Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6.git] / arch / x86 / kernel / tls.c
index 98f428b..9d9d2f9 100644 (file)
@@ -2,13 +2,16 @@
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/user.h>
+#include <linux/regset.h>
 
 #include <asm/uaccess.h>
 #include <asm/desc.h>
-#include <asm/system.h>
 #include <asm/ldt.h>
 #include <asm/processor.h>
 #include <asm/proto.h>
+#include <asm/syscalls.h>
+
+#include "tls.h"
 
 /*
  * sys_alloc_thread_area: get a yet unused TLS descriptor index.
@@ -24,6 +27,33 @@ static int get_free_idx(void)
        return -ESRCH;
 }
 
+static void set_tls_desc(struct task_struct *p, int idx,
+                        const struct user_desc *info, int n)
+{
+       struct thread_struct *t = &p->thread;
+       struct desc_struct *desc = &t->tls_array[idx - GDT_ENTRY_TLS_MIN];
+       int cpu;
+
+       /*
+        * We must not get preempted while modifying the TLS.
+        */
+       cpu = get_cpu();
+
+       while (n-- > 0) {
+               if (LDT_empty(info))
+                       desc->a = desc->b = 0;
+               else
+                       fill_ldt(desc, info);
+               ++info;
+               ++desc;
+       }
+
+       if (t == &current->thread)
+               load_TLS(t, cpu);
+
+       put_cpu();
+}
+
 /*
  * Set a given TLS descriptor:
  */
@@ -31,10 +61,7 @@ int do_set_thread_area(struct task_struct *p, int idx,
                       struct user_desc __user *u_info,
                       int can_allocate)
 {
-       struct thread_struct *t = &p->thread;
        struct user_desc info;
-       u32 *desc;
-       int cpu;
 
        if (copy_from_user(&info, u_info, sizeof(info)))
                return -EFAULT;
@@ -57,29 +84,16 @@ int do_set_thread_area(struct task_struct *p, int idx,
        if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
                return -EINVAL;
 
-       desc = (u32 *) &t->tls_array[idx - GDT_ENTRY_TLS_MIN];
+       set_tls_desc(p, idx, &info, 1);
 
-       /*
-        * We must not get preempted while modifying the TLS.
-        */
-       cpu = get_cpu();
-
-       if (LDT_empty(&info)) {
-               desc[0] = 0;
-               desc[1] = 0;
-       } else
-               fill_ldt((struct desc_struct *)desc, &info);
-
-       if (t == &current->thread)
-               load_TLS(t, cpu);
-
-       put_cpu();
        return 0;
 }
 
 asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
 {
-       return do_set_thread_area(current, -1, u_info, 1);
+       int ret = do_set_thread_area(current, -1, u_info, 1);
+       asmlinkage_protect(1, ret, u_info);
+       return ret;
 }
 
 
@@ -87,42 +101,38 @@ asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
  * Get the current Thread-Local Storage area:
  */
 
-#define GET_LIMIT(desc)                (((desc)[0] & 0x0ffff) | ((desc)[1] & 0xf0000))
-#define GET_32BIT(desc)                (((desc)[1] >> 22) & 1)
-#define GET_CONTENTS(desc)     (((desc)[1] >> 10) & 3)
-#define GET_WRITABLE(desc)     (((desc)[1] >>  9) & 1)
-#define GET_LIMIT_PAGES(desc)  (((desc)[1] >> 23) & 1)
-#define GET_PRESENT(desc)      (((desc)[1] >> 15) & 1)
-#define GET_USEABLE(desc)      (((desc)[1] >> 20) & 1)
-#define GET_LONGMODE(desc)     (((desc)[1] >> 21) & 1)
+static void fill_user_desc(struct user_desc *info, int idx,
+                          const struct desc_struct *desc)
+
+{
+       memset(info, 0, sizeof(*info));
+       info->entry_number = idx;
+       info->base_addr = get_desc_base(desc);
+       info->limit = get_desc_limit(desc);
+       info->seg_32bit = desc->d;
+       info->contents = desc->type >> 2;
+       info->read_exec_only = !(desc->type & 2);
+       info->limit_in_pages = desc->g;
+       info->seg_not_present = !desc->p;
+       info->useable = desc->avl;
+#ifdef CONFIG_X86_64
+       info->lm = desc->l;
+#endif
+}
 
 int do_get_thread_area(struct task_struct *p, int idx,
                       struct user_desc __user *u_info)
 {
-       struct thread_struct *t = &p->thread;
        struct user_desc info;
-       u32 *desc;
 
        if (idx == -1 && get_user(idx, &u_info->entry_number))
                return -EFAULT;
+
        if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
                return -EINVAL;
 
-       desc = (u32 *) &t->tls_array[idx - GDT_ENTRY_TLS_MIN];
-
-       memset(&info, 0, sizeof(struct user_desc));
-       info.entry_number = idx;
-       info.base_addr = get_desc_base((struct desc_struct *)desc);
-       info.limit = GET_LIMIT(desc);
-       info.seg_32bit = GET_32BIT(desc);
-       info.contents = GET_CONTENTS(desc);
-       info.read_exec_only = !GET_WRITABLE(desc);
-       info.limit_in_pages = GET_LIMIT_PAGES(desc);
-       info.seg_not_present = !GET_PRESENT(desc);
-       info.useable = GET_USEABLE(desc);
-#ifdef CONFIG_X86_64
-       info.lm = GET_LONGMODE(desc);
-#endif
+       fill_user_desc(&info, idx,
+                      &p->thread.tls_array[idx - GDT_ENTRY_TLS_MIN]);
 
        if (copy_to_user(u_info, &info, sizeof(info)))
                return -EFAULT;
@@ -131,5 +141,77 @@ int do_get_thread_area(struct task_struct *p, int idx,
 
 asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
 {
-       return do_get_thread_area(current, -1, u_info);
+       int ret = do_get_thread_area(current, -1, u_info);
+       asmlinkage_protect(1, ret, u_info);
+       return ret;
+}
+
+int regset_tls_active(struct task_struct *target,
+                     const struct user_regset *regset)
+{
+       struct thread_struct *t = &target->thread;
+       int n = GDT_ENTRY_TLS_ENTRIES;
+       while (n > 0 && desc_empty(&t->tls_array[n - 1]))
+               --n;
+       return n;
+}
+
+int regset_tls_get(struct task_struct *target, const struct user_regset *regset,
+                  unsigned int pos, unsigned int count,
+                  void *kbuf, void __user *ubuf)
+{
+       const struct desc_struct *tls;
+
+       if (pos >= GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) ||
+           (pos % sizeof(struct user_desc)) != 0 ||
+           (count % sizeof(struct user_desc)) != 0)
+               return -EINVAL;
+
+       pos /= sizeof(struct user_desc);
+       count /= sizeof(struct user_desc);
+
+       tls = &target->thread.tls_array[pos];
+
+       if (kbuf) {
+               struct user_desc *info = kbuf;
+               while (count-- > 0)
+                       fill_user_desc(info++, GDT_ENTRY_TLS_MIN + pos++,
+                                      tls++);
+       } else {
+               struct user_desc __user *u_info = ubuf;
+               while (count-- > 0) {
+                       struct user_desc info;
+                       fill_user_desc(&info, GDT_ENTRY_TLS_MIN + pos++, tls++);
+                       if (__copy_to_user(u_info++, &info, sizeof(info)))
+                               return -EFAULT;
+               }
+       }
+
+       return 0;
+}
+
+int regset_tls_set(struct task_struct *target, const struct user_regset *regset,
+                  unsigned int pos, unsigned int count,
+                  const void *kbuf, const void __user *ubuf)
+{
+       struct user_desc infobuf[GDT_ENTRY_TLS_ENTRIES];
+       const struct user_desc *info;
+
+       if (pos >= GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) ||
+           (pos % sizeof(struct user_desc)) != 0 ||
+           (count % sizeof(struct user_desc)) != 0)
+               return -EINVAL;
+
+       if (kbuf)
+               info = kbuf;
+       else if (__copy_from_user(infobuf, ubuf, count))
+               return -EFAULT;
+       else
+               info = infobuf;
+
+       set_tls_desc(target,
+                    GDT_ENTRY_TLS_MIN + (pos / sizeof(struct user_desc)),
+                    info, count / sizeof(struct user_desc));
+
+       return 0;
 }