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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/system.h>
10#include <asm/ldt.h>
11#include <asm/processor.h>
12#include <asm/proto.h>
13#include <asm/syscalls.h>
14
15#include "tls.h"
16
17/*
18 * sys_alloc_thread_area: get a yet unused TLS descriptor index.
19 */
20static 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++)
26 if (desc_empty(&t->tls_array[idx]))
27 return idx + GDT_ENTRY_TLS_MIN;
28 return -ESRCH;
29}
30
31static void set_tls_desc(struct task_struct *p, int idx,
32 const struct user_desc *info, int n)
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
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 }
51
52 if (t == ¤t->thread)
53 load_TLS(t, cpu);
54
55 put_cpu();
56}
57
58/*
59 * Set a given TLS descriptor:
60 */
61int do_set_thread_area(struct task_struct *p, int idx,
62 struct user_desc __user *u_info,
63 int can_allocate)
64{
65 struct user_desc info;
66
67 if (copy_from_user(&info, u_info, sizeof(info)))
68 return -EFAULT;
69
70 if (idx == -1)
71 idx = info.entry_number;
72
73 /*
74 * index -1 means the kernel should try to find and
75 * allocate an empty descriptor:
76 */
77 if (idx == -1 && can_allocate) {
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
88 set_tls_desc(p, idx, &info, 1);
89
90 return 0;
91}
92
93asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
94{
95 int ret = do_set_thread_area(current, -1, u_info, 1);
96 asmlinkage_protect(1, ret, u_info);
97 return ret;
98}
99
100
101/*
102 * Get the current Thread-Local Storage area:
103 */
104
105static 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}
123
124int do_get_thread_area(struct task_struct *p, int idx,
125 struct user_desc __user *u_info)
126{
127 struct user_desc info;
128
129 if (idx == -1 && get_user(idx, &u_info->entry_number))
130 return -EFAULT;
131
132 if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
133 return -EINVAL;
134
135 fill_user_desc(&info, idx,
136 &p->thread.tls_array[idx - GDT_ENTRY_TLS_MIN]);
137
138 if (copy_to_user(u_info, &info, sizeof(info)))
139 return -EFAULT;
140 return 0;
141}
142
143asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
144{
145 int ret = do_get_thread_area(current, -1, u_info);
146 asmlinkage_protect(1, ret, u_info);
147 return ret;
148}
149
150int 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
160int 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
194int 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}
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#include <linux/syscalls.h>
7
8#include <asm/uaccess.h>
9#include <asm/desc.h>
10#include <asm/ldt.h>
11#include <asm/processor.h>
12#include <asm/proto.h>
13
14#include "tls.h"
15
16/*
17 * sys_alloc_thread_area: get a yet unused TLS descriptor index.
18 */
19static 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++)
25 if (desc_empty(&t->tls_array[idx]))
26 return idx + GDT_ENTRY_TLS_MIN;
27 return -ESRCH;
28}
29
30static 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 == ¤t->thread)
52 load_TLS(t, cpu);
53
54 put_cpu();
55}
56
57/*
58 * Set a given TLS descriptor:
59 */
60int 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
92SYSCALL_DEFINE1(set_thread_area, struct user_desc __user *, u_info)
93{
94 return do_set_thread_area(current, -1, u_info, 1);
95}
96
97
98/*
99 * Get the current Thread-Local Storage area:
100 */
101
102static void fill_user_desc(struct user_desc *info, int idx,
103 const struct desc_struct *desc)
104
105{
106 memset(info, 0, sizeof(*info));
107 info->entry_number = idx;
108 info->base_addr = get_desc_base(desc);
109 info->limit = get_desc_limit(desc);
110 info->seg_32bit = desc->d;
111 info->contents = desc->type >> 2;
112 info->read_exec_only = !(desc->type & 2);
113 info->limit_in_pages = desc->g;
114 info->seg_not_present = !desc->p;
115 info->useable = desc->avl;
116#ifdef CONFIG_X86_64
117 info->lm = desc->l;
118#endif
119}
120
121int do_get_thread_area(struct task_struct *p, int idx,
122 struct user_desc __user *u_info)
123{
124 struct user_desc info;
125
126 if (idx == -1 && get_user(idx, &u_info->entry_number))
127 return -EFAULT;
128
129 if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
130 return -EINVAL;
131
132 fill_user_desc(&info, idx,
133 &p->thread.tls_array[idx - GDT_ENTRY_TLS_MIN]);
134
135 if (copy_to_user(u_info, &info, sizeof(info)))
136 return -EFAULT;
137 return 0;
138}
139
140SYSCALL_DEFINE1(get_thread_area, struct user_desc __user *, u_info)
141{
142 return do_get_thread_area(current, -1, u_info);
143}
144
145int regset_tls_active(struct task_struct *target,
146 const struct user_regset *regset)
147{
148 struct thread_struct *t = &target->thread;
149 int n = GDT_ENTRY_TLS_ENTRIES;
150 while (n > 0 && desc_empty(&t->tls_array[n - 1]))
151 --n;
152 return n;
153}
154
155int regset_tls_get(struct task_struct *target, const struct user_regset *regset,
156 unsigned int pos, unsigned int count,
157 void *kbuf, void __user *ubuf)
158{
159 const struct desc_struct *tls;
160
161 if (pos >= GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) ||
162 (pos % sizeof(struct user_desc)) != 0 ||
163 (count % sizeof(struct user_desc)) != 0)
164 return -EINVAL;
165
166 pos /= sizeof(struct user_desc);
167 count /= sizeof(struct user_desc);
168
169 tls = &target->thread.tls_array[pos];
170
171 if (kbuf) {
172 struct user_desc *info = kbuf;
173 while (count-- > 0)
174 fill_user_desc(info++, GDT_ENTRY_TLS_MIN + pos++,
175 tls++);
176 } else {
177 struct user_desc __user *u_info = ubuf;
178 while (count-- > 0) {
179 struct user_desc info;
180 fill_user_desc(&info, GDT_ENTRY_TLS_MIN + pos++, tls++);
181 if (__copy_to_user(u_info++, &info, sizeof(info)))
182 return -EFAULT;
183 }
184 }
185
186 return 0;
187}
188
189int regset_tls_set(struct task_struct *target, const struct user_regset *regset,
190 unsigned int pos, unsigned int count,
191 const void *kbuf, const void __user *ubuf)
192{
193 struct user_desc infobuf[GDT_ENTRY_TLS_ENTRIES];
194 const struct user_desc *info;
195
196 if (pos >= GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) ||
197 (pos % sizeof(struct user_desc)) != 0 ||
198 (count % sizeof(struct user_desc)) != 0)
199 return -EINVAL;
200
201 if (kbuf)
202 info = kbuf;
203 else if (__copy_from_user(infobuf, ubuf, count))
204 return -EFAULT;
205 else
206 info = infobuf;
207
208 set_tls_desc(target,
209 GDT_ENTRY_TLS_MIN + (pos / sizeof(struct user_desc)),
210 info, count / sizeof(struct user_desc));
211
212 return 0;
213}