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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>
This commit is contained in:
Thomas Gleixner 2008-01-30 13:30:14 +01:00 committed by Ingo Molnar
parent 70f5088dd5
commit 77e463d104
4 changed files with 22 additions and 260 deletions
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2
arch/x86/kernel/Makefile_32
View File

@ -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

2
arch/x86/kernel/Makefile_64
View File

@ -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 \

25
arch/x86/kernel/ldt_64.c → arch/x86/kernel/ldt.c
View File

@ -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 @@ static int read_ldt(void __user *ptr, unsigned long bytecount)
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;

253
arch/x86/kernel/ldt_32.c
View File

@ -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;
}