svn commit: r277055 - in head/sys: amd64/amd64 kern sys vm

[Konstantin Belousov]

Author: kib
Date: Mon Jan 12 08:58:07 2015
New Revision: 277055
URL: https://svnweb.freebsd.org/changeset/base/277055

Log:
  Revert r263475: TDP_DEVMEMIO no longer needed, since amd64 /dev/kmem
  does not access kernel mappings directly.
  
  Reviewed by:	alc
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week

Modified:
  head/sys/amd64/amd64/mem.c
  head/sys/amd64/amd64/trap.c
  head/sys/kern/subr_trap.c
  head/sys/sys/proc.h
  head/sys/vm/vm_fault.c

Modified: head/sys/amd64/amd64/mem.c
==============================================================================
--- head/sys/amd64/amd64/mem.c	Mon Jan 12 08:33:04 2015	(r277054)
+++ head/sys/amd64/amd64/mem.c	Mon Jan 12 08:58:07 2015	(r277055)
@@ -82,10 +82,9 @@ memrw(struct cdev *dev, struct uio *uio,
 	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,
 			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.

Modified: head/sys/amd64/amd64/trap.c
==============================================================================
--- head/sys/amd64/amd64/trap.c	Mon Jan 12 08:33:04 2015	(r277054)
+++ head/sys/amd64/amd64/trap.c	Mon Jan 12 08:58:07 2015	(r277055)
@@ -774,12 +774,6 @@ 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);
 	}

Modified: head/sys/kern/subr_trap.c
==============================================================================
--- head/sys/kern/subr_trap.c	Mon Jan 12 08:33:04 2015	(r277054)
+++ head/sys/kern/subr_trap.c	Mon Jan 12 08:58:07 2015	(r277055)
@@ -157,8 +157,6 @@ userret(struct thread *td, struct trapfr
 	    td->td_rw_rlocks));
 	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,

Modified: head/sys/sys/proc.h
==============================================================================
--- head/sys/sys/proc.h	Mon Jan 12 08:33:04 2015	(r277054)
+++ head/sys/sys/proc.h	Mon Jan 12 08:58:07 2015	(r277055)
@@ -430,7 +430,7 @@ 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 */
 
 /*

Modified: head/sys/vm/vm_fault.c
==============================================================================
--- head/sys/vm/vm_fault.c	Mon Jan 12 08:33:04 2015	(r277054)
+++ head/sys/vm/vm_fault.c	Mon Jan 12 08:58:07 2015	(r277055)
@@ -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);
 	}