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authorJeremy Fitzhardinge <jeremy@goop.org>2008-07-23 14:21:18 -0700
committerIngo Molnar <mingo@elte.hu>2008-07-24 12:30:06 +0200
commit38ffbe66d59051fd9cfcfc8545f164700e2fa3bc (patch)
tree37e76db49cc86b3da550a62f36d101c7269d262e /arch
parent338b9bb3adac0d2c5a1e180491d9b001d624c402 (diff)
x86/paravirt/xen: properly fill out the ldt ops
LTP testing showed that Xen does not properly implement sys_modify_ldt(). This patch does the final little bits needed to make the ldt work properly. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/ldt.c9
-rw-r--r--arch/x86/kernel/paravirt.c4
-rw-r--r--arch/x86/xen/enlighten.c23
3 files changed, 35 insertions, 1 deletions
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index 3fee2aa50f3..4895e0634d2 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -51,6 +51,8 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
memset(newldt + oldsize * LDT_ENTRY_SIZE, 0,
(mincount - oldsize) * LDT_ENTRY_SIZE);
+ paravirt_alloc_ldt(newldt, mincount);
+
#ifdef CONFIG_X86_64
/* CHECKME: Do we really need this ? */
wmb();
@@ -75,6 +77,7 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
#endif
}
if (oldsize) {
+ paravirt_free_ldt(oldldt, oldsize);
if (oldsize * LDT_ENTRY_SIZE > PAGE_SIZE)
vfree(oldldt);
else
@@ -86,10 +89,13 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
static inline int copy_ldt(mm_context_t *new, mm_context_t *old)
{
int err = alloc_ldt(new, old->size, 0);
+ int i;
if (err < 0)
return err;
- memcpy(new->ldt, old->ldt, old->size * LDT_ENTRY_SIZE);
+
+ for(i = 0; i < old->size; i++)
+ write_ldt_entry(new->ldt, i, old->ldt + i * LDT_ENTRY_SIZE);
return 0;
}
@@ -126,6 +132,7 @@ void destroy_context(struct mm_struct *mm)
if (mm == current->active_mm)
clear_LDT();
#endif
+ paravirt_free_ldt(mm->context.ldt, mm->context.size);
if (mm->context.size * LDT_ENTRY_SIZE > PAGE_SIZE)
vfree(mm->context.ldt);
else
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 94da4d52d79..d8f2277be5a 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -348,6 +348,10 @@ struct pv_cpu_ops pv_cpu_ops = {
.write_ldt_entry = native_write_ldt_entry,
.write_gdt_entry = native_write_gdt_entry,
.write_idt_entry = native_write_idt_entry,
+
+ .alloc_ldt = paravirt_nop,
+ .free_ldt = paravirt_nop,
+
.load_sp0 = native_load_sp0,
#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 9ff6e3cbf08..06219e60e9c 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -325,6 +325,26 @@ static unsigned long xen_store_tr(void)
return 0;
}
+static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
+{
+ unsigned pages = roundup(entries * LDT_ENTRY_SIZE, PAGE_SIZE);
+ void *v = ldt;
+ int i;
+
+ for(i = 0; i < pages; i += PAGE_SIZE)
+ make_lowmem_page_readonly(v + i);
+}
+
+static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
+{
+ unsigned pages = roundup(entries * LDT_ENTRY_SIZE, PAGE_SIZE);
+ void *v = ldt;
+ int i;
+
+ for(i = 0; i < pages; i += PAGE_SIZE)
+ make_lowmem_page_readwrite(v + i);
+}
+
static void xen_set_ldt(const void *addr, unsigned entries)
{
struct mmuext_op *op;
@@ -1220,6 +1240,9 @@ static const struct pv_cpu_ops xen_cpu_ops __initdata = {
.load_gs_index = xen_load_gs_index,
#endif
+ .alloc_ldt = xen_alloc_ldt,
+ .free_ldt = xen_free_ldt,
+
.store_gdt = native_store_gdt,
.store_idt = native_store_idt,
.store_tr = xen_store_tr,