits &= ~(1U << j);
+
+                               fp = fp_get_noref_locked(p, fd);
+                               if (fp == NULL) {
+                                       /*
+                                        * If we abort because of a bad
+                                        * fd, let the caller unwind...
+                                        */
+                                       proc_fdunlock(p);
+                                       return EBADF;
+                               }
+                               if (sel_pass == SEL_SECONDPASS) {
+                                       reserved_link = 0;
+                                       rl_ptr = NULL;
+                                       selunlinkfp(fp, seldata->wqp[nc], wqset);
+                               } else {
+                                       reserved_link = waitq_link_reserve((struct waitq *)wqset);
+                                       rl_ptr = &reserved_link;
+                                       if (fp->fp_flags & FP_INSELECT) {
+                                               /* someone is already in select on this fp */
+                                               fp->fp_flags |= FP_SELCONFLICT;
                                        } else {
-                                               wql_ptr = (wql + nc * SIZEOF_WAITQUEUE_LINK);
-                                               if (fp->f_flags & FP_INSELECT) {
-                                                       /* someone is already in select on this fp */
-                                                       fp->f_flags |= FP_SELCONFLICT;
-                                                       wait_queue_link(&select_conflict_queue, (wait_queue_set_t)wqsub);
-                                               } else {
-                                                       fp->f_flags |= FP_INSELECT;
-                                                       fp->f_waddr = (void *)wqsub;
-                                               }
+                                               fp->fp_flags |= FP_INSELECT;
                                        }
 
-                                       context.vc_ucred = fp->f_cred;
+                                       waitq_set_lazy_init_link(wqset);
+                               }
+
+                               context.vc_ucred = fp->f_cred;
+
+                               /*
+                                * stash this value b/c fo_select may replace
+                                * reserved_link with a pointer to a waitq object
+                                */
+                               uint64_t rsvd = reserved_link;
 
-                                       /* The select; set the bit, if true */
-                                       if (fp->f_ops && fp->f_type
-                                               && fo_select(fp, flag[msk], wql_ptr, &context)) {
-                                               optr[fd/NFDBITS] |= (1 << (fd % NFDBITS));
-                                               n++;
+                               /* The select; set the bit, if true */
+                               if (fp->f_ops && fp->f_type
+                                   && fo_select(fp, flag[msk], rl_ptr, &context)) {
+                                       optr[fd / NFDBITS] |= (1U << (fd % NFDBITS));
+                                       n++;
+                               }
+                               if (sel_pass == SEL_FIRSTPASS) {
+                                       waitq_link_release(rsvd);
+                                       /*
+                                        * If the fp's supporting selinfo structure was linked
+                                        * to this thread's waitq set, then 'reserved_link'
+                                        * will have been updated by selrecord to be a pointer
+                                        * to the selinfo's waitq.
+                                        */
+                                       if (reserved_link == rsvd) {
+                                               rl_ptr = NULL; /* fo_select never called selrecord() */
                                        }
-                                       nc++;
+                                       /*
+                                        * Hook up the thread's waitq set either to
+                                        * the fileproc structure, or to the global
+                                        * conflict queue: but only on the first
+                                        * select pass.
+                                        */
+                                       seldata->wqp[nc] = sellinkfp(fp, (void **)rl_ptr, wqset);
                                }
+                               nc++;
                        }
                }
-               proc_fdunlock(p);
        }
+       proc_fdunlock(p);
+
        *retval = n;
-       return (0);
+       return 0;
 }
 
-int poll_callback(struct kqueue *, struct kevent64_s *, void *);
-
-struct poll_continue_args {
-       user_addr_t pca_fds;
-       u_int pca_nfds;
-       u_int pca_rfds;
-};
+static int poll_callback(struct kevent_qos_s *, kevent_ctx_t);
 
 int
 poll(struct proc *p, struct poll_args *uap, int32_t *retval)
 {
        __pthread_testcancel(1);
-       return(poll_nocancel(p, (struct poll_nocancel_args *)uap, retval));
+       return poll_nocancel(p, (struct poll_nocancel_args *)uap, retval);
 }
 
 
 int
 poll_nocancel(struct proc *p, struct poll_nocancel_args *uap, int32_t *retval)
 {
-       struct poll_continue_args *cont;
-       struct pollfd *fds;
-       struct kqueue *kq;
-       struct timeval atv;
+       struct pollfd *fds = NULL;
+       struct kqueue *kq = NULL;
        int ncoll, error = 0;
        u_int nfds = uap->nfds;
        u_int rfds = 0;
-       u_int i;
-       size_t ni;
+       rlim_t nofile = proc_limitgetcur(p, RLIMIT_NOFILE, TRUE);
+       size_t ni = nfds * sizeof(struct pollfd);
 
        /*
         * This is kinda bogus.  We have fd limits, but that is not
@@ -1409,48 +1854,34 @@ poll_nocancel(struct proc *p, struct poll_nocancel_args *uap, int32_t *retval)
         * safe, but not overly restrictive.
         */
        if (nfds > OPEN_MAX ||
-           (nfds > p->p_rlimit[RLIMIT_NOFILE].rlim_cur && (proc_suser(p) || nfds > FD_SETSIZE)))
-               return (EINVAL);
+           (nfds > nofile && (proc_suser(p) || nfds > FD_SETSIZE))) {
+               return EINVAL;
+       }
 
        kq = kqueue_alloc(p);
-       if (kq == NULL)
-               return (EAGAIN);
-
-       ni = nfds * sizeof(struct pollfd) + sizeof(struct poll_continue_args);
-       MALLOC(cont, struct poll_continue_args *, ni, M_TEMP, M_WAITOK);
-       if (NULL == cont) {
-               error = EAGAIN;
-               goto out;
+       if (kq == NULL) {
+               return EAGAIN;
        }
-       
-       fds = (struct pollfd *)&cont[1];
-       error = copyin(uap->fds, fds, nfds * sizeof(struct pollfd));
-       if (error)
-               goto out;
 
-       if (uap->timeout != -1) {
-               struct timeval rtv;
+       if (nfds) {
+               fds = kheap_alloc(KHEAP_TEMP, ni, Z_WAITOK);
+               if (NULL == fds) {
+                       error = EAGAIN;
+                       goto out;
+               }
 
-               atv.tv_sec = uap->timeout / 1000;
-               atv.tv_usec = (uap->timeout % 1000) * 1000;
-               if (itimerfix(&atv)) {
-                       error = EINVAL;
+               error = copyin(uap->fds, fds, nfds * sizeof(struct pollfd));
+               if (error) {
                        goto out;
                }
-               getmicrouptime(&rtv);
-               timevaladd(&atv, &rtv);
-       } else {
-               atv.tv_sec = 0;
-               atv.tv_usec = 0;
        }
 
        /* JMM - all this P_SELECT stuff is bogus */
        ncoll = nselcoll;
        OSBitOrAtomic(P_SELECT, &p->p_flag);
-       for (i = 0; i < nfds; i++) {
+       for (u_int i = 0; i < nfds; i++) {
                short events = fds[i].events;
-               struct kevent64_s kev;
-               int kerror = 0;
+               __assert_only int rc;
 
                /* per spec, ignore fd values below zero */
                if (fds[i].fd < 0) {
@@ -1459,146 +1890,179 @@ poll_nocancel(struct proc *p, struct poll_nocancel_args *uap, int32_t *retval)
                }
 
                /* convert the poll event into a kqueue kevent */
-               kev.ident = fds[i].fd;
-               kev.flags = EV_ADD | EV_ONESHOT | EV_POLL;
-               kev.udata = CAST_USER_ADDR_T(&fds[i]);
-               kev.fflags = 0;
-               kev.data = 0;
-               kev.ext[0] = 0;
-               kev.ext[1] = 0;
+               struct kevent_qos_s kev = {
+                       .ident = fds[i].fd,
+                       .flags = EV_ADD | EV_ONESHOT | EV_POLL,
+                       .udata = CAST_USER_ADDR_T(&fds[i])
+               };
 
                /* Handle input events */
-               if (events & ( POLLIN | POLLRDNORM | POLLPRI | POLLRDBAND | POLLHUP )) {
+               if (events & (POLLIN | POLLRDNORM | POLLPRI | POLLRDBAND | POLLHUP)) {
                        kev.filter = EVFILT_READ;
-                       if (!(events & ( POLLIN | POLLRDNORM )))
+                       if (events & (POLLPRI | POLLRDBAND)) {
                                kev.flags |= EV_OOBAND;
-                       kerror = kevent_register(kq, &kev, p);
+                       }
+                       rc = kevent_register(kq, &kev, NULL);
+                       assert((rc & FILTER_REGISTER_WAIT) == 0);
                }
 
                /* Handle output events */
-               if (kerror == 0 &&
-                   events & ( POLLOUT | POLLWRNORM | POLLWRBAND )) {
+               if ((kev.flags & EV_ERROR) == 0 &&
+                   (events & (POLLOUT | POLLWRNORM | POLLWRBAND))) {
                        kev.filter = EVFILT_WRITE;
-                       kerror = kevent_register(kq, &kev, p);
+                       rc = kevent_register(kq, &kev, NULL);
+                       assert((rc & FILTER_REGISTER_WAIT) == 0);
                }
 
                /* Handle BSD extension vnode events */
-               if (kerror == 0 &&
-                   events & ( POLLEXTEND | POLLATTRIB | POLLNLINK | POLLWRITE )) {
+               if ((kev.flags & EV_ERROR) == 0 &&
+                   (events & (POLLEXTEND | POLLATTRIB | POLLNLINK | POLLWRITE))) {
                        kev.filter = EVFILT_VNODE;
                        kev.fflags = 0;
-                       if (events & POLLEXTEND)
+                       if (events & POLLEXTEND) {
                                kev.fflags |= NOTE_EXTEND;
-                       if (events & POLLATTRIB)
+                       }
+                       if (events & POLLATTRIB) {
                                kev.fflags |= NOTE_ATTRIB;
-                       if (events & POLLNLINK)
+                       }
+                       if (events & POLLNLINK) {
                                kev.fflags |= NOTE_LINK;
-                       if (events & POLLWRITE)
+                       }
+                       if (events & POLLWRITE) {
                                kev.fflags |= NOTE_WRITE;
-                       kerror = kevent_register(kq, &kev, p);
+                       }
+                       rc = kevent_register(kq, &kev, NULL);
+                       assert((rc & FILTER_REGISTER_WAIT) == 0);
                }
 
-               if (kerror != 0) {
+               if (kev.flags & EV_ERROR) {
                        fds[i].revents = POLLNVAL;
                        rfds++;
-               } else
+               } else {
                        fds[i].revents = 0;
+               }
        }
 
-       /* Did we have any trouble registering? */
-       if (rfds > 0)
+       /*
+        * Did we have any trouble registering?
+        * If user space passed 0 FDs, then respect any timeout value passed.
+        * This is an extremely inefficient sleep. If user space passed one or
+        * more FDs, and we had trouble registering _all_ of them, then bail
+        * out. If a subset of the provided FDs failed to register, then we
+        * will still call the kqueue_scan function.
+        */
+       if (nfds && (rfds == nfds)) {
                goto done;
+       }
 
        /* scan for, and possibly wait for, the kevents to trigger */
-       cont->pca_fds = uap->fds;
-       cont->pca_nfds = nfds;
-       cont->pca_rfds = rfds;
-       error = kqueue_scan(kq, poll_callback, NULL, cont, &atv, p);
-       rfds = cont->pca_rfds;
+       kevent_ctx_t kectx = kevent_get_context(current_thread());
+       *kectx = (struct kevent_ctx_s){
+               .kec_process_noutputs = rfds,
+               .kec_process_flags    = KEVENT_FLAG_POLL,
+               .kec_deadline         = 0, /* wait forever */
+       };
+
+       /*
+        * If any events have trouble registering, an event has fired and we
+        * shouldn't wait for events in kqueue_scan.
+        */
+       if (rfds) {
+               kectx->kec_process_flags |= KEVENT_FLAG_IMMEDIATE;
+       } else if (uap->timeout != -1) {
+               clock_interval_to_deadline(uap->timeout, NSEC_PER_MSEC,
+                   &kectx->kec_deadline);
+       }
+
+       error = kqueue_scan(kq, kectx->kec_process_flags, kectx, poll_callback);
+       rfds = kectx->kec_process_noutputs;
 
- done:
+done:
        OSBitAndAtomic(~((uint32_t)P_SELECT), &p->p_flag);
        /* poll is not restarted after signals... */
-       if (error == ERESTART)
+       if (error == ERESTART) {
                error = EINTR;
-       if (error == EWOULDBLOCK)
-               error = 0;
+       }
        if (error == 0) {
                error = copyout(fds, uap->fds, nfds * sizeof(struct pollfd));
                *retval = rfds;
        }
 
- out:
-       if (NULL != cont)
-               FREE(cont, M_TEMP);
+out:
+       kheap_free(KHEAP_TEMP, fds, ni);
 
        kqueue_dealloc(kq);
-       return (error);
+       return error;
 }
 
-int
-poll_callback(__unused struct kqueue *kq, struct kevent64_s *kevp, void *data)
+static int
+poll_callback(struct kevent_qos_s *kevp, kevent_ctx_t kectx)
 {
-       struct poll_continue_args *cont = (struct poll_continue_args *)data;
        struct pollfd *fds = CAST_DOWN(struct pollfd *, kevp->udata);
        short prev_revents = fds->revents;
-       short mask;
+       short mask = 0;
 
        /* convert the results back into revents */
-       if (kevp->flags & EV_EOF)
+       if (kevp->flags & EV_EOF) {
                fds->revents |= POLLHUP;
-       if (kevp->flags & EV_ERROR)
+       }
+       if (kevp->flags & EV_ERROR) {
                fds->revents |= POLLERR;
+       }
 
        switch (kevp->filter) {
        case EVFILT_READ:
-               if (fds->revents & POLLHUP)
-                       mask = (POLLIN | POLLRDNORM | POLLPRI | POLLRDBAND );
-               else {
-                       mask = 0;
-                       if (kevp->data != 0)
-                               mask |= (POLLIN | POLLRDNORM );
-                       if (kevp->flags & EV_OOBAND)
-                               mask |= ( POLLPRI | POLLRDBAND );
+               if (fds->revents & POLLHUP) {
+                       mask = (POLLIN | POLLRDNORM | POLLPRI | POLLRDBAND);
+               } else {
+                       mask = (POLLIN | POLLRDNORM);
+                       if (kevp->flags & EV_OOBAND) {
+                               mask |= (POLLPRI | POLLRDBAND);
+                       }
                }
                fds->revents |= (fds->events & mask);
                break;
 
        case EVFILT_WRITE:
-               if (!(fds->revents & POLLHUP))
-                       fds->revents |= (fds->events & ( POLLOUT | POLLWRNORM | POLLWRBAND ));
+               if (!(fds->revents & POLLHUP)) {
+                       fds->revents |= (fds->events & (POLLOUT | POLLWRNORM | POLLWRBAND));
+               }
                break;
 
        case EVFILT_VNODE:
-               if (kevp->fflags & NOTE_EXTEND)
+               if (kevp->fflags & NOTE_EXTEND) {
                        fds->revents |= (fds->events & POLLEXTEND);
-               if (kevp->fflags & NOTE_ATTRIB)
+               }
+               if (kevp->fflags & NOTE_ATTRIB) {
                        fds->revents |= (fds->events & POLLATTRIB);
-               if (kevp->fflags & NOTE_LINK)
+               }
+               if (kevp->fflags & NOTE_LINK) {
                        fds->revents |= (fds->events & POLLNLINK);
-               if (kevp->fflags & NOTE_WRITE)
+               }
+               if (kevp->fflags & NOTE_WRITE) {
                        fds->revents |= (fds->events & POLLWRITE);
+               }
                break;
        }
 
-       if (fds->revents != 0 && prev_revents == 0)
-               cont->pca_rfds++;
+       if (fds->revents != 0 && prev_revents == 0) {
+               kectx->kec_process_noutputs++;
+       }
 
        return 0;
 }
-       
+
 int
 seltrue(__unused dev_t dev, __unused int flag, __unused struct proc *p)
 {
-
-       return (1);
+       return 1;
 }
 
 /*
  * selcount
  *
  * Count the number of bits set in the input bit vector, and establish an
- * outstanding fp->f_iocount for each of the descriptors which will be in
+ * outstanding fp->fp_iocount for each of the descriptors which will be in
  * use in the select operation.
  *
  * Parameters: p                       The process doing the select
@@ -1628,8 +2092,7 @@ selcount(struct proc *p, u_int32_t *ibits, int nfd, int *countp)
        int n = 0;
        u_int32_t *iptr;
        u_int nw;
-       int error=0; 
-       int dropcount;
+       int error = 0;
        int need_wakeup = 0;
 
        /*
@@ -1638,7 +2101,7 @@ selcount(struct proc *p, u_int32_t *ibits, int nfd, int *countp)
         */
        if (fdp == NULL) {
                *countp = 0;
-               return(EIO);
+               return EIO;
        }
        nw = howmany(nfd, NFDBITS);
 
@@ -1646,17 +2109,17 @@ selcount(struct proc *p, u_int32_t *ibits, int nfd, int *countp)
        for (msk = 0; msk < 3; msk++) {
                iptr = (u_int32_t *)&ibits[msk * nw];
                for (i = 0; i < nfd; i += NFDBITS) {
-                       bits = iptr[i/NFDBITS];
+                       bits = iptr[i / NFDBITS];
                        while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
-                               bits &= ~(1 << j);
-                               fp = fdp->fd_ofiles[fd];
-                               if (fp == NULL ||
-                                       (fdp->fd_ofileflags[fd] & UF_RESERVED)) {
-                                               *countp = 0;
-                                               error = EBADF;
-                                               goto bad;
+                               bits &= ~(1U << j);
+
+                               fp = fp_get_noref_locked(p, fd);
+                               if (fp == NULL) {
+                                       *countp = 0;
+                                       error = EBADF;
+                                       goto bad;
                                }
-                               fp->f_iocount++;
+                               os_ref_retain_locked(&fp->fp_iocount);
                                n++;
                        }
                }
@@ -1664,22 +2127,21 @@ selcount(struct proc *p, u_int32_t *ibits, int nfd, int *countp)
        proc_fdunlock(p);
 
        *countp = n;
-       return (0);
+       return 0;
 
 bad:
-       dropcount = 0;
-       
-       if (n== 0)
+       if (n == 0) {
                goto out;
+       }
        /* Ignore error return; it's already EBADF */
-       (void)seldrop_locked(p, ibits, nfd, n, &need_wakeup, 1);
+       (void)seldrop_locked(p, ibits, nfd, n, &need_wakeup);
 
 out:
        proc_fdunlock(p);
        if (need_wakeup) {
                wakeup(&p->p_fpdrainwait);
        }
-       return(error);
+       return error;
 }
 
 
@@ -1687,10 +2149,10 @@ out:
  * seldrop_locked
  *
  * Drop outstanding wait queue references set up during selscan(); drop the
- * outstanding per fileproc f_iocount() picked up during the selcount().
+ * outstanding per fileproc fp_iocount picked up during the selcount().
  *
  * Parameters: p                       Process performing the select
- *             ibits                   Input pit bector of fd's
+ *             ibits                   Input bit bector of fd's
  *             nfd                     Number of fd's
  *             lim                     Limit to number of vector entries to
  *                                             consider, or -1 for "all"
@@ -1709,17 +2171,17 @@ out:
  *             clean up after the set up on the remaining fds.
  */
 static int
-seldrop_locked(struct proc *p, u_int32_t *ibits, int nfd, int lim, int *need_wakeup, int fromselcount)
+seldrop_locked(struct proc *p, u_int32_t *ibits, int nfd, int lim, int *need_wakeup)
 {
        struct filedesc *fdp = p->p_fd;
-       int msk, i, j, fd;
+       int msk, i, j, nc, fd;
        u_int32_t bits;
        struct fileproc *fp;
        u_int32_t *iptr;
        u_int nw;
        int error = 0;
-       int dropcount = 0;
        uthread_t uth = get_bsdthread_info(current_thread());
+       struct _select_data *seldata;
 
        *need_wakeup = 0;
 
@@ -1728,53 +2190,53 @@ seldrop_locked(struct proc *p, u_int32_t *ibits, int nfd, int lim, int *need_wak
         * in Beaker1C ; verify that the p->p_fd is valid
         */
        if (fdp == NULL) {
-               return(EIO);
+               return EIO;
        }
 
        nw = howmany(nfd, NFDBITS);
+       seldata = &uth->uu_save.uus_select_data;
 
+       nc = 0;
        for (msk = 0; msk < 3; msk++) {
                iptr = (u_int32_t *)&ibits[msk * nw];
                for (i = 0; i < nfd; i += NFDBITS) {
-                       bits = iptr[i/NFDBITS];
+                       bits = iptr[i / NFDBITS];
                        while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
-                               bits &= ~(1 << j);
-                               fp = fdp->fd_ofiles[fd];
+                               bits &= ~(1U << j);
                                /*
                                 * If we've already dropped as many as were
-                                * counted/scanned, then we are done.  
+                                * counted/scanned, then we are done.
                                 */
-                               if ((fromselcount != 0) && (++dropcount > lim))
+                               if (nc >= lim) {
                                        goto done;
-
-                               if (fp == NULL) {
-                                       /* skip (now) bad fds */
-                                       error = EBADF;
-                                       continue;
                                }
+
                                /*
-                                * Only clear the flag if we set it.  We'll
-                                * only find that we set it if we had made
-                                * at least one [partial] pass through selscan().
+                                * We took an I/O reference in selcount,
+                                * so the fp can't possibly be NULL.
                                 */
-                               if ((fp->f_flags & FP_INSELECT) && (fp->f_waddr == (void *)uth->uu_wqset)) {
-                                       fp->f_flags &= ~FP_INSELECT;
-                                       fp->f_waddr = (void *)0;
-                               }
+                               fp = fp_get_noref_locked_with_iocount(p, fd);
+                               selunlinkfp(fp,
+                                   seldata->wqp ? seldata->wqp[nc] : 0,
+                                   uth->uu_wqset);
+
+                               nc++;
 
-                               fp->f_iocount--;
-                               if (fp->f_iocount < 0)
-                                       panic("f_iocount overdecrement!");
+                               const os_ref_count_t refc = os_ref_release_locked(&fp->fp_iocount);
+                               if (0 == refc) {
+                                       panic("fp_iocount overdecrement!");
+                               }
 
-                               if (fp->f_iocount == 0) {
+                               if (1 == refc) {
                                        /*
                                         * The last iocount is responsible for clearing
                                         * selconfict flag - even if we didn't set it -
                                         * and is also responsible for waking up anyone
                                         * waiting on iocounts to drain.
                                         */
-                                       if (fp->f_flags & FP_SELCONFLICT)
-                                               fp->f_flags &= ~FP_SELCONFLICT;
+                                       if (fp->fp_flags & FP_SELCONFLICT) {
+                                               fp->fp_flags &= ~FP_SELCONFLICT;
+                                       }
                                        if (p->p_fpdrainwait) {
                                                p->p_fpdrainwait = 0;
                                                *need_wakeup = 1;
@@ -1784,56 +2246,84 @@ seldrop_locked(struct proc *p, u_int32_t *ibits, int nfd, int lim, int *need_wak
                }
        }
 done:
-       return (error);
+       return error;
 }
 
 
 static int
-seldrop(struct proc *p, u_int32_t *ibits, int nfd)
+seldrop(struct proc *p, u_int32_t *ibits, int nfd, int lim)
 {
        int error;
        int need_wakeup = 0;
 
        proc_fdlock(p);
-       error =  seldrop_locked(p, ibits, nfd, nfd, &need_wakeup, 0);
+       error = seldrop_locked(p, ibits, nfd, lim, &need_wakeup);
        proc_fdunlock(p);
        if (need_wakeup) {
                wakeup(&p->p_fpdrainwait);
        }
-       return (error);
+       return error;
 }
 
 /*
  * Record a select request.
  */
 void
-selrecord(__unused struct proc *selector, struct selinfo *sip, void * p_wql)
+selrecord(__unused struct proc *selector, struct selinfo *sip, void *s_data)
 {
-       thread_t        cur_act = current_thread();
+       thread_t        cur_act = current_thread();
        struct uthread * ut = get_bsdthread_info(cur_act);
+       /* on input, s_data points to the 64-bit ID of a reserved link object */
+       uint64_t *reserved_link = (uint64_t *)s_data;
 
        /* need to look at collisions */
 
        /*do not record if this is second pass of select */
-       if(p_wql == (void *)0) {
+       if (!s_data) {
                return;
        }
 
        if ((sip->si_flags & SI_INITED) == 0) {
-               wait_queue_init(&sip->si_wait_queue, SYNC_POLICY_FIFO);
+               waitq_init(&sip->si_waitq, SYNC_POLICY_FIFO);
                sip->si_flags |= SI_INITED;
                sip->si_flags &= ~SI_CLEAR;
        }
 
        if (sip->si_flags & SI_RECORDED) {
                sip->si_flags |= SI_COLL;
-       } else
+       } else {
                sip->si_flags &= ~SI_COLL;
+       }
 
        sip->si_flags |= SI_RECORDED;
-       if (!wait_queue_member(&sip->si_wait_queue, ut->uu_wqset))
-               wait_queue_link_noalloc(&sip->si_wait_queue, ut->uu_wqset,
-                                       (wait_queue_link_t)p_wql);
+       /* note: this checks for pre-existing linkage */
+       waitq_link(&sip->si_waitq, ut->uu_wqset,
+           WAITQ_SHOULD_LOCK, reserved_link);
+
+       /*
+        * Always consume the reserved link.
+        * We can always call waitq_link_release() safely because if
+        * waitq_link is successful, it consumes the link and resets the
+        * value to 0, in which case our call to release becomes a no-op.
+        * If waitq_link fails, then the following release call will actually
+        * release the reserved link object.
+        */
+       waitq_link_release(*reserved_link);
+       *reserved_link = 0;
+
+       /*
+        * Use the s_data pointer as an output parameter as well
+        * This avoids changing the prototype for this function which is
+        * used by many kexts. We need to surface the waitq object
+        * associated with the selinfo we just added to the thread's select
+        * set. New waitq sets do not have back-pointers to set members, so
+        * the only way to clear out set linkage objects is to go from the
+        * waitq to the set. We use a memcpy because s_data could be
+        * pointing to an unaligned value on the stack
+        * (especially on 32-bit systems)
+        */
+       void *wqptr = (void *)&sip->si_waitq;
+       memcpy((void *)s_data, (void *)&wqptr, sizeof(void *));
 
        return;
 }
@@ -1841,7 +2331,6 @@ selrecord(__unused struct proc *selector, struct selinfo *sip, void * p_wql)
 void
 selwakeup(struct selinfo *sip)
 {
-       
        if ((sip->si_flags & SI_INITED) == 0) {
                return;
        }
@@ -1856,1096 +2345,1247 @@ selwakeup(struct selinfo *sip)
        }
 
        if (sip->si_flags & SI_RECORDED) {
-               wait_queue_wakeup_all(&sip->si_wait_queue, NULL, THREAD_AWAKENED);
+               waitq_wakeup64_all(&sip->si_waitq, NO_EVENT64,
+                   THREAD_AWAKENED, WAITQ_ALL_PRIORITIES);
                sip->si_flags &= ~SI_RECORDED;
        }
-
 }
 
-void 
+void
 selthreadclear(struct selinfo *sip)
 {
+       struct waitq *wq;
 
        if ((sip->si_flags & SI_INITED) == 0) {
                return;
        }
        if (sip->si_flags & SI_RECORDED) {
-                       selwakeup(sip);
-                       sip->si_flags &= ~(SI_RECORDED | SI_COLL);
+               selwakeup(sip);
+               sip->si_flags &= ~(SI_RECORDED | SI_COLL);
        }
        sip->si_flags |= SI_CLEAR;
-       wait_queue_unlink_all(&sip->si_wait_queue);
-}
-
-
-
-
-#define DBG_POST       0x10
-#define DBG_WATCH      0x11
-#define DBG_WAIT       0x12
-#define DBG_MOD                0x13
-#define DBG_EWAKEUP    0x14
-#define DBG_ENQUEUE    0x15
-#define DBG_DEQUEUE    0x16
-
-#define DBG_MISC_POST MISCDBG_CODE(DBG_EVENT,DBG_POST)
-#define DBG_MISC_WATCH MISCDBG_CODE(DBG_EVENT,DBG_WATCH)
-#define DBG_MISC_WAIT MISCDBG_CODE(DBG_EVENT,DBG_WAIT)
-#define DBG_MISC_MOD MISCDBG_CODE(DBG_EVENT,DBG_MOD)
-#define DBG_MISC_EWAKEUP MISCDBG_CODE(DBG_EVENT,DBG_EWAKEUP)
-#define DBG_MISC_ENQUEUE MISCDBG_CODE(DBG_EVENT,DBG_ENQUEUE)
-#define DBG_MISC_DEQUEUE MISCDBG_CODE(DBG_EVENT,DBG_DEQUEUE)
+       sip->si_flags &= ~SI_INITED;
 
+       wq = &sip->si_waitq;
 
-#define EVPROCDEQUE(p, evq)    do {                            \
-       proc_lock(p);                                           \
-       if (evq->ee_flags & EV_QUEUED) {                        \
-               TAILQ_REMOVE(&p->p_evlist, evq, ee_plist);      \
-               evq->ee_flags &= ~EV_QUEUED;                    \
-       }                                                       \
-       proc_unlock(p);                                         \
-} while (0);
+       /*
+        * Higher level logic may have a handle on this waitq's prepost ID,
+        * but that's OK because the waitq_deinit will remove/invalidate the
+        * prepost object (as well as mark the waitq invalid). This de-couples
+        * us from any callers that may have a handle to this waitq via the
+        * prepost ID.
+        */
+       waitq_deinit(wq);
+}
 
 
 /*
- * called upon socket close. deque and free all events for
- * the socket...  socket must be locked by caller.
+ * gethostuuid
+ *
+ * Description:        Get the host UUID from IOKit and return it to user space.
+ *
+ * Parameters: uuid_buf                Pointer to buffer to receive UUID
+ *             timeout                 Timespec for timout
+ *
+ * Returns:    0                       Success
+ *             EWOULDBLOCK             Timeout is too short
+ *             copyout:EFAULT          Bad user buffer
+ *             mac_system_check_info:EPERM             Client not allowed to perform this operation
+ *
+ * Notes:      A timeout seems redundant, since if it's tolerable to not
+ *             have a system UUID in hand, then why ask for one?
  */
-void
-evsofree(struct socket *sp)
+int
+gethostuuid(struct proc *p, struct gethostuuid_args *uap, __unused int32_t *retval)
 {
-        struct eventqelt *evq, *next;
-       proc_t  p;
-
-       if (sp == NULL)
-               return;
-
-       for (evq = sp->so_evlist.tqh_first; evq != NULL; evq = next) {
-               next = evq->ee_slist.tqe_next;
-               p = evq->ee_proc;
+       kern_return_t kret;
+       int error;
+       mach_timespec_t mach_ts;        /* for IOKit call */
+       __darwin_uuid_t uuid_kern = {}; /* for IOKit call */
 
-               if (evq->ee_flags & EV_QUEUED) {
-                       EVPROCDEQUE(p, evq);
+       /* Check entitlement */
+       if (!IOTaskHasEntitlement(current_task(), "com.apple.private.getprivatesysid")) {
+#if !defined(XNU_TARGET_OS_OSX)
+#if CONFIG_MACF
+               if ((error = mac_system_check_info(kauth_cred_get(), "hw.uuid")) != 0) {
+                       /* EPERM invokes userspace upcall if present */
+                       return error;
                }
-               TAILQ_REMOVE(&sp->so_evlist, evq, ee_slist); // remove from socket q
-               FREE(evq, M_TEMP);
+#endif
+#endif
        }
-}
-
-
-/*
- * called upon pipe close. deque and free all events for
- * the pipe... pipe must be locked by caller
- */
-void
-evpipefree(struct pipe *cpipe)
-{
-        struct eventqelt *evq, *next;
-       proc_t  p;
 
-       for (evq = cpipe->pipe_evlist.tqh_first; evq != NULL; evq = next) {
-               next = evq->ee_slist.tqe_next;
-               p = evq->ee_proc;
+       /* Convert the 32/64 bit timespec into a mach_timespec_t */
+       if (proc_is64bit(p)) {
+               struct user64_timespec ts;
+               error = copyin(uap->timeoutp, &ts, sizeof(ts));
+               if (error) {
+                       return error;
+               }
+               mach_ts.tv_sec = (unsigned int)ts.tv_sec;
+               mach_ts.tv_nsec = (clock_res_t)ts.tv_nsec;
+       } else {
+               struct user32_timespec ts;
+               error = copyin(uap->timeoutp, &ts, sizeof(ts));
+               if (error) {
+                       return error;
+               }
+               mach_ts.tv_sec = ts.tv_sec;
+               mach_ts.tv_nsec = ts.tv_nsec;
+       }
 
-               EVPROCDEQUE(p, evq);
+       /* Call IOKit with the stack buffer to get the UUID */
+       kret = IOBSDGetPlatformUUID(uuid_kern, mach_ts);
 
-               TAILQ_REMOVE(&cpipe->pipe_evlist, evq, ee_slist); // remove from pipe q
-               FREE(evq, M_TEMP);
+       /*
+        * If we get it, copy out the data to the user buffer; note that a
+        * uuid_t is an array of characters, so this is size invariant for
+        * 32 vs. 64 bit.
+        */
+       if (kret == KERN_SUCCESS) {
+               error = copyout(uuid_kern, uap->uuid_buf, sizeof(uuid_kern));
+       } else {
+               error = EWOULDBLOCK;
        }
-}
 
+       return error;
+}
 
 /*
- * enqueue this event if it's not already queued. wakeup
- * the proc if we do queue this event to it...
- * entered with proc lock held... we drop it before
- * doing the wakeup and return in that state
+ * ledger
+ *
+ * Description:        Omnibus system call for ledger operations
  */
-static void
-evprocenque(struct eventqelt *evq)
+int
+ledger(struct proc *p, struct ledger_args *args, __unused int32_t *retval)
 {
-        proc_t p;
-
-       assert(evq);
-       p = evq->ee_proc;
-
-       KERNEL_DEBUG(DBG_MISC_ENQUEUE|DBG_FUNC_START, (uint32_t)evq, evq->ee_flags, evq->ee_eventmask,0,0);
-
-       proc_lock(p);
-
-       if (evq->ee_flags & EV_QUEUED) {
-               proc_unlock(p);
+#if !CONFIG_MACF
+#pragma unused(p)
+#endif
+       int rval, pid, len, error;
+#ifdef LEDGER_DEBUG
+       struct ledger_limit_args lla;
+#endif
+       task_t task;
+       proc_t proc;
 
-               KERNEL_DEBUG(DBG_MISC_ENQUEUE|DBG_FUNC_END, 0,0,0,0,0);
-               return;
+       /* Finish copying in the necessary args before taking the proc lock */
+       error = 0;
+       len = 0;
+       if (args->cmd == LEDGER_ENTRY_INFO) {
+               error = copyin(args->arg3, (char *)&len, sizeof(len));
+       } else if (args->cmd == LEDGER_TEMPLATE_INFO) {
+               error = copyin(args->arg2, (char *)&len, sizeof(len));
+       } else if (args->cmd == LEDGER_LIMIT)
+#ifdef LEDGER_DEBUG
+       { error = copyin(args->arg2, (char *)&lla, sizeof(lla));}
+#else
+       { return EINVAL; }
+#endif
+       else if ((args->cmd < 0) || (args->cmd > LEDGER_MAX_CMD)) {
+               return EINVAL;
        }
-       evq->ee_flags |= EV_QUEUED;
 
-       TAILQ_INSERT_TAIL(&p->p_evlist, evq, ee_plist);
+       if (error) {
+               return error;
+       }
+       if (len < 0) {
+               return EINVAL;
+       }
 
-       proc_unlock(p);
+       rval = 0;
+       if (args->cmd != LEDGER_TEMPLATE_INFO) {
+               pid = (int)args->arg1;
+               proc = proc_find(pid);
+               if (proc == NULL) {
+                       return ESRCH;
+               }
 
-       wakeup(&p->p_evlist);
+#if CONFIG_MACF
+               error = mac_proc_check_ledger(p, proc, args->cmd);
+               if (error) {
+                       proc_rele(proc);
+                       return error;
+               }
+#endif
 
-       KERNEL_DEBUG(DBG_MISC_ENQUEUE|DBG_FUNC_END, 0,0,0,0,0);
-}
+               task = proc->task;
+       }
 
+       switch (args->cmd) {
+#ifdef LEDGER_DEBUG
+       case LEDGER_LIMIT: {
+               if (!kauth_cred_issuser(kauth_cred_get())) {
+                       rval = EPERM;
+               }
+               rval = ledger_limit(task, &lla);
+               proc_rele(proc);
+               break;
+       }
+#endif
+       case LEDGER_INFO: {
+               struct ledger_info info = {};
+
+               rval = ledger_info(task, &info);
+               proc_rele(proc);
+               if (rval == 0) {
+                       rval = copyout(&info, args->arg2,
+                           sizeof(info));
+               }
+               break;
+       }
 
-/*
- * pipe lock must be taken by the caller
- */
-void
-postpipeevent(struct pipe *pipep, int event)
-{
-       int     mask;
-       struct eventqelt *evq;
-
-       if (pipep == NULL)
-               return;
-       KERNEL_DEBUG(DBG_MISC_POST|DBG_FUNC_START, event,0,0,1,0);
-
-       for (evq = pipep->pipe_evlist.tqh_first;
-            evq != NULL; evq = evq->ee_slist.tqe_next) {
-
-               if (evq->ee_eventmask == 0)
-                       continue;
-               mask = 0;
-
-               switch (event & (EV_RWBYTES | EV_RCLOSED | EV_WCLOSED)) {
-
-               case EV_RWBYTES:
-                 if ((evq->ee_eventmask & EV_RE) && pipep->pipe_buffer.cnt) {
-                         mask |= EV_RE;
-                         evq->ee_req.er_rcnt = pipep->pipe_buffer.cnt;
-                 }
-                 if ((evq->ee_eventmask & EV_WR) && 
-                     (MAX(pipep->pipe_buffer.size,PIPE_SIZE) - pipep->pipe_buffer.cnt) >= PIPE_BUF) {
-
-                         if (pipep->pipe_state & PIPE_EOF) {
-                                 mask |= EV_WR|EV_RESET;
-                                 break;
-                         }
-                         mask |= EV_WR;
-                         evq->ee_req.er_wcnt = MAX(pipep->pipe_buffer.size, PIPE_SIZE) - pipep->pipe_buffer.cnt;
-                 }
-                 break;
-
-               case EV_WCLOSED:
-               case EV_RCLOSED:
-                 if ((evq->ee_eventmask & EV_RE)) {
-                         mask |= EV_RE|EV_RCLOSED;
-                 }
-                 if ((evq->ee_eventmask & EV_WR)) {
-                         mask |= EV_WR|EV_WCLOSED;
-                 }
-                 break;
-
-               default:
-                 return;
-               }
-               if (mask) {
-                       /*
-                        * disarm... postevents are nops until this event is 'read' via
-                        * waitevent and then re-armed via modwatch
-                        */
-                       evq->ee_eventmask = 0;
+       case LEDGER_ENTRY_INFO: {
+               void *buf;
+               int sz;
 
-                       /*
-                        * since events are disarmed until after the waitevent
-                        * the ee_req.er_xxxx fields can't change once we've
-                        * inserted this event into the proc queue...
-                        * therefore, the waitevent will see a 'consistent'
-                        * snapshot of the event, even though it won't hold
-                        * the pipe lock, and we're updating the event outside
-                        * of the proc lock, which it will hold
-                        */
-                       evq->ee_req.er_eventbits |= mask;
+               rval = ledger_get_task_entry_info_multiple(task, &buf, &len);
+               proc_rele(proc);
+               if ((rval == 0) && (len >= 0)) {
+                       sz = len * sizeof(struct ledger_entry_info);
+                       rval = copyout(buf, args->arg2, sz);
+                       kheap_free(KHEAP_DATA_BUFFERS, buf, sz);
+               }
+               if (rval == 0) {
+                       rval = copyout(&len, args->arg3, sizeof(len));
+               }
+               break;
+       }
 
-                       KERNEL_DEBUG(DBG_MISC_POST, (uint32_t)evq, evq->ee_req.er_eventbits, mask, 1,0);
+       case LEDGER_TEMPLATE_INFO: {
+               void *buf;
+               int sz;
 
-                       evprocenque(evq);
+               rval = ledger_template_info(&buf, &len);
+               if ((rval == 0) && (len >= 0)) {
+                       sz = len * sizeof(struct ledger_template_info);
+                       rval = copyout(buf, args->arg1, sz);
+                       kheap_free(KHEAP_DATA_BUFFERS, buf, sz);
                }
+               if (rval == 0) {
+                       rval = copyout(&len, args->arg2, sizeof(len));
+               }
+               break;
        }
-       KERNEL_DEBUG(DBG_MISC_POST|DBG_FUNC_END, 0,0,0,1,0);
-}
 
-#if SOCKETS
-/*
- * given either a sockbuf or a socket run down the
- * event list and queue ready events found...
- * the socket must be locked by the caller
- */
-void
-postevent(struct socket *sp, struct sockbuf *sb, int event)
-{
-        int    mask;
-       struct  eventqelt *evq;
-       struct  tcpcb *tp;
-
-       if (sb)
-               sp = sb->sb_so;
-       if (sp == NULL)
-               return;
-
-       KERNEL_DEBUG(DBG_MISC_POST|DBG_FUNC_START, (int)sp, event, 0, 0, 0);
-
-       for (evq = sp->so_evlist.tqh_first;
-            evq != NULL; evq = evq->ee_slist.tqe_next) {
-
-               if (evq->ee_eventmask == 0)
-                       continue;
-               mask = 0;
-
-               /* ready for reading:
-                  - byte cnt >= receive low water mark
-                  - read-half of conn closed
-                  - conn pending for listening sock
-                  - socket error pending
-
-                  ready for writing
-                  - byte cnt avail >= send low water mark
-                  - write half of conn closed
-                  - socket error pending
-                  - non-blocking conn completed successfully
-
-                  exception pending
-                  - out of band data
-                  - sock at out of band mark
-               */
-
-               switch (event & EV_DMASK) {
-
-               case EV_OOB:
-                 if ((evq->ee_eventmask & EV_EX)) {
-                         if (sp->so_oobmark || ((sp->so_state & SS_RCVATMARK)))
-                                 mask |= EV_EX|EV_OOB;
-                 }
-                 break;
-
-               case EV_RWBYTES|EV_OOB:
-                 if ((evq->ee_eventmask & EV_EX)) {
-                         if (sp->so_oobmark || ((sp->so_state & SS_RCVATMARK)))
-                                 mask |= EV_EX|EV_OOB;
-                 }
-                 /*
-                  * fall into the next case
-                  */
-               case EV_RWBYTES:
-                 if ((evq->ee_eventmask & EV_RE) && soreadable(sp)) {
-                         /* for AFP/OT purposes; may go away in future */
-                         if ((SOCK_DOM(sp) == PF_INET ||
-                             SOCK_DOM(sp) == PF_INET6) &&
-                             SOCK_PROTO(sp) == IPPROTO_TCP &&
-                             (sp->so_error == ECONNREFUSED ||
-                             sp->so_error == ECONNRESET)) {
-                                 if (sp->so_pcb == NULL ||
-                                     sotoinpcb(sp)->inp_state ==
-                                     INPCB_STATE_DEAD ||
-                                     (tp = sototcpcb(sp)) == NULL ||
-                                     tp->t_state == TCPS_CLOSED) {
-                                         mask |= EV_RE|EV_RESET;
-                                         break;
-                                 }
-                         }
-                         mask |= EV_RE;
-                         evq->ee_req.er_rcnt = sp->so_rcv.sb_cc;
-
-                         if (sp->so_state & SS_CANTRCVMORE) {
-                                 mask |= EV_FIN;
-                                 break;
-                         }
-                 }
-                 if ((evq->ee_eventmask & EV_WR) && sowriteable(sp)) {
-                         /* for AFP/OT purposes; may go away in future */
-                         if ((SOCK_DOM(sp) == PF_INET ||
-                             SOCK_DOM(sp) == PF_INET6) &&
-                             SOCK_PROTO(sp) == IPPROTO_TCP &&
-                             (sp->so_error == ECONNREFUSED ||
-                             sp->so_error == ECONNRESET)) {
-                                 if (sp->so_pcb == NULL ||
-                                     sotoinpcb(sp)->inp_state ==
-                                     INPCB_STATE_DEAD ||
-                                     (tp = sototcpcb(sp)) == NULL ||
-                                     tp->t_state == TCPS_CLOSED) {
-                                         mask |= EV_WR|EV_RESET;
-                                         break;
-                                 }
-                         }
-                         mask |= EV_WR;
-                         evq->ee_req.er_wcnt = sbspace(&sp->so_snd);
-                 }
-                 break;
-
-               case EV_RCONN:
-                 if ((evq->ee_eventmask & EV_RE)) {
-                         mask |= EV_RE|EV_RCONN;
-                         evq->ee_req.er_rcnt = sp->so_qlen + 1;  // incl this one
-                 }
-                 break;
-
-               case EV_WCONN:
-                 if ((evq->ee_eventmask & EV_WR)) {
-                         mask |= EV_WR|EV_WCONN;
-                 }
-                 break;
-
-               case EV_RCLOSED:
-                 if ((evq->ee_eventmask & EV_RE)) {
-                         mask |= EV_RE|EV_RCLOSED;
-                 }
-                 break;
-
-               case EV_WCLOSED:
-                 if ((evq->ee_eventmask & EV_WR)) {
-                         mask |= EV_WR|EV_WCLOSED;
-                 }
-                 break;
-
-               case EV_FIN:
-                 if (evq->ee_eventmask & EV_RE) {
-                         mask |= EV_RE|EV_FIN;
-                 }
-                 break;
-
-               case EV_RESET:
-               case EV_TIMEOUT:
-                 if (evq->ee_eventmask & EV_RE) {
-                         mask |= EV_RE | event;
-                 } 
-                 if (evq->ee_eventmask & EV_WR) {
-                         mask |= EV_WR | event;
-                 }
-                 break;
-
-               default:
-                 KERNEL_DEBUG(DBG_MISC_POST|DBG_FUNC_END, (int)sp, -1, 0, 0, 0);
-                 return;
-               } /* switch */
-
-               KERNEL_DEBUG(DBG_MISC_POST, (int)evq, evq->ee_eventmask, evq->ee_req.er_eventbits, mask, 0);
-
-               if (mask) {
-                       /*
-                        * disarm... postevents are nops until this event is 'read' via
-                        * waitevent and then re-armed via modwatch
-                        */
-                       evq->ee_eventmask = 0;
+       default:
+               panic("ledger syscall logic error -- command type %d", args->cmd);
+               proc_rele(proc);
+               rval = EINVAL;
+       }
 
-                       /*
-                        * since events are disarmed until after the waitevent
-                        * the ee_req.er_xxxx fields can't change once we've
-                        * inserted this event into the proc queue...
-                        * since waitevent can't see this event until we 
-                        * enqueue it, waitevent will see a 'consistent'
-                        * snapshot of the event, even though it won't hold
-                        * the socket lock, and we're updating the event outside
-                        * of the proc lock, which it will hold
-                        */
-                       evq->ee_req.er_eventbits |= mask;
+       return rval;
+}
+
+int
+telemetry(__unused struct proc *p, struct telemetry_args *args, __unused int32_t *retval)
+{
+       int error = 0;
 
-                       evprocenque(evq);
+       switch (args->cmd) {
+#if CONFIG_TELEMETRY
+       case TELEMETRY_CMD_TIMER_EVENT:
+               error = telemetry_timer_event(args->deadline, args->interval, args->leeway);
+               break;
+       case TELEMETRY_CMD_PMI_SETUP:
+               error = telemetry_pmi_setup((enum telemetry_pmi)args->deadline, args->interval);
+               break;
+#endif /* CONFIG_TELEMETRY */
+       case TELEMETRY_CMD_VOUCHER_NAME:
+               if (thread_set_voucher_name((mach_port_name_t)args->deadline)) {
+                       error = EINVAL;
                }
+               break;
+
+       default:
+               error = EINVAL;
+               break;
        }
-       KERNEL_DEBUG(DBG_MISC_POST|DBG_FUNC_END, (int)sp, 0, 0, 0, 0);
-}
-#endif /* SOCKETS */
 
+       return error;
+}
 
 /*
- * watchevent system call. user passes us an event to watch
- * for. we malloc an event object, initialize it, and queue
- * it to the open socket. when the event occurs, postevent()
- * will enque it back to our proc where we can retrieve it
- * via waitevent().
+ * Logging
  *
- * should this prevent duplicate events on same socket?
+ * Description: syscall to access kernel logging from userspace
  *
- * Returns:
- *             ENOMEM                  No memory for operation
- *     copyin:EFAULT
+ * Args:
+ *     tag - used for syncing with userspace on the version.
+ *     flags - flags used by the syscall.
+ *     buffer - userspace address of string to copy.
+ *     size - size of buffer.
  */
 int
-watchevent(proc_t p, struct watchevent_args *uap, __unused int *retval)
+log_data(__unused struct proc *p, struct log_data_args *args, int *retval)
 {
-       struct eventqelt *evq = (struct eventqelt *)0;
-       struct eventqelt *np = NULL;
-       struct eventreq64 *erp;
-       struct fileproc *fp = NULL;
+       unsigned int tag = args->tag;
+       unsigned int flags = args->flags;
+       user_addr_t buffer = args->buffer;
+       unsigned int size = args->size;
+       int ret = 0;
+       char *log_msg = NULL;
        int error;
+       *retval = 0;
 
-       KERNEL_DEBUG(DBG_MISC_WATCH|DBG_FUNC_START, 0,0,0,0,0);
-
-       // get a qelt and fill with users req
-       MALLOC(evq, struct eventqelt *, sizeof(struct eventqelt), M_TEMP, M_WAITOK);
-
-       if (evq == NULL)
-               return (ENOMEM);
-       erp = &evq->ee_req;
-
-       // get users request pkt
-
-       if (IS_64BIT_PROCESS(p)) {
-               error = copyin(uap->u_req, (caddr_t)erp, sizeof(struct eventreq64));
-       } else {
-               struct eventreq32 er32;
+       /*
+        * Tag synchronize the syscall version with userspace.
+        * Tag == 0 => flags == OS_LOG_TYPE
+        */
+       if (tag != 0) {
+               return EINVAL;
+       }
 
-               error = copyin(uap->u_req, (caddr_t)&er32, sizeof(struct eventreq32));
-               if (error == 0) {
-                      /*
-                       * the user only passes in the
-                       * er_type, er_handle and er_data...
-                       * the other fields are initialized
-                       * below, so don't bother to copy
-                       */
-                       erp->er_type = er32.er_type;
-                       erp->er_handle = er32.er_handle;
-                       erp->er_data = (user_addr_t)er32.er_data;
-               }
+       /*
+        * OS_LOG_TYPE are defined in libkern/os/log.h
+        * In userspace they are defined in libtrace/os/log.h
+        */
+       if (flags != OS_LOG_TYPE_DEFAULT &&
+           flags != OS_LOG_TYPE_INFO &&
+           flags != OS_LOG_TYPE_DEBUG &&
+           flags != OS_LOG_TYPE_ERROR &&
+           flags != OS_LOG_TYPE_FAULT) {
+               return EINVAL;
        }
-       if (error) {
-               FREE(evq, M_TEMP);
-               KERNEL_DEBUG(DBG_MISC_WATCH|DBG_FUNC_END, error,0,0,0,0);
 
-               return(error);          
+       if (size == 0) {
+               return EINVAL;
        }
-       KERNEL_DEBUG(DBG_MISC_WATCH, erp->er_handle,uap->u_eventmask,(uint32_t)evq,0,0);
 
-       // validate, freeing qelt if errors
-       error = 0;
-       proc_fdlock(p);
+       /* truncate to OS_LOG_DATA_MAX_SIZE */
+       if (size > OS_LOG_DATA_MAX_SIZE) {
+               printf("%s: WARNING msg is going to be truncated from %u to %u\n",
+                   __func__, size, OS_LOG_DATA_MAX_SIZE);
+               size = OS_LOG_DATA_MAX_SIZE;
+       }
 
-       if (erp->er_type != EV_FD) {
-               error = EINVAL;
-       } else if ((error = fp_lookup(p, erp->er_handle, &fp, 1)) != 0) {
-               error = EBADF;
-#if SOCKETS
-       } else if (fp->f_type == DTYPE_SOCKET) {
-               socket_lock((struct socket *)fp->f_data, 1);
-               np = ((struct socket *)fp->f_data)->so_evlist.tqh_first;
-#endif /* SOCKETS */
-       } else if (fp->f_type == DTYPE_PIPE) {
-               PIPE_LOCK((struct pipe *)fp->f_data);
-               np = ((struct pipe *)fp->f_data)->pipe_evlist.tqh_first;
-       } else {
-               fp_drop(p, erp->er_handle, fp, 1);
-               error = EINVAL;
+       log_msg = kheap_alloc(KHEAP_TEMP, size, Z_WAITOK);
+       if (!log_msg) {
+               return ENOMEM;
        }
-       proc_fdunlock(p);
 
+       error = copyin(buffer, log_msg, size);
        if (error) {
-               FREE(evq, M_TEMP);
-
-               KERNEL_DEBUG(DBG_MISC_WATCH|DBG_FUNC_END, error,0,0,0,0);
-               return(error);
+               ret = EFAULT;
+               goto out;
        }
-               
+       log_msg[size - 1] = '\0';
+
        /*
-        * only allow one watch per file per proc
+        * This will log to dmesg and logd.
+        * The call will fail if the current
+        * process is not a driverKit process.
         */
-       for ( ; np != NULL; np = np->ee_slist.tqe_next) {
-               if (np->ee_proc == p) {
-#if SOCKETS
-                       if (fp->f_type == DTYPE_SOCKET)
-                               socket_unlock((struct socket *)fp->f_data, 1);
-                       else 
-#endif /* SOCKETS */
-                               PIPE_UNLOCK((struct pipe *)fp->f_data);
-                       fp_drop(p, erp->er_handle, fp, 0);
-                       FREE(evq, M_TEMP);
-                       
-                       KERNEL_DEBUG(DBG_MISC_WATCH|DBG_FUNC_END, EINVAL,0,0,0,0);
-                       return(EINVAL);
-               }
-       }
-       erp->er_ecnt = erp->er_rcnt = erp->er_wcnt = erp->er_eventbits = 0;
-       evq->ee_proc = p;
-       evq->ee_eventmask = uap->u_eventmask & EV_MASK;
-       evq->ee_flags = 0;
-
-#if SOCKETS
-       if (fp->f_type == DTYPE_SOCKET) {
-               TAILQ_INSERT_TAIL(&((struct socket *)fp->f_data)->so_evlist, evq, ee_slist);
-               postevent((struct socket *)fp->f_data, 0, EV_RWBYTES); // catch existing events
+       os_log_driverKit(&ret, OS_LOG_DEFAULT, (os_log_type_t)flags, "%s", log_msg);
 
-               socket_unlock((struct socket *)fp->f_data, 1);
-       } else
-#endif /* SOCKETS */
-       {
-               TAILQ_INSERT_TAIL(&((struct pipe *)fp->f_data)->pipe_evlist, evq, ee_slist);
-               postpipeevent((struct pipe *)fp->f_data, EV_RWBYTES);
-
-               PIPE_UNLOCK((struct pipe *)fp->f_data);
+out:
+       if (log_msg != NULL) {
+               kheap_free(KHEAP_TEMP, log_msg, size);
        }
-       fp_drop_event(p, erp->er_handle, fp);
 
-       KERNEL_DEBUG(DBG_MISC_WATCH|DBG_FUNC_END, 0,0,0,0,0);
-       return(0);
+       return ret;
 }
 
+#if DEVELOPMENT || DEBUG
+#if CONFIG_WAITQ_DEBUG
+static uint64_t g_wqset_num = 0;
+struct g_wqset {
+       queue_chain_t      link;
+       struct waitq_set  *wqset;
+};
 
+static queue_head_t         g_wqset_list;
+static struct waitq_set    *g_waitq_set = NULL;
 
-/*
- * waitevent system call.
- * grabs the next waiting event for this proc and returns
- * it. if no events, user can request to sleep with timeout
- * or without or poll mode
- *    ((tv != NULL && interval == 0) || tv == -1)
- */
-int
-waitevent(proc_t p, struct waitevent_args *uap, int *retval)
+static inline struct waitq_set *
+sysctl_get_wqset(int idx)
 {
-        int error = 0;
-       struct eventqelt *evq;
-       struct eventreq64 *erp;
-       uint64_t abstime, interval;
-       boolean_t fast_poll = FALSE;
-       union {
-               struct eventreq64 er64;
-               struct eventreq32 er32;
-       } uer;
+       struct g_wqset *gwqs;
 
-       interval = 0;
-
-       if (uap->tv) {
-               struct timeval atv;
-               /*
-                * check for fast poll method
-                */
-               if (IS_64BIT_PROCESS(p)) {
-                       if (uap->tv == (user_addr_t)-1)
-                               fast_poll = TRUE;
-               } else if (uap->tv == (user_addr_t)((uint32_t)-1))
-                       fast_poll = TRUE;
-
-               if (fast_poll == TRUE) {
-                       if (p->p_evlist.tqh_first == NULL) {
-                               KERNEL_DEBUG(DBG_MISC_WAIT|DBG_FUNC_NONE, -1,0,0,0,0);
-                               /*
-                                * poll failed
-                                */
-                               *retval = 1;
-                               return (0);
-                       }
-                       proc_lock(p);
-                       goto retry;
-               }
-               if (IS_64BIT_PROCESS(p)) {
-                       struct user64_timeval atv64;
-                       error = copyin(uap->tv, (caddr_t)&atv64, sizeof(atv64));
-                       /* Loses resolution - assume timeout < 68 years */
-                       atv.tv_sec = atv64.tv_sec;
-                       atv.tv_usec = atv64.tv_usec;
-               } else {
-                       struct user32_timeval atv32;
-                       error = copyin(uap->tv, (caddr_t)&atv32, sizeof(atv32));
-                       atv.tv_sec = atv32.tv_sec;
-                       atv.tv_usec = atv32.tv_usec;
-               }
+       if (!g_wqset_num) {
+               queue_init(&g_wqset_list);
+       }
 
-               if (error)
-                       return(error);
-               if (itimerfix(&atv)) {
-                       error = EINVAL;
-                       return(error);
+       /* don't bother with locks: this is test-only code! */
+       qe_foreach_element(gwqs, &g_wqset_list, link) {
+               if ((int)(wqset_id(gwqs->wqset) & 0xffffffff) == idx) {
+                       return gwqs->wqset;
                }
-               interval = tvtoabstime(&atv);
        }
-       KERNEL_DEBUG(DBG_MISC_WAIT|DBG_FUNC_START, 0,0,0,0,0);
-
-       proc_lock(p);
-retry:
-       if ((evq = p->p_evlist.tqh_first) != NULL) {
-               /*
-                * found one... make a local copy while it's still on the queue
-                * to prevent it from changing while in the midst of copying
-                * don't want to hold the proc lock across a copyout because
-                * it might block on a page fault at the target in user space
-                */
-               erp = &evq->ee_req;
 
-               if (IS_64BIT_PROCESS(p))
-                       bcopy((caddr_t)erp, (caddr_t)&uer.er64, sizeof (struct eventreq64));
-               else {
-                       uer.er32.er_type  = erp->er_type;
-                       uer.er32.er_handle  = erp->er_handle;
-                       uer.er32.er_data  = (uint32_t)erp->er_data;
-                       uer.er32.er_ecnt  = erp->er_ecnt;
-                       uer.er32.er_rcnt  = erp->er_rcnt;
-                       uer.er32.er_wcnt  = erp->er_wcnt;
-                       uer.er32.er_eventbits = erp->er_eventbits;
-               }
-               TAILQ_REMOVE(&p->p_evlist, evq, ee_plist);
+       /* allocate a new one */
+       ++g_wqset_num;
+       gwqs = (struct g_wqset *)kalloc(sizeof(*gwqs));
+       assert(gwqs != NULL);
 
-               evq->ee_flags &= ~EV_QUEUED;
+       gwqs->wqset = waitq_set_alloc(SYNC_POLICY_FIFO | SYNC_POLICY_PREPOST, NULL);
+       enqueue_tail(&g_wqset_list, &gwqs->link);
+       printf("[WQ]: created new waitq set 0x%llx\n", wqset_id(gwqs->wqset));
 
-               proc_unlock(p);
+       return gwqs->wqset;
+}
 
-               if (IS_64BIT_PROCESS(p))
-                       error = copyout((caddr_t)&uer.er64, uap->u_req, sizeof(struct eventreq64));
-               else
-                       error = copyout((caddr_t)&uer.er32, uap->u_req, sizeof(struct eventreq32));
+#define MAX_GLOBAL_TEST_QUEUES 64
+static int g_wq_init = 0;
+static struct waitq  g_wq[MAX_GLOBAL_TEST_QUEUES];
 
-               KERNEL_DEBUG(DBG_MISC_WAIT|DBG_FUNC_END, error,
-                            evq->ee_req.er_handle,evq->ee_req.er_eventbits,(uint32_t)evq,0);
-               return (error);
+static inline struct waitq *
+global_test_waitq(int idx)
+{
+       if (idx < 0) {
+               return NULL;
        }
-       else {
-               if (uap->tv && interval == 0) {
-                       proc_unlock(p);
-                       *retval = 1;  // poll failed
 
-                       KERNEL_DEBUG(DBG_MISC_WAIT|DBG_FUNC_END, error,0,0,0,0);
-                       return (error);
+       if (!g_wq_init) {
+               g_wq_init = 1;
+               for (int i = 0; i < MAX_GLOBAL_TEST_QUEUES; i++) {
+                       waitq_init(&g_wq[i], SYNC_POLICY_FIFO);
                }
-               if (interval != 0)
-                       clock_absolutetime_interval_to_deadline(interval, &abstime);
-               else
-                       abstime = 0;
+       }
 
-               KERNEL_DEBUG(DBG_MISC_WAIT, 1,(uint32_t)&p->p_evlist,0,0,0);
+       return &g_wq[idx % MAX_GLOBAL_TEST_QUEUES];
+}
 
-               error = msleep1(&p->p_evlist, &p->p_mlock, (PSOCK | PCATCH), "waitevent", abstime);
+static int sysctl_waitq_wakeup_one SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       int error;
+       int index;
+       struct waitq *waitq;
+       kern_return_t kr;
+       int64_t event64 = 0;
 
-               KERNEL_DEBUG(DBG_MISC_WAIT, 2,(uint32_t)&p->p_evlist,0,0,0);
+       error = SYSCTL_IN(req, &event64, sizeof(event64));
+       if (error) {
+               return error;
+       }
 
-               if (error == 0)
-                       goto retry;
-               if (error == ERESTART)
-                       error = EINTR;
-               if (error == EWOULDBLOCK) {
-                       *retval = 1;
-                       error = 0;
-               }
+       if (!req->newptr) {
+               return SYSCTL_OUT(req, &event64, sizeof(event64));
        }
-       proc_unlock(p);
 
-       KERNEL_DEBUG(DBG_MISC_WAIT|DBG_FUNC_END, 0,0,0,0,0);
-       return (error);
+       if (event64 < 0) {
+               index = (int)((-event64) & 0xffffffff);
+               waitq = wqset_waitq(sysctl_get_wqset(index));
+               index = -index;
+       } else {
+               index = (int)event64;
+               waitq = global_test_waitq(index);
+       }
+
+       event64 = 0;
+
+       printf("[WQ]: Waking one thread on waitq [%d] event:0x%llx\n",
+           index, event64);
+       kr = waitq_wakeup64_one(waitq, (event64_t)event64, THREAD_AWAKENED,
+           WAITQ_ALL_PRIORITIES);
+       printf("[WQ]: \tkr=%d\n", kr);
+
+       return SYSCTL_OUT(req, &kr, sizeof(kr));
 }
+SYSCTL_PROC(_kern, OID_AUTO, waitq_wakeup_one, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_waitq_wakeup_one, "Q", "wakeup one thread waiting on given event");
 
 
-/*
- * modwatch system call. user passes in event to modify.
- * if we find it we reset the event bits and que/deque event
- * it needed.
- */
-int
-modwatch(proc_t p, struct modwatch_args *uap, __unused int *retval)
+static int sysctl_waitq_wakeup_all SYSCTL_HANDLER_ARGS
 {
-       struct eventreq64 er;
-       struct eventreq64 *erp = &er;
-       struct eventqelt *evq = NULL;   /* protected by error return */
+#pragma unused(oidp, arg1, arg2)
        int error;
-       struct fileproc *fp;
-       int flag;
+       int index;
+       struct waitq *waitq;
+       kern_return_t kr;
+       int64_t event64 = 0;
 
-       KERNEL_DEBUG(DBG_MISC_MOD|DBG_FUNC_START, 0,0,0,0,0);
+       error = SYSCTL_IN(req, &event64, sizeof(event64));
+       if (error) {
+               return error;
+       }
 
-       /*
-        * get user's request pkt
-        * just need the er_type and er_handle which sit above the
-        * problematic er_data (32/64 issue)... so only copy in
-        * those 2 fields
-        */
-       if ((error = copyin(uap->u_req, (caddr_t)erp, sizeof(er.er_type) + sizeof(er.er_handle)))) {
-               KERNEL_DEBUG(DBG_MISC_MOD|DBG_FUNC_END, error,0,0,0,0);
-               return(error);
+       if (!req->newptr) {
+               return SYSCTL_OUT(req, &event64, sizeof(event64));
        }
-       proc_fdlock(p);
 
-       if (erp->er_type != EV_FD) {
-               error = EINVAL;
-       } else if ((error = fp_lookup(p, erp->er_handle, &fp, 1)) != 0) {
-               error = EBADF;
-#if SOCKETS
-       } else if (fp->f_type == DTYPE_SOCKET) {
-               socket_lock((struct socket *)fp->f_data, 1);
-               evq = ((struct socket *)fp->f_data)->so_evlist.tqh_first;
-#endif /* SOCKETS */
-       } else if (fp->f_type == DTYPE_PIPE) {
-               PIPE_LOCK((struct pipe *)fp->f_data);
-               evq = ((struct pipe *)fp->f_data)->pipe_evlist.tqh_first;
+       if (event64 < 0) {
+               index = (int)((-event64) & 0xffffffff);
+               waitq = wqset_waitq(sysctl_get_wqset(index));
+               index = -index;
        } else {
-               fp_drop(p, erp->er_handle, fp, 1);
-               error = EINVAL;
+               index = (int)event64;
+               waitq = global_test_waitq(index);
        }
 
+       event64 = 0;
+
+       printf("[WQ]: Waking all threads on waitq [%d] event:0x%llx\n",
+           index, event64);
+       kr = waitq_wakeup64_all(waitq, (event64_t)event64,
+           THREAD_AWAKENED, WAITQ_ALL_PRIORITIES);
+       printf("[WQ]: \tkr=%d\n", kr);
+
+       return SYSCTL_OUT(req, &kr, sizeof(kr));
+}
+SYSCTL_PROC(_kern, OID_AUTO, waitq_wakeup_all, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_waitq_wakeup_all, "Q", "wakeup all threads waiting on given event");
+
+
+static int sysctl_waitq_wait SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       int error;
+       int index;
+       struct waitq *waitq;
+       kern_return_t kr;
+       int64_t event64 = 0;
+
+       error = SYSCTL_IN(req, &event64, sizeof(event64));
        if (error) {
-               proc_fdunlock(p);
-               KERNEL_DEBUG(DBG_MISC_MOD|DBG_FUNC_END, error,0,0,0,0);
-               return(error);
+               return error;
        }
 
-       if ((uap->u_eventmask == EV_RM) && (fp->f_flags & FP_WAITEVENT)) {
-               fp->f_flags &= ~FP_WAITEVENT;
+       if (!req->newptr) {
+               return SYSCTL_OUT(req, &event64, sizeof(event64));
        }
-       proc_fdunlock(p);
 
-       // locate event if possible
-       for ( ; evq != NULL; evq = evq->ee_slist.tqe_next) {
-               if (evq->ee_proc == p)
-                       break;
+       if (event64 < 0) {
+               index = (int)((-event64) & 0xffffffff);
+               waitq = wqset_waitq(sysctl_get_wqset(index));
+               index = -index;
+       } else {
+               index = (int)event64;
+               waitq = global_test_waitq(index);
        }
-       if (evq == NULL) {
-#if SOCKETS
-               if (fp->f_type == DTYPE_SOCKET) 
-                       socket_unlock((struct socket *)fp->f_data, 1);
-               else
-#endif /* SOCKETS */
-                       PIPE_UNLOCK((struct pipe *)fp->f_data);
-               fp_drop(p, erp->er_handle, fp, 0);
-               KERNEL_DEBUG(DBG_MISC_MOD|DBG_FUNC_END, EINVAL,0,0,0,0);
-               return(EINVAL);
+
+       event64 = 0;
+
+       printf("[WQ]: Current thread waiting on waitq [%d] event:0x%llx\n",
+           index, event64);
+       kr = waitq_assert_wait64(waitq, (event64_t)event64, THREAD_INTERRUPTIBLE, 0);
+       if (kr == THREAD_WAITING) {
+               thread_block(THREAD_CONTINUE_NULL);
        }
-       KERNEL_DEBUG(DBG_MISC_MOD, erp->er_handle,uap->u_eventmask,(uint32_t)evq,0,0);
+       printf("[WQ]: \tWoke Up: kr=%d\n", kr);
 
-       if (uap->u_eventmask == EV_RM) {
-               EVPROCDEQUE(p, evq);
+       return SYSCTL_OUT(req, &kr, sizeof(kr));
+}
+SYSCTL_PROC(_kern, OID_AUTO, waitq_wait, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_waitq_wait, "Q", "start waiting on given event");
 
-#if SOCKETS
-               if (fp->f_type == DTYPE_SOCKET) {
-                       TAILQ_REMOVE(&((struct socket *)fp->f_data)->so_evlist, evq, ee_slist);
-                       socket_unlock((struct socket *)fp->f_data, 1);
-               } else
-#endif /* SOCKETS */
-               {
-                       TAILQ_REMOVE(&((struct pipe *)fp->f_data)->pipe_evlist, evq, ee_slist);
-                       PIPE_UNLOCK((struct pipe *)fp->f_data);
-               }
-               fp_drop(p, erp->er_handle, fp, 0);
-               FREE(evq, M_TEMP);
-               KERNEL_DEBUG(DBG_MISC_MOD|DBG_FUNC_END, 0,0,0,0,0);
-               return(0);
-       }
-       switch (uap->u_eventmask & EV_MASK) {
-       case 0:
-               flag = 0;
-               break;
 
-       case EV_RE:
-       case EV_WR:
-       case EV_RE|EV_WR:
-               flag = EV_RWBYTES;
-               break;
+static int sysctl_wqset_select SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       int error;
+       struct waitq_set *wqset;
+       uint64_t event64 = 0;
 
-       case EV_EX:
-               flag = EV_OOB;
-               break;
+       error = SYSCTL_IN(req, &event64, sizeof(event64));
+       if (error) {
+               return error;
+       }
 
-       case EV_EX|EV_RE:
-       case EV_EX|EV_WR:
-       case EV_EX|EV_RE|EV_WR:
-               flag = EV_OOB|EV_RWBYTES;
-               break;
+       if (!req->newptr) {
+               goto out;
+       }
 
-       default:
-#if SOCKETS
-               if (fp->f_type == DTYPE_SOCKET) 
-                       socket_unlock((struct socket *)fp->f_data, 1);
-               else 
-#endif /* SOCKETS */
-                       PIPE_UNLOCK((struct pipe *)fp->f_data);
-               fp_drop(p, erp->er_handle, fp, 0);
-               KERNEL_DEBUG(DBG_MISC_WATCH|DBG_FUNC_END, EINVAL,0,0,0,0);
-               return(EINVAL);
+       wqset = sysctl_get_wqset((int)(event64 & 0xffffffff));
+       g_waitq_set = wqset;
+
+       event64 = wqset_id(wqset);
+       printf("[WQ]: selected wqset 0x%llx\n", event64);
+
+out:
+       if (g_waitq_set) {
+               event64 = wqset_id(g_waitq_set);
+       } else {
+               event64 = (uint64_t)(-1);
        }
-       /*
-        * since we're holding the socket/pipe lock, the event
-        * cannot go from the unqueued state to the queued state
-        * however, it can go from the queued state to the unqueued state
-        * since that direction is protected by the proc_lock...
-        * so do a quick check for EV_QUEUED w/o holding the proc lock
-        * since by far the common case will be NOT EV_QUEUED, this saves
-        * us taking the proc_lock the majority of the time
-        */
-       if (evq->ee_flags & EV_QUEUED) {
-               /*
-                * EVPROCDEQUE will recheck the state after it grabs the proc_lock
-                */
-               EVPROCDEQUE(p, evq);
+
+       return SYSCTL_OUT(req, &event64, sizeof(event64));
+}
+SYSCTL_PROC(_kern, OID_AUTO, wqset_select, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_wqset_select, "Q", "select/create a global waitq set");
+
+
+static int sysctl_waitq_link SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       int error;
+       int index;
+       struct waitq *waitq;
+       struct waitq_set *wqset;
+       kern_return_t kr;
+       uint64_t reserved_link = 0;
+       int64_t event64 = 0;
+
+       error = SYSCTL_IN(req, &event64, sizeof(event64));
+       if (error) {
+               return error;
        }
-       /*
-        * while the event is off the proc queue and
-        * we're holding the socket/pipe lock
-        * it's safe to update these fields...
-        */
-       evq->ee_req.er_eventbits = 0;
-       evq->ee_eventmask = uap->u_eventmask & EV_MASK;
 
-#if SOCKETS
-       if (fp->f_type == DTYPE_SOCKET) {
-               postevent((struct socket *)fp->f_data, 0, flag);
-               socket_unlock((struct socket *)fp->f_data, 1);
-       } else
-#endif /* SOCKETS */
-       {
-               postpipeevent((struct pipe *)fp->f_data, flag);
-               PIPE_UNLOCK((struct pipe *)fp->f_data);
+       if (!req->newptr) {
+               return SYSCTL_OUT(req, &event64, sizeof(event64));
+       }
+
+       if (!g_waitq_set) {
+               g_waitq_set = sysctl_get_wqset(1);
+       }
+       wqset = g_waitq_set;
+
+       if (event64 < 0) {
+               struct waitq_set *tmp;
+               index = (int)((-event64) & 0xffffffff);
+               tmp = sysctl_get_wqset(index);
+               if (tmp == wqset) {
+                       goto out;
+               }
+               waitq = wqset_waitq(tmp);
+               index = -index;
+       } else {
+               index = (int)event64;
+               waitq = global_test_waitq(index);
        }
-       fp_drop(p, erp->er_handle, fp, 0);
-       KERNEL_DEBUG(DBG_MISC_MOD|DBG_FUNC_END, evq->ee_req.er_handle,evq->ee_eventmask,(uint32_t)fp->f_data,flag,0);
-       return(0);
+
+       printf("[WQ]: linking waitq [%d] to global wqset (0x%llx)\n",
+           index, wqset_id(wqset));
+       reserved_link = waitq_link_reserve(waitq);
+       kr = waitq_link(waitq, wqset, WAITQ_SHOULD_LOCK, &reserved_link);
+       waitq_link_release(reserved_link);
+
+       printf("[WQ]: \tkr=%d\n", kr);
+
+out:
+       return SYSCTL_OUT(req, &kr, sizeof(kr));
 }
+SYSCTL_PROC(_kern, OID_AUTO, waitq_link, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_waitq_link, "Q", "link global waitq to test waitq set");
 
-/* this routine is called from the close of fd with proc_fdlock held */
-int
-waitevent_close(struct proc *p, struct fileproc *fp)
+
+static int sysctl_waitq_unlink SYSCTL_HANDLER_ARGS
 {
-       struct eventqelt *evq;
+#pragma unused(oidp, arg1, arg2)
+       int error;
+       int index;
+       struct waitq *waitq;
+       struct waitq_set *wqset;
+       kern_return_t kr;
+       uint64_t event64 = 0;
 
+       error = SYSCTL_IN(req, &event64, sizeof(event64));
+       if (error) {
+               return error;
+       }
 
-       fp->f_flags &= ~FP_WAITEVENT;
+       if (!req->newptr) {
+               return SYSCTL_OUT(req, &event64, sizeof(event64));
+       }
 
-#if SOCKETS
-       if (fp->f_type == DTYPE_SOCKET) {
-               socket_lock((struct socket *)fp->f_data, 1);
-               evq = ((struct socket *)fp->f_data)->so_evlist.tqh_first;
-       } else
-#endif /* SOCKETS */
-       if (fp->f_type == DTYPE_PIPE) {
-               PIPE_LOCK((struct pipe *)fp->f_data);
-               evq = ((struct pipe *)fp->f_data)->pipe_evlist.tqh_first;
+       if (!g_waitq_set) {
+               g_waitq_set = sysctl_get_wqset(1);
        }
-       else {
-               return(EINVAL);
+       wqset = g_waitq_set;
+
+       index = (int)event64;
+       waitq = global_test_waitq(index);
+
+       printf("[WQ]: unlinking waitq [%d] from global wqset (0x%llx)\n",
+           index, wqset_id(wqset));
+
+       kr = waitq_unlink(waitq, wqset);
+       printf("[WQ]: \tkr=%d\n", kr);
+
+       return SYSCTL_OUT(req, &kr, sizeof(kr));
+}
+SYSCTL_PROC(_kern, OID_AUTO, waitq_unlink, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_waitq_unlink, "Q", "unlink global waitq from test waitq set");
+
+
+static int sysctl_waitq_clear_prepost SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       struct waitq *waitq;
+       uint64_t event64 = 0;
+       int error, index;
+
+       error = SYSCTL_IN(req, &event64, sizeof(event64));
+       if (error) {
+               return error;
        }
-       proc_fdunlock(p);
 
+       if (!req->newptr) {
+               return SYSCTL_OUT(req, &event64, sizeof(event64));
+       }
+
+       index = (int)event64;
+       waitq = global_test_waitq(index);
+
+       printf("[WQ]: clearing prepost on waitq [%d]\n", index);
+       waitq_clear_prepost(waitq);
+
+       return SYSCTL_OUT(req, &event64, sizeof(event64));
+}
+SYSCTL_PROC(_kern, OID_AUTO, waitq_clear_prepost, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_waitq_clear_prepost, "Q", "clear prepost on given waitq");
+
+
+static int sysctl_wqset_unlink_all SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       int error;
+       struct waitq_set *wqset;
+       kern_return_t kr;
+       uint64_t event64 = 0;
+
+       error = SYSCTL_IN(req, &event64, sizeof(event64));
+       if (error) {
+               return error;
+       }
 
-       // locate event if possible
-       for ( ; evq != NULL; evq = evq->ee_slist.tqe_next) {
-               if (evq->ee_proc == p)
-                       break;
+       if (!req->newptr) {
+               return SYSCTL_OUT(req, &event64, sizeof(event64));
        }
-       if (evq == NULL) {
-#if SOCKETS
-               if (fp->f_type == DTYPE_SOCKET) 
-                       socket_unlock((struct socket *)fp->f_data, 1);
-               else 
-#endif /* SOCKETS */
-                       PIPE_UNLOCK((struct pipe *)fp->f_data);
 
-               proc_fdlock(p);
+       if (!g_waitq_set) {
+               g_waitq_set = sysctl_get_wqset(1);
+       }
+       wqset = g_waitq_set;
+
+       printf("[WQ]: unlinking all queues from global wqset (0x%llx)\n",
+           wqset_id(wqset));
+
+       kr = waitq_set_unlink_all(wqset);
+       printf("[WQ]: \tkr=%d\n", kr);
+
+       return SYSCTL_OUT(req, &kr, sizeof(kr));
+}
+SYSCTL_PROC(_kern, OID_AUTO, wqset_unlink_all, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_wqset_unlink_all, "Q", "unlink all queues from test waitq set");
 
-               return(EINVAL);
+
+static int sysctl_wqset_clear_preposts SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       struct waitq_set *wqset = NULL;
+       uint64_t event64 = 0;
+       int error, index;
+
+       error = SYSCTL_IN(req, &event64, sizeof(event64));
+       if (error) {
+               return error;
        }
-       EVPROCDEQUE(p, evq);
 
-#if SOCKETS
-       if (fp->f_type == DTYPE_SOCKET) {
-               TAILQ_REMOVE(&((struct socket *)fp->f_data)->so_evlist, evq, ee_slist);
-               socket_unlock((struct socket *)fp->f_data, 1);
-       } else
-#endif /* SOCKETS */
-       {
-               TAILQ_REMOVE(&((struct pipe *)fp->f_data)->pipe_evlist, evq, ee_slist);
-               PIPE_UNLOCK((struct pipe *)fp->f_data);
+       if (!req->newptr) {
+               goto out;
        }
-       FREE(evq, M_TEMP);
 
-       proc_fdlock(p);
+       index = (int)((event64) & 0xffffffff);
+       wqset = sysctl_get_wqset(index);
+       assert(wqset != NULL);
 
-       return(0);
+       printf("[WQ]: clearing preposts on wqset 0x%llx\n", wqset_id(wqset));
+       waitq_set_clear_preposts(wqset);
+
+out:
+       if (wqset) {
+               event64 = wqset_id(wqset);
+       } else {
+               event64 = (uint64_t)(-1);
+       }
+
+       return SYSCTL_OUT(req, &event64, sizeof(event64));
 }
+SYSCTL_PROC(_kern, OID_AUTO, wqset_clear_preposts, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_wqset_clear_preposts, "Q", "clear preposts on given waitq set");
 
+#endif /* CONFIG_WAITQ_DEBUG */
 
-/*
- * gethostuuid
- *
- * Description:        Get the host UUID from IOKit and return it to user space.
- *
- * Parameters: uuid_buf                Pointer to buffer to receive UUID
- *             timeout                 Timespec for timout
- *             spi                             SPI, skip sandbox check (temporary)
- *
- * Returns:    0                       Success
- *             EWOULDBLOCK             Timeout is too short
- *             copyout:EFAULT          Bad user buffer
- *
- * Notes:      A timeout seems redundant, since if it's tolerable to not
- *             have a system UUID in hand, then why ask for one?
- */
-int
-gethostuuid(struct proc *p, struct gethostuuid_args *uap, __unused int32_t *retval)
+static int
+sysctl_waitq_set_nelem SYSCTL_HANDLER_ARGS
 {
-       kern_return_t kret;
+#pragma unused(oidp, arg1, arg2)
+       int nelem;
+
+       /* Read only  */
+       if (req->newptr != USER_ADDR_NULL) {
+               return EPERM;
+       }
+
+       nelem = sysctl_helper_waitq_set_nelem();
+
+       return SYSCTL_OUT(req, &nelem, sizeof(nelem));
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, n_ltable_entries, CTLFLAG_RD | CTLFLAG_LOCKED,
+    0, 0, sysctl_waitq_set_nelem, "I", "ltable elementis currently used");
+
+
+static int
+sysctl_mpsc_test_pingpong SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       uint64_t value = 0;
        int error;
-       mach_timespec_t mach_ts;        /* for IOKit call */
-       __darwin_uuid_t uuid_kern;      /* for IOKit call */
 
-       if (!uap->spi) {
-#if 13841988
-               uint32_t flags;
-               if (temp_debug_13841988 && (0 == proc_get_darwinbgstate(p->task, &flags)) && (flags & PROC_FLAG_IOS_APPLICATION)) {
-                       printf("Unauthorized access to gethostuuid() by %s(%d)\n", p->p_comm, proc_pid(p));
-                       return (EPERM);
+       error = SYSCTL_IN(req, &value, sizeof(value));
+       if (error) {
+               return error;
+       }
+
+       if (error == 0 && req->newptr) {
+               error = mpsc_test_pingpong(value, &value);
+               if (error == 0) {
+                       error = SYSCTL_OUT(req, &value, sizeof(value));
                }
-#else
-               /* Perform sandbox check */
-#endif
        }
 
-       /* Convert the 32/64 bit timespec into a mach_timespec_t */
-       if ( proc_is64bit(p) ) {
-               struct user64_timespec ts;
-               error = copyin(uap->timeoutp, &ts, sizeof(ts));
-               if (error)
-                       return (error);
-               mach_ts.tv_sec = ts.tv_sec;
-               mach_ts.tv_nsec = ts.tv_nsec;
-       } else {
-               struct user32_timespec ts;
-               error = copyin(uap->timeoutp, &ts, sizeof(ts) );
-               if (error)
-                       return (error);
-               mach_ts.tv_sec = ts.tv_sec;
-               mach_ts.tv_nsec = ts.tv_nsec;
+       return error;
+}
+SYSCTL_PROC(_kern, OID_AUTO, mpsc_test_pingpong, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_mpsc_test_pingpong, "Q", "MPSC tests: pingpong");
+
+#endif /* DEVELOPMENT || DEBUG */
+
+/*Remote Time api*/
+SYSCTL_NODE(_machdep, OID_AUTO, remotetime, CTLFLAG_RD | CTLFLAG_LOCKED, 0, "Remote time api");
+
+#if DEVELOPMENT || DEBUG
+#if CONFIG_MACH_BRIDGE_SEND_TIME
+extern _Atomic uint32_t bt_init_flag;
+extern uint32_t mach_bridge_timer_enable(uint32_t, int);
+
+SYSCTL_INT(_machdep_remotetime, OID_AUTO, bridge_timer_init_flag,
+    CTLFLAG_RD | CTLFLAG_LOCKED, &bt_init_flag, 0, "");
+
+static int sysctl_mach_bridge_timer_enable SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       uint32_t value = 0;
+       int error = 0;
+       /* User is querying buffer size */
+       if (req->oldptr == USER_ADDR_NULL && req->newptr == USER_ADDR_NULL) {
+               req->oldidx = sizeof(value);
+               return 0;
+       }
+       if (os_atomic_load(&bt_init_flag, acquire)) {
+               if (req->newptr) {
+                       int new_value = 0;
+                       error = SYSCTL_IN(req, &new_value, sizeof(new_value));
+                       if (error) {
+                               return error;
+                       }
+                       if (new_value == 0 || new_value == 1) {
+                               value = mach_bridge_timer_enable(new_value, 1);
+                       } else {
+                               return EPERM;
+                       }
+               } else {
+                       value = mach_bridge_timer_enable(0, 0);
+               }
        }
+       error = SYSCTL_OUT(req, &value, sizeof(value));
+       return error;
+}
 
-       /* Call IOKit with the stack buffer to get the UUID */
-       kret = IOBSDGetPlatformUUID(uuid_kern, mach_ts);
+SYSCTL_PROC(_machdep_remotetime, OID_AUTO, bridge_timer_enable,
+    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_mach_bridge_timer_enable, "I", "");
+
+#endif /* CONFIG_MACH_BRIDGE_SEND_TIME */
+
+static int sysctl_mach_bridge_remote_time SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       uint64_t ltime = 0, rtime = 0;
+       if (req->oldptr == USER_ADDR_NULL) {
+               req->oldidx = sizeof(rtime);
+               return 0;
+       }
+       if (req->newptr) {
+               int error = SYSCTL_IN(req, &ltime, sizeof(ltime));
+               if (error) {
+                       return error;
+               }
+       }
+       rtime = mach_bridge_remote_time(ltime);
+       return SYSCTL_OUT(req, &rtime, sizeof(rtime));
+}
+SYSCTL_PROC(_machdep_remotetime, OID_AUTO, mach_bridge_remote_time,
+    CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_mach_bridge_remote_time, "Q", "");
+
+#endif /* DEVELOPMENT || DEBUG */
+
+#if CONFIG_MACH_BRIDGE_RECV_TIME
+extern struct bt_params bt_params_get_latest(void);
+
+static int sysctl_mach_bridge_conversion_params SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       struct bt_params params = {};
+       if (req->oldptr == USER_ADDR_NULL) {
+               req->oldidx = sizeof(struct bt_params);
+               return 0;
+       }
+       if (req->newptr) {
+               return EPERM;
+       }
+       params = bt_params_get_latest();
+       return SYSCTL_OUT(req, &params, MIN(sizeof(params), req->oldlen));
+}
+
+SYSCTL_PROC(_machdep_remotetime, OID_AUTO, conversion_params,
+    CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED, 0,
+    0, sysctl_mach_bridge_conversion_params, "S,bt_params", "");
+
+#endif /* CONFIG_MACH_BRIDGE_RECV_TIME */
+
+#if DEVELOPMENT || DEBUG
+
+#include <pexpert/pexpert.h>
+extern int32_t sysctl_get_bound_cpuid(void);
+extern kern_return_t sysctl_thread_bind_cpuid(int32_t cpuid);
+static int
+sysctl_kern_sched_thread_bind_cpu SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
 
        /*
-        * If we get it, copy out the data to the user buffer; note that a
-        * uuid_t is an array of characters, so this is size invariant for
-        * 32 vs. 64 bit.
+        * DO NOT remove this bootarg guard or make this non-development.
+        * This kind of binding should only be used for tests and
+        * experiments in a custom configuration, never shipping code.
         */
-       if (kret == KERN_SUCCESS) {
-               error = copyout(uuid_kern, uap->uuid_buf, sizeof(uuid_kern));
-       } else {
-               error = EWOULDBLOCK;
+
+       if (!PE_parse_boot_argn("enable_skstb", NULL, 0)) {
+               return ENOENT;
+       }
+
+       int32_t cpuid = sysctl_get_bound_cpuid();
+
+       int32_t new_value;
+       int changed;
+       int error = sysctl_io_number(req, cpuid, sizeof cpuid, &new_value, &changed);
+       if (error) {
+               return error;
+       }
+
+       if (changed) {
+               kern_return_t kr = sysctl_thread_bind_cpuid(new_value);
+
+               if (kr == KERN_NOT_SUPPORTED) {
+                       return ENOTSUP;
+               }
+
+               if (kr == KERN_INVALID_VALUE) {
+                       return ERANGE;
+               }
+       }
+
+       return error;
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, sched_thread_bind_cpu, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_kern_sched_thread_bind_cpu, "I", "");
+
+#if __AMP__
+extern char sysctl_get_bound_cluster_type(void);
+extern void sysctl_thread_bind_cluster_type(char cluster_type);
+static int
+sysctl_kern_sched_thread_bind_cluster_type SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       char buff[4];
+
+       if (!PE_parse_boot_argn("enable_skstb", NULL, 0)) {
+               return ENOENT;
+       }
+
+       int error = SYSCTL_IN(req, buff, 1);
+       if (error) {
+               return error;
+       }
+       char cluster_type = buff[0];
+
+       if (!req->newptr) {
+               goto out;
+       }
+
+       sysctl_thread_bind_cluster_type(cluster_type);
+out:
+       cluster_type = sysctl_get_bound_cluster_type();
+       buff[0] = cluster_type;
+
+       return SYSCTL_OUT(req, buff, 1);
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, sched_thread_bind_cluster_type, CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_kern_sched_thread_bind_cluster_type, "A", "");
+
+extern char sysctl_get_task_cluster_type(void);
+extern void sysctl_task_set_cluster_type(char cluster_type);
+static int
+sysctl_kern_sched_task_set_cluster_type SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       char buff[4];
+
+       if (!PE_parse_boot_argn("enable_skstsct", NULL, 0)) {
+               return ENOENT;
+       }
+
+       int error = SYSCTL_IN(req, buff, 1);
+       if (error) {
+               return error;
+       }
+       char cluster_type = buff[0];
+
+       if (!req->newptr) {
+               goto out;
        }
 
-       return (error);
+       sysctl_task_set_cluster_type(cluster_type);
+out:
+       cluster_type = sysctl_get_task_cluster_type();
+       buff[0] = cluster_type;
+
+       return SYSCTL_OUT(req, buff, 1);
 }
 
+SYSCTL_PROC(_kern, OID_AUTO, sched_task_set_cluster_type, CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_kern_sched_task_set_cluster_type, "A", "");
+
+#if CONFIG_SCHED_EDGE
+
 /*
- * ledger
+ * Edge Scheduler Sysctls
  *
- * Description:        Omnibus system call for ledger operations
+ * The Edge scheduler uses edge configurations to decide feasability of
+ * migrating threads across clusters. The sysctls allow dynamic configuration
+ * of the edge properties and edge weights. This configuration is typically
+ * updated via callouts from CLPC.
+ *
+ * <Edge Multi-cluster Support Needed>
  */
-int
-ledger(struct proc *p, struct ledger_args *args, __unused int32_t *retval)
+extern sched_clutch_edge sched_edge_config_e_to_p;
+extern sched_clutch_edge sched_edge_config_p_to_e;
+extern kern_return_t sched_edge_sysctl_configure_e_to_p(uint64_t);
+extern kern_return_t sched_edge_sysctl_configure_p_to_e(uint64_t);
+extern sched_clutch_edge sched_edge_e_to_p(void);
+extern sched_clutch_edge sched_edge_p_to_e(void);
+
+static int sysctl_sched_edge_config_e_to_p SYSCTL_HANDLER_ARGS
 {
-#if !CONFIG_MACF
-#pragma unused(p)
-#endif
-       int rval, pid, len, error;
-#ifdef LEDGER_DEBUG
-       struct ledger_limit_args lla;
-#endif
-       task_t task;
-       proc_t proc;
+#pragma unused(oidp, arg1, arg2)
+       int error;
+       kern_return_t kr;
+       int64_t edge_config = 0;
 
-       /* Finish copying in the necessary args before taking the proc lock */
-       error = 0;
-       len = 0;
-       if (args->cmd == LEDGER_ENTRY_INFO)
-               error = copyin(args->arg3, (char *)&len, sizeof (len));
-       else if (args->cmd == LEDGER_TEMPLATE_INFO)
-               error = copyin(args->arg2, (char *)&len, sizeof (len));
-#ifdef LEDGER_DEBUG
-       else if (args->cmd == LEDGER_LIMIT)
-               error = copyin(args->arg2, (char *)&lla, sizeof (lla));
-#endif
-       if (error)
-               return (error);
-       if (len < 0)
-               return (EINVAL);
+       error = SYSCTL_IN(req, &edge_config, sizeof(edge_config));
+       if (error) {
+               return error;
+       }
 
-       rval = 0;
-       if (args->cmd != LEDGER_TEMPLATE_INFO) {
-               pid = args->arg1;
-               proc = proc_find(pid);
-               if (proc == NULL)
-                       return (ESRCH);
+       if (!req->newptr) {
+               edge_config = sched_edge_e_to_p().sce_edge_packed;
+               return SYSCTL_OUT(req, &edge_config, sizeof(edge_config));
+       }
 
-#if CONFIG_MACF
-               error = mac_proc_check_ledger(p, proc, args->cmd);
-               if (error) {
-                       proc_rele(proc);
-                       return (error);
-               }
-#endif
+       kr = sched_edge_sysctl_configure_e_to_p(edge_config);
+       return SYSCTL_OUT(req, &kr, sizeof(kr));
+}
+SYSCTL_PROC(_kern, OID_AUTO, sched_edge_config_e_to_p, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_sched_edge_config_e_to_p, "Q", "Edge Scheduler Config for E-to-P cluster");
 
-               task = proc->task;
+static int sysctl_sched_edge_config_p_to_e SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       int error;
+       kern_return_t kr;
+       int64_t edge_config = 0;
+
+       error = SYSCTL_IN(req, &edge_config, sizeof(edge_config));
+       if (error) {
+               return error;
        }
-               
-       switch (args->cmd) {
-#ifdef LEDGER_DEBUG
-               case LEDGER_LIMIT: {
-                       if (!kauth_cred_issuser(kauth_cred_get()))
-                               rval = EPERM;
-                       rval = ledger_limit(task, &lla);
-                       proc_rele(proc);
-                       break;
-               }
-#endif
-               case LEDGER_INFO: {
-                       struct ledger_info info;
 
-                       rval = ledger_info(task, &info);
-                       proc_rele(proc);
-                       if (rval == 0)
-                               rval = copyout(&info, args->arg2,
-                                   sizeof (info));
-                       break;
-               }
+       if (!req->newptr) {
+               edge_config = sched_edge_p_to_e().sce_edge_packed;
+               return SYSCTL_OUT(req, &edge_config, sizeof(edge_config));
+       }
 
-               case LEDGER_ENTRY_INFO: {
-                       void *buf;
-                       int sz;
+       kr = sched_edge_sysctl_configure_p_to_e(edge_config);
+       return SYSCTL_OUT(req, &kr, sizeof(kr));
+}
+SYSCTL_PROC(_kern, OID_AUTO, sched_edge_config_p_to_e, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_sched_edge_config_p_to_e, "Q", "Edge Scheduler Config for P-to-E cluster");
+
+extern int sched_edge_restrict_ut;
+SYSCTL_INT(_kern, OID_AUTO, sched_edge_restrict_ut, CTLFLAG_RW | CTLFLAG_LOCKED, &sched_edge_restrict_ut, 0, "Edge Scheduler Restrict UT Threads");
+extern int sched_edge_restrict_bg;
+SYSCTL_INT(_kern, OID_AUTO, sched_edge_restrict_bg, CTLFLAG_RW | CTLFLAG_LOCKED, &sched_edge_restrict_ut, 0, "Edge Scheduler Restrict BG Threads");
+extern int sched_edge_migrate_ipi_immediate;
+SYSCTL_INT(_kern, OID_AUTO, sched_edge_migrate_ipi_immediate, CTLFLAG_RW | CTLFLAG_LOCKED, &sched_edge_migrate_ipi_immediate, 0, "Edge Scheduler uses immediate IPIs for migration event based on execution latency");
+
+#endif /* CONFIG_SCHED_EDGE */
+
+#endif /* __AMP__ */
+
+/* used for testing by exception_tests */
+extern uint32_t ipc_control_port_options;
+SYSCTL_INT(_kern, OID_AUTO, ipc_control_port_options,
+    CTLFLAG_RD | CTLFLAG_LOCKED, &ipc_control_port_options, 0, "");
+
+#endif /* DEVELOPMENT || DEBUG */
+
+extern uint32_t task_exc_guard_default;
+
+SYSCTL_INT(_kern, OID_AUTO, task_exc_guard_default,
+    CTLFLAG_RD | CTLFLAG_LOCKED, &task_exc_guard_default, 0, "");
 
-                       rval = ledger_get_task_entry_info_multiple(task, &buf, &len);
-                       proc_rele(proc);
-                       if ((rval == 0) && (len > 0)) {
-                               sz = len * sizeof (struct ledger_entry_info);
-                               rval = copyout(buf, args->arg2, sz);
-                               kfree(buf, sz);
-                       }
-                       if (rval == 0)
-                               rval = copyout(&len, args->arg3, sizeof (len));
-                       break;
-               }
 
-               case LEDGER_TEMPLATE_INFO: {
-                       void *buf;
-                       int sz;
+static int
+sysctl_kern_tcsm_available SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       uint32_t value = machine_csv(CPUVN_CI) ? 1 : 0;
+
+       if (req->newptr) {
+               return EINVAL;
+       }
+
+       return SYSCTL_OUT(req, &value, sizeof(value));
+}
+SYSCTL_PROC(_kern, OID_AUTO, tcsm_available,
+    CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_LOCKED | CTLFLAG_MASKED | CTLFLAG_ANYBODY,
+    0, 0, sysctl_kern_tcsm_available, "I", "");
+
+
+static int
+sysctl_kern_tcsm_enable SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       uint32_t soflags = 0;
+       uint32_t old_value = thread_get_no_smt() ? 1 : 0;
+
+       int error = SYSCTL_IN(req, &soflags, sizeof(soflags));
+       if (error) {
+               return error;
+       }
+
+       if (soflags && machine_csv(CPUVN_CI)) {
+               thread_set_no_smt(true);
+               machine_tecs(current_thread());
+       }
+
+       return SYSCTL_OUT(req, &old_value, sizeof(old_value));
+}
+SYSCTL_PROC(_kern, OID_AUTO, tcsm_enable,
+    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED | CTLFLAG_ANYBODY,
+    0, 0, sysctl_kern_tcsm_enable, "I", "");
+
+
+#if DEVELOPMENT || DEBUG
+extern void sysctl_task_set_no_smt(char no_smt);
+extern char sysctl_task_get_no_smt(void);
+
+static int
+sysctl_kern_sched_task_set_no_smt SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       char buff[4];
 
-                       rval = ledger_template_info(&buf, &len);
-                       if ((rval == 0) && (len > 0)) {
-                               sz = len * sizeof (struct ledger_template_info);
-                               rval = copyout(buf, args->arg1, sz);
-                               kfree(buf, sz);
+       int error = SYSCTL_IN(req, buff, 1);
+       if (error) {
+               return error;
+       }
+       char no_smt = buff[0];
+
+       if (!req->newptr) {
+               goto out;
+       }
+
+       sysctl_task_set_no_smt(no_smt);
+out:
+       no_smt = sysctl_task_get_no_smt();
+       buff[0] = no_smt;
+
+       return SYSCTL_OUT(req, buff, 1);
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, sched_task_set_no_smt, CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_ANYBODY,
+    0, 0, sysctl_kern_sched_task_set_no_smt, "A", "");
+
+static int
+sysctl_kern_sched_thread_set_no_smt(__unused struct sysctl_oid *oidp, __unused void *arg1, __unused int arg2, struct sysctl_req *req)
+{
+       int new_value, changed;
+       int old_value = thread_get_no_smt() ? 1 : 0;
+       int error = sysctl_io_number(req, old_value, sizeof(int), &new_value, &changed);
+
+       if (changed) {
+               thread_set_no_smt(!!new_value);
+       }
+
+       return error;
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, sched_thread_set_no_smt,
+    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_ANYBODY,
+    0, 0, sysctl_kern_sched_thread_set_no_smt, "I", "");
+
+static int
+sysctl_kern_debug_get_preoslog SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       static bool oneshot_executed = false;
+       size_t preoslog_size = 0;
+       const char *preoslog = NULL;
+
+       // DumpPanic pases a non-zero write value when it needs oneshot behaviour
+       if (req->newptr) {
+               uint8_t oneshot = 0;
+               int error = SYSCTL_IN(req, &oneshot, sizeof(oneshot));
+               if (error) {
+                       return error;
+               }
+
+               if (oneshot) {
+                       if (!OSCompareAndSwap8(false, true, &oneshot_executed)) {
+                               return EPERM;
                        }
-                       if (rval == 0)
-                               rval = copyout(&len, args->arg2, sizeof (len));
-                       break;
                }
+       }
+
+       preoslog = sysctl_debug_get_preoslog(&preoslog_size);
+       if (preoslog == NULL || preoslog_size == 0) {
+               return 0;
+       }
 
-               default:
-                       rval = EINVAL;
+       if (req->oldptr == USER_ADDR_NULL) {
+               req->oldidx = preoslog_size;
+               return 0;
        }
 
-       return (rval);
+       return SYSCTL_OUT(req, preoslog, preoslog_size);
 }
 
-#if CONFIG_TELEMETRY
-int
-telemetry(__unused struct proc *p, struct telemetry_args *args, __unused int32_t *retval)
+SYSCTL_PROC(_kern, OID_AUTO, preoslog, CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_kern_debug_get_preoslog, "-", "");
+
+static int
+sysctl_kern_task_set_filter_msg_flag SYSCTL_HANDLER_ARGS
 {
-       int error = 0;
+#pragma unused(oidp, arg1, arg2)
+       int new_value, changed;
+       int old_value = task_get_filter_msg_flag(current_task()) ? 1 : 0;
+       int error = sysctl_io_number(req, old_value, sizeof(int), &new_value, &changed);
 
-       switch (args->cmd) {
-       case TELEMETRY_CMD_TIMER_EVENT:
-               error = telemetry_timer_event(args->deadline, args->interval, args->leeway);
-               break;
-       default:
-               error = EINVAL;
-               break;
+       if (changed) {
+               task_set_filter_msg_flag(current_task(), !!new_value);
        }
 
-       return (error);
+       return error;
 }
-#endif /* CONFIG_TELEMETRY */
+
+SYSCTL_PROC(_kern, OID_AUTO, task_set_filter_msg_flag, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+    0, 0, sysctl_kern_task_set_filter_msg_flag, "I", "");
+
+#endif /* DEVELOPMENT || DEBUG */