[src/trunk]: src/sys/arch/amd64/amd64 Do mask the upper 16 bits, when sanity ...

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

details:   https://anonhg.NetBSD.org/src/rev/a8a01271436b
branches:  trunk
changeset: 761419:a8a01271436b
user:      njoly <njoly%NetBSD.org@localhost>
date:      Wed Jan 26 21:44:31 2011 +0000

description:
Do mask the upper 16 bits, when sanity checking fs/gs register values.
Fix my own PR/43842.

diffstat:

 sys/arch/amd64/amd64/netbsd32_machdep.c |  18 ++++++++++++------
 1 files changed, 12 insertions(+), 6 deletions(-)

diffs (57 lines):

diff -r 9e4ea89c66f1 -r a8a01271436b sys/arch/amd64/amd64/netbsd32_machdep.c
--- a/sys/arch/amd64/amd64/netbsd32_machdep.c   Wed Jan 26 21:35:14 2011 +0000
+++ b/sys/arch/amd64/amd64/netbsd32_machdep.c   Wed Jan 26 21:44:31 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: netbsd32_machdep.c,v 1.68 2010/11/17 18:22:17 dholland Exp $   */
+/*     $NetBSD: netbsd32_machdep.c,v 1.69 2011/01/26 21:44:31 njoly Exp $      */
 
 /*
  * Copyright (c) 2001 Wasabi Systems, Inc.
@@ -36,7 +36,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_machdep.c,v 1.68 2010/11/17 18:22:17 dholland Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_machdep.c,v 1.69 2011/01/26 21:44:31 njoly Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_compat_netbsd.h"
@@ -952,6 +952,12 @@
  * and rely on catching invalid user contexts on exit from the kernel.
  * These functions perform the needed checks.
  */
+
+#define        VALID_FS32(s) \
+    (((s) & 0xffff) == GSEL(GUFS_SEL, SEL_UPL))
+#define        VALID_GS32(s) \
+    (((s) & 0xffff) == GSEL(GUGS_SEL, SEL_UPL))
+
 static int
 check_sigcontext32(struct lwp *l, const struct netbsd32_sigcontext *scp)
 {
@@ -965,10 +971,10 @@
            !VALID_USER_CSEL32(scp->sc_cs))
                return EINVAL;
        if (scp->sc_fs != 0 && !VALID_USER_DSEL32(scp->sc_fs) &&
-           !(scp->sc_fs == GSEL(GUFS_SEL, SEL_UPL) && pcb->pcb_fs != 0))
+           !(VALID_FS32(scp->sc_fs) && pcb->pcb_fs != 0))
                return EINVAL;
        if (scp->sc_gs != 0 && !VALID_USER_DSEL32(scp->sc_gs) &&
-           !(scp->sc_gs == GSEL(GUGS_SEL, SEL_UPL) && pcb->pcb_gs != 0))
+           !(VALID_GS32(scp->sc_gs) && pcb->pcb_gs != 0))
                return EINVAL;
        if (scp->sc_es != 0 && !VALID_USER_DSEL32(scp->sc_es))
                return EINVAL;
@@ -994,10 +1000,10 @@
            !VALID_USER_CSEL32(gr[_REG32_CS]))
                return EINVAL;
        if (gr[_REG32_FS] != 0 && !VALID_USER_DSEL32(gr[_REG32_FS]) &&
-           !(gr[_REG32_FS] == GSEL(GUFS_SEL, SEL_UPL) && pcb->pcb_fs != 0))
+           !(VALID_FS32(gr[_REG32_FS]) && pcb->pcb_fs != 0))
                return EINVAL;
        if (gr[_REG32_GS] != 0 && !VALID_USER_DSEL32(gr[_REG32_GS]) &&
-           !(gr[_REG32_GS] == GSEL(GUGS_SEL, SEL_UPL) && pcb->pcb_gs != 0))
+           !(VALID_GS32(gr[_REG32_GS]) && pcb->pcb_gs != 0))
                return EINVAL;
        if (gr[_REG32_ES] != 0 && !VALID_USER_DSEL32(gr[_REG32_ES]))
                return EINVAL;