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x86: TLS cleanup

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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>
This commit is contained in:
Roland McGrath
2008-01-30 13:30:46 +01:00
committed by Ingo Molnar
parent 13abd0e504
commit efd1ca52d0
9 changed files with 76 additions and 301 deletions
Download Patch File Download Diff File Expand all files Collapse all files

94
arch/x86/kernel/tls.c
View File

@@ -19,31 +19,34 @@ static int get_free_idx(void)
int idx;
for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
if (desc_empty((struct n_desc_struct *)(t->tls_array) + idx))
if (desc_empty(&t->tls_array[idx]))
return idx + GDT_ENTRY_TLS_MIN;
return -ESRCH;
}
/*
* Set a given TLS descriptor:
* When you want addresses > 32bit use arch_prctl()
*/
int do_set_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
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;
struct n_desc_struct *desc;
int cpu, idx;
u32 *desc;
int cpu;
if (copy_from_user(&info, u_info, sizeof(info)))
return -EFAULT;
idx = info.entry_number;
if (idx == -1)
idx = info.entry_number;
/*
* index -1 means the kernel should try to find and
* allocate an empty descriptor:
*/
if (idx == -1) {
if (idx == -1 && can_allocate) {
idx = get_free_idx();
if (idx < 0)
return idx;
@@ -54,7 +57,7 @@ int do_set_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
return -EINVAL;
desc = ((struct n_desc_struct *)t->tls_array) + idx - GDT_ENTRY_TLS_MIN;
desc = (u32 *) &t->tls_array[idx - GDT_ENTRY_TLS_MIN];
/*
* We must not get preempted while modifying the TLS.
@@ -62,11 +65,11 @@ int do_set_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
cpu = get_cpu();
if (LDT_empty(&info)) {
desc->a = 0;
desc->b = 0;
desc[0] = 0;
desc[1] = 0;
} else {
desc->a = LDT_entry_a(&info);
desc->b = LDT_entry_b(&info);
desc[0] = LDT_entry_a(&info);
desc[1] = LDT_entry_b(&info);
}
if (t == &current->thread)
load_TLS(t, cpu);
@@ -75,9 +78,9 @@ int do_set_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
return 0;
}
asmlinkage long sys32_set_thread_area(struct user_desc __user *u_info)
asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
{
return do_set_thread_area(&current->thread, u_info);
return do_set_thread_area(current, -1, u_info, 1);
}
@@ -85,34 +88,32 @@ asmlinkage long sys32_set_thread_area(struct user_desc __user *u_info)
* Get the current Thread-Local Storage area:
*/
#define GET_LIMIT(desc) ( \
((desc)->a & 0x0ffff) | \
((desc)->b & 0xf0000) )
#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)
#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)
#define GET_LONGMODE(desc) (((desc)->b >> 21) & 1)
int do_get_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
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;
struct n_desc_struct *desc;
int idx;
u32 *desc;
if (get_user(idx, &u_info->entry_number))
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 = ((struct n_desc_struct *)t->tls_array) + idx - GDT_ENTRY_TLS_MIN;
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(desc);
info.base_addr = get_desc_base((void *)desc);
info.limit = GET_LIMIT(desc);
info.seg_32bit = GET_32BIT(desc);
info.contents = GET_CONTENTS(desc);
@@ -120,39 +121,16 @@ int do_get_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
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
if (copy_to_user(u_info, &info, sizeof(info)))
return -EFAULT;
return 0;
}
asmlinkage long sys32_get_thread_area(struct user_desc __user *u_info)
asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
{
return do_get_thread_area(&current->thread, u_info);
}
int ia32_child_tls(struct task_struct *p, struct pt_regs *childregs)
{
struct n_desc_struct *desc;
struct user_desc info;
struct user_desc __user *cp;
int idx;
cp = (void __user *)childregs->rsi;
if (copy_from_user(&info, cp, sizeof(info)))
return -EFAULT;
if (LDT_empty(&info))
return -EINVAL;
idx = info.entry_number;
if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
return -EINVAL;
desc = (struct n_desc_struct *)(p->thread.tls_array) + idx - GDT_ENTRY_TLS_MIN;
desc->a = LDT_entry_a(&info);
desc->b = LDT_entry_b(&info);
return 0;
return do_get_thread_area(current, -1, u_info);
}