From efd1ca52d04d2f6df337a3332cee56cd60e6d4c4 Mon Sep 17 00:00:00 2001
From: Roland McGrath <roland@redhat.com>
Date: Wed, 30 Jan 2008 13:30:46 +0100
Subject: x86: TLS cleanup
This consolidates the four different places that implemented the same
encoding magic for the GDT-slot 32-bit TLS support. The old tls32.c was
renamed and is now only slightly modified to be the shared implementation.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/process_32.c | 141 ++-----------------------------------------
1 file changed, 5 insertions(+), 136 deletions(-)
(limited to 'arch/x86/kernel/process_32.c')
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 631af167bc51..4d66a56280d3 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -501,32 +501,15 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long esp,
set_tsk_thread_flag(p, TIF_IO_BITMAP);
}
+ err = 0;
+
/*
* Set a new TLS for the child thread?
*/
- if (clone_flags & CLONE_SETTLS) {
- struct desc_struct *desc;
- struct user_desc info;
- int idx;
-
- err = -EFAULT;
- if (copy_from_user(&info, (void __user *)childregs->esi, sizeof(info)))
- goto out;
- err = -EINVAL;
- if (LDT_empty(&info))
- goto out;
-
- idx = info.entry_number;
- if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
- goto out;
-
- desc = p->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
- desc->a = LDT_entry_a(&info);
- desc->b = LDT_entry_b(&info);
- }
+ if (clone_flags & CLONE_SETTLS)
+ err = do_set_thread_area(p, -1,
+ (struct user_desc __user *)childregs->esi, 0);
- err = 0;
- out:
if (err && p->thread.io_bitmap_ptr) {
kfree(p->thread.io_bitmap_ptr);
p->thread.io_bitmap_max = 0;
@@ -872,120 +855,6 @@ unsigned long get_wchan(struct task_struct *p)
return 0;
}
-/*
- * sys_alloc_thread_area: get a yet unused TLS descriptor index.
- */
-static int get_free_idx(void)
-{
- struct thread_struct *t = ¤t->thread;
- int idx;
-
- for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
- if (desc_empty(t->tls_array + idx))
- return idx + GDT_ENTRY_TLS_MIN;
- return -ESRCH;
-}
-
-/*
- * Set a given TLS descriptor:
- */
-asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
-{
- struct thread_struct *t = ¤t->thread;
- struct user_desc info;
- struct desc_struct *desc;
- int cpu, idx;
-
- if (copy_from_user(&info, u_info, sizeof(info)))
- return -EFAULT;
- idx = info.entry_number;
-
- /*
- * index -1 means the kernel should try to find and
- * allocate an empty descriptor:
- */
- if (idx == -1) {
- idx = get_free_idx();
- if (idx < 0)
- return idx;
- if (put_user(idx, &u_info->entry_number))
- return -EFAULT;
- }
-
- if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
- return -EINVAL;
-
- desc = t->tls_array + idx - GDT_ENTRY_TLS_MIN;
-
- /*
- * We must not get preempted while modifying the TLS.
- */
- cpu = get_cpu();
-
- if (LDT_empty(&info)) {
- desc->a = 0;
- desc->b = 0;
- } else {
- desc->a = LDT_entry_a(&info);
- desc->b = LDT_entry_b(&info);
- }
- load_TLS(t, cpu);
-
- put_cpu();
-
- return 0;
-}
-
-/*
- * Get the current Thread-Local Storage area:
- */
-
-#define GET_BASE(desc) ( \
- (((desc)->a >> 16) & 0x0000ffff) | \
- (((desc)->b << 16) & 0x00ff0000) | \
- ( (desc)->b & 0xff000000) )
-
-#define GET_LIMIT(desc) ( \
- ((desc)->a & 0x0ffff) | \
- ((desc)->b & 0xf0000) )
-
-#define GET_32BIT(desc) (((desc)->b >> 22) & 1)
-#define GET_CONTENTS(desc) (((desc)->b >> 10) & 3)
-#define GET_WRITABLE(desc) (((desc)->b >> 9) & 1)
-#define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1)
-#define GET_PRESENT(desc) (((desc)->b >> 15) & 1)
-#define GET_USEABLE(desc) (((desc)->b >> 20) & 1)
-
-asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
-{
- struct user_desc info;
- struct desc_struct *desc;
- int idx;
-
- if (get_user(idx, &u_info->entry_number))
- return -EFAULT;
- if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
- return -EINVAL;
-
- memset(&info, 0, sizeof(info));
-
- desc = current->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
-
- info.entry_number = idx;
- info.base_addr = GET_BASE(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);
-
- if (copy_to_user(u_info, &info, sizeof(info)))
- return -EFAULT;
- return 0;
-}
-
unsigned long arch_align_stack(unsigned long sp)
{
if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
--
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