Various and sundry style fixes and comment cleanups.

Approved by:	re (scottl)

2 files changed, 21 insertions, 14 deletions

diff --git a/sys/i386/i386/sys_machdep.c b/sys/i386/i386/sys_machdep.c
index 1f4e907..467ee65 100644
--- a/sys/i386/i386/sys_machdep.c
+++ b/sys/i386/i386/sys_machdep.c
@@ -510,7 +510,7 @@ i386_set_ldt(td, uap, descs)
 	int error = 0, i;
 	int largest_ld;
 	struct mdproc *mdp = &td->td_proc->p_md;
-	struct proc_ldt *pldt = NULL;
+	struct proc_ldt *pldt;
 	union descriptor *dp;
 
 #ifdef	DEBUG
@@ -697,14 +697,18 @@ i386_ldt_grow(struct thread *td, int len)
 		return (ENOMEM);
 	if (len < NLDT + 1)
 		len = NLDT + 1;
+
+	/* Allocate a user ldt. */
 	pldt = mdp->md_ldt;
-	/* allocate user ldt */
 	if (!pldt || len > pldt->ldt_len) {
-		struct proc_ldt *new_ldt = user_ldt_alloc(mdp, len);
+		struct proc_ldt *new_ldt;
+
+		new_ldt = user_ldt_alloc(mdp, len);
 		if (new_ldt == NULL)
 			return (ENOMEM);
 		pldt = mdp->md_ldt;
-		/* sched_lock was held by user_ldt_alloc */
+
+		/* sched_lock was acquired by user_ldt_alloc. */
 		if (pldt) {
 			if (new_ldt->ldt_len > pldt->ldt_len) {
 				old_ldt_base = pldt->ldt_base;
@@ -720,7 +724,7 @@ i386_ldt_grow(struct thread *td, int len)
 			} else {
 				/*
 				 * If other threads already did the work,
-				 * do nothing
+				 * do nothing.
 				 */
 				mtx_unlock_spin(&sched_lock);
 				kmem_free(kernel_map,
diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c
index df01592..7a9837d 100644
--- a/sys/i386/i386/vm_machdep.c
+++ b/sys/i386/i386/vm_machdep.c
@@ -153,7 +153,9 @@ cpu_fork(td1, p2, td2, flags)
 		if ((flags & RFMEM) == 0) {
 			/* unshare user LDT */
 			struct mdproc *mdp1 = &p1->p_md;
-			struct proc_ldt *pldt = mdp1->md_ldt;
+			struct proc_ldt *pldt;
+
+			pldt = mdp1->md_ldt;
 			if (pldt && pldt->ldt_refcnt > 1) {
 				pldt = user_ldt_alloc(mdp1, pldt->ldt_len);
 				if (pldt == NULL)
@@ -295,11 +297,12 @@ cpu_set_fork_handler(td, func, arg)
 void
 cpu_exit(struct thread *td)
 {
-	struct mdproc *mdp;
 
-	/* Reset pc->pcb_gs and %gs before possibly invalidating it. */
-	mdp = &td->td_proc->p_md;
-	if (mdp->md_ldt) {
+	/*
+	 * If this process has a custom LDT, release it.  Reset pc->pcb_gs
+	 * and %gs before we free it in case they refer to an LDT entry.
+	 */
+	if (td->td_proc->p_md.md_ldt) {
 		td->td_pcb->pcb_gs = _udatasel;
 		load_gs(_udatasel);
 		user_ldt_free(td);
@@ -309,16 +312,16 @@ cpu_exit(struct thread *td)
 void
 cpu_thread_exit(struct thread *td)
 {
-	struct pcb *pcb = td->td_pcb; 
 
 #ifdef DEV_NPX
 	if (td == PCPU_GET(fpcurthread))
 		npxdrop();
 #endif
-	if (pcb->pcb_flags & PCB_DBREGS) {
-		/* disable all hardware breakpoints */
+
+	/* Disable any hardware breakpoints. */
+	if (td->td_pcb->pcb_flags & PCB_DBREGS) {
 		reset_dbregs();
-		pcb->pcb_flags &= ~PCB_DBREGS;
+		td->td_pcb->pcb_flags &= ~PCB_DBREGS;
 	}
 }