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Commit efd1ca52 authored by Roland McGrath's avatar Roland McGrath Committed by Ingo Molnar
Browse files

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: default avatarRoland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 13abd0e5

arch/x86/ia32/ia32entry.S

+2 −2
Original line number Diff line number Diff line
@@ -643,8 +643,8 @@ ia32_sys_call_table: 
	.quad compat_sys_futex		/* 240 */

	.quad compat_sys_sched_setaffinity

	.quad compat_sys_sched_getaffinity

	.quad sys32_set_thread_area

	.quad sys32_get_thread_area

	.quad sys_set_thread_area

	.quad sys_get_thread_area

	.quad compat_sys_io_setup	/* 245 */

	.quad sys_io_destroy

	.quad compat_sys_io_getevents

arch/x86/kernel/Makefile_32

+1 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ obj-y := process_32.o signal_32.o entry_32.o traps_32.o irq_32.o \ 
		pci-dma_32.o i386_ksyms_32.o i387_32.o bootflag.o e820_32.o\

		quirks.o i8237.o topology.o alternative.o i8253.o tsc_32.o io_delay.o rtc.o



obj-y				+= tls.o

obj-$(CONFIG_STACKTRACE)	+= stacktrace.o

obj-y				+= cpu/

obj-y				+= acpi/

arch/x86/kernel/process_32.c

+5 −136
Original line number Diff line number Diff line
@@ -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;

	if (clone_flags & CLONE_SETTLS)

		err = do_set_thread_area(p, -1,

			(struct user_desc __user *)childregs->esi, 0);



		desc = p->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;

		desc->a = LDT_entry_a(&info);

		desc->b = LDT_entry_b(&info);

	}



	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 = &current->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 = &current->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)

arch/x86/kernel/process_64.c

+2 −1
Original line number Diff line number Diff line
@@ -524,7 +524,8 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long rsp, 
	if (clone_flags & CLONE_SETTLS) {

#ifdef CONFIG_IA32_EMULATION

		if (test_thread_flag(TIF_IA32))

			err = ia32_child_tls(p, childregs); 

			err = do_set_thread_area(p, -1,

				(struct user_desc __user *)childregs->rsi, 0);

		else 			

#endif	 

			err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8);

arch/x86/kernel/ptrace_32.c

+8 −83
Original line number Diff line number Diff line
@@ -276,85 +276,6 @@ void ptrace_disable(struct task_struct *child) 
	clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);

}



/*

 * Perform get_thread_area on behalf of the traced child.

 */

static int

ptrace_get_thread_area(struct task_struct *child,

		       int idx, struct user_desc __user *user_desc)

{

	struct user_desc info;

	struct desc_struct *desc;



/*

 * 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)



	if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)

		return -EINVAL;



	desc = child->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(user_desc, &info, sizeof(info)))

		return -EFAULT;



	return 0;

}



/*

 * Perform set_thread_area on behalf of the traced child.

 */

static int

ptrace_set_thread_area(struct task_struct *child,

		       int idx, struct user_desc __user *user_desc)

{

	struct user_desc info;

	struct desc_struct *desc;



	if (copy_from_user(&info, user_desc, sizeof(info)))

		return -EFAULT;



	if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)

		return -EINVAL;



	desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;

	if (LDT_empty(&info)) {

		desc->a = 0;

		desc->b = 0;

	} else {

		desc->a = LDT_entry_a(&info);

		desc->b = LDT_entry_b(&info);

	}



	return 0;

}



long arch_ptrace(struct task_struct *child, long request, long addr, long data)

{

	struct user * dummy = NULL;
@@ -601,13 +522,17 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) 
	}



	case PTRACE_GET_THREAD_AREA:

		ret = ptrace_get_thread_area(child, addr,

		if (addr < 0)

			return -EIO;

		ret = do_get_thread_area(child, addr,

					 (struct user_desc __user *) data);

		break;



	case PTRACE_SET_THREAD_AREA:

		ret = ptrace_set_thread_area(child, addr,

					(struct user_desc __user *) data);

		if (addr < 0)

			return -EIO;

		ret = do_set_thread_area(child, addr,

					 (struct user_desc __user *) data, 0);

		break;



	default: