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>

1 files changed, 0 insertions, 7 deletions

diff --git a/arch/m68k/include/asm/segment.h b/arch/m68k/include/asm/segment.h
index 0b4cc1e079b5..c6686559e9b7 100644
--- a/arch/m68k/include/asm/segment.h
+++ b/arch/m68k/include/asm/segment.h
@@ -45,16 +45,9 @@ static inline void set_fs(mm_segment_t val)
 			      : /* no outputs */ : "r" (val.seg) : "memory");
 }
 
-static inline mm_segment_t get_ds(void)
-{
-    /* return the supervisor data space code */
-    return KERNEL_DS;
-}
-
 #else
 #define USER_DS		MAKE_MM_SEG(TASK_SIZE)
 #define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFF)
-#define get_ds()	(KERNEL_DS)
 #define get_fs()	(current_thread_info()->addr_limit)
 #define set_fs(x)	(current_thread_info()->addr_limit = (x))
 #endif