[src/netbsd-1-5]: src/sys/arch/i386/i386 Pull up revision 1.59 (requested by ...

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

details:   https://anonhg.NetBSD.org/src/rev/93723b6a77a8
branches:  netbsd-1-5
changeset: 491924:93723b6a77a8
user:      he <he%NetBSD.org@localhost>
date:      Sun Jun 17 22:27:10 2001 +0000

description:
Pull up revision 1.59 (requested by sommerfeld):
  Add %fs/%gs to trap frame and save/restore them on trap/interupt/
  syscall entry from userspace.

  Remove special-case ``by hand'' validation of %fs/%gs register
  values s well as special handling of them in various signal
  handling paths.  Now, like %ds and %es, they are validated by
  the hardware on return to userland.

  This paves the way for the use of %fs for per-cpu data on multi-
  processor systems, and fixes an otherwise difficult-to-fix
  interaction between threads/clone(2) and USER_LDT.

diffstat:

 sys/arch/i386/i386/sys_machdep.c |  18 +-----------------
 1 files changed, 1 insertions(+), 17 deletions(-)

diffs (53 lines):

diff -r 406b139d7475 -r 93723b6a77a8 sys/arch/i386/i386/sys_machdep.c
--- a/sys/arch/i386/i386/sys_machdep.c  Sun Jun 17 22:27:07 2001 +0000
+++ b/sys/arch/i386/i386/sys_machdep.c  Sun Jun 17 22:27:10 2001 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sys_machdep.c,v 1.48.14.2 2001/06/10 19:37:12 he Exp $ */
+/*     $NetBSD: sys_machdep.c,v 1.48.14.3 2001/06/17 22:27:10 he Exp $ */
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -237,7 +237,6 @@
        int error, i, n;
        struct pcb *pcb = &p->p_addr->u_pcb;
        pmap_t pmap = p->p_vmspace->vm_map.pmap;
-       int fsslot, gsslot;
        struct i386_set_ldt_args ua;
        union descriptor *descv;
 
@@ -308,10 +307,6 @@
 #endif
        }
 
-       if (pcb == curpcb)
-               savectx(curpcb);
-       fsslot = IDXSEL(pcb->pcb_fs);
-       gsslot = IDXSEL(pcb->pcb_gs);
        error = 0;
 
        /* Check descriptors for access violations. */
@@ -338,11 +333,6 @@
                                error = EACCES;
                                goto out;
                        }
-                       /* Can't replace in use descriptor with gate. */
-                       if (n == fsslot || n == gsslot) {
-                               error = EBUSY;
-                               goto out;
-                       }
                        break;
                case SDT_MEMEC:
                case SDT_MEMEAC:
@@ -383,12 +373,6 @@
                                error = EACCES;
                                goto out;
                        }
-               } else {
-                       /* Must be "present" if in use. */
-                       if (n == fsslot || n == gsslot) {
-                               error = EACCES;
-                               goto out;
-                       }
                }
        }