Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=77e463d1040d6310211ac5162729f5d4afc4dd8c
Commit:     77e463d1040d6310211ac5162729f5d4afc4dd8c
Parent:     70f5088dd5e9fbd3a71b3a5b01395c676158194b
Author:     Thomas Gleixner <[EMAIL PROTECTED]>
AuthorDate: Wed Jan 30 13:30:14 2008 +0100
Committer:  Ingo Molnar <[EMAIL PROTECTED]>
CommitDate: Wed Jan 30 13:30:14 2008 +0100

    x86: merge arch/x86/kernel/ldt_32/64.c
    
    Signed-off-by: Thomas Gleixner <[EMAIL PROTECTED]>
    Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]>
---
 arch/x86/kernel/Makefile_32 |    2 +-
 arch/x86/kernel/Makefile_64 |    2 +-
 arch/x86/kernel/ldt.c       |  264 +++++++++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/ldt_32.c    |  253 -----------------------------------------
 arch/x86/kernel/ldt_64.c    |  249 ----------------------------------------
 5 files changed, 266 insertions(+), 504 deletions(-)

diff --git a/arch/x86/kernel/Makefile_32 b/arch/x86/kernel/Makefile_32
index 0cc1981..31ff982 100644
--- a/arch/x86/kernel/Makefile_32
+++ b/arch/x86/kernel/Makefile_32
@@ -6,7 +6,7 @@ extra-y := head_32.o init_task.o vmlinux.lds
 CPPFLAGS_vmlinux.lds += -Ui386
 
 obj-y  := process_32.o signal_32.o entry_32.o traps_32.o irq_32.o \
-               ptrace_32.o time_32.o ioport_32.o ldt_32.o setup_32.o 
i8259_32.o sys_i386_32.o \
+               ptrace_32.o time_32.o ioport_32.o ldt.o setup_32.o i8259_32.o 
sys_i386_32.o \
                pci-dma_32.o i386_ksyms_32.o i387_32.o bootflag.o e820_32.o\
                quirks.o i8237.o topology.o alternative.o i8253.o tsc_32.o 
io_delay.o
 
diff --git a/arch/x86/kernel/Makefile_64 b/arch/x86/kernel/Makefile_64
index 08a68f0..9cb3df2 100644
--- a/arch/x86/kernel/Makefile_64
+++ b/arch/x86/kernel/Makefile_64
@@ -7,7 +7,7 @@ CPPFLAGS_vmlinux.lds += -Ux86_64
 EXTRA_AFLAGS   := -traditional
 
 obj-y  := process_64.o signal_64.o entry_64.o traps_64.o irq_64.o \
-               ptrace_64.o time_64.o ioport_64.o ldt_64.o setup_64.o 
i8259_64.o sys_x86_64.o \
+               ptrace_64.o time_64.o ioport_64.o ldt.o setup_64.o i8259_64.o 
sys_x86_64.o \
                x8664_ksyms_64.o i387_64.o syscall_64.o vsyscall_64.o \
                setup64.o bootflag.o e820_64.o reboot_64.o quirks.o i8237.o \
                pci-dma_64.o pci-nommu_64.o alternative.o hpet.o tsc_64.o 
bugs_64.o \
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
new file mode 100644
index 0000000..a8cdca3
--- /dev/null
+++ b/arch/x86/kernel/ldt.c
@@ -0,0 +1,264 @@
+/*
+ * Copyright (C) 1992 Krishna Balasubramanian and Linus Torvalds
+ * Copyright (C) 1999 Ingo Molnar <[EMAIL PROTECTED]>
+ * 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/vmalloc.h>
+#include <linux/slab.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/ldt.h>
+#include <asm/desc.h>
+#include <asm/mmu_context.h>
+
+#ifdef CONFIG_SMP
+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, int mincount, int reload)
+{
+       void *oldldt, *newldt;
+       int oldsize;
+
+       if (mincount <= 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);
+
+#ifdef CONFIG_X86_64
+       /* CHECKME: Do we really need this ? */
+       wmb();
+#endif
+       pc->ldt = newldt;
+       wmb();
+       pc->size = mincount;
+       wmb();
+
+       if (reload) {
+#ifdef CONFIG_SMP
+               cpumask_t mask;
+
+               preempt_disable();
+               load_LDT(pc);
+               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();
+#else
+               load_LDT(pc);
+#endif
+       }
+       if (oldsize) {
+               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);
+       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;
+
+       mutex_init(&mm->context.lock);
+       mm->context.size = 0;
+       old_mm = current->mm;
+       if (old_mm && old_mm->context.size > 0) {
+               mutex_lock(&old_mm->context.lock);
+               retval = copy_ldt(&mm->context, &old_mm->context);
+               mutex_unlock(&old_mm->context.lock);
+       }
+       return retval;
+}
+
+/*
+ * No need to lock the MM as we are the last user
+ *
+ * 64bit: Don't touch the LDT register - we're already in the next thread.
+ */
+void destroy_context(struct mm_struct *mm)
+{
+       if (mm->context.size) {
+#ifdef CONFIG_X86_32
+               /* CHECKME: Can this ever happen ? */
+               if (mm == current->active_mm)
+                       clear_LDT();
+#endif
+               if (mm->context.size * LDT_ENTRY_SIZE > PAGE_SIZE)
+                       vfree(mm->context.ldt);
+               else
+                       kfree(mm->context.ldt);
+               mm->context.size = 0;
+       }
+}
+
+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;
+
+       mutex_lock(&mm->context.lock);
+       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;
+       mutex_unlock(&mm->context.lock);
+       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)
+{
+       /* CHECKME: Can we use _one_ random number ? */
+#ifdef CONFIG_X86_32
+       unsigned long size = 5 * sizeof(struct desc_struct);
+#else
+       unsigned long size = 128;
+#endif
+       if (bytecount > size)
+               bytecount = size;
+       if (clear_user(ptr, bytecount))
+               return -EFAULT;
+       return bytecount;
+}
+
+static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
+{
+       struct mm_struct *mm = current->mm;
+       __u32 entry_1, entry_2;
+       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, sizeof(ldt_info)))
+               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;
+       }
+
+       mutex_lock(&mm->context.lock);
+       if (ldt_info.entry_number >= mm->context.size) {
+               error = alloc_ldt(&current->mm->context,
+                                 ldt_info.entry_number + 1, 1);
+               if (error < 0)
+                       goto out_unlock;
+       }
+
+       /* 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:
+       write_ldt_entry(mm->context.ldt, ldt_info.entry_number, entry_1,
+                       entry_2);
+       error = 0;
+
+out_unlock:
+       mutex_unlock(&mm->context.lock);
+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;
+}
diff --git a/arch/x86/kernel/ldt_32.c b/arch/x86/kernel/ldt_32.c
deleted file mode 100644
index bb15753..0000000
--- a/arch/x86/kernel/ldt_32.c
+++ /dev/null
@@ -1,253 +0,0 @@
-/*
- * Copyright (C) 1992 Krishna Balasubramanian and Linus Torvalds
- * Copyright (C) 1999 Ingo Molnar <[EMAIL PROTECTED]>
- */
-
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/string.h>
-#include <linux/mm.h>
-#include <linux/smp.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/mmu_context.h>
-
-#ifdef CONFIG_SMP
-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, int mincount, int reload)
-{
-       void *oldldt, *newldt;
-       int oldsize;
-
-       if (mincount <= 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);
-       pc->ldt = newldt;
-       wmb();
-       pc->size = mincount;
-       wmb();
-
-       if (reload) {
-#ifdef CONFIG_SMP
-               cpumask_t mask;
-
-               preempt_disable();
-               load_LDT(pc);
-               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();
-#else
-               load_LDT(pc);
-#endif
-       }
-       if (oldsize) {
-               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);
-       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;
-
-       mutex_init(&mm->context.lock);
-       mm->context.size = 0;
-       old_mm = current->mm;
-       if (old_mm && old_mm->context.size > 0) {
-               mutex_lock(&old_mm->context.lock);
-               retval = copy_ldt(&mm->context, &old_mm->context);
-               mutex_unlock(&old_mm->context.lock);
-       }
-       return retval;
-}
-
-/*
- * No need to lock the MM as we are the last user
- */
-void destroy_context(struct mm_struct *mm)
-{
-       if (mm->context.size) {
-               if (mm == current->active_mm)
-                       clear_LDT();
-               if (mm->context.size * LDT_ENTRY_SIZE > PAGE_SIZE)
-                       vfree(mm->context.ldt);
-               else
-                       kfree(mm->context.ldt);
-               mm->context.size = 0;
-       }
-}
-
-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;
-
-       mutex_lock(&mm->context.lock);
-       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;
-       mutex_unlock(&mm->context.lock);
-       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)
-{
-       int err;
-       unsigned long size;
-
-       err = 0;
-       size = 5 * sizeof(struct desc_struct);
-       if (size > bytecount)
-               size = bytecount;
-
-       err = size;
-       if (clear_user(ptr, size))
-               err = -EFAULT;
-
-       return err;
-}
-
-static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
-{
-       struct mm_struct *mm = current->mm;
-       __u32 entry_1, entry_2;
-       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, sizeof(ldt_info)))
-               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;
-       }
-
-       mutex_lock(&mm->context.lock);
-       if (ldt_info.entry_number >= mm->context.size) {
-               error = alloc_ldt(&current->mm->context,
-                                 ldt_info.entry_number + 1, 1);
-               if (error < 0)
-                       goto out_unlock;
-       }
-
-       /* 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:
-       write_ldt_entry(mm->context.ldt, ldt_info.entry_number, entry_1,
-                       entry_2);
-       error = 0;
-
-out_unlock:
-       mutex_unlock(&mm->context.lock);
-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;
-}
diff --git a/arch/x86/kernel/ldt_64.c b/arch/x86/kernel/ldt_64.c
deleted file mode 100644
index 9590393..0000000
--- a/arch/x86/kernel/ldt_64.c
+++ /dev/null
@@ -1,249 +0,0 @@
-/*
- * Copyright (C) 1992 Krishna Balasubramanian and Linus Torvalds
- * Copyright (C) 1999 Ingo Molnar <[EMAIL PROTECTED]>
- * 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/vmalloc.h>
-#include <linux/slab.h>
-
-#include <asm/uaccess.h>
-#include <asm/system.h>
-#include <asm/ldt.h>
-#include <asm/desc.h>
-#include <asm/mmu_context.h>
-
-#ifdef CONFIG_SMP
-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, int mincount, int reload)
-{
-       void *oldldt, *newldt;
-       int oldsize;
-
-       if (mincount <= 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();
-               load_LDT(pc);
-               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();
-#else
-               load_LDT(pc);
-#endif
-       }
-       if (oldsize) {
-               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);
-       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;
-
-       mutex_init(&mm->context.lock);
-       mm->context.size = 0;
-       old_mm = current->mm;
-       if (old_mm && old_mm->context.size > 0) {
-               mutex_lock(&old_mm->context.lock);
-               retval = copy_ldt(&mm->context, &old_mm->context);
-               mutex_unlock(&old_mm->context.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->context.size * LDT_ENTRY_SIZE > PAGE_SIZE)
-                       vfree(mm->context.ldt);
-               else
-                       kfree(mm->context.ldt);
-               mm->context.size = 0;
-       }
-}
-
-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;
-
-       mutex_lock(&mm->context.lock);
-       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;
-       mutex_unlock(&mm->context.lock);
-       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 mm_struct *mm = current->mm;
-       __u32 entry_1, entry_2;
-       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, sizeof(ldt_info)))
-               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;
-       }
-
-       mutex_lock(&mm->context.lock);
-       if (ldt_info.entry_number >= mm->context.size) {
-               error = alloc_ldt(&current->mm->context,
-                                 ldt_info.entry_number + 1, 1);
-               if (error < 0)
-                       goto out_unlock;
-       }
-
-       /* 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:
-       write_ldt_entry(mm->context.ldt, ldt_info.entry_number, entry_1,
-                       entry_2);
-       error = 0;
-
-out_unlock:
-       mutex_unlock(&mm->context.lock);
-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;
-}
-
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