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-rw-r--r--arch/x86/kernel/ldt_32.c253
1 files changed, 0 insertions, 253 deletions
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 @@
1/*
2 * Copyright (C) 1992 Krishna Balasubramanian and Linus Torvalds
3 * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
4 */
5
6#include <linux/errno.h>
7#include <linux/sched.h>
8#include <linux/string.h>
9#include <linux/mm.h>
10#include <linux/smp.h>
11#include <linux/vmalloc.h>
12#include <linux/slab.h>
13
14#include <asm/uaccess.h>
15#include <asm/system.h>
16#include <asm/ldt.h>
17#include <asm/desc.h>
18#include <asm/mmu_context.h>
19
20#ifdef CONFIG_SMP
21static void flush_ldt(void *null)
22{
23 if (current->active_mm)
24 load_LDT(&current->active_mm->context);
25}
26#endif
27
28static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
29{
30 void *oldldt, *newldt;
31 int oldsize;
32
33 if (mincount <= pc->size)
34 return 0;
35 oldsize = pc->size;
36 mincount = (mincount + 511) & (~511);
37 if (mincount * LDT_ENTRY_SIZE > PAGE_SIZE)
38 newldt = vmalloc(mincount * LDT_ENTRY_SIZE);
39 else
40 newldt = kmalloc(mincount * LDT_ENTRY_SIZE, GFP_KERNEL);
41
42 if (!newldt)
43 return -ENOMEM;
44
45 if (oldsize)
46 memcpy(newldt, pc->ldt, oldsize * LDT_ENTRY_SIZE);
47 oldldt = pc->ldt;
48 memset(newldt + oldsize * LDT_ENTRY_SIZE, 0,
49 (mincount - oldsize) * LDT_ENTRY_SIZE);
50 pc->ldt = newldt;
51 wmb();
52 pc->size = mincount;
53 wmb();
54
55 if (reload) {
56#ifdef CONFIG_SMP
57 cpumask_t mask;
58
59 preempt_disable();
60 load_LDT(pc);
61 mask = cpumask_of_cpu(smp_processor_id());
62 if (!cpus_equal(current->mm->cpu_vm_mask, mask))
63 smp_call_function(flush_ldt, NULL, 1, 1);
64 preempt_enable();
65#else
66 load_LDT(pc);
67#endif
68 }
69 if (oldsize) {
70 if (oldsize * LDT_ENTRY_SIZE > PAGE_SIZE)
71 vfree(oldldt);
72 else
73 kfree(oldldt);
74 }
75 return 0;
76}
77
78static inline int copy_ldt(mm_context_t *new, mm_context_t *old)
79{
80 int err = alloc_ldt(new, old->size, 0);
81
82 if (err < 0)
83 return err;
84 memcpy(new->ldt, old->ldt, old->size * LDT_ENTRY_SIZE);
85 return 0;
86}
87
88/*
89 * we do not have to muck with descriptors here, that is
90 * done in switch_mm() as needed.
91 */
92int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
93{
94 struct mm_struct *old_mm;
95 int retval = 0;
96
97 mutex_init(&mm->context.lock);
98 mm->context.size = 0;
99 old_mm = current->mm;
100 if (old_mm && old_mm->context.size > 0) {
101 mutex_lock(&old_mm->context.lock);
102 retval = copy_ldt(&mm->context, &old_mm->context);
103 mutex_unlock(&old_mm->context.lock);
104 }
105 return retval;
106}
107
108/*
109 * No need to lock the MM as we are the last user
110 */
111void destroy_context(struct mm_struct *mm)
112{
113 if (mm->context.size) {
114 if (mm == current->active_mm)
115 clear_LDT();
116 if (mm->context.size * LDT_ENTRY_SIZE > PAGE_SIZE)
117 vfree(mm->context.ldt);
118 else
119 kfree(mm->context.ldt);
120 mm->context.size = 0;
121 }
122}
123
124static int read_ldt(void __user *ptr, unsigned long bytecount)
125{
126 int err;
127 unsigned long size;
128 struct mm_struct *mm = current->mm;
129
130 if (!mm->context.size)
131 return 0;
132 if (bytecount > LDT_ENTRY_SIZE * LDT_ENTRIES)
133 bytecount = LDT_ENTRY_SIZE * LDT_ENTRIES;
134
135 mutex_lock(&mm->context.lock);
136 size = mm->context.size * LDT_ENTRY_SIZE;
137 if (size > bytecount)
138 size = bytecount;
139
140 err = 0;
141 if (copy_to_user(ptr, mm->context.ldt, size))
142 err = -EFAULT;
143 mutex_unlock(&mm->context.lock);
144 if (err < 0)
145 goto error_return;
146 if (size != bytecount) {
147 /* zero-fill the rest */
148 if (clear_user(ptr + size, bytecount - size) != 0) {
149 err = -EFAULT;
150 goto error_return;
151 }
152 }
153 return bytecount;
154error_return:
155 return err;
156}
157
158static int read_default_ldt(void __user *ptr, unsigned long bytecount)
159{
160 int err;
161 unsigned long size;
162
163 err = 0;
164 size = 5 * sizeof(struct desc_struct);
165 if (size > bytecount)
166 size = bytecount;
167
168 err = size;
169 if (clear_user(ptr, size))
170 err = -EFAULT;
171
172 return err;
173}
174
175static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
176{
177 struct mm_struct *mm = current->mm;
178 __u32 entry_1, entry_2;
179 int error;
180 struct user_desc ldt_info;
181
182 error = -EINVAL;
183 if (bytecount != sizeof(ldt_info))
184 goto out;
185 error = -EFAULT;
186 if (copy_from_user(&ldt_info, ptr, sizeof(ldt_info)))
187 goto out;
188
189 error = -EINVAL;
190 if (ldt_info.entry_number >= LDT_ENTRIES)
191 goto out;
192 if (ldt_info.contents == 3) {
193 if (oldmode)
194 goto out;
195 if (ldt_info.seg_not_present == 0)
196 goto out;
197 }
198
199 mutex_lock(&mm->context.lock);
200 if (ldt_info.entry_number >= mm->context.size) {
201 error = alloc_ldt(&current->mm->context,
202 ldt_info.entry_number + 1, 1);
203 if (error < 0)
204 goto out_unlock;
205 }
206
207 /* Allow LDTs to be cleared by the user. */
208 if (ldt_info.base_addr == 0 && ldt_info.limit == 0) {
209 if (oldmode || LDT_empty(&ldt_info)) {
210 entry_1 = 0;
211 entry_2 = 0;
212 goto install;
213 }
214 }
215
216 entry_1 = LDT_entry_a(&ldt_info);
217 entry_2 = LDT_entry_b(&ldt_info);
218 if (oldmode)
219 entry_2 &= ~(1 << 20);
220
221 /* Install the new entry ... */
222install:
223 write_ldt_entry(mm->context.ldt, ldt_info.entry_number, entry_1,
224 entry_2);
225 error = 0;
226
227out_unlock:
228 mutex_unlock(&mm->context.lock);
229out:
230 return error;
231}
232
233asmlinkage int sys_modify_ldt(int func, void __user *ptr,
234 unsigned long bytecount)
235{
236 int ret = -ENOSYS;
237
238 switch (func) {
239 case 0:
240 ret = read_ldt(ptr, bytecount);
241 break;
242 case 1:
243 ret = write_ldt(ptr, bytecount, 1);
244 break;
245 case 2:
246 ret = read_default_ldt(ptr, bytecount);
247 break;
248 case 0x11:
249 ret = write_ldt(ptr, bytecount, 0);
250 break;
251 }
252 return ret;
253}
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