[src/trunk]: src/sys/arch/amd64/amd64 This branch must be static, otherwise t...

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

details:   https://anonhg.NetBSD.org/src/rev/ce00fe403874
branches:  trunk
changeset: 825621:ce00fe403874
user:      maxv <maxv%NetBSD.org@localhost>
date:      Tue Jul 25 18:03:56 2017 +0000

description:
This branch must be static, otherwise there is a condition under which
the KASSERT in startlwp32 would be triggered.

diffstat:

 sys/arch/amd64/amd64/netbsd32_machdep.c |  47 ++++++++++++++++----------------
 1 files changed, 23 insertions(+), 24 deletions(-)

diffs (77 lines):

diff -r b99fc82c0719 -r ce00fe403874 sys/arch/amd64/amd64/netbsd32_machdep.c
--- a/sys/arch/amd64/amd64/netbsd32_machdep.c   Tue Jul 25 17:43:44 2017 +0000
+++ b/sys/arch/amd64/amd64/netbsd32_machdep.c   Tue Jul 25 18:03:56 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: netbsd32_machdep.c,v 1.106 2017/07/22 13:00:42 maxv Exp $      */
+/*     $NetBSD: netbsd32_machdep.c,v 1.107 2017/07/25 18:03:56 maxv Exp $      */
 
 /*
  * Copyright (c) 2001 Wasabi Systems, Inc.
@@ -36,7 +36,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_machdep.c,v 1.106 2017/07/22 13:00:42 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_machdep.c,v 1.107 2017/07/25 18:03:56 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_compat_netbsd.h"
@@ -1086,37 +1086,36 @@
 int
 cpu_mcontext32_validate(struct lwp *l, const mcontext32_t *mcp)
 {
-       struct pmap *pmap = l->l_proc->p_vmspace->vm_map.pmap;
        const __greg32_t *gr;
        struct trapframe *tf;
-       struct pcb *pcb;
 
        gr = mcp->__gregs;
        tf = l->l_md.md_regs;
-       pcb = lwp_getpcb(l);
 
        if (((gr[_REG32_EFL] ^ tf->tf_rflags) & PSL_USERSTATIC) != 0)
                return EINVAL;
 
-       if (__predict_false(pmap->pm_ldt != NULL)) {
-               /* Only when the LDT is user-set (with USER_LDT) */
-               if (!USERMODE(gr[_REG32_CS], gr[_REG32_EFL]))
-                       return EINVAL;
-       } else {
-               if (!VALID_USER_CSEL32(gr[_REG32_CS]))
-                       return EINVAL;
-               if (gr[_REG32_FS] != 0 && !VALID_USER_DSEL32(gr[_REG32_FS]) &&
-                   !(VALID_USER_FSEL32(gr[_REG32_FS]) && pcb->pcb_fs != 0))
-                       return EINVAL;
-               if (gr[_REG32_GS] != 0 && !VALID_USER_DSEL32(gr[_REG32_GS]) &&
-                   !(VALID_USER_GSEL32(gr[_REG32_GS]) && pcb->pcb_gs != 0))
-                       return EINVAL;
-               if (gr[_REG32_ES] != 0 && !VALID_USER_DSEL32(gr[_REG32_ES]))
-                       return EINVAL;
-               if (!VALID_USER_DSEL32(gr[_REG32_DS]) ||
-                   !VALID_USER_DSEL32(gr[_REG32_SS]))
-                       return EINVAL;
-       }
+#ifdef USER_LDT
+       /* Userland is allowed to have unfamiliar segment register values */
+       if (!USERMODE(gr[_REG32_CS], gr[_REG32_EFL]))
+               return EINVAL;
+#else
+       struct pcb *pcb = lwp_getpcb(l);
+
+       if (!VALID_USER_CSEL32(gr[_REG32_CS]))
+               return EINVAL;
+       if (gr[_REG32_FS] != 0 && !VALID_USER_DSEL32(gr[_REG32_FS]) &&
+           !(VALID_USER_FSEL32(gr[_REG32_FS]) && pcb->pcb_fs != 0))
+               return EINVAL;
+       if (gr[_REG32_GS] != 0 && !VALID_USER_DSEL32(gr[_REG32_GS]) &&
+           !(VALID_USER_GSEL32(gr[_REG32_GS]) && pcb->pcb_gs != 0))
+               return EINVAL;
+       if (gr[_REG32_ES] != 0 && !VALID_USER_DSEL32(gr[_REG32_ES]))
+               return EINVAL;
+       if (!VALID_USER_DSEL32(gr[_REG32_DS]) ||
+           !VALID_USER_DSEL32(gr[_REG32_SS]))
+               return EINVAL;
+#endif
 
        if (gr[_REG32_EIP] >= VM_MAXUSER_ADDRESS32)
                return EINVAL;