[PATCH] zd1211rw: Add ID for ZyXEL ZyAIR G-220 v2
[linux-2.6/sactl.git] / arch / x86_64 / ia32 / tls32.c
blob1cc4340de3ca4997b9966e8a5065f21b42e8c6c2
1 #include <linux/kernel.h>
2 #include <linux/errno.h>
3 #include <linux/sched.h>
4 #include <linux/user.h>
6 #include <asm/uaccess.h>
7 #include <asm/desc.h>
8 #include <asm/system.h>
9 #include <asm/ldt.h>
10 #include <asm/processor.h>
11 #include <asm/proto.h>
14 * sys_alloc_thread_area: get a yet unused TLS descriptor index.
16 static int get_free_idx(void)
18 struct thread_struct *t = &current->thread;
19 int idx;
21 for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
22 if (desc_empty((struct n_desc_struct *)(t->tls_array) + idx))
23 return idx + GDT_ENTRY_TLS_MIN;
24 return -ESRCH;
28 * Set a given TLS descriptor:
29 * When you want addresses > 32bit use arch_prctl()
31 int do_set_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
33 struct user_desc info;
34 struct n_desc_struct *desc;
35 int cpu, idx;
37 if (copy_from_user(&info, u_info, sizeof(info)))
38 return -EFAULT;
40 idx = info.entry_number;
43 * index -1 means the kernel should try to find and
44 * allocate an empty descriptor:
46 if (idx == -1) {
47 idx = get_free_idx();
48 if (idx < 0)
49 return idx;
50 if (put_user(idx, &u_info->entry_number))
51 return -EFAULT;
54 if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
55 return -EINVAL;
57 desc = ((struct n_desc_struct *)t->tls_array) + idx - GDT_ENTRY_TLS_MIN;
60 * We must not get preempted while modifying the TLS.
62 cpu = get_cpu();
64 if (LDT_empty(&info)) {
65 desc->a = 0;
66 desc->b = 0;
67 } else {
68 desc->a = LDT_entry_a(&info);
69 desc->b = LDT_entry_b(&info);
71 if (t == &current->thread)
72 load_TLS(t, cpu);
74 put_cpu();
75 return 0;
78 asmlinkage long sys32_set_thread_area(struct user_desc __user *u_info)
80 return do_set_thread_area(&current->thread, u_info);
85 * Get the current Thread-Local Storage area:
88 #define GET_BASE(desc) ( \
89 (((desc)->a >> 16) & 0x0000ffff) | \
90 (((desc)->b << 16) & 0x00ff0000) | \
91 ( (desc)->b & 0xff000000) )
93 #define GET_LIMIT(desc) ( \
94 ((desc)->a & 0x0ffff) | \
95 ((desc)->b & 0xf0000) )
97 #define GET_32BIT(desc) (((desc)->b >> 22) & 1)
98 #define GET_CONTENTS(desc) (((desc)->b >> 10) & 3)
99 #define GET_WRITABLE(desc) (((desc)->b >> 9) & 1)
100 #define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1)
101 #define GET_PRESENT(desc) (((desc)->b >> 15) & 1)
102 #define GET_USEABLE(desc) (((desc)->b >> 20) & 1)
103 #define GET_LONGMODE(desc) (((desc)->b >> 21) & 1)
105 int do_get_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
107 struct user_desc info;
108 struct n_desc_struct *desc;
109 int idx;
111 if (get_user(idx, &u_info->entry_number))
112 return -EFAULT;
113 if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
114 return -EINVAL;
116 desc = ((struct n_desc_struct *)t->tls_array) + idx - GDT_ENTRY_TLS_MIN;
118 memset(&info, 0, sizeof(struct user_desc));
119 info.entry_number = idx;
120 info.base_addr = GET_BASE(desc);
121 info.limit = GET_LIMIT(desc);
122 info.seg_32bit = GET_32BIT(desc);
123 info.contents = GET_CONTENTS(desc);
124 info.read_exec_only = !GET_WRITABLE(desc);
125 info.limit_in_pages = GET_LIMIT_PAGES(desc);
126 info.seg_not_present = !GET_PRESENT(desc);
127 info.useable = GET_USEABLE(desc);
128 info.lm = GET_LONGMODE(desc);
130 if (copy_to_user(u_info, &info, sizeof(info)))
131 return -EFAULT;
132 return 0;
135 asmlinkage long sys32_get_thread_area(struct user_desc __user *u_info)
137 return do_get_thread_area(&current->thread, u_info);
141 int ia32_child_tls(struct task_struct *p, struct pt_regs *childregs)
143 struct n_desc_struct *desc;
144 struct user_desc info;
145 struct user_desc __user *cp;
146 int idx;
148 cp = (void __user *)childregs->rsi;
149 if (copy_from_user(&info, cp, sizeof(info)))
150 return -EFAULT;
151 if (LDT_empty(&info))
152 return -EINVAL;
154 idx = info.entry_number;
155 if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
156 return -EINVAL;
158 desc = (struct n_desc_struct *)(p->thread.tls_array) + idx - GDT_ENTRY_TLS_MIN;
159 desc->a = LDT_entry_a(&info);
160 desc->b = LDT_entry_b(&info);
162 return 0;