Commit | Line | Data |
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1da177e4 LT |
1 | #include <linux/kernel.h> |
2 | #include <linux/errno.h> | |
3 | #include <linux/sched.h> | |
4 | #include <linux/user.h> | |
4c79a2d8 | 5 | #include <linux/regset.h> |
1da177e4 LT |
6 | |
7 | #include <asm/uaccess.h> | |
8 | #include <asm/desc.h> | |
9 | #include <asm/system.h> | |
10 | #include <asm/ldt.h> | |
11 | #include <asm/processor.h> | |
12 | #include <asm/proto.h> | |
13 | ||
4c79a2d8 RM |
14 | #include "tls.h" |
15 | ||
1da177e4 LT |
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 = ¤t->thread; | |
22 | int idx; | |
23 | ||
24 | for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++) | |
efd1ca52 | 25 | if (desc_empty(&t->tls_array[idx])) |
1da177e4 LT |
26 | return idx + GDT_ENTRY_TLS_MIN; |
27 | return -ESRCH; | |
28 | } | |
29 | ||
1bd5718c | 30 | static void set_tls_desc(struct task_struct *p, int idx, |
4c79a2d8 | 31 | const struct user_desc *info, int n) |
1bd5718c RM |
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 | ||
4c79a2d8 RM |
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 | } | |
1bd5718c RM |
50 | |
51 | if (t == ¤t->thread) | |
52 | load_TLS(t, cpu); | |
53 | ||
54 | put_cpu(); | |
55 | } | |
56 | ||
1da177e4 LT |
57 | /* |
58 | * Set a given TLS descriptor: | |
1da177e4 | 59 | */ |
efd1ca52 RM |
60 | int do_set_thread_area(struct task_struct *p, int idx, |
61 | struct user_desc __user *u_info, | |
62 | int can_allocate) | |
1da177e4 LT |
63 | { |
64 | struct user_desc info; | |
1da177e4 LT |
65 | |
66 | if (copy_from_user(&info, u_info, sizeof(info))) | |
67 | return -EFAULT; | |
68 | ||
efd1ca52 RM |
69 | if (idx == -1) |
70 | idx = info.entry_number; | |
1da177e4 LT |
71 | |
72 | /* | |
73 | * index -1 means the kernel should try to find and | |
74 | * allocate an empty descriptor: | |
75 | */ | |
efd1ca52 | 76 | if (idx == -1 && can_allocate) { |
1da177e4 LT |
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 | ||
4c79a2d8 | 87 | set_tls_desc(p, idx, &info, 1); |
1da177e4 | 88 | |
1da177e4 LT |
89 | return 0; |
90 | } | |
91 | ||
efd1ca52 | 92 | asmlinkage int sys_set_thread_area(struct user_desc __user *u_info) |
13abd0e5 | 93 | { |
3d00daf4 | 94 | int ret = do_set_thread_area(current, -1, u_info, 1); |
54a01510 | 95 | asmlinkage_protect(1, ret, u_info); |
3d00daf4 | 96 | return ret; |
13abd0e5 | 97 | } |
1da177e4 LT |
98 | |
99 | ||
100 | /* | |
101 | * Get the current Thread-Local Storage area: | |
102 | */ | |
103 | ||
1bd5718c RM |
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 | } | |
efd1ca52 RM |
122 | |
123 | int do_get_thread_area(struct task_struct *p, int idx, | |
124 | struct user_desc __user *u_info) | |
1da177e4 LT |
125 | { |
126 | struct user_desc info; | |
1da177e4 | 127 | |
efd1ca52 | 128 | if (idx == -1 && get_user(idx, &u_info->entry_number)) |
1da177e4 | 129 | return -EFAULT; |
1bd5718c | 130 | |
1da177e4 LT |
131 | if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) |
132 | return -EINVAL; | |
133 | ||
1bd5718c RM |
134 | fill_user_desc(&info, idx, |
135 | &p->thread.tls_array[idx - GDT_ENTRY_TLS_MIN]); | |
1da177e4 LT |
136 | |
137 | if (copy_to_user(u_info, &info, sizeof(info))) | |
138 | return -EFAULT; | |
139 | return 0; | |
140 | } | |
141 | ||
efd1ca52 | 142 | asmlinkage int sys_get_thread_area(struct user_desc __user *u_info) |
1da177e4 | 143 | { |
3d00daf4 | 144 | int ret = do_get_thread_area(current, -1, u_info); |
54a01510 | 145 | asmlinkage_protect(1, ret, u_info); |
3d00daf4 | 146 | return ret; |
1da177e4 | 147 | } |
4c79a2d8 RM |
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 | } |