aboutsummaryrefslogtreecommitdiffstats
path: root/linux-2.6-xen-sparse/arch/x86_64/kernel/ldt-xen.c
diff options
context:
space:
mode:
Diffstat (limited to 'linux-2.6-xen-sparse/arch/x86_64/kernel/ldt-xen.c')
-rw-r--r--linux-2.6-xen-sparse/arch/x86_64/kernel/ldt-xen.c282
1 files changed, 0 insertions, 282 deletions
diff --git a/linux-2.6-xen-sparse/arch/x86_64/kernel/ldt-xen.c b/linux-2.6-xen-sparse/arch/x86_64/kernel/ldt-xen.c
deleted file mode 100644
index 6efbb64f80..0000000000
--- a/linux-2.6-xen-sparse/arch/x86_64/kernel/ldt-xen.c
+++ /dev/null
@@ -1,282 +0,0 @@
-/*
- * linux/arch/x86_64/kernel/ldt.c
- *
- * Copyright (C) 1992 Krishna Balasubramanian and Linus Torvalds
- * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
- * Copyright (C) 2002 Andi Kleen
- *
- * This handles calls from both 32bit and 64bit mode.
- */
-
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/string.h>
-#include <linux/mm.h>
-#include <linux/smp.h>
-#include <linux/smp_lock.h>
-#include <linux/vmalloc.h>
-#include <linux/slab.h>
-
-#include <asm/uaccess.h>
-#include <asm/system.h>
-#include <asm/ldt.h>
-#include <asm/desc.h>
-#include <asm/proto.h>
-#include <asm/pgalloc.h>
-
-#ifdef CONFIG_SMP /* avoids "defined but not used" warnig */
-static void flush_ldt(void *null)
-{
- if (current->active_mm)
- load_LDT(&current->active_mm->context);
-}
-#endif
-
-static int alloc_ldt(mm_context_t *pc, unsigned mincount, int reload)
-{
- void *oldldt;
- void *newldt;
- unsigned oldsize;
-
- if (mincount <= (unsigned)pc->size)
- return 0;
- oldsize = pc->size;
- mincount = (mincount+511)&(~511);
- if (mincount*LDT_ENTRY_SIZE > PAGE_SIZE)
- newldt = vmalloc(mincount*LDT_ENTRY_SIZE);
- else
- newldt = kmalloc(mincount*LDT_ENTRY_SIZE, GFP_KERNEL);
-
- if (!newldt)
- return -ENOMEM;
-
- if (oldsize)
- memcpy(newldt, pc->ldt, oldsize*LDT_ENTRY_SIZE);
- oldldt = pc->ldt;
- memset(newldt+oldsize*LDT_ENTRY_SIZE, 0, (mincount-oldsize)*LDT_ENTRY_SIZE);
- wmb();
- pc->ldt = newldt;
- wmb();
- pc->size = mincount;
- wmb();
- if (reload) {
-#ifdef CONFIG_SMP
- cpumask_t mask;
-
- preempt_disable();
-#endif
- make_pages_readonly(
- pc->ldt,
- (pc->size * LDT_ENTRY_SIZE) / PAGE_SIZE,
- XENFEAT_writable_descriptor_tables);
- load_LDT(pc);
-#ifdef CONFIG_SMP
- mask = cpumask_of_cpu(smp_processor_id());
- if (!cpus_equal(current->mm->cpu_vm_mask, mask))
- smp_call_function(flush_ldt, NULL, 1, 1);
- preempt_enable();
-#endif
- }
- if (oldsize) {
- make_pages_writable(
- oldldt,
- (oldsize * LDT_ENTRY_SIZE) / PAGE_SIZE,
- XENFEAT_writable_descriptor_tables);
- if (oldsize*LDT_ENTRY_SIZE > PAGE_SIZE)
- vfree(oldldt);
- else
- kfree(oldldt);
- }
- return 0;
-}
-
-static inline int copy_ldt(mm_context_t *new, mm_context_t *old)
-{
- int err = alloc_ldt(new, old->size, 0);
- if (err < 0)
- return err;
- memcpy(new->ldt, old->ldt, old->size*LDT_ENTRY_SIZE);
- make_pages_readonly(
- new->ldt,
- (new->size * LDT_ENTRY_SIZE) / PAGE_SIZE,
- XENFEAT_writable_descriptor_tables);
- return 0;
-}
-
-/*
- * we do not have to muck with descriptors here, that is
- * done in switch_mm() as needed.
- */
-int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
-{
- struct mm_struct * old_mm;
- int retval = 0;
-
- memset(&mm->context, 0, sizeof(mm->context));
- init_MUTEX(&mm->context.sem);
- old_mm = current->mm;
- if (old_mm && old_mm->context.size > 0) {
- down(&old_mm->context.sem);
- retval = copy_ldt(&mm->context, &old_mm->context);
- up(&old_mm->context.sem);
- }
- if (retval == 0) {
- spin_lock(&mm_unpinned_lock);
- list_add(&mm->context.unpinned, &mm_unpinned);
- spin_unlock(&mm_unpinned_lock);
- }
- return retval;
-}
-
-/*
- *
- * Don't touch the LDT register - we're already in the next thread.
- */
-void destroy_context(struct mm_struct *mm)
-{
- if (mm->context.size) {
- if (mm == current->active_mm)
- clear_LDT();
- make_pages_writable(
- mm->context.ldt,
- (mm->context.size * LDT_ENTRY_SIZE) / PAGE_SIZE,
- XENFEAT_writable_descriptor_tables);
- if (mm->context.size*LDT_ENTRY_SIZE > PAGE_SIZE)
- vfree(mm->context.ldt);
- else
- kfree(mm->context.ldt);
- mm->context.size = 0;
- }
- if (!mm->context.pinned) {
- spin_lock(&mm_unpinned_lock);
- list_del(&mm->context.unpinned);
- spin_unlock(&mm_unpinned_lock);
- }
-}
-
-static int read_ldt(void __user * ptr, unsigned long bytecount)
-{
- int err;
- unsigned long size;
- struct mm_struct * mm = current->mm;
-
- if (!mm->context.size)
- return 0;
- if (bytecount > LDT_ENTRY_SIZE*LDT_ENTRIES)
- bytecount = LDT_ENTRY_SIZE*LDT_ENTRIES;
-
- down(&mm->context.sem);
- size = mm->context.size*LDT_ENTRY_SIZE;
- if (size > bytecount)
- size = bytecount;
-
- err = 0;
- if (copy_to_user(ptr, mm->context.ldt, size))
- err = -EFAULT;
- up(&mm->context.sem);
- if (err < 0)
- goto error_return;
- if (size != bytecount) {
- /* zero-fill the rest */
- if (clear_user(ptr+size, bytecount-size) != 0) {
- err = -EFAULT;
- goto error_return;
- }
- }
- return bytecount;
-error_return:
- return err;
-}
-
-static int read_default_ldt(void __user * ptr, unsigned long bytecount)
-{
- /* Arbitrary number */
- /* x86-64 default LDT is all zeros */
- if (bytecount > 128)
- bytecount = 128;
- if (clear_user(ptr, bytecount))
- return -EFAULT;
- return bytecount;
-}
-
-static int write_ldt(void __user * ptr, unsigned long bytecount, int oldmode)
-{
- struct task_struct *me = current;
- struct mm_struct * mm = me->mm;
- __u32 entry_1, entry_2, *lp;
- unsigned long mach_lp;
- int error;
- struct user_desc ldt_info;
-
- error = -EINVAL;
-
- if (bytecount != sizeof(ldt_info))
- goto out;
- error = -EFAULT;
- if (copy_from_user(&ldt_info, ptr, bytecount))
- goto out;
-
- error = -EINVAL;
- if (ldt_info.entry_number >= LDT_ENTRIES)
- goto out;
- if (ldt_info.contents == 3) {
- if (oldmode)
- goto out;
- if (ldt_info.seg_not_present == 0)
- goto out;
- }
-
- down(&mm->context.sem);
- if (ldt_info.entry_number >= (unsigned)mm->context.size) {
- error = alloc_ldt(&current->mm->context, ldt_info.entry_number+1, 1);
- if (error < 0)
- goto out_unlock;
- }
-
- lp = (__u32 *) ((ldt_info.entry_number << 3) + (char *) mm->context.ldt);
- mach_lp = arbitrary_virt_to_machine(lp);
-
- /* Allow LDTs to be cleared by the user. */
- if (ldt_info.base_addr == 0 && ldt_info.limit == 0) {
- if (oldmode || LDT_empty(&ldt_info)) {
- entry_1 = 0;
- entry_2 = 0;
- goto install;
- }
- }
-
- entry_1 = LDT_entry_a(&ldt_info);
- entry_2 = LDT_entry_b(&ldt_info);
- if (oldmode)
- entry_2 &= ~(1 << 20);
-
- /* Install the new entry ... */
-install:
- error = HYPERVISOR_update_descriptor(mach_lp, (unsigned long)((entry_1 | (unsigned long) entry_2 << 32)));
-
-out_unlock:
- up(&mm->context.sem);
-out:
- return error;
-}
-
-asmlinkage int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount)
-{
- int ret = -ENOSYS;
-
- switch (func) {
- case 0:
- ret = read_ldt(ptr, bytecount);
- break;
- case 1:
- ret = write_ldt(ptr, bytecount, 1);
- break;
- case 2:
- ret = read_default_ldt(ptr, bytecount);
- break;
- case 0x11:
- ret = write_ldt(ptr, bytecount, 0);
- break;
- }
- return ret;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-28 20:00:43 +0000