Include missing linux/slab.h inclusions
[linux-3.10.git] / arch / x86 / kernel / tls.c
1 #include <linux/kernel.h>
2 #include <linux/errno.h>
3 #include <linux/sched.h>
4 #include <linux/user.h>
5 #include <linux/regset.h>
6
7 #include <asm/uaccess.h>
8 #include <asm/desc.h>
9 #include <asm/ldt.h>
10 #include <asm/processor.h>
11 #include <asm/proto.h>
12 #include <asm/syscalls.h>
13
14 #include "tls.h"
15
16 /*
17  * sys_alloc_thread_area: get a yet unused TLS descriptor index.
18  */
19 static int get_free_idx(void)
20 {
21         struct thread_struct *t = &current->thread;
22         int idx;
23
24         for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
25                 if (desc_empty(&t->tls_array[idx]))
26                         return idx + GDT_ENTRY_TLS_MIN;
27         return -ESRCH;
28 }
29
30 static void set_tls_desc(struct task_struct *p, int idx,
31                          const struct user_desc *info, int n)
32 {
33         struct thread_struct *t = &p->thread;
34         struct desc_struct *desc = &t->tls_array[idx - GDT_ENTRY_TLS_MIN];
35         int cpu;
36
37         /*
38          * We must not get preempted while modifying the TLS.
39          */
40         cpu = get_cpu();
41
42         while (n-- > 0) {
43                 if (LDT_empty(info))
44                         desc->a = desc->b = 0;
45                 else
46                         fill_ldt(desc, info);
47                 ++info;
48                 ++desc;
49         }
50
51         if (t == &current->thread)
52                 load_TLS(t, cpu);
53
54         put_cpu();
55 }
56
57 /*
58  * Set a given TLS descriptor:
59  */
60 int do_set_thread_area(struct task_struct *p, int idx,
61                        struct user_desc __user *u_info,
62                        int can_allocate)
63 {
64         struct user_desc info;
65
66         if (copy_from_user(&info, u_info, sizeof(info)))
67                 return -EFAULT;
68
69         if (idx == -1)
70                 idx = info.entry_number;
71
72         /*
73          * index -1 means the kernel should try to find and
74          * allocate an empty descriptor:
75          */
76         if (idx == -1 && can_allocate) {
77                 idx = get_free_idx();
78                 if (idx < 0)
79                         return idx;
80                 if (put_user(idx, &u_info->entry_number))
81                         return -EFAULT;
82         }
83
84         if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
85                 return -EINVAL;
86
87         set_tls_desc(p, idx, &info, 1);
88
89         return 0;
90 }
91
92 asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
93 {
94         int ret = do_set_thread_area(current, -1, u_info, 1);
95         asmlinkage_protect(1, ret, u_info);
96         return ret;
97 }
98
99
100 /*
101  * Get the current Thread-Local Storage area:
102  */
103
104 static void fill_user_desc(struct user_desc *info, int idx,
105                            const struct desc_struct *desc)
106
107 {
108         memset(info, 0, sizeof(*info));
109         info->entry_number = idx;
110         info->base_addr = get_desc_base(desc);
111         info->limit = get_desc_limit(desc);
112         info->seg_32bit = desc->d;
113         info->contents = desc->type >> 2;
114         info->read_exec_only = !(desc->type & 2);
115         info->limit_in_pages = desc->g;
116         info->seg_not_present = !desc->p;
117         info->useable = desc->avl;
118 #ifdef CONFIG_X86_64
119         info->lm = desc->l;
120 #endif
121 }
122
123 int do_get_thread_area(struct task_struct *p, int idx,
124                        struct user_desc __user *u_info)
125 {
126         struct user_desc info;
127
128         if (idx == -1 && get_user(idx, &u_info->entry_number))
129                 return -EFAULT;
130
131         if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
132                 return -EINVAL;
133
134         fill_user_desc(&info, idx,
135                        &p->thread.tls_array[idx - GDT_ENTRY_TLS_MIN]);
136
137         if (copy_to_user(u_info, &info, sizeof(info)))
138                 return -EFAULT;
139         return 0;
140 }
141
142 asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
143 {
144         int ret = do_get_thread_area(current, -1, u_info);
145         asmlinkage_protect(1, ret, u_info);
146         return ret;
147 }
148
149 int regset_tls_active(struct task_struct *target,
150                       const struct user_regset *regset)
151 {
152         struct thread_struct *t = &target->thread;
153         int n = GDT_ENTRY_TLS_ENTRIES;
154         while (n > 0 && desc_empty(&t->tls_array[n - 1]))
155                 --n;
156         return n;
157 }
158
159 int regset_tls_get(struct task_struct *target, const struct user_regset *regset,
160                    unsigned int pos, unsigned int count,
161                    void *kbuf, void __user *ubuf)
162 {
163         const struct desc_struct *tls;
164
165         if (pos >= GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) ||
166             (pos % sizeof(struct user_desc)) != 0 ||
167             (count % sizeof(struct user_desc)) != 0)
168                 return -EINVAL;
169
170         pos /= sizeof(struct user_desc);
171         count /= sizeof(struct user_desc);
172
173         tls = &target->thread.tls_array[pos];
174
175         if (kbuf) {
176                 struct user_desc *info = kbuf;
177                 while (count-- > 0)
178                         fill_user_desc(info++, GDT_ENTRY_TLS_MIN + pos++,
179                                        tls++);
180         } else {
181                 struct user_desc __user *u_info = ubuf;
182                 while (count-- > 0) {
183                         struct user_desc info;
184                         fill_user_desc(&info, GDT_ENTRY_TLS_MIN + pos++, tls++);
185                         if (__copy_to_user(u_info++, &info, sizeof(info)))
186                                 return -EFAULT;
187                 }
188         }
189
190         return 0;
191 }
192
193 int regset_tls_set(struct task_struct *target, const struct user_regset *regset,
194                    unsigned int pos, unsigned int count,
195                    const void *kbuf, const void __user *ubuf)
196 {
197         struct user_desc infobuf[GDT_ENTRY_TLS_ENTRIES];
198         const struct user_desc *info;
199
200         if (pos >= GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) ||
201             (pos % sizeof(struct user_desc)) != 0 ||
202             (count % sizeof(struct user_desc)) != 0)
203                 return -EINVAL;
204
205         if (kbuf)
206                 info = kbuf;
207         else if (__copy_from_user(infobuf, ubuf, count))
208                 return -EFAULT;
209         else
210                 info = infobuf;
211
212         set_tls_desc(target,
213                      GDT_ENTRY_TLS_MIN + (pos / sizeof(struct user_desc)),
214                      info, count / sizeof(struct user_desc));
215
216         return 0;
217 }