MFC r303382:

Provide the getboottime(9) and getboottimebin(9) KPI.

MFC r303387:
Prevent parallel tc_windup() calls.  Keep boottime in timehands,
and adjust it from tc_windup().

MFC notes:

The boottime and boottimebin globals are still exported from
the kernel dyn symbol table in stable/11, but their declarations are
removed from sys/time.h.  This preserves KBI but not KPI, while all
in-tree consumers are converted to getboottime().

The variables are updated after tc_setclock_mtx is dropped, which gives
approximately same unlocked bugs as before.

The boottime and boottimebin locals in several sys/kern_tc.c functions
were renamed by adding the '_x' suffix to avoid name conficts.

4 files changed, 8 insertions, 2 deletions

diff --git a/sys/fs/devfs/devfs_vnops.c b/sys/fs/devfs/devfs_vnops.c
index 7cc0f9e..afa3da4 100644
--- a/sys/fs/devfs/devfs_vnops.c
+++ b/sys/fs/devfs/devfs_vnops.c
@@ -707,10 +707,11 @@ devfs_getattr(struct vop_getattr_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct vattr *vap = ap->a_vap;
-	int error;
 	struct devfs_dirent *de;
 	struct devfs_mount *dmp;
 	struct cdev *dev;
+	struct timeval boottime;
+	int error;
 
 	error = devfs_populate_vp(vp);
 	if (error != 0)
@@ -740,6 +741,7 @@ devfs_getattr(struct vop_getattr_args *ap)
 	vap->va_blocksize = DEV_BSIZE;
 	vap->va_type = vp->v_type;
 
+	getboottime(&boottime);
 #define fix(aa)							\
 	do {							\
 		if ((aa).tv_sec <= 3600) {			\
diff --git a/sys/fs/fdescfs/fdesc_vnops.c b/sys/fs/fdescfs/fdesc_vnops.c
index 4f6e1b9..65b8a54 100644
--- a/sys/fs/fdescfs/fdesc_vnops.c
+++ b/sys/fs/fdescfs/fdesc_vnops.c
@@ -394,7 +394,9 @@ fdesc_getattr(struct vop_getattr_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct vattr *vap = ap->a_vap;
+	struct timeval boottime;
 
+	getboottime(&boottime);
 	vap->va_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
 	vap->va_fileid = VTOFDESC(vp)->fd_ix;
 	vap->va_uid = 0;
diff --git a/sys/fs/nfs/nfsport.h b/sys/fs/nfs/nfsport.h
index 921df2d..6b41e2f 100644
--- a/sys/fs/nfs/nfsport.h
+++ b/sys/fs/nfs/nfsport.h
@@ -872,7 +872,7 @@ int newnfs_realign(struct mbuf **, int);
 /*
  * Set boottime.
  */
-#define	NFSSETBOOTTIME(b)	((b) = boottime)
+#define	NFSSETBOOTTIME(b)	(getboottime(&b))
 
 /*
  * The size of directory blocks in the buffer cache.
diff --git a/sys/fs/procfs/procfs_status.c b/sys/fs/procfs/procfs_status.c
index 5a00ee1..defdec3 100644
--- a/sys/fs/procfs/procfs_status.c
+++ b/sys/fs/procfs/procfs_status.c
@@ -70,6 +70,7 @@ procfs_doprocstatus(PFS_FILL_ARGS)
 	const char *wmesg;
 	char *pc;
 	char *sep;
+	struct timeval boottime;
 	int pid, ppid, pgid, sid;
 	int i;
 
@@ -129,6 +130,7 @@ procfs_doprocstatus(PFS_FILL_ARGS)
 		calcru(p, &ut, &st);
 		PROC_STATUNLOCK(p);
 		start = p->p_stats->p_start;
+		getboottime(&boottime);
 		timevaladd(&start, &boottime);
 		sbuf_printf(sb, " %jd,%ld %jd,%ld %jd,%ld",
 		    (intmax_t)start.tv_sec, start.tv_usec,