diff options
Diffstat (limited to 'arch/ia64/ia32/ia32_ldt.c')
-rw-r--r-- | arch/ia64/ia32/ia32_ldt.c | 146 |
1 files changed, 0 insertions, 146 deletions
diff --git a/arch/ia64/ia32/ia32_ldt.c b/arch/ia64/ia32/ia32_ldt.c deleted file mode 100644 index 16d51c1..0000000 --- a/arch/ia64/ia32/ia32_ldt.c +++ /dev/null @@ -1,146 +0,0 @@ -/* - * Copyright (C) 2001, 2004 Hewlett-Packard Co - * David Mosberger-Tang <davidm@hpl.hp.com> - * - * Adapted from arch/i386/kernel/ldt.c - */ - -#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 <asm/uaccess.h> - -#include "ia32priv.h" - -/* - * read_ldt() is not really atomic - this is not a problem since synchronization of reads - * and writes done to the LDT has to be assured by user-space anyway. Writes are atomic, - * to protect the security checks done on new descriptors. - */ -static int -read_ldt (void __user *ptr, unsigned long bytecount) -{ - unsigned long bytes_left, n; - char __user *src, *dst; - char buf[256]; /* temporary buffer (don't overflow kernel stack!) */ - - if (bytecount > IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE) - bytecount = IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE; - - bytes_left = bytecount; - - src = (void __user *) IA32_LDT_OFFSET; - dst = ptr; - - while (bytes_left) { - n = sizeof(buf); - if (n > bytes_left) - n = bytes_left; - - /* - * We know we're reading valid memory, but we still must guard against - * running out of memory. - */ - if (__copy_from_user(buf, src, n)) - return -EFAULT; - - if (copy_to_user(dst, buf, n)) - return -EFAULT; - - src += n; - dst += n; - bytes_left -= n; - } - return bytecount; -} - -static int -read_default_ldt (void __user * ptr, unsigned long bytecount) -{ - unsigned long size; - int err; - - /* XXX fix me: should return equivalent of default_ldt[0] */ - err = 0; - size = 8; - 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 ia32_user_desc ldt_info; - __u64 entry; - int ret; - - if (bytecount != sizeof(ldt_info)) - return -EINVAL; - if (copy_from_user(&ldt_info, ptr, sizeof(ldt_info))) - return -EFAULT; - - if (ldt_info.entry_number >= IA32_LDT_ENTRIES) - return -EINVAL; - if (ldt_info.contents == 3) { - if (oldmode) - return -EINVAL; - if (ldt_info.seg_not_present == 0) - return -EINVAL; - } - - if (ldt_info.base_addr == 0 && ldt_info.limit == 0 - && (oldmode || (ldt_info.contents == 0 && ldt_info.read_exec_only == 1 - && ldt_info.seg_32bit == 0 && ldt_info.limit_in_pages == 0 - && ldt_info.seg_not_present == 1 && ldt_info.useable == 0))) - /* allow LDTs to be cleared by the user */ - entry = 0; - else - /* we must set the "Accessed" bit as IVE doesn't emulate it */ - entry = IA32_SEG_DESCRIPTOR(ldt_info.base_addr, ldt_info.limit, - (((ldt_info.read_exec_only ^ 1) << 1) - | (ldt_info.contents << 2)) | 1, - 1, 3, ldt_info.seg_not_present ^ 1, - (oldmode ? 0 : ldt_info.useable), - ldt_info.seg_32bit, - ldt_info.limit_in_pages); - /* - * Install the new entry. We know we're accessing valid (mapped) user-level - * memory, but we still need to guard against out-of-memory, hence we must use - * put_user(). - */ - ret = __put_user(entry, (__u64 __user *) IA32_LDT_OFFSET + ldt_info.entry_number); - ia32_load_segment_descriptors(current); - return ret; -} - -asmlinkage int -sys32_modify_ldt (int func, unsigned int ptr, unsigned int bytecount) -{ - int ret = -ENOSYS; - - switch (func) { - case 0: - ret = read_ldt(compat_ptr(ptr), bytecount); - break; - case 1: - ret = write_ldt(compat_ptr(ptr), bytecount, 1); - break; - case 2: - ret = read_default_ldt(compat_ptr(ptr), bytecount); - break; - case 0x11: - ret = write_ldt(compat_ptr(ptr), bytecount, 0); - break; - } - return ret; -} |