diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/x86/kernel/ldt.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/x86/kernel/ldt.c | 267 |
1 files changed, 0 insertions, 267 deletions
diff --git a/ANDROID_3.4.5/arch/x86/kernel/ldt.c b/ANDROID_3.4.5/arch/x86/kernel/ldt.c deleted file mode 100644 index ebc98739..00000000 --- a/ANDROID_3.4.5/arch/x86/kernel/ldt.c +++ /dev/null @@ -1,267 +0,0 @@ -/* - * 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/gfp.h> -#include <linux/sched.h> -#include <linux/string.h> -#include <linux/mm.h> -#include <linux/smp.h> -#include <linux/vmalloc.h> -#include <linux/uaccess.h> - -#include <asm/ldt.h> -#include <asm/desc.h> -#include <asm/mmu_context.h> -#include <asm/syscalls.h> - -#ifdef CONFIG_SMP -static void flush_ldt(void *current_mm) -{ - if (current->active_mm == current_mm) - load_LDT(¤t->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 + (PAGE_SIZE / LDT_ENTRY_SIZE - 1)) & - (~(PAGE_SIZE / LDT_ENTRY_SIZE - 1)); - if (mincount * LDT_ENTRY_SIZE > PAGE_SIZE) - newldt = vmalloc(mincount * LDT_ENTRY_SIZE); - else - newldt = (void *)__get_free_page(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); - - paravirt_alloc_ldt(newldt, mincount); - -#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 - preempt_disable(); - load_LDT(pc); - if (!cpumask_equal(mm_cpumask(current->mm), - cpumask_of(smp_processor_id()))) - smp_call_function(flush_ldt, current->mm, 1); - preempt_enable(); -#else - load_LDT(pc); -#endif - } - if (oldsize) { - paravirt_free_ldt(oldldt, oldsize); - if (oldsize * LDT_ENTRY_SIZE > PAGE_SIZE) - vfree(oldldt); - else - put_page(virt_to_page(oldldt)); - } - return 0; -} - -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; - - for (i = 0; i < old->size; i++) - write_ldt_entry(new->ldt, i, old->ldt + i * 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 - paravirt_free_ldt(mm->context.ldt, mm->context.size); - if (mm->context.size * LDT_ENTRY_SIZE > PAGE_SIZE) - vfree(mm->context.ldt); - else - put_page(virt_to_page(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; - struct desc_struct ldt; - 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(¤t->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)) { - memset(&ldt, 0, sizeof(ldt)); - goto install; - } - } - - fill_ldt(&ldt, &ldt_info); - if (oldmode) - ldt.avl = 0; - - /* Install the new entry ... */ -install: - write_ldt_entry(mm->context.ldt, ldt_info.entry_number, &ldt); - 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; -} |