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Commit a5c2a893 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

x86, 386 removal: Remove CONFIG_X86_WP_WORKS_OK 



All 486+ CPUs support WP in supervisor mode, so remove the fallback
386 support code.

Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1354132230-21854-7-git-send-email-hpa@linux.intel.com
parent 094ab1db

arch/x86/Kconfig.cpu

+0 −3
Original line number Diff line number Diff line
@@ -325,9 +325,6 @@ config X86_INVD_BUG 
	def_bool y

	depends on M486



config X86_WP_WORKS_OK

	def_bool y



config X86_POPAD_OK

	def_bool y

	depends on X86_32

arch/x86/include/asm/uaccess.h

+0 −42
Original line number Diff line number Diff line
@@ -237,8 +237,6 @@ extern void __put_user_2(void); 
extern void __put_user_4(void);

extern void __put_user_8(void);



#ifdef CONFIG_X86_WP_WORKS_OK



/**

 * put_user: - Write a simple value into user space.

 * @x:   Value to copy to user space.
@@ -326,29 +324,6 @@ do { \ 
	}								\

} while (0)



#else



#define __put_user_size(x, ptr, size, retval, errret)			\

do {									\

	__typeof__(*(ptr))__pus_tmp = x;				\

	retval = 0;							\

									\

	if (unlikely(__copy_to_user_ll(ptr, &__pus_tmp, size) != 0))	\

		retval = errret;					\

} while (0)



#define put_user(x, ptr)					\

({								\

	int __ret_pu;						\

	__typeof__(*(ptr))__pus_tmp = x;			\

	__ret_pu = 0;						\

	if (unlikely(__copy_to_user_ll(ptr, &__pus_tmp,		\

				       sizeof(*(ptr))) != 0))	\

		__ret_pu = -EFAULT;				\

	__ret_pu;						\

})

#endif



#ifdef CONFIG_X86_32

#define __get_user_asm_u64(x, ptr, retval, errret)	(x) = __get_user_bad()

#define __get_user_asm_ex_u64(x, ptr)			(x) = __get_user_bad()
@@ -543,29 +518,12 @@ struct __large_struct { unsigned long buf[100]; }; 
	(x) = (__force __typeof__(*(ptr)))__gue_val;			\

} while (0)



#ifdef CONFIG_X86_WP_WORKS_OK



#define put_user_try		uaccess_try

#define put_user_catch(err)	uaccess_catch(err)



#define put_user_ex(x, ptr)						\

	__put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))



#else /* !CONFIG_X86_WP_WORKS_OK */



#define put_user_try		do {		\

	int __uaccess_err = 0;



#define put_user_catch(err)			\

	(err) |= __uaccess_err;			\

} while (0)



#define put_user_ex(x, ptr)	do {		\

	__uaccess_err |= __put_user(x, ptr);	\

} while (0)



#endif /* CONFIG_X86_WP_WORKS_OK */



extern unsigned long

copy_from_user_nmi(void *to, const void __user *from, unsigned long n);

extern __must_check long

arch/x86/lib/usercopy_32.c

+0 −57
Original line number Diff line number Diff line
@@ -570,63 +570,6 @@ do { \ 
unsigned long __copy_to_user_ll(void __user *to, const void *from,

				unsigned long n)

{

#ifndef CONFIG_X86_WP_WORKS_OK

	if (unlikely(boot_cpu_data.wp_works_ok == 0) &&

			((unsigned long)to) < TASK_SIZE) {

		/*

		 * When we are in an atomic section (see

		 * mm/filemap.c:file_read_actor), return the full

		 * length to take the slow path.

		 */

		if (in_atomic())

			return n;



		/*

		 * CPU does not honor the WP bit when writing

		 * from supervisory mode, and due to preemption or SMP,

		 * the page tables can change at any time.

		 * Do it manually.	Manfred <manfred@colorfullife.com>

		 */

		while (n) {

			unsigned long offset = ((unsigned long)to)%PAGE_SIZE;

			unsigned long len = PAGE_SIZE - offset;

			int retval;

			struct page *pg;

			void *maddr;



			if (len > n)

				len = n;



survive:

			down_read(&current->mm->mmap_sem);

			retval = get_user_pages(current, current->mm,

					(unsigned long)to, 1, 1, 0, &pg, NULL);



			if (retval == -ENOMEM && is_global_init(current)) {

				up_read(&current->mm->mmap_sem);

				congestion_wait(BLK_RW_ASYNC, HZ/50);

				goto survive;

			}



			if (retval != 1) {

				up_read(&current->mm->mmap_sem);

				break;

			}



			maddr = kmap_atomic(pg);

			memcpy(maddr + offset, from, len);

			kunmap_atomic(maddr);

			set_page_dirty_lock(pg);

			put_page(pg);

			up_read(&current->mm->mmap_sem);



			from += len;

			to += len;

			n -= len;

		}

		return n;

	}

#endif

	stac();

	if (movsl_is_ok(to, from, n))

		__copy_user(to, from, n);

arch/x86/mm/init_32.c

+1 −4
Original line number Diff line number Diff line
@@ -715,10 +715,7 @@ static void __init test_wp_bit(void) 


	if (!boot_cpu_data.wp_works_ok) {

		printk(KERN_CONT "No.\n");

#ifdef CONFIG_X86_WP_WORKS_OK

		panic(

  "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");

#endif

		panic("Linux doesn't support CPUs with broken WP.");

	} else {

		printk(KERN_CONT "Ok.\n");

	}