linux/arch/h8300/include/asm/segment.h
Linus Torvalds 736706bee3 get rid of legacy 'get_ds()' function
Every in-kernel use of this function defined it to KERNEL_DS (either as
an actual define, or as an inline function).  It's an entirely
historical artifact, and long long long ago used to actually read the
segment selector valueof '%ds' on x86.

Which in the kernel is always KERNEL_DS.

Inspired by a patch from Jann Horn that just did this for a very small
subset of users (the ones in fs/), along with Al who suggested a script.
I then just took it to the logical extreme and removed all the remaining
gunk.

Roughly scripted with

   git grep -l '(get_ds())' -- :^tools/ | xargs sed -i 's/(get_ds())/(KERNEL_DS)/'
   git grep -lw 'get_ds' -- :^tools/ | xargs sed -i '/^#define get_ds()/d'

plus manual fixups to remove a few unusual usage patterns, the couple of
inline function cases and to fix up a comment that had become stale.

The 'get_ds()' function remains in an x86 kvm selftest, since in user
space it actually does something relevant.

Inspired-by: Jann Horn <jannh@google.com>
Inspired-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-04 10:50:14 -08:00

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C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _H8300_SEGMENT_H
#define _H8300_SEGMENT_H
/* define constants */
#define USER_DATA (1)
#ifndef __USER_DS
#define __USER_DS (USER_DATA)
#endif
#define USER_PROGRAM (2)
#define SUPER_DATA (3)
#ifndef __KERNEL_DS
#define __KERNEL_DS (SUPER_DATA)
#endif
#define SUPER_PROGRAM (4)
#ifndef __ASSEMBLY__
typedef struct {
unsigned long seg;
} mm_segment_t;
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
#define USER_DS MAKE_MM_SEG(__USER_DS)
#define KERNEL_DS MAKE_MM_SEG(__KERNEL_DS)
/*
* Get/set the SFC/DFC registers for MOVES instructions
*/
static inline mm_segment_t get_fs(void)
{
return USER_DS;
}
#define segment_eq(a, b) ((a).seg == (b).seg)
#endif /* __ASSEMBLY__ */
#endif /* _H8300_SEGMENT_H */