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> | |
bbc1f698 | 13 | #include <asm/syscalls.h> |
1da177e4 | 14 | |
4c79a2d8 RM |
15 | #include "tls.h" |
16 | ||
1da177e4 LT |
17 | /* |
18 | * sys_alloc_thread_area: get a yet unused TLS descriptor index. | |
19 | */ | |
20 | static int get_free_idx(void) | |
21 | { | |
22 | struct thread_struct *t = ¤t->thread; | |
23 | int idx; | |
24 | ||
25 | for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++) | |
efd1ca52 | 26 | if (desc_empty(&t->tls_array[idx])) |
1da177e4 LT |
27 | return idx + GDT_ENTRY_TLS_MIN; |
28 | return -ESRCH; | |
29 | } | |
30 | ||
1bd5718c | 31 | static void set_tls_desc(struct task_struct *p, int idx, |
4c79a2d8 | 32 | const struct user_desc *info, int n) |
1bd5718c RM |
33 | { |
34 | struct thread_struct *t = &p->thread; | |
35 | struct desc_struct *desc = &t->tls_array[idx - GDT_ENTRY_TLS_MIN]; | |
36 | int cpu; | |
37 | ||
38 | /* | |
39 | * We must not get preempted while modifying the TLS. | |
40 | */ | |
41 | cpu = get_cpu(); | |
42 | ||
4c79a2d8 RM |
43 | while (n-- > 0) { |
44 | if (LDT_empty(info)) | |
45 | desc->a = desc->b = 0; | |
46 | else | |
47 | fill_ldt(desc, info); | |
48 | ++info; | |
49 | ++desc; | |
50 | } | |
1bd5718c RM |
51 | |
52 | if (t == ¤t->thread) | |
53 | load_TLS(t, cpu); | |
54 | ||
55 | put_cpu(); | |
56 | } | |
57 | ||
1da177e4 LT |
58 | /* |
59 | * Set a given TLS descriptor: | |
1da177e4 | 60 | */ |
efd1ca52 RM |
61 | int do_set_thread_area(struct task_struct *p, int idx, |
62 | struct user_desc __user *u_info, | |
63 | int can_allocate) | |
1da177e4 LT |
64 | { |
65 | struct user_desc info; | |
1da177e4 LT |
66 | |
67 | if (copy_from_user(&info, u_info, sizeof(info))) | |
68 | return -EFAULT; | |
69 | ||
efd1ca52 RM |
70 | if (idx == -1) |
71 | idx = info.entry_number; | |
1da177e4 LT |
72 | |
73 | /* | |
74 | * index -1 means the kernel should try to find and | |
75 | * allocate an empty descriptor: | |
76 | */ | |
efd1ca52 | 77 | if (idx == -1 && can_allocate) { |
1da177e4 LT |
78 | idx = get_free_idx(); |
79 | if (idx < 0) | |
80 | return idx; | |
81 | if (put_user(idx, &u_info->entry_number)) | |
82 | return -EFAULT; | |
83 | } | |
84 | ||
85 | if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) | |
86 | return -EINVAL; | |
87 | ||
4c79a2d8 | 88 | set_tls_desc(p, idx, &info, 1); |
1da177e4 | 89 | |
1da177e4 LT |
90 | return 0; |
91 | } | |
92 | ||
efd1ca52 | 93 | asmlinkage int sys_set_thread_area(struct user_desc __user *u_info) |
13abd0e5 | 94 | { |
3d00daf4 | 95 | int ret = do_set_thread_area(current, -1, u_info, 1); |
54a01510 | 96 | asmlinkage_protect(1, ret, u_info); |
3d00daf4 | 97 | return ret; |
13abd0e5 | 98 | } |
1da177e4 LT |
99 | |
100 | ||
101 | /* | |
102 | * Get the current Thread-Local Storage area: | |
103 | */ | |
104 | ||
1bd5718c RM |
105 | static void fill_user_desc(struct user_desc *info, int idx, |
106 | const struct desc_struct *desc) | |
107 | ||
108 | { | |
109 | memset(info, 0, sizeof(*info)); | |
110 | info->entry_number = idx; | |
111 | info->base_addr = get_desc_base(desc); | |
112 | info->limit = get_desc_limit(desc); | |
113 | info->seg_32bit = desc->d; | |
114 | info->contents = desc->type >> 2; | |
115 | info->read_exec_only = !(desc->type & 2); | |
116 | info->limit_in_pages = desc->g; | |
117 | info->seg_not_present = !desc->p; | |
118 | info->useable = desc->avl; | |
119 | #ifdef CONFIG_X86_64 | |
120 | info->lm = desc->l; | |
121 | #endif | |
122 | } | |
efd1ca52 RM |
123 | |
124 | int do_get_thread_area(struct task_struct *p, int idx, | |
125 | struct user_desc __user *u_info) | |
1da177e4 LT |
126 | { |
127 | struct user_desc info; | |
1da177e4 | 128 | |
efd1ca52 | 129 | if (idx == -1 && get_user(idx, &u_info->entry_number)) |
1da177e4 | 130 | return -EFAULT; |
1bd5718c | 131 | |
1da177e4 LT |
132 | if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) |
133 | return -EINVAL; | |
134 | ||
1bd5718c RM |
135 | fill_user_desc(&info, idx, |
136 | &p->thread.tls_array[idx - GDT_ENTRY_TLS_MIN]); | |
1da177e4 LT |
137 | |
138 | if (copy_to_user(u_info, &info, sizeof(info))) | |
139 | return -EFAULT; | |
140 | return 0; | |
141 | } | |
142 | ||
efd1ca52 | 143 | asmlinkage int sys_get_thread_area(struct user_desc __user *u_info) |
1da177e4 | 144 | { |
3d00daf4 | 145 | int ret = do_get_thread_area(current, -1, u_info); |
54a01510 | 146 | asmlinkage_protect(1, ret, u_info); |
3d00daf4 | 147 | return ret; |
1da177e4 | 148 | } |
4c79a2d8 RM |
149 | |
150 | int regset_tls_active(struct task_struct *target, | |
151 | const struct user_regset *regset) | |
152 | { | |
153 | struct thread_struct *t = &target->thread; | |
154 | int n = GDT_ENTRY_TLS_ENTRIES; | |
155 | while (n > 0 && desc_empty(&t->tls_array[n - 1])) | |
156 | --n; | |
157 | return n; | |
158 | } | |
159 | ||
160 | int regset_tls_get(struct task_struct *target, const struct user_regset *regset, | |
161 | unsigned int pos, unsigned int count, | |
162 | void *kbuf, void __user *ubuf) | |
163 | { | |
164 | const struct desc_struct *tls; | |
165 | ||
166 | if (pos > GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) || | |
167 | (pos % sizeof(struct user_desc)) != 0 || | |
168 | (count % sizeof(struct user_desc)) != 0) | |
169 | return -EINVAL; | |
170 | ||
171 | pos /= sizeof(struct user_desc); | |
172 | count /= sizeof(struct user_desc); | |
173 | ||
174 | tls = &target->thread.tls_array[pos]; | |
175 | ||
176 | if (kbuf) { | |
177 | struct user_desc *info = kbuf; | |
178 | while (count-- > 0) | |
179 | fill_user_desc(info++, GDT_ENTRY_TLS_MIN + pos++, | |
180 | tls++); | |
181 | } else { | |
182 | struct user_desc __user *u_info = ubuf; | |
183 | while (count-- > 0) { | |
184 | struct user_desc info; | |
185 | fill_user_desc(&info, GDT_ENTRY_TLS_MIN + pos++, tls++); | |
186 | if (__copy_to_user(u_info++, &info, sizeof(info))) | |
187 | return -EFAULT; | |
188 | } | |
189 | } | |
190 | ||
191 | return 0; | |
192 | } | |
193 | ||
194 | int regset_tls_set(struct task_struct *target, const struct user_regset *regset, | |
195 | unsigned int pos, unsigned int count, | |
196 | const void *kbuf, const void __user *ubuf) | |
197 | { | |
198 | struct user_desc infobuf[GDT_ENTRY_TLS_ENTRIES]; | |
199 | const struct user_desc *info; | |
200 | ||
201 | if (pos > GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) || | |
202 | (pos % sizeof(struct user_desc)) != 0 || | |
203 | (count % sizeof(struct user_desc)) != 0) | |
204 | return -EINVAL; | |
205 | ||
206 | if (kbuf) | |
207 | info = kbuf; | |
208 | else if (__copy_from_user(infobuf, ubuf, count)) | |
209 | return -EFAULT; | |
210 | else | |
211 | info = infobuf; | |
212 | ||
213 | set_tls_desc(target, | |
214 | GDT_ENTRY_TLS_MIN + (pos / sizeof(struct user_desc)), | |
215 | info, count / sizeof(struct user_desc)); | |
216 | ||
217 | return 0; | |
218 | } |