[src/trunk]: src/sys/arch/amd64/amd64 Declare onfault_restore, and be stricte...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7e5741bcd253
branches:  trunk
changeset: 356124:7e5741bcd253
user:      maxv <maxv%NetBSD.org@localhost>
date:      Sun Sep 03 09:19:51 2017 +0000

description:
Declare onfault_restore, and be stricter with SMEP.

diffstat:

 sys/arch/amd64/amd64/trap.c |  29 ++++++++++++++++++-----------
 1 files changed, 18 insertions(+), 11 deletions(-)

diffs (78 lines):

diff -r 08de41d94878 -r 7e5741bcd253 sys/arch/amd64/amd64/trap.c
--- a/sys/arch/amd64/amd64/trap.c       Sun Sep 03 09:01:03 2017 +0000
+++ b/sys/arch/amd64/amd64/trap.c       Sun Sep 03 09:19:51 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: trap.c,v 1.98 2017/09/03 09:01:03 maxv Exp $   */
+/*     $NetBSD: trap.c,v 1.99 2017/09/03 09:19:51 maxv Exp $   */
 
 /*
  * Copyright (c) 1998, 2000, 2017 The NetBSD Foundation, Inc.
@@ -64,7 +64,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.98 2017/09/03 09:01:03 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.99 2017/09/03 09:19:51 maxv Exp $");
 
 #include "opt_ddb.h"
 #include "opt_kgdb.h"
@@ -153,6 +153,13 @@
 
 #define        IDTVEC(name)    __CONCAT(X, name)
 
+static void
+onfault_restore(struct trapframe *frame, void *onfault, int error)
+{
+       frame->tf_rip = (uintptr_t)onfault;
+       frame->tf_rax = error;
+}
+
 static void *
 onfault_handler(const struct pcb *pcb, const struct trapframe *tf)
 {
@@ -405,11 +412,7 @@
                /* Check for copyin/copyout fault. */
                onfault = onfault_handler(pcb, frame);
                if (onfault != NULL) {
-copyefault:
-                       error = EFAULT;
-copyfault:
-                       frame->tf_rip = (uintptr_t)onfault;
-                       frame->tf_rax = error;
+                       onfault_restore(frame, onfault, EFAULT);
                        return;
                }
 
@@ -537,7 +540,8 @@
                 */
                onfault = pcb->pcb_onfault;
                if (onfault == fusuintrfailure) {
-                       goto copyefault;
+                       onfault_restore(frame, fusuintrfailure, EFAULT);
+                       return;
                }
                if (cpu_intr_p() || (l->l_pflag & LP_INTR) != 0) {
                        goto we_re_toast;
@@ -547,7 +551,7 @@
 
                if (frame->tf_err & PGEX_X) {
                        /* SMEP might have brought us here */
-                       if (cr2 > VM_MIN_ADDRESS && cr2 <= VM_MAXUSER_ADDRESS)
+                       if (cr2 < VM_MAXUSER_ADDRESS)
                                panic("prevented execution of %p (SMEP)",
                                    (void *)cr2);
                }
@@ -658,8 +662,11 @@
 
                if (type == T_PAGEFLT) {
                        onfault = onfault_handler(pcb, frame);
-                       if (onfault != NULL)
-                               goto copyfault;
+                       if (onfault != NULL) {
+                               onfault_restore(frame, onfault, error);
+                               return;
+                       }
+
                        printf("uvm_fault(%p, 0x%lx, %d) -> %x\n",
                            map, va, ftype, error);
                        goto we_re_toast;