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, 2 insertions, 2 deletions

diff --git a/drivers/staging/rtl8723bs/os_dep/osdep_service.c b/drivers/staging/rtl8723bs/os_dep/osdep_service.c
index e14d7cc411c9..73b87da15eb2 100644
--- a/drivers/staging/rtl8723bs/os_dep/osdep_service.c
+++ b/drivers/staging/rtl8723bs/os_dep/osdep_service.c
@@ -137,7 +137,7 @@ static int isFileReadable(char *path)
 		ret = PTR_ERR(fp);
 	}
 	else {
-		oldfs = get_fs(); set_fs(get_ds());
+		oldfs = get_fs(); set_fs(KERNEL_DS);
 
 		if (1!=readFile(fp, &buf, 1))
 			ret = -EINVAL;
@@ -165,7 +165,7 @@ static int retriveFromFile(char *path, u8 *buf, u32 sz)
 		if (0 == (ret =openFile(&fp, path, O_RDONLY, 0))) {
 			DBG_871X("%s openFile path:%s fp =%p\n", __func__, path , fp);
 
-			oldfs = get_fs(); set_fs(get_ds());
+			oldfs = get_fs(); set_fs(KERNEL_DS);
 			ret =readFile(fp, buf, sz);
 			set_fs(oldfs);
 			closeFile(fp);