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on Xen the GDT has to be updated though HYPERVISOR_update_descriptor().

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Export i386/i386/gdt.c:update_descriptor() and use it in x86_set_sdbase(),
as a direct write to the GDT will cause a kernel trap.
Fix PR port-xen/41401.
This commit is contained in:
bouyer 2009-05-17 18:24:23 +00:00
parent bcf861f849
commit cc56ebe228
3 changed files with 24 additions and 21 deletions
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6
sys/arch/i386/i386/gdt.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: gdt.c,v 1.47 2009/03/21 14:41:29 ad Exp $ */
/* $NetBSD: gdt.c,v 1.48 2009/05/17 18:24:23 bouyer Exp $ */
/*-
* Copyright (c) 1996, 1997, 2009 The NetBSD Foundation, Inc.
@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: gdt.c,v 1.47 2009/03/21 14:41:29 ad Exp $");
__KERNEL_RCSID(0, "$NetBSD: gdt.c,v 1.48 2009/05/17 18:24:23 bouyer Exp $");
#include "opt_multiprocessor.h"
#include "opt_xen.h"
@ -66,7 +66,7 @@ void gdt_grow(int);
int gdt_get_slot1(int);
void gdt_put_slot1(int, int);
static void
void
update_descriptor(union descriptor *table, union descriptor *entry)
{
#ifndef XEN

3
sys/arch/i386/include/segments.h
View File

@ -1,4 +1,4 @@
/* $NetBSD: segments.h,v 1.52 2009/03/21 22:17:13 ad Exp $ */
/* $NetBSD: segments.h,v 1.53 2009/05/17 18:24:23 bouyer Exp $ */
/*-
* Copyright (c) 1990 The Regents of the University of California.
@ -197,6 +197,7 @@ void setsegment(struct segment_descriptor *, const void *, size_t, int, int,
void setgdt(int, const void *, size_t, int, int, int, int);
void unsetgate(struct gate_descriptor *);
void cpu_init_idt(void);
void update_descriptor(union descriptor *, union descriptor *);
#if !defined(XEN)
void idt_init(void);

36
sys/arch/x86/x86/sys_machdep.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: sys_machdep.c,v 1.18 2009/03/29 09:24:52 ad Exp $ */
/* $NetBSD: sys_machdep.c,v 1.19 2009/05/17 18:24:24 bouyer Exp $ */
/*-
* Copyright (c) 1998, 2007, 2009 The NetBSD Foundation, Inc.
@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sys_machdep.c,v 1.18 2009/03/29 09:24:52 ad Exp $");
__KERNEL_RCSID(0, "$NetBSD: sys_machdep.c,v 1.19 2009/05/17 18:24:24 bouyer Exp $");
#include "opt_mtrr.h"
#include "opt_perfctrs.h"
@ -591,7 +591,7 @@ int
x86_set_sdbase(void *arg, char which, lwp_t *l, bool direct)
{
#ifdef i386
struct segment_descriptor sd;
union descriptor usd;
struct pcb *pcb;
vaddr_t base;
int error;
@ -604,28 +604,30 @@ x86_set_sdbase(void *arg, char which, lwp_t *l, bool direct)
return error;
}
sd.sd_lobase = base & 0xffffff;
sd.sd_hibase = (base >> 24) & 0xff;
sd.sd_lolimit = 0xffff;
sd.sd_hilimit = 0xf;
sd.sd_type = SDT_MEMRWA;
sd.sd_dpl = SEL_UPL;
sd.sd_p = 1;
sd.sd_xx = 0;
sd.sd_def32 = 1;
sd.sd_gran = 1;
usd.sd.sd_lobase = base & 0xffffff;
usd.sd.sd_hibase = (base >> 24) & 0xff;
usd.sd.sd_lolimit = 0xffff;
usd.sd.sd_hilimit = 0xf;
usd.sd.sd_type = SDT_MEMRWA;
usd.sd.sd_dpl = SEL_UPL;
usd.sd.sd_p = 1;
usd.sd.sd_xx = 0;
usd.sd.sd_def32 = 1;
usd.sd.sd_gran = 1;
kpreempt_disable();
pcb = &l->l_addr->u_pcb;
if (which == 'f') {
memcpy(&pcb->pcb_fsd, &sd, sizeof(sd));
memcpy(&pcb->pcb_fsd, &usd.sd,
sizeof(struct segment_descriptor));
if (l == curlwp) {
memcpy(&curcpu()->ci_gdt[GUFS_SEL], &sd, sizeof(sd));
update_descriptor(&curcpu()->ci_gdt[GUFS_SEL], &usd);
}
} else /* which == 'g' */ {
memcpy(&pcb->pcb_gsd, &sd, sizeof(sd));
memcpy(&pcb->pcb_gsd, &usd.sd,
sizeof(struct segment_descriptor));
if (l == curlwp) {
memcpy(&curcpu()->ci_gdt[GUGS_SEL], &sd, sizeof(sd));
update_descriptor(&curcpu()->ci_gdt[GUGS_SEL], &usd);
}
}
kpreempt_enable();