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linux-next/arch/frv/include/asm/segment.h
David Howells 08dc179b9b frv: fix kernel/user segment handling in NOMMU mode
In NOMMU mode, the FRV segment handling is broken because KERNEL_DS ==
USER_DS.  This causes tests of the following sort:

	/* don't pin down non-user-based iovecs */
	if (segment_eq(get_fs(), KERNEL_DS))
		return NULL;

to malfunction.

To fix this, make USER_DS the top of RAM instead of the top of the non-IO
address space, and make KERNEL_DS one more than the top of the non-IO
address space.

Also get rid of FRV's __addr_ok() as nothing uses it.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07 08:38:05 -07:00

46 lines
1.1 KiB
C

/* segment.h: MMU segment settings
*
* Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _ASM_SEGMENT_H
#define _ASM_SEGMENT_H
#ifndef __ASSEMBLY__
typedef struct {
unsigned long seg;
} mm_segment_t;
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
#ifdef CONFIG_MMU
#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
#define KERNEL_DS MAKE_MM_SEG(0xdfffffffUL)
#else
#define USER_DS MAKE_MM_SEG(memory_end)
#define KERNEL_DS MAKE_MM_SEG(0xe0000000UL)
#endif
#define get_ds() (KERNEL_DS)
#define get_fs() (__current_thread_info->addr_limit)
#define segment_eq(a,b) ((a).seg == (b).seg)
#define __kernel_ds_p() segment_eq(get_fs(), KERNEL_DS)
#define get_addr_limit() (get_fs().seg)
#define set_fs(_x) \
do { \
__current_thread_info->addr_limit = (_x); \
} while(0)
#endif /* __ASSEMBLY__ */
#endif /* _ASM_SEGMENT_H */