From 44ff2e7b6295195e4f265c653b57d314a00ae587 Mon Sep 17 00:00:00 2001
From: kib <kib@FreeBSD.org>
Date: Mon, 19 Jan 2015 11:07:29 +0000
Subject: MFC r277055: Revert r263475: TDP_DEVMEMIO no longer needed.

---
 sys/amd64/amd64/mem.c  | 4 +---
 sys/amd64/amd64/trap.c | 6 ------
 sys/kern/subr_trap.c   | 2 --
 sys/sys/proc.h         | 2 +-
 sys/vm/vm_fault.c      | 4 ----
 5 files changed, 2 insertions(+), 16 deletions(-)

diff --git a/sys/amd64/amd64/mem.c b/sys/amd64/amd64/mem.c
index 3a1f4a4..225fe66 100644
--- a/sys/amd64/amd64/mem.c
+++ b/sys/amd64/amd64/mem.c
@@ -82,10 +82,9 @@ memrw(struct cdev *dev, struct uio *uio, int flags)
 	ssize_t orig_resid;
 	u_long v, vd;
 	u_int c;
-	int error, sflags;
+	int error;
 
 	error = 0;
-	sflags = curthread_pflags_set(TDP_DEVMEMIO);
 	orig_resid = uio->uio_resid;
 	while (uio->uio_resid > 0 && error == 0) {
 		iov = uio->uio_iov;
@@ -151,7 +150,6 @@ memrw(struct cdev *dev, struct uio *uio, int flags)
 			break;
 		}
 	}
-	curthread_pflags_restore(sflags);
 	/*
 	 * Don't return error if any byte was written.  Read and write
 	 * can return error only if no i/o was performed.
diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index a181554..9a8f61e 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -772,12 +772,6 @@ nogo:
 			frame->tf_rip = (long)curpcb->pcb_onfault;
 			return (0);
 		}
-		if ((td->td_pflags & TDP_DEVMEMIO) != 0) {
-			KASSERT(curpcb->pcb_onfault != NULL,
-			    ("/dev/mem without pcb_onfault"));
-			frame->tf_rip = (long)curpcb->pcb_onfault;
-			return (0);
-		}
 		trap_fatal(frame, eva);
 		return (-1);
 	}
diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c
index 8af60bc..19729a4 100644
--- a/sys/kern/subr_trap.c
+++ b/sys/kern/subr_trap.c
@@ -155,8 +155,6 @@ userret(struct thread *td, struct trapframe *frame)
 	    ("userret: Returning with %d locks held", td->td_locks));
 	KASSERT((td->td_pflags & TDP_NOFAULTING) == 0,
 	    ("userret: Returning with pagefaults disabled"));
-	KASSERT((td->td_pflags & TDP_DEVMEMIO) == 0,
-	    ("userret: Returning with /dev/mem i/o leaked"));
 	KASSERT(td->td_no_sleeping == 0,
 	    ("userret: Returning with sleep disabled"));
 	KASSERT(td->td_pinned == 0 || (td->td_pflags & TDP_CALLCHAIN) != 0,
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 9607bfa..488ba07 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -424,7 +424,7 @@ do {									\
 #define	TDP_RESETSPUR	0x04000000 /* Reset spurious page fault history. */
 #define	TDP_NERRNO	0x08000000 /* Last errno is already in td_errno */
 #define	TDP_UIOHELD	0x10000000 /* Current uio has pages held in td_ma */
-#define	TDP_DEVMEMIO	0x20000000 /* Accessing memory for /dev/mem */
+#define	TDP_UNUSED29	0x20000000 /* --available-- */
 #define	TDP_EXECVMSPC	0x40000000 /* Execve destroyed old vmspace */
 
 /*
diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
index 80dc3d7..3f3c62b 100644
--- a/sys/vm/vm_fault.c
+++ b/sys/vm/vm_fault.c
@@ -334,10 +334,6 @@ RetryFault:;
 	map_generation = fs.map->timestamp;
 
 	if (fs.entry->eflags & MAP_ENTRY_NOFAULT) {
-		if ((curthread->td_pflags & TDP_DEVMEMIO) != 0) {
-			vm_map_unlock_read(fs.map);
-			return (KERN_FAILURE);
-		}
 		panic("vm_fault: fault on nofault entry, addr: %lx",
 		    (u_long)vaddr);
 	}
-- 
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