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authorRoland McGrath <roland@redhat.com>2008-01-30 13:31:52 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:31:52 +0100
commit4c79a2d8e5b7e0a2f987ace9b6af9e7a1655447b (patch)
tree6f29726cabe888dcd1b6865c4e995eb5718f84b7 /arch/x86/kernel/tls.c
parent1bd5718ce58fb49ac158653380fa200f4759daad (diff)
x86: x86 user_regset TLS
This adds accessor functions in the user_regset style for the TLS data. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/tls.c')
-rw-r--r--arch/x86/kernel/tls.c89
1 files changed, 83 insertions, 6 deletions
diff --git a/arch/x86/kernel/tls.c b/arch/x86/kernel/tls.c
index f11c92a3faa..6dfd4e76661 100644
--- a/arch/x86/kernel/tls.c
+++ b/arch/x86/kernel/tls.c
@@ -2,6 +2,7 @@
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/user.h>
+#include <linux/regset.h>
#include <asm/uaccess.h>
#include <asm/desc.h>
@@ -10,6 +11,8 @@
#include <asm/processor.h>
#include <asm/proto.h>
+#include "tls.h"
+
/*
* sys_alloc_thread_area: get a yet unused TLS descriptor index.
*/
@@ -25,7 +28,7 @@ static int get_free_idx(void)
}
static void set_tls_desc(struct task_struct *p, int idx,
- const struct user_desc *info)
+ 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];
@@ -36,10 +39,14 @@ static void set_tls_desc(struct task_struct *p, int idx,
*/
cpu = get_cpu();
- if (LDT_empty(info))
- desc->a = desc->b = 0;
- else
- fill_ldt(desc, info);
+ 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);
@@ -77,7 +84,7 @@ int do_set_thread_area(struct task_struct *p, int idx,
if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
return -EINVAL;
- set_tls_desc(p, idx, &info);
+ set_tls_desc(p, idx, &info, 1);
return 0;
}
@@ -134,3 +141,73 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
{
return do_get_thread_area(current, -1, u_info);
}
+
+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;
+}