[src/trunk]: src/sys/arch/amd64/amd64 Branch for USER_LDT.

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

details:   https://anonhg.NetBSD.org/src/rev/a89e97b05a25
branches:  trunk
changeset: 355267:a89e97b05a25
user:      maxv <maxv%NetBSD.org@localhost>
date:      Sat Jul 22 13:00:42 2017 +0000

description:
Branch for USER_LDT.

diffstat:

 sys/arch/amd64/amd64/netbsd32_machdep.c |  44 ++++++++++++++++++++------------
 1 files changed, 27 insertions(+), 17 deletions(-)

diffs (78 lines):

diff -r f4276d088718 -r a89e97b05a25 sys/arch/amd64/amd64/netbsd32_machdep.c
--- a/sys/arch/amd64/amd64/netbsd32_machdep.c   Sat Jul 22 09:20:01 2017 +0000
+++ b/sys/arch/amd64/amd64/netbsd32_machdep.c   Sat Jul 22 13:00:42 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: netbsd32_machdep.c,v 1.105 2017/06/01 02:45:05 chs Exp $       */
+/*     $NetBSD: netbsd32_machdep.c,v 1.106 2017/07/22 13:00:42 maxv Exp $      */
 
 /*
  * Copyright (c) 2001 Wasabi Systems, Inc.
@@ -36,7 +36,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_machdep.c,v 1.105 2017/06/01 02:45:05 chs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_machdep.c,v 1.106 2017/07/22 13:00:42 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_compat_netbsd.h"
@@ -1042,34 +1042,44 @@
 
 /*
  * For various reasons, the amd64 port can't do what the i386 port does,
- * and rely on catching invalid user contexts on exit from the kernel.
+ * and relies on catching invalid user contexts on exit from the kernel.
  * These functions perform the needed checks.
  */
 
 static int
 check_sigcontext32(struct lwp *l, const struct netbsd32_sigcontext *scp)
 {
+       struct pmap *pmap = l->l_proc->p_vmspace->vm_map.pmap;
        struct trapframe *tf;
        struct pcb *pcb;
 
        tf = l->l_md.md_regs;
        pcb = lwp_getpcb(curlwp);
 
-       if (((scp->sc_eflags ^ tf->tf_rflags) & PSL_USERSTATIC) != 0 ||
-           !VALID_USER_CSEL32(scp->sc_cs))
-               return EINVAL;
-       if (scp->sc_fs != 0 && !VALID_USER_DSEL32(scp->sc_fs) &&
-           !(VALID_USER_FSEL32(scp->sc_fs) && pcb->pcb_fs != 0))
+       if (((scp->sc_eflags ^ tf->tf_rflags) & PSL_USERSTATIC) != 0)
                return EINVAL;
-       if (scp->sc_gs != 0 && !VALID_USER_DSEL32(scp->sc_gs) &&
-           !(VALID_USER_GSEL32(scp->sc_gs) && pcb->pcb_gs != 0))
-               return EINVAL;
-       if (scp->sc_es != 0 && !VALID_USER_DSEL32(scp->sc_es))
-               return EINVAL;
-       if (!VALID_USER_DSEL32(scp->sc_ds) || !VALID_USER_DSEL32(scp->sc_ss))
-               return EINVAL;
-       if (scp->sc_eip >= VM_MAXUSER_ADDRESS32)
-               return EINVAL;
+
+       if (__predict_false(pmap->pm_ldt != NULL)) {
+               /* Only when the LDT is user-set (with USER_LDT) */
+               if (!USERMODE(scp->sc_cs, scp->sc_eflags))
+                       return EINVAL;
+       } else {
+               if (!VALID_USER_CSEL32(scp->sc_cs))
+                       return EINVAL;
+               if (scp->sc_fs != 0 && !VALID_USER_DSEL32(scp->sc_fs) &&
+                       !(VALID_USER_FSEL32(scp->sc_fs) && pcb->pcb_fs != 0))
+                       return EINVAL;
+               if (scp->sc_gs != 0 && !VALID_USER_DSEL32(scp->sc_gs) &&
+                       !(VALID_USER_GSEL32(scp->sc_gs) && pcb->pcb_gs != 0))
+                       return EINVAL;
+               if (scp->sc_es != 0 && !VALID_USER_DSEL32(scp->sc_es))
+                       return EINVAL;
+               if (!VALID_USER_DSEL32(scp->sc_ds) || !VALID_USER_DSEL32(scp->sc_ss))
+                       return EINVAL;
+               if (scp->sc_eip >= VM_MAXUSER_ADDRESS32)
+                       return EINVAL;
+       }
+
        return 0;
 }