x86: merge arch/x86/kernel/ldt_32/64.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 22 insertions, 260 deletions

diff --git a/arch/x86/kernel/Makefile_32 b/arch/x86/kernel/Makefile_32
index 0cc1981d1e38..31ff982bc26b 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 08a68f0d8fda..9cb3df27c413 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_64.c b/arch/x86/kernel/ldt.c
index 95903938e7ad..a8cdca3615bf 100644
--- a/arch/x86/kernel/ldt_64.c
+++ b/arch/x86/kernel/ldt.c
@@ -50,7 +50,11 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
         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;
@@ -110,11 +114,18 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 }
 
 /*
- * Don't touch the LDT register - we're already in the next thread.
+ * 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
@@ -159,10 +170,14 @@ error_return:
 
 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;
+        /* 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;
diff --git a/arch/x86/kernel/ldt_32.c b/arch/x86/kernel/ldt_32.c
deleted file mode 100644
index bb15753abaf2..000000000000
--- 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 <mingo@redhat.com>
- */
-
-#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;
-}