]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/kern/sys_pipe.c
xnu-4903.270.47.tar.gz
[apple/xnu.git] / bsd / kern / sys_pipe.c
index 374d82381f46dc38b56986ac68bf6a043e894dec..cf0e5f2b02a26d55ee9abd05e69141c7dacbc287 100644 (file)
@@ -20,7 +20,7 @@
  * Copyright (c) 2003-2014 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,
@@ -40,7 +40,7 @@
  * 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@
  */
 /*
  * do.
  *
  * Pipes are implemented as circular buffers. Following are the valid states in pipes operations
- *  
+ *
  *      _________________________________
  * 1.  |_________________________________| r=w, c=0
- * 
+ *
  *      _________________________________
  * 2.  |__r:::::wc_______________________| r <= w , c > 0
  *
  *  a-z define the steps in a program flow
  *  1-4 are the states as defined aboe
  *  Action: is what file operation is done on the pipe
- *  
+ *
  *  Current:None  Action: initialize with size M=200
  *  a. State 1 ( r=0, w=0, c=0)
- *  
+ *
  *  Current: a    Action: write(100) (w < M)
  *  b. State 2 (r=0, w=100, c=100)
- *  
+ *
  *  Current: b    Action: write(100) (w = M-w)
  *  c. State 4 (r=0,w=0,c=200)
- *  
+ *
  *  Current: b    Action: read(70)  ( r < c )
  *  d. State 2(r=70,w=100,c=30)
- *  
+ *
  *  Current: d   Action: write(75) ( w < (m-w))
  *  e. State 2 (r=70,w=175,c=105)
- *  
+ *
  *  Current: d    Action: write(110) ( w > (m-w))
  *  f. State 3 (r=70,w=10,c=140)
- *  
+ *
  *  Current: d   Action: read(30) (r >= c )
  *  g. State 1 (r=100,w=100,c=0)
- *  
+ *
  */
 
 /*
  * dynamically change to larger sizes based on usage. The buffer size is never
  * reduced. The total amount of kernel memory used is governed by maxpipekva.
  * In case of dynamic expansion limit is reached, the output thread is blocked
- * until the pipe buffer empties enough to continue. 
+ * until the pipe buffer empties enough to continue.
  *
  * In order to limit the resource use of pipes, two sysctls exist:
  *
  * kern.ipc.maxpipekva - This is a hard limit on the amount of pageable
- * address space available to us in pipe_map. 
+ * address space available to us in pipe_map.
  *
  * Memory usage may be monitored through the sysctls
  * kern.ipc.pipes, kern.ipc.pipekva.
 #include <kern/kalloc.h>
 #include <vm/vm_kern.h>
 #include <libkern/OSAtomic.h>
+#include <libkern/section_keywords.h>
+
+#if CONFIG_MACF
+#include <security/mac_framework.h>
+#endif
 
 #define f_flag f_fglob->fg_flag
 #define f_msgcount f_fglob->fg_msgcount
 #define f_data f_fglob->fg_data
 
 /*
- * interfaces to the outside world exported through file operations 
+ * interfaces to the outside world exported through file operations
  */
 static int pipe_read(struct fileproc *fp, struct uio *uio,
-                int flags, vfs_context_t ctx);
+    int flags, vfs_context_t ctx);
 static int pipe_write(struct fileproc *fp, struct uio *uio,
-                int flags, vfs_context_t ctx);
+    int flags, vfs_context_t ctx);
 static int pipe_close(struct fileglob *fg, vfs_context_t ctx);
 static int pipe_select(struct fileproc *fp, int which, void * wql,
-               vfs_context_t ctx);
+    vfs_context_t ctx);
 static int pipe_kqfilter(struct fileproc *fp, struct knote *kn,
-               vfs_context_t ctx);
+    struct kevent_internal_s *kev, vfs_context_t ctx);
 static int pipe_ioctl(struct fileproc *fp, u_long cmd, caddr_t data,
-               vfs_context_t ctx);
-static int pipe_drain(struct fileproc *fp,vfs_context_t ctx);
+    vfs_context_t ctx);
+static int pipe_drain(struct fileproc *fp, vfs_context_t ctx);
 
 static const struct fileops pipeops = {
-       DTYPE_PIPE,
-       pipe_read,
-       pipe_write,
-       pipe_ioctl,
-       pipe_select,
-       pipe_close,
-       pipe_kqfilter,
-       pipe_drain
+       .fo_type = DTYPE_PIPE,
+       .fo_read = pipe_read,
+       .fo_write = pipe_write,
+       .fo_ioctl = pipe_ioctl,
+       .fo_select = pipe_select,
+       .fo_close = pipe_close,
+       .fo_kqfilter = pipe_kqfilter,
+       .fo_drain = pipe_drain,
 };
 
-static void    filt_pipedetach(struct knote *kn);
-static int     filt_piperead(struct knote *kn, long hint);
-static int     filt_pipewrite(struct knote *kn, long hint);
+static void filt_pipedetach(struct knote *kn);
 
-static struct filterops pipe_rfiltops = {
-        .f_isfd = 1,
-        .f_detach = filt_pipedetach,
-        .f_event = filt_piperead,
+static int filt_piperead(struct knote *kn, long hint);
+static int filt_pipereadtouch(struct knote *kn, struct kevent_internal_s *kev);
+static int filt_pipereadprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev);
+
+static int filt_pipewrite(struct knote *kn, long hint);
+static int filt_pipewritetouch(struct knote *kn, struct kevent_internal_s *kev);
+static int filt_pipewriteprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev);
+
+SECURITY_READ_ONLY_EARLY(struct filterops) pipe_rfiltops = {
+       .f_isfd = 1,
+       .f_detach = filt_pipedetach,
+       .f_event = filt_piperead,
+       .f_touch = filt_pipereadtouch,
+       .f_process = filt_pipereadprocess,
 };
 
-static struct filterops pipe_wfiltops = {
-        .f_isfd = 1,
-        .f_detach = filt_pipedetach,
-        .f_event = filt_pipewrite,
+SECURITY_READ_ONLY_EARLY(struct filterops) pipe_wfiltops = {
+       .f_isfd = 1,
+       .f_detach = filt_pipedetach,
+       .f_event = filt_pipewrite,
+       .f_touch = filt_pipewritetouch,
+       .f_process = filt_pipewriteprocess,
 };
 
 static int nbigpipe;      /* for compatibility sake. no longer used */
@@ -206,18 +221,18 @@ int maxpipekva __attribute__((used)) = PIPE_KVAMAX;  /* allowing 16MB max. */
 #if PIPE_SYSCTLS
 SYSCTL_DECL(_kern_ipc);
 
-SYSCTL_INT(_kern_ipc, OID_AUTO, maxpipekva, CTLFLAG_RD|CTLFLAG_LOCKED,
-          &maxpipekva, 0, "Pipe KVA limit");
-SYSCTL_INT(_kern_ipc, OID_AUTO, maxpipekvawired, CTLFLAG_RW|CTLFLAG_LOCKED,
-          &maxpipekvawired, 0, "Pipe KVA wired limit");
-SYSCTL_INT(_kern_ipc, OID_AUTO, pipes, CTLFLAG_RD|CTLFLAG_LOCKED,
-          &amountpipes, 0, "Current # of pipes");
-SYSCTL_INT(_kern_ipc, OID_AUTO, bigpipes, CTLFLAG_RD|CTLFLAG_LOCKED,
-          &nbigpipe, 0, "Current # of big pipes");
-SYSCTL_INT(_kern_ipc, OID_AUTO, pipekva, CTLFLAG_RD|CTLFLAG_LOCKED,
-          &amountpipekva, 0, "Pipe KVA usage");
-SYSCTL_INT(_kern_ipc, OID_AUTO, pipekvawired, CTLFLAG_RD|CTLFLAG_LOCKED,
-          &amountpipekvawired, 0, "Pipe wired KVA usage");
+SYSCTL_INT(_kern_ipc, OID_AUTO, maxpipekva, CTLFLAG_RD | CTLFLAG_LOCKED,
+    &maxpipekva, 0, "Pipe KVA limit");
+SYSCTL_INT(_kern_ipc, OID_AUTO, maxpipekvawired, CTLFLAG_RW | CTLFLAG_LOCKED,
+    &maxpipekvawired, 0, "Pipe KVA wired limit");
+SYSCTL_INT(_kern_ipc, OID_AUTO, pipes, CTLFLAG_RD | CTLFLAG_LOCKED,
+    &amountpipes, 0, "Current # of pipes");
+SYSCTL_INT(_kern_ipc, OID_AUTO, bigpipes, CTLFLAG_RD | CTLFLAG_LOCKED,
+    &nbigpipe, 0, "Current # of big pipes");
+SYSCTL_INT(_kern_ipc, OID_AUTO, pipekva, CTLFLAG_RD | CTLFLAG_LOCKED,
+    &amountpipekva, 0, "Pipe KVA usage");
+SYSCTL_INT(_kern_ipc, OID_AUTO, pipekvawired, CTLFLAG_RD | CTLFLAG_LOCKED,
+    &amountpipekvawired, 0, "Pipe wired KVA usage");
 #endif
 
 static void pipeclose(struct pipe *cpipe);
@@ -233,21 +248,21 @@ static __inline void pipeio_unlock(struct pipe *cpipe);
 extern int postpipeevent(struct pipe *, int);
 extern void evpipefree(struct pipe *cpipe);
 
-static lck_grp_t       *pipe_mtx_grp;
-static lck_attr_t      *pipe_mtx_attr;
-static lck_grp_attr_t  *pipe_mtx_grp_attr;
+static lck_grp_t        *pipe_mtx_grp;
+static lck_attr_t       *pipe_mtx_attr;
+static lck_grp_attr_t   *pipe_mtx_grp_attr;
 
 static zone_t pipe_zone;
 
-#define MAX_PIPESIZE(pipe)             ( MAX(PIPE_SIZE, (pipe)->pipe_buffer.size) )
+#define MAX_PIPESIZE(pipe)              ( MAX(PIPE_SIZE, (pipe)->pipe_buffer.size) )
 
-#define        PIPE_GARBAGE_AGE_LIMIT          5000    /* In milliseconds */
-#define PIPE_GARBAGE_QUEUE_LIMIT       32000
+#define PIPE_GARBAGE_AGE_LIMIT          5000    /* In milliseconds */
+#define PIPE_GARBAGE_QUEUE_LIMIT        32000
 
 struct pipe_garbage {
-       struct pipe             *pg_pipe;
-       struct pipe_garbage     *pg_next;
-       uint64_t                pg_timestamp;
+       struct pipe             *pg_pipe;
+       struct pipe_garbage     *pg_next;
+       uint64_t                pg_timestamp;
 };
 
 static zone_t pipe_garbage_zone;
@@ -264,11 +279,11 @@ SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_ANY, pipeinit, NULL);
 void
 pipeinit(void)
 {
-       nbigpipe=0;
+       nbigpipe = 0;
        vm_size_t zone_size;
+
        zone_size = 8192 * sizeof(struct pipe);
-        pipe_zone = zinit(sizeof(struct pipe), zone_size, 4096, "pipe zone");
+       pipe_zone = zinit(sizeof(struct pipe), zone_size, 4096, "pipe zone");
 
 
        /* allocate lock group attribute and group for pipe mutexes */
@@ -283,62 +298,69 @@ pipeinit(void)
         */
        zone_size = (PIPE_GARBAGE_QUEUE_LIMIT + 20) *
            sizeof(struct pipe_garbage);
-        pipe_garbage_zone = (zone_t)zinit(sizeof(struct pipe_garbage),
+       pipe_garbage_zone = (zone_t)zinit(sizeof(struct pipe_garbage),
            zone_size, 4096, "pipe garbage zone");
        pipe_garbage_lock = lck_mtx_alloc_init(pipe_mtx_grp, pipe_mtx_attr);
-       
 }
 
+#ifndef CONFIG_EMBEDDED
 /* Bitmap for things to touch in pipe_touch() */
-#define        PIPE_ATIME      0x00000001      /* time of last access */
-#define        PIPE_MTIME      0x00000002      /* time of last modification */
-#define        PIPE_CTIME      0x00000004      /* time of last status change */
+#define PIPE_ATIME      0x00000001      /* time of last access */
+#define PIPE_MTIME      0x00000002      /* time of last modification */
+#define PIPE_CTIME      0x00000004      /* time of last status change */
 
 static void
 pipe_touch(struct pipe *tpipe, int touch)
 {
-       struct timeval now;
+       struct timespec now;
 
-       microtime(&now);
+       nanotime(&now);
 
        if (touch & PIPE_ATIME) {
                tpipe->st_atimespec.tv_sec  = now.tv_sec;
-               tpipe->st_atimespec.tv_nsec = now.tv_usec * 1000;
+               tpipe->st_atimespec.tv_nsec = now.tv_nsec;
        }
 
        if (touch & PIPE_MTIME) {
                tpipe->st_mtimespec.tv_sec  = now.tv_sec;
-               tpipe->st_mtimespec.tv_nsec = now.tv_usec * 1000;
+               tpipe->st_mtimespec.tv_nsec = now.tv_nsec;
        }
 
        if (touch & PIPE_CTIME) {
                tpipe->st_ctimespec.tv_sec  = now.tv_sec;
-               tpipe->st_ctimespec.tv_nsec = now.tv_usec * 1000;
+               tpipe->st_ctimespec.tv_nsec = now.tv_nsec;
        }
 }
+#endif
 
-static const unsigned int pipesize_blocks[] = {128,256,1024,2048,4096, 4096 * 2, PIPE_SIZE , PIPE_SIZE * 4 };
+static const unsigned int pipesize_blocks[] = {512, 1024, 2048, 4096, 4096 * 2, PIPE_SIZE, PIPE_SIZE * 4 };
 
-/* 
- * finds the right size from possible sizes in pipesize_blocks 
- * returns the size which matches max(current,expected) 
+/*
+ * finds the right size from possible sizes in pipesize_blocks
+ * returns the size which matches max(current,expected)
  */
-static int 
+static int
 choose_pipespace(unsigned long current, unsigned long expected)
 {
-       int i = sizeof(pipesize_blocks)/sizeof(unsigned int) -1;
+       int i = sizeof(pipesize_blocks) / sizeof(unsigned int) - 1;
        unsigned long target;
 
-       if (expected > current) 
+       /*
+        * assert that we always get an atomic transaction sized pipe buffer,
+        * even if the system pipe buffer high-water mark has been crossed.
+        */
+       assert(PIPE_BUF == pipesize_blocks[0]);
+
+       if (expected > current) {
                target = expected;
-       else
+       } else {
                target = current;
+       }
 
-       while ( i >0 && pipesize_blocks[i-1] > target) {
-               i=i-1;
-
+       while (i > 0 && pipesize_blocks[i - 1] > target) {
+               i = i - 1;
        }
-       
+
        return pipesize_blocks[i];
 }
 
@@ -350,27 +372,28 @@ choose_pipespace(unsigned long current, unsigned long expected)
  * Required: PIPE_LOCK and io lock to be held by caller.
  * returns 0 on success or no expansion possible
  */
-static int 
+static int
 expand_pipespace(struct pipe *p, int target_size)
 {
        struct pipe tmp, oldpipe;
        int error;
        tmp.pipe_buffer.buffer = 0;
-       
+
        if (p->pipe_buffer.size >= (unsigned) target_size) {
                return 0; /* the existing buffer is max size possible */
        }
-       
+
        /* create enough space in the target */
        error = pipespace(&tmp, target_size);
-       if (error != 0)
-               return (error);
+       if (error != 0) {
+               return error;
+       }
 
        oldpipe.pipe_buffer.buffer = p->pipe_buffer.buffer;
        oldpipe.pipe_buffer.size = p->pipe_buffer.size;
-       
+
        memcpy(tmp.pipe_buffer.buffer, p->pipe_buffer.buffer, p->pipe_buffer.size);
-       if (p->pipe_buffer.cnt > 0 && p->pipe_buffer.in <= p->pipe_buffer.out ){
+       if (p->pipe_buffer.cnt > 0 && p->pipe_buffer.in <= p->pipe_buffer.out{
                /* we are in State 3 and need extra copying for read to be consistent */
                memcpy(&tmp.pipe_buffer.buffer[p->pipe_buffer.size], p->pipe_buffer.buffer, p->pipe_buffer.size);
                p->pipe_buffer.in += p->pipe_buffer.size;
@@ -386,11 +409,11 @@ expand_pipespace(struct pipe *p, int target_size)
 
 /*
  * The pipe system call for the DTYPE_PIPE type of pipes
- * 
+ *
  * returns:
- *  FREAD  | fd0 | -->[struct rpipe] --> |~~buffer~~| \  
+ *  FREAD  | fd0 | -->[struct rpipe] --> |~~buffer~~| \
  *                                                    (pipe_mutex)
- *  FWRITE | fd1 | -->[struct wpipe] --X              / 
+ *  FWRITE | fd1 | -->[struct wpipe] --X              /
  */
 
 /* ARGSUSED */
@@ -402,34 +425,36 @@ pipe(proc_t p, __unused struct pipe_args *uap, int32_t *retval)
        lck_mtx_t   *pmtx;
        int fd, error;
 
-       if ((pmtx = lck_mtx_alloc_init(pipe_mtx_grp, pipe_mtx_attr)) == NULL)
-               return (ENOMEM);
-       
+       if ((pmtx = lck_mtx_alloc_init(pipe_mtx_grp, pipe_mtx_attr)) == NULL) {
+               return ENOMEM;
+       }
+
        rpipe = wpipe = NULL;
        if (pipe_create(&rpipe) || pipe_create(&wpipe)) {
-               error = ENFILE;
+               error = ENFILE;
                goto freepipes;
        }
-        /*
+       /*
         * allocate the space for the normal I/O direction up
         * front... we'll delay the allocation for the other
         * direction until a write actually occurs (most likely it won't)...
-         */
+        */
        error = pipespace(rpipe, choose_pipespace(rpipe->pipe_buffer.size, 0));
-        if (error)
-               goto freepipes;
+       if (error) {
+               goto freepipes;
+       }
 
        TAILQ_INIT(&rpipe->pipe_evlist);
        TAILQ_INIT(&wpipe->pipe_evlist);
 
        error = falloc(p, &rf, &fd, vfs_context_current());
        if (error) {
-               goto freepipes;
+               goto freepipes;
        }
        retval[0] = fd;
 
        /*
-        * for now we'll create half-duplex pipes(refer returns section above). 
+        * for now we'll create half-duplex pipes(refer returns section above).
         * this is what we've always supported..
         */
        rf->f_flag = FREAD;
@@ -439,7 +464,7 @@ pipe(proc_t p, __unused struct pipe_args *uap, int32_t *retval)
        error = falloc(p, &wf, &fd, vfs_context_current());
        if (error) {
                fp_free(p, retval[0], rf);
-               goto freepipes;
+               goto freepipes;
        }
        wf->f_flag = FWRITE;
        wf->f_data = (caddr_t)wpipe;
@@ -448,7 +473,7 @@ pipe(proc_t p, __unused struct pipe_args *uap, int32_t *retval)
        rpipe->pipe_peer = wpipe;
        wpipe->pipe_peer = rpipe;
        /* both structures share the same mutex */
-       rpipe->pipe_mtxp = wpipe->pipe_mtxp = pmtx; 
+       rpipe->pipe_mtxp = wpipe->pipe_mtxp = pmtx;
 
        retval[1] = fd;
 #if CONFIG_MACF
@@ -472,73 +497,75 @@ pipe(proc_t p, __unused struct pipe_args *uap, int32_t *retval)
        proc_fdunlock(p);
 
 
-       return (0);
+       return 0;
 
 freepipes:
-       pipeclose(rpipe); 
-       pipeclose(wpipe); 
+       pipeclose(rpipe);
+       pipeclose(wpipe);
        lck_mtx_free(pmtx, pipe_mtx_grp);
 
-       return (error);
+       return error;
 }
 
 int
 pipe_stat(struct pipe *cpipe, void *ub, int isstat64)
 {
 #if CONFIG_MACF
-        int error;
+       int error;
 #endif
-       int     pipe_size = 0;
-       int     pipe_count;
-       struct stat *sb = (struct stat *)0;     /* warning avoidance ; protected by isstat64 */
+       int     pipe_size = 0;
+       int     pipe_count;
+       struct stat *sb = (struct stat *)0;     /* warning avoidance ; protected by isstat64 */
        struct stat64 * sb64 = (struct stat64 *)0;  /* warning avoidance ; protected by isstat64 */
 
-       if (cpipe == NULL)
-               return (EBADF);
+       if (cpipe == NULL) {
+               return EBADF;
+       }
        PIPE_LOCK(cpipe);
 
 #if CONFIG_MACF
        error = mac_pipe_check_stat(kauth_cred_get(), cpipe);
        if (error) {
                PIPE_UNLOCK(cpipe);
-               return (error);
+               return error;
        }
 #endif
        if (cpipe->pipe_buffer.buffer == 0) {
-               /* must be stat'ing the write fd */
-               if (cpipe->pipe_peer) {
-                       /* the peer still exists, use it's info */
-                       pipe_size  = MAX_PIPESIZE(cpipe->pipe_peer);
+               /* must be stat'ing the write fd */
+               if (cpipe->pipe_peer) {
+                       /* the peer still exists, use it's info */
+                       pipe_size  = MAX_PIPESIZE(cpipe->pipe_peer);
                        pipe_count = cpipe->pipe_peer->pipe_buffer.cnt;
                } else {
                        pipe_count = 0;
                }
        } else {
-               pipe_size  = MAX_PIPESIZE(cpipe);
+               pipe_size  = MAX_PIPESIZE(cpipe);
                pipe_count = cpipe->pipe_buffer.cnt;
        }
        /*
         * since peer's buffer is setup ouside of lock
         * we might catch it in transient state
         */
-       if (pipe_size == 0)
+       if (pipe_size == 0) {
                pipe_size  = MAX(PIPE_SIZE, pipesize_blocks[0]);
+       }
 
        if (isstat64 != 0) {
-               sb64 = (struct stat64 *)ub;     
+               sb64 = (struct stat64 *)ub;
 
                bzero(sb64, sizeof(*sb64));
                sb64->st_mode = S_IFIFO | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
                sb64->st_blksize = pipe_size;
                sb64->st_size = pipe_count;
                sb64->st_blocks = (sb64->st_size + sb64->st_blksize - 1) / sb64->st_blksize;
-       
+
                sb64->st_uid = kauth_getuid();
                sb64->st_gid = kauth_getgid();
-       
+
                sb64->st_atimespec.tv_sec  = cpipe->st_atimespec.tv_sec;
                sb64->st_atimespec.tv_nsec = cpipe->st_atimespec.tv_nsec;
-       
+
                sb64->st_mtimespec.tv_sec  = cpipe->st_mtimespec.tv_sec;
                sb64->st_mtimespec.tv_nsec = cpipe->st_mtimespec.tv_nsec;
 
@@ -546,26 +573,26 @@ pipe_stat(struct pipe *cpipe, void *ub, int isstat64)
                sb64->st_ctimespec.tv_nsec = cpipe->st_ctimespec.tv_nsec;
 
                /*
-               * Return a relatively unique inode number based on the current
-               * address of this pipe's struct pipe.  This number may be recycled
-               * relatively quickly.
-               */
+                * Return a relatively unique inode number based on the current
+                * address of this pipe's struct pipe.  This number may be recycled
+                * relatively quickly.
+                */
                sb64->st_ino = (ino64_t)VM_KERNEL_ADDRPERM((uintptr_t)cpipe);
        } else {
-               sb = (struct stat *)ub; 
+               sb = (struct stat *)ub;
 
                bzero(sb, sizeof(*sb));
                sb->st_mode = S_IFIFO | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
                sb->st_blksize = pipe_size;
                sb->st_size = pipe_count;
                sb->st_blocks = (sb->st_size + sb->st_blksize - 1) / sb->st_blksize;
-       
+
                sb->st_uid = kauth_getuid();
                sb->st_gid = kauth_getgid();
-       
+
                sb->st_atimespec.tv_sec  = cpipe->st_atimespec.tv_sec;
                sb->st_atimespec.tv_nsec = cpipe->st_atimespec.tv_nsec;
-       
+
                sb->st_mtimespec.tv_sec  = cpipe->st_mtimespec.tv_sec;
                sb->st_mtimespec.tv_nsec = cpipe->st_mtimespec.tv_nsec;
 
@@ -573,10 +600,10 @@ pipe_stat(struct pipe *cpipe, void *ub, int isstat64)
                sb->st_ctimespec.tv_nsec = cpipe->st_ctimespec.tv_nsec;
 
                /*
-               * Return a relatively unique inode number based on the current
-               * address of this pipe's struct pipe.  This number may be recycled
-               * relatively quickly.
-               */
+                * Return a relatively unique inode number based on the current
+                * address of this pipe's struct pipe.  This number may be recycled
+                * relatively quickly.
+                */
                sb->st_ino = (ino_t)VM_KERNEL_ADDRPERM((uintptr_t)cpipe);
        }
        PIPE_UNLOCK(cpipe);
@@ -589,7 +616,7 @@ pipe_stat(struct pipe *cpipe, void *ub, int isstat64)
         * XXX is associated with pipes, since they are implemented via a
         * XXX struct fileops indirection rather than as FS objects.
         */
-       return (0);
+       return 0;
 }
 
 
@@ -604,11 +631,13 @@ pipespace(struct pipe *cpipe, int size)
 {
        vm_offset_t buffer;
 
-       if (size <= 0)
-               return(EINVAL);
+       if (size <= 0) {
+               return EINVAL;
+       }
 
-       if ((buffer = (vm_offset_t)kalloc(size)) == 0 )
-               return(ENOMEM);
+       if ((buffer = (vm_offset_t)kalloc(size)) == 0) {
+               return ENOMEM;
+       }
 
        /* free old resources if we're resizing */
        pipe_free_kmem(cpipe);
@@ -621,7 +650,7 @@ pipespace(struct pipe *cpipe, int size)
        OSAddAtomic(1, &amountpipes);
        OSAddAtomic(cpipe->pipe_buffer.size, &amountpipekva);
 
-       return (0);
+       return 0;
 }
 
 /*
@@ -633,8 +662,9 @@ pipe_create(struct pipe **cpipep)
        struct pipe *cpipe;
        cpipe = (struct pipe *)zalloc(pipe_zone);
 
-       if ((*cpipep = cpipe) == NULL)
-               return (ENOMEM);
+       if ((*cpipep = cpipe) == NULL) {
+               return ENOMEM;
+       }
 
        /*
         * protect so pipespace or pipeclose don't follow a junk pointer
@@ -642,9 +672,11 @@ pipe_create(struct pipe **cpipep)
         */
        bzero(cpipe, sizeof *cpipe);
 
+#ifndef CONFIG_EMBEDDED
        /* Initial times are all the time of creation of the pipe */
        pipe_touch(cpipe, PIPE_ATIME | PIPE_MTIME | PIPE_CTIME);
-       return (0);
+#endif
+       return 0;
 }
 
 
@@ -658,12 +690,13 @@ pipeio_lock(struct pipe *cpipe, int catch)
        while (cpipe->pipe_state & PIPE_LOCKFL) {
                cpipe->pipe_state |= PIPE_LWANT;
                error = msleep(cpipe, PIPE_MTX(cpipe), catch ? (PRIBIO | PCATCH) : PRIBIO,
-                              "pipelk", 0);
-               if (error != 0) 
-                       return (error);
+                   "pipelk", 0);
+               if (error != 0) {
+                       return error;
+               }
        }
        cpipe->pipe_state |= PIPE_LOCKFL;
-       return (0);
+       return 0;
 }
 
 /*
@@ -689,17 +722,19 @@ pipeselwakeup(struct pipe *cpipe, struct pipe *spipe)
                cpipe->pipe_state &= ~PIPE_SEL;
                selwakeup(&cpipe->pipe_sel);
        }
-        if (cpipe->pipe_state & PIPE_KNOTE) 
-              KNOTE(&cpipe->pipe_sel.si_note, 1);
+       if (cpipe->pipe_state & PIPE_KNOTE) {
+               KNOTE(&cpipe->pipe_sel.si_note, 1);
+       }
 
        postpipeevent(cpipe, EV_RWBYTES);
 
        if (spipe && (spipe->pipe_state & PIPE_ASYNC) && spipe->pipe_pgid) {
-               if (spipe->pipe_pgid < 0)
-                       gsignal(-spipe->pipe_pgid, SIGIO);
-               else 
-                       proc_signal(spipe->pipe_pgid, SIGIO);
-        }
+               if (spipe->pipe_pgid < 0) {
+                       gsignal(-spipe->pipe_pgid, SIGIO);
+               } else {
+                       proc_signal(spipe->pipe_pgid, SIGIO);
+               }
+       }
 }
 
 /*
@@ -709,7 +744,7 @@ pipeselwakeup(struct pipe *cpipe, struct pipe *spipe)
 /* ARGSUSED */
 static int
 pipe_read(struct fileproc *fp, struct uio *uio, __unused int flags,
-       __unused vfs_context_t ctx)
+    __unused vfs_context_t ctx)
 {
        struct pipe *rpipe = (struct pipe *)fp->f_data;
        int error;
@@ -720,13 +755,15 @@ pipe_read(struct fileproc *fp, struct uio *uio, __unused int flags,
        ++rpipe->pipe_busy;
 
        error = pipeio_lock(rpipe, 1);
-       if (error)
+       if (error) {
                goto unlocked_error;
+       }
 
 #if CONFIG_MACF
        error = mac_pipe_check_read(kauth_cred_get(), rpipe);
-       if (error)
+       if (error) {
                goto locked_error;
+       }
 #endif
 
 
@@ -737,30 +774,34 @@ pipe_read(struct fileproc *fp, struct uio *uio, __unused int flags,
                if (rpipe->pipe_buffer.cnt > 0) {
                        /*
                         * # bytes to read is min( bytes from read pointer until end of buffer,
-                        *                         total unread bytes, 
+                        *                         total unread bytes,
                         *                         user requested byte count)
                         */
                        size = rpipe->pipe_buffer.size - rpipe->pipe_buffer.out;
-                       if (size > rpipe->pipe_buffer.cnt)
+                       if (size > rpipe->pipe_buffer.cnt) {
                                size = rpipe->pipe_buffer.cnt;
+                       }
                        // LP64todo - fix this!
-                       if (size > (u_int) uio_resid(uio))
+                       if (size > (u_int) uio_resid(uio)) {
                                size = (u_int) uio_resid(uio);
+                       }
 
                        PIPE_UNLOCK(rpipe); /* we still hold io lock.*/
                        error = uiomove(
-                           &rpipe->pipe_buffer.buffer[rpipe->pipe_buffer.out],
-                           size, uio);
+                               &rpipe->pipe_buffer.buffer[rpipe->pipe_buffer.out],
+                               size, uio);
                        PIPE_LOCK(rpipe);
-                       if (error)
+                       if (error) {
                                break;
+                       }
 
                        rpipe->pipe_buffer.out += size;
-                       if (rpipe->pipe_buffer.out >= rpipe->pipe_buffer.size)
+                       if (rpipe->pipe_buffer.out >= rpipe->pipe_buffer.size) {
                                rpipe->pipe_buffer.out = 0;
+                       }
 
                        rpipe->pipe_buffer.cnt -= size;
-                       
+
                        /*
                         * If there is no more to read in the pipe, reset
                         * its pointers to the beginning.  This improves
@@ -791,11 +832,12 @@ pipe_read(struct fileproc *fp, struct uio *uio, __unused int flags,
                        /*
                         * Break if some data was read in previous iteration.
                         */
-                       if (nread > 0)
+                       if (nread > 0) {
                                break;
+                       }
 
                        /*
-                        * Unlock the pipe buffer for our remaining processing. 
+                        * Unlock the pipe buffer for our remaining processing.
                         * We will either break out with an error or we will
                         * sleep and relock to loop.
                         */
@@ -810,11 +852,13 @@ pipe_read(struct fileproc *fp, struct uio *uio, __unused int flags,
                        } else {
                                rpipe->pipe_state |= PIPE_WANTR;
                                error = msleep(rpipe, PIPE_MTX(rpipe), PRIBIO | PCATCH, "piperd", 0);
-                               if (error == 0)
-                                       error = pipeio_lock(rpipe, 1);
+                               if (error == 0) {
+                                       error = pipeio_lock(rpipe, 1);
+                               }
                        }
-                       if (error)
+                       if (error) {
                                goto unlocked_error;
+                       }
                }
        }
 #if CONFIG_MACF
@@ -829,7 +873,7 @@ unlocked_error:
         * PIPE_WANT processing only makes sense if pipe_busy is 0.
         */
        if ((rpipe->pipe_busy == 0) && (rpipe->pipe_state & PIPE_WANT)) {
-               rpipe->pipe_state &= ~(PIPE_WANT|PIPE_WANTW);
+               rpipe->pipe_state &= ~(PIPE_WANT | PIPE_WANTW);
                wakeup(rpipe);
        } else if (rpipe->pipe_buffer.cnt < rpipe->pipe_buffer.size) {
                /*
@@ -841,24 +885,27 @@ unlocked_error:
                }
        }
 
-       if ((rpipe->pipe_buffer.size - rpipe->pipe_buffer.cnt) > 0)
+       if ((rpipe->pipe_buffer.size - rpipe->pipe_buffer.cnt) > 0) {
                pipeselwakeup(rpipe, rpipe->pipe_peer);
+       }
 
+#ifndef CONFIG_EMBEDDED
        /* update last read time */
        pipe_touch(rpipe, PIPE_ATIME);
+#endif
 
        PIPE_UNLOCK(rpipe);
 
-       return (error);
+       return error;
 }
 
 /*
- * perform a write of n bytes into the read side of buffer. Since 
+ * perform a write of n bytes into the read side of buffer. Since
  * pipes are unidirectional a write is meant to be read by the otherside only.
  */
 static int
 pipe_write(struct fileproc *fp, struct uio *uio, __unused int flags,
-       __unused vfs_context_t ctx)
+    __unused vfs_context_t ctx)
 {
        int error = 0;
        int orig_resid;
@@ -878,13 +925,13 @@ pipe_write(struct fileproc *fp, struct uio *uio, __unused int flags,
         */
        if (wpipe == NULL || (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF))) {
                PIPE_UNLOCK(rpipe);
-               return (EPIPE);
+               return EPIPE;
        }
 #if CONFIG_MACF
        error = mac_pipe_check_write(kauth_cred_get(), wpipe);
        if (error) {
                PIPE_UNLOCK(rpipe);
-               return (error);
+               return error;
        }
 #endif
        ++wpipe->pipe_busy;
@@ -898,71 +945,71 @@ pipe_write(struct fileproc *fp, struct uio *uio, __unused int flags,
         * fd[1], so allocating space for both ends is a waste...
         */
 
-       if ( wpipe->pipe_buffer.buffer == 0 || ( 
-               (unsigned)orig_resid > wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt &&
-               amountpipekva < maxpipekva ) ) {
-
-               pipe_size = choose_pipespace(wpipe->pipe_buffer.size, wpipe->pipe_buffer.cnt + orig_resid);
+       if (wpipe->pipe_buffer.buffer == 0 || (
+                   (unsigned)orig_resid > wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt &&
+                   amountpipekva < maxpipekva)) {
+               pipe_size = choose_pipespace(wpipe->pipe_buffer.size, wpipe->pipe_buffer.cnt + orig_resid);
        }
        if (pipe_size) {
-               /*
+               /*
                 * need to do initial allocation or resizing of pipe
-                * holding both structure and io locks. 
+                * holding both structure and io locks.
                 */
                if ((error = pipeio_lock(wpipe, 1)) == 0) {
-                       if (wpipe->pipe_buffer.cnt == 0)                        
+                       if (wpipe->pipe_buffer.cnt == 0) {
                                error = pipespace(wpipe, pipe_size);
-                       else 
+                       } else {
                                error = expand_pipespace(wpipe, pipe_size);
-               
+                       }
+
                        pipeio_unlock(wpipe);
-                       
+
                        /* allocation failed */
-                       if (wpipe->pipe_buffer.buffer == 0)
-                               error = ENOMEM;
+                       if (wpipe->pipe_buffer.buffer == 0) {
+                               error = ENOMEM;
+                       }
                }
                if (error) {
-                       /*
+                       /*
                         * If an error occurred unbusy and return, waking up any pending
                         * readers.
                         */
-                       --wpipe->pipe_busy;
-                       if ((wpipe->pipe_busy == 0) && 
+                       --wpipe->pipe_busy;
+                       if ((wpipe->pipe_busy == 0) &&
                            (wpipe->pipe_state & PIPE_WANT)) {
-                               wpipe->pipe_state &= ~(PIPE_WANT | PIPE_WANTR);
+                               wpipe->pipe_state &= ~(PIPE_WANT | PIPE_WANTR);
                                wakeup(wpipe);
                        }
                        PIPE_UNLOCK(rpipe);
-                       return(error);
+                       return error;
                }
        }
 
        while (uio_resid(uio)) {
-
-       retrywrite:
+retrywrite:
                space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt;
 
                /* Writes of size <= PIPE_BUF must be atomic. */
-               if ((space < uio_resid(uio)) && (orig_resid <= PIPE_BUF))
+               if ((space < uio_resid(uio)) && (orig_resid <= PIPE_BUF)) {
                        space = 0;
+               }
 
                if (space > 0) {
-
-                       if ((error = pipeio_lock(wpipe,1)) == 0) {
-                               int size;       /* Transfer size */
-                               int segsize;    /* first segment to transfer */
+                       if ((error = pipeio_lock(wpipe, 1)) == 0) {
+                               int size;       /* Transfer size */
+                               int segsize;    /* first segment to transfer */
 
                                if (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF)) {
                                        pipeio_unlock(wpipe);
-                                       error = EPIPE;
+                                       error = EPIPE;
                                        break;
                                }
-                               /* 
+                               /*
                                 * If a process blocked in pipeio_lock, our
                                 * value for space might be bad... the mutex
                                 * is dropped while we're blocked
                                 */
-                               if (space > (int)(wpipe->pipe_buffer.size - 
+                               if (space > (int)(wpipe->pipe_buffer.size -
                                    wpipe->pipe_buffer.cnt)) {
                                        pipeio_unlock(wpipe);
                                        goto retrywrite;
@@ -973,47 +1020,50 @@ pipe_write(struct fileproc *fp, struct uio *uio, __unused int flags,
                                 * and free space in pipe buffer.
                                 */
                                // LP64todo - fix this!
-                               if (space > uio_resid(uio))
+                               if (space > uio_resid(uio)) {
                                        size = uio_resid(uio);
-                               else
+                               } else {
                                        size = space;
+                               }
                                /*
-                                * First segment to transfer is minimum of 
+                                * First segment to transfer is minimum of
                                 * transfer size and contiguous space in
                                 * pipe buffer.  If first segment to transfer
                                 * is less than the transfer size, we've got
                                 * a wraparound in the buffer.
                                 */
-                               segsize = wpipe->pipe_buffer.size - 
-                                       wpipe->pipe_buffer.in;
-                               if (segsize > size)
+                               segsize = wpipe->pipe_buffer.size -
+                                   wpipe->pipe_buffer.in;
+                               if (segsize > size) {
                                        segsize = size;
-                               
+                               }
+
                                /* Transfer first segment */
 
                                PIPE_UNLOCK(rpipe);
-                               error = uiomove(&wpipe->pipe_buffer.buffer[wpipe->pipe_buffer.in], 
-                                               segsize, uio);
+                               error = uiomove(&wpipe->pipe_buffer.buffer[wpipe->pipe_buffer.in],
+                                   segsize, uio);
                                PIPE_LOCK(rpipe);
-                               
+
                                if (error == 0 && segsize < size) {
-                                       /* 
+                                       /*
                                         * Transfer remaining part now, to
                                         * support atomic writes.  Wraparound
                                         * happened. (State 3)
                                         */
-                                       if (wpipe->pipe_buffer.in + segsize != 
-                                           wpipe->pipe_buffer.size)
+                                       if (wpipe->pipe_buffer.in + segsize !=
+                                           wpipe->pipe_buffer.size) {
                                                panic("Expected pipe buffer "
                                                    "wraparound disappeared");
-                                               
+                                       }
+
                                        PIPE_UNLOCK(rpipe);
                                        error = uiomove(
-                                           &wpipe->pipe_buffer.buffer[0],
-                                           size - segsize, uio);
+                                               &wpipe->pipe_buffer.buffer[0],
+                                               size - segsize, uio);
                                        PIPE_LOCK(rpipe);
                                }
-                               /* 
+                               /*
                                 * readers never know to read until count is updated.
                                 */
                                if (error == 0) {
@@ -1022,24 +1072,25 @@ pipe_write(struct fileproc *fp, struct uio *uio, __unused int flags,
                                            wpipe->pipe_buffer.size) {
                                                if (wpipe->pipe_buffer.in !=
                                                    size - segsize +
-                                                   wpipe->pipe_buffer.size)
+                                                   wpipe->pipe_buffer.size) {
                                                        panic("Expected "
                                                            "wraparound bad");
+                                               }
                                                wpipe->pipe_buffer.in = size -
                                                    segsize;
                                        }
-                               
+
                                        wpipe->pipe_buffer.cnt += size;
                                        if (wpipe->pipe_buffer.cnt >
-                                           wpipe->pipe_buffer.size)
+                                           wpipe->pipe_buffer.size) {
                                                panic("Pipe buffer overflow");
-                               
+                                       }
                                }
                                pipeio_unlock(wpipe);
                        }
-                       if (error)
+                       if (error) {
                                break;
-
+                       }
                } else {
                        /*
                         * If the "read-side" has been blocked, wake it up now.
@@ -1064,7 +1115,7 @@ pipe_write(struct fileproc *fp, struct uio *uio, __unused int flags,
                        if (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF)) {
                                error = EPIPE;
                                break;
-                       }       
+                       }
 
                        /*
                         * We have no more space and have something to offer,
@@ -1076,8 +1127,9 @@ pipe_write(struct fileproc *fp, struct uio *uio, __unused int flags,
 
                        error = msleep(wpipe, PIPE_MTX(wpipe), PRIBIO | PCATCH, "pipewr", 0);
 
-                       if (error != 0)
+                       if (error != 0) {
                                break;
+                       }
                }
        }
        --wpipe->pipe_busy;
@@ -1101,12 +1153,14 @@ pipe_write(struct fileproc *fp, struct uio *uio, __unused int flags,
                pipeselwakeup(wpipe, wpipe);
        }
 
+#ifndef CONFIG_EMBEDDED
        /* Update modification, status change (# of bytes in pipe) times */
        pipe_touch(rpipe, PIPE_MTIME | PIPE_CTIME);
        pipe_touch(wpipe, PIPE_MTIME | PIPE_CTIME);
+#endif
        PIPE_UNLOCK(rpipe);
 
-       return (error);
+       return error;
 }
 
 /*
@@ -1115,7 +1169,7 @@ pipe_write(struct fileproc *fp, struct uio *uio, __unused int flags,
 /* ARGSUSED 3 */
 static int
 pipe_ioctl(struct fileproc *fp, u_long cmd, caddr_t data,
-       __unused vfs_context_t ctx)
+    __unused vfs_context_t ctx)
 {
        struct pipe *mpipe = (struct pipe *)fp->f_data;
 #if CONFIG_MACF
@@ -1129,15 +1183,14 @@ pipe_ioctl(struct fileproc *fp, u_long cmd, caddr_t data,
        if (error) {
                PIPE_UNLOCK(mpipe);
 
-               return (error);
+               return error;
        }
 #endif
 
        switch (cmd) {
-
        case FIONBIO:
                PIPE_UNLOCK(mpipe);
-               return (0);
+               return 0;
 
        case FIOASYNC:
                if (*(int *)data) {
@@ -1146,28 +1199,27 @@ pipe_ioctl(struct fileproc *fp, u_long cmd, caddr_t data,
                        mpipe->pipe_state &= ~PIPE_ASYNC;
                }
                PIPE_UNLOCK(mpipe);
-               return (0);
+               return 0;
 
        case FIONREAD:
                *(int *)data = mpipe->pipe_buffer.cnt;
                PIPE_UNLOCK(mpipe);
-               return (0);
+               return 0;
 
        case TIOCSPGRP:
                mpipe->pipe_pgid = *(int *)data;
 
                PIPE_UNLOCK(mpipe);
-               return (0);
+               return 0;
 
        case TIOCGPGRP:
                *(int *)data = mpipe->pipe_pgid;
 
                PIPE_UNLOCK(mpipe);
-               return (0);
-
+               return 0;
        }
        PIPE_UNLOCK(mpipe);
-       return (ENOTTY);
+       return ENOTTY;
 }
 
 
@@ -1178,13 +1230,14 @@ pipe_select(struct fileproc *fp, int which, void *wql, vfs_context_t ctx)
        struct pipe *wpipe;
        int    retnum = 0;
 
-       if (rpipe == NULL || rpipe == (struct pipe *)-1)
-               return (retnum);
+       if (rpipe == NULL || rpipe == (struct pipe *)-1) {
+               return retnum;
+       }
 
        PIPE_LOCK(rpipe);
 
        wpipe = rpipe->pipe_peer;
-       
+
 
 #if CONFIG_MACF
        /*
@@ -1194,44 +1247,42 @@ pipe_select(struct fileproc *fp, int which, void *wql, vfs_context_t ctx)
         */
        if (mac_pipe_check_select(vfs_context_ucred(ctx), rpipe, which)) {
                PIPE_UNLOCK(rpipe);
-               return (0);
+               return 0;
        }
 #endif
-        switch (which) {
-
-        case FREAD:
+       switch (which) {
+       case FREAD:
                if ((rpipe->pipe_state & PIPE_DIRECTW) ||
                    (rpipe->pipe_buffer.cnt > 0) ||
                    (rpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF))) {
-
-                       retnum = 1;
+                       retnum = 1;
                } else {
-                       rpipe->pipe_state |= PIPE_SEL;
-                       selrecord(vfs_context_proc(ctx), &rpipe->pipe_sel, wql);
+                       rpipe->pipe_state |= PIPE_SEL;
+                       selrecord(vfs_context_proc(ctx), &rpipe->pipe_sel, wql);
                }
                break;
 
-        case FWRITE:
-               if (wpipe)
+       case FWRITE:
+               if (wpipe) {
                        wpipe->pipe_state |= PIPE_WSELECT;
+               }
                if (wpipe == NULL || (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF)) ||
                    (((wpipe->pipe_state & PIPE_DIRECTW) == 0) &&
-                    (MAX_PIPESIZE(wpipe) - wpipe->pipe_buffer.cnt) >= PIPE_BUF)) {
-
-                       retnum = 1;
+                   (MAX_PIPESIZE(wpipe) - wpipe->pipe_buffer.cnt) >= PIPE_BUF)) {
+                       retnum = 1;
                } else {
-                       wpipe->pipe_state |= PIPE_SEL;
+                       wpipe->pipe_state |= PIPE_SEL;
                        selrecord(vfs_context_proc(ctx), &wpipe->pipe_sel, wql);
                }
                break;
-        case 0:
-               rpipe->pipe_state |= PIPE_SEL;
+       case 0:
+               rpipe->pipe_state |= PIPE_SEL;
                selrecord(vfs_context_proc(ctx), &rpipe->pipe_sel, wql);
                break;
-        }
+       }
        PIPE_UNLOCK(rpipe);
 
-        return (retnum);
+       return retnum;
 }
 
 
@@ -1239,16 +1290,17 @@ pipe_select(struct fileproc *fp, int which, void *wql, vfs_context_t ctx)
 static int
 pipe_close(struct fileglob *fg, __unused vfs_context_t ctx)
 {
-        struct pipe *cpipe;
+       struct pipe *cpipe;
 
        proc_fdlock_spin(vfs_context_proc(ctx));
        cpipe = (struct pipe *)fg->fg_data;
        fg->fg_data = NULL;
        proc_fdunlock(vfs_context_proc(ctx));
-       if (cpipe)
-               pipeclose(cpipe);
+       if (cpipe) {
+               pipeclose(cpipe);
+       }
 
-       return (0);
+       return 0;
 }
 
 static void
@@ -1257,8 +1309,8 @@ pipe_free_kmem(struct pipe *cpipe)
        if (cpipe->pipe_buffer.buffer != NULL) {
                OSAddAtomic(-(cpipe->pipe_buffer.size), &amountpipekva);
                OSAddAtomic(-1, &amountpipes);
-               kfree((void *)cpipe->pipe_buffer.buffer,
-                         cpipe->pipe_buffer.size);
+               kfree(cpipe->pipe_buffer.buffer,
+                   cpipe->pipe_buffer.size);
                cpipe->pipe_buffer.buffer = NULL;
                cpipe->pipe_buffer.size = 0;
        }
@@ -1272,12 +1324,14 @@ pipeclose(struct pipe *cpipe)
 {
        struct pipe *ppipe;
 
-       if (cpipe == NULL)
+       if (cpipe == NULL) {
                return;
+       }
        /* partially created pipes won't have a valid mutex. */
-       if (PIPE_MTX(cpipe) != NULL)
+       if (PIPE_MTX(cpipe) != NULL) {
                PIPE_LOCK(cpipe);
-               
+       }
+
 
        /*
         * If the other side is blocked, wake it up saying that
@@ -1286,35 +1340,36 @@ pipeclose(struct pipe *cpipe)
        cpipe->pipe_state &= ~PIPE_DRAIN;
        cpipe->pipe_state |= PIPE_EOF;
        pipeselwakeup(cpipe, cpipe);
-       
+
        while (cpipe->pipe_busy) {
                cpipe->pipe_state |= PIPE_WANT;
 
                wakeup(cpipe);
-               msleep(cpipe, PIPE_MTX(cpipe), PRIBIO, "pipecl", 0);
+               msleep(cpipe, PIPE_MTX(cpipe), PRIBIO, "pipecl", 0);
        }
 
 #if CONFIG_MACF
        /*
         * Free the shared pipe label only after the two ends are disconnected.
         */
-       if (cpipe->pipe_label != NULL && cpipe->pipe_peer == NULL)
+       if (cpipe->pipe_label != NULL && cpipe->pipe_peer == NULL) {
                mac_pipe_label_destroy(cpipe);
+       }
 #endif
 
        /*
         * Disconnect from peer
         */
        if ((ppipe = cpipe->pipe_peer) != NULL) {
-
                ppipe->pipe_state &= ~(PIPE_DRAIN);
                ppipe->pipe_state |= PIPE_EOF;
 
                pipeselwakeup(ppipe, ppipe);
                wakeup(ppipe);
 
-               if (cpipe->pipe_state & PIPE_KNOTE)
-                       KNOTE(&ppipe->pipe_sel.si_note, 1);
+               if (cpipe->pipe_state & PIPE_KNOTE) {
+                       KNOTE(&ppipe->pipe_sel.si_note, 1);
+               }
 
                postpipeevent(ppipe, EV_RCLOSED);
 
@@ -1348,16 +1403,180 @@ pipeclose(struct pipe *cpipe)
                zfree(pipe_zone, cpipe);
                pipe_garbage_collect(NULL);
        }
+}
+
+/*ARGSUSED*/
+static int
+filt_piperead_common(struct knote *kn, struct pipe *rpipe)
+{
+       struct pipe *wpipe;
+       int    retval;
+
+       /*
+        * we're being called back via the KNOTE post
+        * we made in pipeselwakeup, and we already hold the mutex...
+        */
+
+       wpipe = rpipe->pipe_peer;
+       kn->kn_data = rpipe->pipe_buffer.cnt;
+       if ((rpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF)) ||
+           (wpipe == NULL) || (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF))) {
+               kn->kn_flags |= EV_EOF;
+               retval = 1;
+       } else {
+               int64_t lowwat = 1;
+               if (kn->kn_sfflags & NOTE_LOWAT) {
+                       if (rpipe->pipe_buffer.size && kn->kn_sdata > MAX_PIPESIZE(rpipe)) {
+                               lowwat = MAX_PIPESIZE(rpipe);
+                       } else if (kn->kn_sdata > lowwat) {
+                               lowwat = kn->kn_sdata;
+                       }
+               }
+               retval = kn->kn_data >= lowwat;
+       }
+       return retval;
+}
+
+static int
+filt_piperead(struct knote *kn, long hint)
+{
+#pragma unused(hint)
+       struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
+
+       return filt_piperead_common(kn, rpipe);
+}
+
+static int
+filt_pipereadtouch(struct knote *kn, struct kevent_internal_s *kev)
+{
+       struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
+       int retval;
+
+       PIPE_LOCK(rpipe);
+
+       /* accept new inputs (and save the low water threshold and flag) */
+       kn->kn_sdata = kev->data;
+       kn->kn_sfflags = kev->fflags;
+
+       /* identify if any events are now fired */
+       retval = filt_piperead_common(kn, rpipe);
+
+       PIPE_UNLOCK(rpipe);
+
+       return retval;
+}
+
+static int
+filt_pipereadprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev)
+{
+#pragma unused(data)
+       struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
+       int    retval;
+
+       PIPE_LOCK(rpipe);
+       retval = filt_piperead_common(kn, rpipe);
+       if (retval) {
+               *kev = kn->kn_kevent;
+               if (kn->kn_flags & EV_CLEAR) {
+                       kn->kn_fflags = 0;
+                       kn->kn_data = 0;
+               }
+       }
+       PIPE_UNLOCK(rpipe);
 
+       return retval;
 }
 
 /*ARGSUSED*/
 static int
-pipe_kqfilter(__unused struct fileproc *fp, struct knote *kn, __unused vfs_context_t ctx)
+filt_pipewrite_common(struct knote *kn, struct pipe *rpipe)
 {
-       struct pipe *cpipe;
+       struct pipe *wpipe;
+
+       /*
+        * we're being called back via the KNOTE post
+        * we made in pipeselwakeup, and we already hold the mutex...
+        */
+       wpipe = rpipe->pipe_peer;
+
+       if ((wpipe == NULL) || (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF))) {
+               kn->kn_data = 0;
+               kn->kn_flags |= EV_EOF;
+               return 1;
+       }
+       kn->kn_data = MAX_PIPESIZE(wpipe) - wpipe->pipe_buffer.cnt;
+
+       int64_t lowwat = PIPE_BUF;
+       if (kn->kn_sfflags & NOTE_LOWAT) {
+               if (wpipe->pipe_buffer.size && kn->kn_sdata > MAX_PIPESIZE(wpipe)) {
+                       lowwat = MAX_PIPESIZE(wpipe);
+               } else if (kn->kn_sdata > lowwat) {
+                       lowwat = kn->kn_sdata;
+               }
+       }
+
+       return kn->kn_data >= lowwat;
+}
+
+/*ARGSUSED*/
+static int
+filt_pipewrite(struct knote *kn, long hint)
+{
+#pragma unused(hint)
+       struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
+
+       return filt_pipewrite_common(kn, rpipe);
+}
+
+
+static int
+filt_pipewritetouch(struct knote *kn, struct kevent_internal_s *kev)
+{
+       struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
+       int res;
+
+       PIPE_LOCK(rpipe);
+
+       /* accept new kevent data (and save off lowat threshold and flag) */
+       kn->kn_sfflags = kev->fflags;
+       kn->kn_sdata = kev->data;
 
-       cpipe = (struct pipe *)kn->kn_fp->f_data;
+       /* determine if any event is now deemed fired */
+       res = filt_pipewrite_common(kn, rpipe);
+
+       PIPE_UNLOCK(rpipe);
+
+       return res;
+}
+
+static int
+filt_pipewriteprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev)
+{
+#pragma unused(data)
+       struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
+       int res;
+
+       PIPE_LOCK(rpipe);
+       res = filt_pipewrite_common(kn, rpipe);
+       if (res) {
+               *kev = kn->kn_kevent;
+               if (kn->kn_flags & EV_CLEAR) {
+                       kn->kn_fflags = 0;
+                       kn->kn_data = 0;
+               }
+       }
+       PIPE_UNLOCK(rpipe);
+
+       return res;
+}
+
+/*ARGSUSED*/
+static int
+pipe_kqfilter(__unused struct fileproc *fp, struct knote *kn,
+    __unused struct kevent_internal_s *kev, __unused vfs_context_t ctx)
+{
+       struct pipe *cpipe = (struct pipe *)kn->kn_fp->f_data;
+       int res;
 
        PIPE_LOCK(cpipe);
 #if CONFIG_MACF
@@ -1368,38 +1587,52 @@ pipe_kqfilter(__unused struct fileproc *fp, struct knote *kn, __unused vfs_conte
         */
        if (mac_pipe_check_kqfilter(vfs_context_ucred(ctx), kn, cpipe) != 0) {
                PIPE_UNLOCK(cpipe);
-               return (1);
+               kn->kn_flags = EV_ERROR;
+               kn->kn_data = EPERM;
+               return 0;
        }
 #endif
 
        switch (kn->kn_filter) {
        case EVFILT_READ:
-               kn->kn_fop = &pipe_rfiltops;
+               kn->kn_filtid = EVFILTID_PIPE_R;
 
+               /* determine initial state */
+               res = filt_piperead_common(kn, cpipe);
                break;
+
        case EVFILT_WRITE:
-               kn->kn_fop = &pipe_wfiltops;
+               kn->kn_filtid = EVFILTID_PIPE_W;
 
                if (cpipe->pipe_peer == NULL) {
                        /*
                         * other end of pipe has been closed
                         */
-                       PIPE_UNLOCK(cpipe);
-                       return (EPIPE);
+                       PIPE_UNLOCK(cpipe);
+                       kn->kn_flags = EV_ERROR;
+                       kn->kn_data = EPIPE;
+                       return 0;
                }
-               if (cpipe->pipe_peer)
-               cpipe = cpipe->pipe_peer;
+               if (cpipe->pipe_peer) {
+                       cpipe = cpipe->pipe_peer;
+               }
+
+               /* determine inital state */
+               res = filt_pipewrite_common(kn, cpipe);
                break;
        default:
-               PIPE_UNLOCK(cpipe);
-               return (1);
+               PIPE_UNLOCK(cpipe);
+               kn->kn_flags = EV_ERROR;
+               kn->kn_data = EINVAL;
+               return 0;
        }
 
-       if (KNOTE_ATTACH(&cpipe->pipe_sel.si_note, kn))
-               cpipe->pipe_state |= PIPE_KNOTE;
+       if (KNOTE_ATTACH(&cpipe->pipe_sel.si_note, kn)) {
+               cpipe->pipe_state |= PIPE_KNOTE;
+       }
 
        PIPE_UNLOCK(cpipe);
-       return (0);
+       return res;
 }
 
 static void
@@ -1410,146 +1643,67 @@ filt_pipedetach(struct knote *kn)
        PIPE_LOCK(cpipe);
 
        if (kn->kn_filter == EVFILT_WRITE) {
-               if (cpipe->pipe_peer == NULL) {
-                       PIPE_UNLOCK(cpipe);
+               if (cpipe->pipe_peer == NULL) {
+                       PIPE_UNLOCK(cpipe);
                        return;
                }
                cpipe = cpipe->pipe_peer;
        }
        if (cpipe->pipe_state & PIPE_KNOTE) {
-               if (KNOTE_DETACH(&cpipe->pipe_sel.si_note, kn))
-                       cpipe->pipe_state &= ~PIPE_KNOTE;
-       }
-       PIPE_UNLOCK(cpipe);
-}
-
-/*ARGSUSED*/
-static int
-filt_piperead(struct knote *kn, long hint)
-{
-       struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
-       struct pipe *wpipe;
-       int    retval;
-
-       /*
-        * if hint == 0, then we've been called from the kevent
-        * world directly and do not currently hold the pipe mutex...
-        * if hint == 1, we're being called back via the KNOTE post
-        * we made in pipeselwakeup, and we already hold the mutex...
-        */
-       if (hint == 0)
-               PIPE_LOCK(rpipe);
-
-       wpipe = rpipe->pipe_peer;
-       kn->kn_data = rpipe->pipe_buffer.cnt;
-       if ((rpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF)) ||
-           (wpipe == NULL) || (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF))) {
-               kn->kn_flags |= EV_EOF;
-               retval = 1;
-       } else {
-               int64_t lowwat = 1;
-               if (kn->kn_sfflags & NOTE_LOWAT) {
-                       if (rpipe->pipe_buffer.size && kn->kn_sdata > MAX_PIPESIZE(rpipe))
-                               lowwat = MAX_PIPESIZE(rpipe);
-                       else if (kn->kn_sdata > lowwat)
-                               lowwat = kn->kn_sdata;
+               if (KNOTE_DETACH(&cpipe->pipe_sel.si_note, kn)) {
+                       cpipe->pipe_state &= ~PIPE_KNOTE;
                }
-               retval = kn->kn_data >= lowwat;
        }
-
-       if (hint == 0)
-               PIPE_UNLOCK(rpipe);
-
-       return (retval);
-}
-
-/*ARGSUSED*/
-static int
-filt_pipewrite(struct knote *kn, long hint)
-{
-       struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
-       struct pipe *wpipe;
-
-       /*
-        * if hint == 0, then we've been called from the kevent
-        * world directly and do not currently hold the pipe mutex...
-        * if hint == 1, we're being called back via the KNOTE post
-        * we made in pipeselwakeup, and we already hold the mutex...
-        */
-       if (hint == 0)
-               PIPE_LOCK(rpipe);
-
-       wpipe = rpipe->pipe_peer;
-
-       if ((wpipe == NULL) || (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF))) {
-               kn->kn_data = 0;
-               kn->kn_flags |= EV_EOF; 
-
-               if (hint == 0)
-                       PIPE_UNLOCK(rpipe);
-               return (1);
-       }
-       kn->kn_data = MAX_PIPESIZE(wpipe) - wpipe->pipe_buffer.cnt;
-
-       int64_t lowwat = PIPE_BUF;
-       if (kn->kn_sfflags & NOTE_LOWAT) {
-               if (wpipe->pipe_buffer.size && kn->kn_sdata > MAX_PIPESIZE(wpipe))
-                       lowwat = MAX_PIPESIZE(wpipe);
-               else if (kn->kn_sdata > lowwat)
-                       lowwat = kn->kn_sdata;
-       }
-       
-       if (hint == 0)
-               PIPE_UNLOCK(rpipe);
-
-       return (kn->kn_data >= lowwat);
+       PIPE_UNLOCK(cpipe);
 }
 
 int
 fill_pipeinfo(struct pipe * cpipe, struct pipe_info * pinfo)
 {
 #if CONFIG_MACF
-        int error;
+       int error;
 #endif
-       struct timeval now;
+       struct timespec now;
        struct vinfo_stat * ub;
        int pipe_size = 0;
        int pipe_count;
 
-       if (cpipe == NULL)
-               return (EBADF);
+       if (cpipe == NULL) {
+               return EBADF;
+       }
        PIPE_LOCK(cpipe);
 
 #if CONFIG_MACF
        error = mac_pipe_check_stat(kauth_cred_get(), cpipe);
        if (error) {
                PIPE_UNLOCK(cpipe);
-               return (error);
+               return error;
        }
 #endif
        if (cpipe->pipe_buffer.buffer == 0) {
-               /*
+               /*
                 * must be stat'ing the write fd
                 */
-               if (cpipe->pipe_peer) {
-                       /*
+               if (cpipe->pipe_peer) {
+                       /*
                         * the peer still exists, use it's info
                         */
-                       pipe_size  = MAX_PIPESIZE(cpipe->pipe_peer);
+                       pipe_size  = MAX_PIPESIZE(cpipe->pipe_peer);
                        pipe_count = cpipe->pipe_peer->pipe_buffer.cnt;
                } else {
                        pipe_count = 0;
                }
        } else {
-               pipe_size  = MAX_PIPESIZE(cpipe);
+               pipe_size  = MAX_PIPESIZE(cpipe);
                pipe_count = cpipe->pipe_buffer.cnt;
        }
        /*
         * since peer's buffer is setup ouside of lock
         * we might catch it in transient state
         */
-       if (pipe_size == 0)
+       if (pipe_size == 0) {
                pipe_size  = PIPE_SIZE;
+       }
 
        ub = &pinfo->pipe_stat;
 
@@ -1557,22 +1711,23 @@ fill_pipeinfo(struct pipe * cpipe, struct pipe_info * pinfo)
        ub->vst_mode = S_IFIFO | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
        ub->vst_blksize = pipe_size;
        ub->vst_size = pipe_count;
-       if (ub->vst_blksize != 0)
+       if (ub->vst_blksize != 0) {
                ub->vst_blocks = (ub->vst_size + ub->vst_blksize - 1) / ub->vst_blksize;
+       }
        ub->vst_nlink = 1;
 
        ub->vst_uid = kauth_getuid();
        ub->vst_gid = kauth_getgid();
 
-       microtime(&now);
+       nanotime(&now);
        ub->vst_atime  = now.tv_sec;
-       ub->vst_atimensec = now.tv_usec * 1000;
+       ub->vst_atimensec = now.tv_nsec;
 
        ub->vst_mtime  = now.tv_sec;
-       ub->vst_mtimensec = now.tv_usec * 1000;
+       ub->vst_mtimensec = now.tv_nsec;
 
        ub->vst_ctime  = now.tv_sec;
-       ub->vst_ctimensec = now.tv_usec * 1000;
+       ub->vst_ctimensec = now.tv_nsec;
 
        /*
         * Left as 0: st_dev, st_ino, st_nlink, st_rdev, st_flags, st_gen, st_uid, st_gid.
@@ -1585,30 +1740,29 @@ fill_pipeinfo(struct pipe * cpipe, struct pipe_info * pinfo)
 
        PIPE_UNLOCK(cpipe);
 
-       return (0);
+       return 0;
 }
 
 
-static int 
+static int
 pipe_drain(struct fileproc *fp, __unused vfs_context_t ctx)
 {
-
        /* Note: fdlock already held */
        struct pipe *ppipe, *cpipe = (struct pipe *)(fp->f_fglob->fg_data);
 
        if (cpipe) {
                PIPE_LOCK(cpipe);
-               cpipe->pipe_state |= PIPE_DRAIN; 
+               cpipe->pipe_state |= PIPE_DRAIN;
                cpipe->pipe_state &= ~(PIPE_WANTR | PIPE_WANTW);
                wakeup(cpipe);
-               
+
                /* Must wake up peer: a writer sleeps on the read side */
                if ((ppipe = cpipe->pipe_peer)) {
                        ppipe->pipe_state |= PIPE_DRAIN;
                        ppipe->pipe_state &= ~(PIPE_WANTR | PIPE_WANTW);
                        wakeup(ppipe);
                }
-               
+
                PIPE_UNLOCK(cpipe);
                return 0;
        }
@@ -1617,7 +1771,7 @@ pipe_drain(struct fileproc *fp, __unused vfs_context_t ctx)
 }
 
 
- /*
+/*
  * When a thread sets a write-select on a pipe, it creates an implicit,
  * untracked dependency between that thread and the peer of the pipe
  * on which the select is set.  If the peer pipe is closed and freed
@@ -1626,7 +1780,7 @@ pipe_drain(struct fileproc *fp, __unused vfs_context_t ctx)
  * we notice whenever a dangerous select() is set on a pipe, and
  * defer the final deletion of the pipe until that select()s are all
  * resolved.  Since we can't currently detect exactly when that
- * resolution happens, we use a simple garbage collection queue to 
+ * resolution happens, we use a simple garbage collection queue to
  * reap the at-risk pipes 'later'.
  */
 static void
@@ -1646,8 +1800,9 @@ pipe_garbage_collect(struct pipe *cpipe)
        old = now - old;
        while ((pgp = pipe_garbage_head) && pgp->pg_timestamp < old) {
                pipe_garbage_head = pgp->pg_next;
-               if (pipe_garbage_head == NULL)
+               if (pipe_garbage_head == NULL) {
                        pipe_garbage_tail = NULL;
+               }
                pipe_garbage_count--;
                zfree(pipe_zone, pgp->pg_pipe);
                zfree(pipe_garbage_zone, pgp);
@@ -1676,16 +1831,18 @@ pipe_garbage_collect(struct pipe *cpipe)
                pgp->pg_timestamp = now;
                pgp->pg_next = NULL;
 
-               if (pipe_garbage_tail)
+               if (pipe_garbage_tail) {
                        pipe_garbage_tail->pg_next = pgp;
+               }
                pipe_garbage_tail = pgp;
-               if (pipe_garbage_head == NULL)
+               if (pipe_garbage_head == NULL) {
                        pipe_garbage_head = pipe_garbage_tail;
+               }
 
-               if (pipe_garbage_count++ >= PIPE_GARBAGE_QUEUE_LIMIT)
+               if (pipe_garbage_count++ >= PIPE_GARBAGE_QUEUE_LIMIT) {
                        panic("Length of pipe garbage queue exceeded %d",
                            PIPE_GARBAGE_QUEUE_LIMIT);
+               }
        }
        lck_mtx_unlock(pipe_garbage_lock);
 }
-